Trong chuyến thăm và thao tác tại thức giấc Nghệ An, sáng 20-5, sở tại Tỉnh ủy Bình Phước đã có buổi thao tác làm việc với sở tại Tỉnh ủy Nghệ An.
Bạn đang xem: Bi hài chuyện “phượt thủ” chém gió
Một fan lạ mặt sẽ để cháu bé bỏng trước cổng cùng với tờ giấy ghi chiếc chữ, vì đk không nuôi con được nên nhờ nhà chùa giúp đỡ.
“Kết quả cho thấy thêm nội dung phản ánh là tất cả cơ sở. Tại hiện trường có hàng trăm m3 đá “mồ côi” bị hướng đến lên khỏi mặt khu đất từ trước đó, diện tích bị hướng đến khoảng 2000 m2…”.
Ông Thái Minh Sỹ - Phó bí thư thường trực Tỉnh Đoàn tỉnh nghệ an được bầu làm Phó chủ tịch Liên đoàn Lao rượu cồn tỉnh tỉnh nghệ an nhiệm kỳ 2018-2023.
Tháng 10/2015, công trình dự án công trình Trung tâm bảo đảm và phạt huy di sản dân ca Ví, Giặm Nghệ Tĩnh được phê duyệt giai đoạn 1 cùng với tổng mức đầu tư chi tiêu gần 70 tỷ việt nam đồng nhưng tới lúc này vẫn không thể chuyển vào sử dụng.
Tối 19/5, Tỉnh nghệ an phối phù hợp với Thành phố hồ nước Chí Minh tổ chức triển khai Chương trình nghệ thuật đặc biệt bế mạc tiệc tùng, lễ hội Làng Sen năm 2023 với chủ thể “Từ thôn Sen đến tp Hồ Chí Minh” đáng nhớ 133 năm Ngày sinh quản trị Hồ Chí Minh.
Ngày19/5, tại tha ma Liệt sĩ huyện Nghi Lộc, tỉnh giấc ủy, HĐND, UBND, Ủy ban chiến trận Tổ quốc vn tỉnh, lực lượng trang bị tỉnh tỉnh nghệ an trọng thể tổ chức Lễ truy tìm điệu, táng 96 tro cốt Liệt sĩ quân tự nguyện và chuyên viên Việt Nam hy sinh tại Lào.
Bệnh viện hữu hảo Đa khoa nghệ an có tổng mức đầu tư 1.300 tỷ đồng, tất cả quy tế bào 600 chóng bệnh, tổng diện tích sàn là ngay sát 55.000m2.
Chiều 19/5, Đoàn thống kê giám sát chuyên đề của sở tại HĐND tỉnh về “Công tác cách tân hành chủ yếu trên địa phận tỉnh tỉnh nghệ an giai đoạn 2020 -2022” tổ chức thao tác với ubnd tỉnh. Các đồng chí: Lê Hồng Vinh - Ủy viên Ban thường vụ thức giấc ủy, Phó quản trị Thường trực ubnd tỉnh; Nguyễn Như Khôi – tỉnh giấc ủy viên, Phó quản trị HĐND thức giấc đồng chủ trì buổi làm cho việc.
Tiếng rít chát chúa xen lẫn tiếng đồ vật nổ sầm sầm cả ngày đêm với lớp lớp những vết bụi trắng bay lên mù mịt từ nhà máy sản xuất chế trở nên bột đá trắng rất mịn của công ty Cổ phần tài nguyên Đông Á sẽ là nỗi hết hồn hết vía đến hồi hộp của hàng chục hộ gia đình xóm Đột Vả, buôn bản Nghĩa Xuân, thị xã Quỳ thích hợp (Nghệ An) vào suốt nhiều năm qua.
Chiều 18/5, Ban thường xuyên vụ thức giấc ủy tổ chức triển khai Hội nghị biểu dương, khen thưởng điển hình nổi bật tiêu biểu trong học tập và làm theo tư tưởng, đạo đức, phong cách Hồ Chí Minh năm 2022 cùng trao giải thưởng sáng tác, quảng bá các tác phẩm văn học, nghệ thuật, báo chí về đề tài học tập và làm theo tưởng, đạo đức, phong cách Hồ Chí Minh dịp I giai đoạn 2021 – 2025.
Chiều 18/5, Ban hay vụ thức giấc ủy tổ chức trao giải thưởng sáng tác, quảng bá các tác phẩm văn học, nghệ thuật, báo chí về đề tài học tập và làm theo tư tưởng, đạo đức, phong cách Hồ Chí Minh đợt I và phát động giải thưởng đợt II, tiến độ 2021 – 2025.
Trong chuyến thăm và thao tác làm việc tại Nghệ An, sáng 18/5, Đoàn Đại biểu v.i.p Ủy ban đảm bảo an toàn Cách mạng Cuba do ông Gerardo Hernandez Nordelo - Ủy viên tw Đảng cộng sản Cuba, Ủy viên Hội đồng bên nước, chủ tịch Ủy ban đảm bảo Cách mạng Cuba (CDR) làm trưởng đoàn có buổi chào xã giao chỉ huy tỉnh Nghệ An.
Sáng 18/5, Đoàn đại biểu v.i.p Ủy ban đảm bảo an toàn Cách mạng Cu-ba do đồng minh Gerardo Hernandez Nordelo - Ủy viên tw Đảng cùng sản Cu-ba, Ủy viên Hội đồng bên nước, chủ tịch Ủy ban bảo vệ Cách mạng Cu-ba (CDR) làm Trưởng đoàn đã đi vào dâng hoa, thắp hương tại khu di tích Kim Liên – khu di tích đất nước đặc biệt.
Để cố gắng 100% các khu phượt có trung trọng tâm vui chơi, vui chơi trong quy hoạch tỉnh tỉnh nghệ an giai đoạn 2021-2030 cùng tầm nhìn mang đến 2050, địa phương đang tiến cho tới thu hút chi tiêu xây dựng thêm 9 sảnh golf.
Mặc dù thường niên CTCP nntt BAF vn báo lãi hàng chục, thậm chí hàng trăm ngàn tỷ đồng, mặc dù nhiên, sau gần hai năm được đồng ý chủ trương chi tiêu hai dự án công trình nuôi lợn hơn 1.200 tỷ ngơi nghỉ Nghệ An, doanh nghiệp lớn này vẫn chưa thể tiến hành khởi công dự án.
Không chỉ dựng xưởng để sơ chế phế truất liệu trên khu đất lâm nghiệp, mà chuyển động sơ chế truất phế liệu này còn có dấu hiệu gây ô nhiễm môi trường, dẫu đã biết thành chính quyền địa phương đình chỉ nhưng vẫn ngang nhiên hoạt động.
Tại một số trong những bệnh viện trong tỉnh, nắng nóng nóng khiến cho số trẻ nhỏ và tín đồ già vào viện tăng cao hơn so với những ngày thường. Bạn nhập viện phần lớn mắc một trong những bệnh tương quan đến đường hô hấp, tự dưng quỵ...
Một nhóm học viên lớp 5 sinh sống tỉnh Bình Thuận rửa ráy kênh bị mát nước khiến cho 4 em tử vong.
Ngày 20-5, Công an thị trấn Quan Hóa, tỉnh Thanh Hóa cho biết thêm cơ quan liêu này đã củng nạm hồ sơ để giải pháp xử lý vụ bài toán xô xát thân 2 vợ ck xuất phát từ các việc vợ đi dạo bóng chuyền về muộn
Một người lạ mặt đã để cháu nhỏ xíu trước cổng cùng với tờ giấy ghi dòng chữ, vì đk không nuôi nhỏ được đề nghị nhờ nhà chùa giúp đỡ.
Chúng tôi chia ly đã 2 năm. New đây, anh gọi điện hẹn chạm mặt tôi. Anh nói dù chia ly nhưng anh vẫn ghi nhớ tôi, anh yêu thương những cô bé khác và phân chia tay gấp rút vì luôn nhớ được tôi.
Techcombank, MB, Vietcombank thường xuyên nằm vào nhóm đứng vị trí số 1 về cuộc đua trả lương "khủng" nhất hiện nay cho nhân viên.
MC, diễn viên Bùi Thu hương thơm - nữ giới cũ ước thủ Minh vương - lại khiến cho dân tình phạt sốt với những tập ảnh nóng bỏng, khoe vòng một đẫy đà vào trang phục nội y những ngày đầu hè.
Trang Oddity Central cung cấp tin về một người bọn ông xứ sở của những nụ cười thân thiện uống máu cá sấu trộn rượu hàng ngày để tăng tốc sức khỏe.
Mạng làng mạc hội lan truyền thông tin hoa khôi Hoàn vũ Philippines 2023 Michelle Marquez Dee là đồng tính nữ, từng có bạn gái và yêu thương nhau cho 10 năm.
Gia đình nghệ sỹ Xuân Phong báo tin, ông đã trút tương đối thở ở đầu cuối lúc 21 tiếng 10 ngày 19-5 tận nhà riêng do bệnh già, thọ 94 tuổi.
Theo Trung chổ chính giữa Dự báo Khí tượng thuỷ văn quốc gia, ngày 19/5, ở bắc bộ và khu vực từ Thanh Hóa cho Phú Yên vẫn xảy ra nóng ran và nóng ran gay gắt, có nơi quan trọng gay gắt với nhiệt độ lúc 13h tất cả nơi bên trên 39 độ C.
Hội nghị ra mắt Quy hoạch tỉnh tp hà tĩnh thời kỳ 2021- 2030, tầm nhìn cho năm 2050, sẽ ra mắt vào ngày 26-28/5 với chủ đề “Hà Tĩnh - hiện thực hóa tiềm năng với khát vọng ”.
Thủ tướng chính phủ nước nhà yêu cầu bộ Y tế kết hợp các bộ, ngành liên quan chuẩn bị hồ sơ theo nguyên lý để vận động và di chuyển COVID-19 từ căn bệnh truyền nhiễm nhóm A sang team B và chào làng hết dịch.
Đại học nước nhà Hà Nội vừa ra mắt đề án tuyển sinh đh năm 2023, trong số đó có chi tiết học tổn phí từng ngành, từng trường thành viên.
Trung vệ trẻ em Lê Văn Hưng vẫn giúp Quảng nam giới FC bay cao trên BXH giải hạng độc nhất QG bằng công suất ghi bàn rất ‘khủng’ khiến cho các trung phong cũng đề nghị ước mơ.
Chính quyền TP Tịnh Tây ở quần thể tự trị Choang Quảng Tây - trung hoa cho xuất xắc 11 người, trong các số đó có 9 fan mang giấy tờ tùy thân Việt Nam, vừa bỏ mạng trong một vụ tai nạn đáng tiếc giao thông.
Lê Tân Định (SN 2006, ngụ thức giấc Vĩnh Long) hẹn bạn tình đồng tính mang lại nhà nghỉ dẫu vậy do bất đồng trong bài toán quan hệ đề nghị đã bóp cổ nạn nhân rồi chiếm điện thoại.
“Kết quả cho biết nội dung phản chiếu là có cơ sở. Tại hiện tại trường có hàng trăm m3 đá “mồ côi” bị đào bới lên khỏi mặt khu đất từ trước đó, diện tích bị hướng đến khoảng 2000 m2…”.
Đại diện phòng GD&ĐT huyện Ứng Hoà (Hà Nội) thông tin về đoạn clip nữ sinh lớp 8 bị chúng ta đánh hội đồng trong chống học gây xôn xao mạng buôn bản hội.
Ngọn lửa bùng cháy từ khu vực tầng 2 của quán coffe 3 tầng tại nút giao Phùng Hưng - hàng Cót (Hà Nội) vào sáng sủa 20/5. Sức nóng khiến cho cửa kính vỡ vụn kèm nhiều tiếng nổ.
Thủ tướng chủ yếu phủ chỉ định Thiếu tướng Nguyễn Văn Hiền, Phó tứ lệnh Quân chủng Phòng không - ko quân, giữ lại chức tứ lệnh Quân chủng Phòng không - ko quân, bộ Quốc phòng.
Trước mắt, "Chuyến xe cộ 0 đồng" tiến hành thí điểm trợ giúp người dân di chuyển lúa ở các quanh vùng cánh đồng làng mạc Tây Hương, Đông Vinh, Phú lâu (xã Tùng Lộc, thị trấn Can Lộc, thức giấc Hà Tĩnh) về nhà, với quãng đường xa độc nhất vô nhị là khoảng chừng 2-3km, ngay sát nhất khoảng chừng 200-300m.
tình nghĩa “Chuyến xe pháo 0 đồng” giúp người dân trở ngại vượt nóng ran
Institute of Waste Management and Circular Economy, Department of Hydrosciences, Faculty of Environmental Sciences, Technische Universität Dresden, Pratzschwitzer Str. 15, 01796 Pirna, Germany
Faculty of Chemical Engineering, Industrial University of Ho chi Minh City, Nguyen Van Bao Str. 12, Ho chi Minh đô thị 70000, Vietnam
Institute for Environmental Science, Engineering and Management, Industrial University of Ho đưa ra Minh City, Nguyen Van Bao Str. 12, Ho chi Minh city 70000, Vietnam
Geographical map of Vietnam, study areas & sampling locations. SG stands for Saigon, another name of Ho-Chi-Minh City, CT stands for Can Gio Mangrove—Transition zone, CB stands for Can Gio Mangrove—Buffer zone, CC stands for Can Gio Mangrove—Core zone, ES stands for East Sea, a name by the Vietnamese people for South đài loan trung quốc Sea. The detailed location names are found in Table S1 in Supplementary Materials.
">Non-microplastics & microplastics extracted from the marine environment of Southern Vietnam: non-microplastic fibers (a); microplastics in Saigon urban canals (b), Can Gio (c), ghen tuông Rai (d), trắng Tiger oilfield (e).
">Total microplastics in Saigon urban canal systems. NL-TN Canal System is from Bridge No.1 to Bach Đang Wharf; Tau Hu (TH) Canal System is from Lo Gom lớn Letter Y Bridge; Te Canal (KT) is from Nguyen Van Cu Bridge to Tan Thuan Bridge; Ben Nghe Canal (BN) is from Nguyen Van Cu Bridge khổng lồ Khanh Hoi Bridge. The names of locations (from left lớn right) in Figure 3 are abbreviated as SG1, SG2, SG3, SG4, SG5, SG6, SG7, SG8, SG9, SG10, SG11, SG12, SG13, SG14 và SG15 in the maps (Figure 1).
">Microplastic distribution (%) in the zones of UNESCO Can Gio Biosphere Reserve.
">The decrease in microplastic concentration from Saigon to the East Sea through UNESCO Can Gio Mangrove Biosphere Reserve. Binh Khanh ferry is the intersection of HCMC and Can Gio; The confluence of Soai Rap River is the natural border of Can Gio with Mekong Delta; ghen tuông Rai Gulf is the confluence of Long Tau River; white Tiger Oilfield is in the East Sea belonging to lớn Đong Nai city (not HCMC).
">Plastic pollution is one of the significant environmental concerns due to lớn the threefold increase in global plastic waste. Marine microplastics, including petroleum-based plastic pieces và synthetic and artificial fibers smaller than 5 mm, are not only ubiquitous in natural water but also high in wastewater streams due to lớn the direct discharge, transfer and breakdown of plastic items. This research aims to investigate the presence & dispersion of microplastics in the downtown area and coastal suburban area of Ho-Chi-Minh đô thị by using Raman microscopy. As a result, the most common plastics (PE, PET, PA, PP, PVC, PS và PMMA) were detected, and most of them were fibrous shorter than 500 μm. The total microplastics decreased gradually from the urban waterborne (up lớn 220 MPs/L) via Can Gio UNESCO Mangrove Biosphere Reserve (10 MPs/L) and to the East Sea (3 MPs/L), which reveals the potential role of the mangrove in reducing marine contaminants including microplastics. This study provides important insights into microplastic pollution in the Western Pacific Region, especially the Saigon-Dong Nai river systems, supporting useful data for natural water resources management.
marine microfibers; Raman microscope; Saigon–Đong Nai river system; UNESCO Can Gio Mangrove Biosphere reserve; ghen Rai gulf
Plastic products are generally inexpensive, lightweight, và durable, bringing technological and medical advances, energy savings, and other societal benefits. Therefore, the plastic industry has increased global manufacture substantially, up to lớn nearly 370 million tons in 2019 <1>. Mismanaged plastic waste has introduced 8–12.7 million tons of plastic (PP, PE in prevalence) into the ocean every year <2>. The đứng top polluting rivers globally are primarily located in Asia, accounting for 67% of the global total. Vietnam is in the world-top countries with the estimated amount of plastic waste discharged into the sea from 0.28 to lớn 0.73 million tons/year <3>, và ranked fourth in the world about plastic waste mismanagement <4>. Southern Vietnam featured an interlaced system of rivers, streams & canals with asymmetric semi-diurnal tides. Ho đưa ra Minh thành phố (HCMC, Saigon) is the most populous and largest economic center of Vietnam. In 2014, about 8175 tons of municipal solid waste were generated daily, textile & plastic components accounted for 5–7.2% và 16–25%, respectively <5>. Saigon (SG) River flows to lớn HCMC, forming main canal systems—Nhieu Loc-Thi Nghe (NL-TN), Te (KT), Đôi (KĐ), Tau Hu (TH), rã Hoa-Lo Gom (LG). At least 2000 metric tons of floating debris are collected every year on the main urban canals of Saigon <6>. Saigon River merging with Đong Nai River flows through Can Gio Mangrove to ghen tuông Rai Gulf of the East Sea (South đài loan trung quốc Sea). Can Gio, a coastal district of HCMC, is the first Mangrove Biosphere Reserve of Vietnam designated by UNESCO in 2000. It functions as a natural water filter for the marine environment by remaining and diluting soluble pollutants in rivers from the city. The reserve is divided into three zones: (1) vi xử lý core zone (4720 ha) with few households và strict forest protection; (2) buffer zone (37,340 ha) where traditional exploitation in rivers is unregulated; (3) transition zone (29,310 ha) where intensive aquaculture (oysters, shrimps, clams, etc.) & tourism are along the shoreline <7>.
Plastic items tend khổng lồ be broken into small particles with a wide range of shapes & sizes under chemical weathering, photo-degradation & physical & biological reactions. Annually between 0.8 và 2.5 million tons of microplastics (MPs), two-thirds of them are synthetic fibers released during washing và erosion of tires while driving <8>. According to the size, they are classified as mesoplastics (>5 mm), large microplastics (1–5 mm), small microplastics (≤1 mm) và nano plastics (9>. Plastic debris causes an aesthetic loss of urban landscape và poses a hazard to aquatic wildlife và human maritime activities. Nearly 700 marine species such as dolphins, sharks, crocodiles, crabs & invertebrates have been reported lớn be affected by microplastics. “Ghost fishing” from fishing nets left on the beach due khổng lồ accidental or deliberate fishing activities could entangle turtles, coral reefs, other valuable creatures, và even human divers, resulting in losses to commercial fisheries & lethal dangers of marine entertainment <10>. Some species specifically select plastic debris since they mistake similar-size microplastics for food <11>. The uptake of microplastics results in physical conditions such as bowel obstructions <12>, reduced food intake, behavior changes, & chemical effects such as inflammation, hepatic stress and reduced reproductive output đầu ra due to plastic additives <13>.
The monitoring of microplastic pollution is still a big challenge because the distribution of plastic debris is affected by different factors in the marine environment. Moreover, microplastics analysis is a very complicated field, which has been conducted for many years. It has been difficult lớn validate the procedures và reproduce and compare the results between studies since the standardized and validated methods are still under development <14>. Different methods have been used khổng lồ sample microplastics in the sweater. In volume-reduced methods, manta trawls or nets are used to lớn collect floating microplastics around 300 μm <9>. In contrast, bulk sampling takes the whole volume of water samples by using pumps or other techniques, và therefore can be used lớn obtain particles smaller than 300 μm <15>. Nets or manta trawls are preferable for large-scale surface water sampling in the sea since they can filter a large volume of water to collect the target-sized microplastics <9>. Nonetheless, a manta trawl system is expensive, and the result depends on the net size. Microplastic abundance can be underestimated because plastics smaller than the net aperture kích thước may pass through trawls <9>. On the other hand, bulk sampling is more advantageous for point sampling <16>. As there are no kích thước limitations in the sampling, a wide range of form size fractions, from large to smaller microplastics, can be identified.
A typical workflow for microplastic analysis comprises physical & chemical characterizations. Physical identification includes a microscope, và if necessary, combined with a melting chạy thử for >50 μm microplastics <17>. The visual sorting is based on microplastics’ morphology observed under a dissection microscope with or without stained with Rose Bengal <18>, a fluorescence microscope after dyed with Nile Red <19>, or a scanning electron microscope (SEM) <20>. Although the Nile Red method is highly sensitive, biogenic materials such as lipids và chitin will interfere with the plastic detection, & plastic types may give similar màu sắc signals <21>. Hence, the visual methods should be combined with a spectrometer. FT-IR spectroscopy is a convenient tool khổng lồ determine marine microplastics <22,23>. Raman spectroscopy based on the interaction of molecules with photons in monochromatic light has recently attracted more attention <24,25> due lớn the non-destructive feature, better resolution, wider spectral coverage và lower water interference <26>. It can replace FT-IR or be used with FT-IR khổng lồ obtain the best results <27>. Confocal Raman microscopy (CRM) is an improved system involving the pairing of an optical microscope with a Raman spectroscopy. This system provides chemical information with spatial resolution images of very small pieces, up to lớn 1 μm <28>. It has many benefits over fluorescence microscopy since it does not need external labeling. In addition, thermal analysis such as TED-GC/MS and pyrolysis-GC/MS has been employed with high reliability <20,29>. However, the chromatographic operation & procedure are more complicated, compared with the spectroscopic methods.
Saigon-Dong Nai basin is one of the main river systems of Vietnam, but there have been several studies on its plastic pollution <6,30,31,32>. According lớn the data of <31> the number of anthropogenic fibers varied from 22 to lớn 25 items per liter during the 1.5-year survey, và there was no relation between their concentration variations with rainfall, water discharge or abiotic factors. There are four main river systems through Can Gio Mangrove: (1) Soai Rap (Western border with Mekong Delta), (2) Đong Tranh (Northern border with Đong Nai), (3) Thi Vai River (Eastern border with Vung Tau province) and (4) Long Tau, which flows to ghen Rai Gulf. To the best of the authors’ knowledge from searching the literature, there were no official published research articles on microplastics in the Can Gio Biosphere Reserve by other research groups. All publications focused on the microplastic accumulation in the Saigon-Dong Nai basin (172–519 fibers/L, 0.01–0.223 fragments/L) <30> and Vung Tau (Dinh River, 32> by using FT-IR and/or stereomicroscopic methods. This article aims khổng lồ prove the spec-ificity & versatility of Confocal Raman microscopy (CRM, or μ-Raman spectroscopy) & employ the method in investigating the prevalence and dispersion of microplastics from Saigon urban canals to Can Gio Mangrove & eventually to the East Sea of Vietnam.
The powdered standard plastics were purchased from Goodfellow (Hamburg, Germany): low-density polyethylene (LDPE) with an average particle form size of smaller than 300 microns; polyethylene terephthalate (PET) 300 µm, un-plasticized polyvinyl chloride (u
PVC) 250 µm, poly(methyl methacrylate) (PMMA) 85 µm, và nylon-6 (PA-6) particles 15–20 µm in size. In addition, the raw pure plastic particles (diameter of 3 mm) of PP, HDPE & PS were supplied by Vietnamese plastic production companies.
Filtered deionized water (FDW) was prepared by filtering deionized water through a 0.4-μm filter membrane (Sigma Aldrich, Ho-Chi-Minh City, Vietnam) with the tư vấn of a vacuum filtration system before use. Whatman GF/A glass-fiber filter paper (diameter 47 mm, pore size 1.6 µm) was used khổng lồ extract microplastics.
A ZEISS Stemi 508 Stereo Microscope with 8:1 Zoom was firstly used lớn observe the whole area of the GF/A membrane & count the total number of particles. Every single piece was then analyzed in viewing & Raman modes with the Xplo
RA Horiba Raman One 532 nm integrating with optical parts of Olympus (Horiba Scientific, Montpellier, France).
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The sampling locations were marked on the maps (Figure 1) (see detailed description and coordinates in Table S1 in Supplementary Materials). Bulk sampling was used in previous studies <30,33,34,35> from February 2020 to lớn March 2021. Wildco horizontal alpha water sampler or bucket (Table S2i in Supplementary Materials) was used khổng lồ take the water at the surface (surface water deep to 30 cm) during the slack water (end of low tide). To lớn obtain the reproducible & representative results for each canal system or zone of the reserve, water was taken in different sampling locations (Table S1 in Supplementary Materials). At each location, at least five water samples (1 L per sample) for five replicate analyses (up to lớn 45 replicates for the ghen Rai location in the East Sea) were taken in the middle along every canal system in the center of Ho đưa ra Minh city (Saigon urban canals); randomly in transition, buffer and core zones of Can Gio mangrove from the boat; và in the sea (ES1, ES2, ES3 và ES4) from the canoe.
Microplastics were extracted from the water samples by using the procedure of Khuyen et al. <36>. With the aid of a vacuum pump, 1 L of water sample was directly filtered through a GF/A membrane until the membrane became brownish yellow. Visible items on the filter membranes were picked up, cleaned with filtered deionized water (FDW), & stored for microplastic observation. All materials were immediately washed off with FDW, & the final volume of supernatant containing microplastics was reduced to lớn only 100–200 m
L. The supernatant was then digested with 30% hydrogen peroxide at 70–80 °C until the solution was discolored, và the mixture was incubated at room temperature overnight. Finally, the mixture was filtered và microplastics deposited on the filter membranes were analyzed with a Raman microscope. Five replicates of 1 Liter were applied for each sampling location.
There was a field control sample at each sampling location. Glass bottle containing 1 L of FDW was opened and placed during the sampling collection. Bottles containing samples were carefully sealed và transported lớn the laboratory. The air control samples were clean filter membranes on glass Petri dishes around the working area during sampling handling, vacuum filtering, và microplastic analysis. The water control samples were bottles containing 500 m
L FDW. All the control samples were directly analyzed khổng lồ observe whether contaminating microplastics were found in the actual samples. As a result, no microfibers were found, showing that fibers found in the study were not from clothes worn in the laboratory and during the sampling.
The number of pieces was counted manually & classified by polymer type, shape và color. The detailed procedure for distinguishing microplastics will be described in Section 3.1. The microplastic abundance in samples was expressed as items per liter of water (MPs/L), and the results were evaluated for statistical homogeneity by analysis of variance (ANOVA). Tukey’s multiple comparison kiểm tra was used to lớn analyze the mean differences between sampling locations in Saigon canal systems, between locations in Saigon with Can Gio, and with the East Sea. All statistical analyses were performed at a 95% confidence interval on SPSS v22 software (IBM SPSS Statistics 22, Armonk, NY, USA).
3. Results & Discussion
3.1. Combined Qualification & Quantification of Microplastics by Raman Microscopy 3.1.1. Visual IdentificationThe viewing mode includes two objectives: 10× and 50×. The larger objective allowed khổng lồ zoom powdered particles in the case of PA và PMMA. However, the images were not always clear. Thus, the shape, color and size (μm) were observed at 10×. The final kích cỡ was calculated depending on the shape. It was expressed as length for microfibers, và the sum of width and length for non-fibrous forms.
The morphology of debris under the microscopic mode could be used khổng lồ quantify the microplastics. Some criteria described by <37> were applied khổng lồ distinguish microplastic fibers (clothing, fishing nets, for instance) from non-plastic fibers (organic, or cellular structures, Figure 2a). Microplastic fibers were (1) clear và homogeneously colored, (2) soft and three-dimensional bendable Figure 2c; (3) equally thick, not segmented and not tapered towards the ends. Fibers, especially dark-colored ones, meeting the above requirements but having complicated spectra were called “unidentified group”. Moreover, the lengths of some fibers were close lớn the widths, & these cases were recorded in the shape of “bars or sticks” instead of particles as suggested by <15>. Non-fibrous shapes included particles with either spherical or aggregate of spheres, fragments (particles with jagged edges as a signal of fragmentation) and films with square or rectangle images. However, the film category always accounted for a small percentage, mainly because they were broken down into threads và filaments, thereby classified into fiber categories <38>. The other groups are foams & pellets (granules with the shape of a cylinder or a disk manufactured as a raw material of plastic goods).
In addition to shapes, colors can be a preliminary tool lớn guess the plastic type, behavior và origin of microplastics. Clear & transparent particles have been ascribed to polypropylene (PP) <39>, while black represented the sorption of PAHs & PCBs on PP and polystyrene (PS) <40>. Trắng pieces were assigned to polyethylene (PE) <39>, & their film or sheet shapes suggest they come from shopping bags & agricultural và food packaging films <41>. Colors can also indicate the weathering và decomposition degree, & residence time at the seawater surface. The discoloration can be caused by long exposure khổng lồ UV light (translucent color) <42,43>. In other words, the discoloration (yellowing) is a result of oxidized PCBs adsorbed on plastic resins in the environment <44>.
The Raman spectrometer with a 532 nm excitation laser and a charge-coupled device (CDC) detector was used lớn measure spectra of each thành công at ×50 objective in an integration time of 15 s và a grating of 900 gr/mm in a range wavelength from 50 lớn 3600 cm−1. In practice, plastic additives và organic pollutants such as PCBs, PAHs adsorbed on microplastics’ surface made the spectra more complex. Hydrogen peroxide (H2O2 30–35%) is a conventional oxidizing agent with higher efficiency, but little khổng lồ no degradation of polymers, compared with HCl và Na
OH <45>. The effectiveness depends on its concentration (15–35%), temperature (room temperature up khổng lồ 70 °C) of incubation & reaction times (a few hours lớn a week) <45,46>. The sample treatment was performed on all polymer standards before it was applied khổng lồ the actual samples khổng lồ evaluate the deterioration effects on the plastic types. The results showed their morphology và Raman spectra were not affected by peroxide oxidation. Thus, the peak shifts of sampled microplastics were mainly caused by the degradation in the environment. Nevertheless, as can be seen in Table 1, vibration wavenumbers of functional groups in pure plastic molecules could be recognized in the sampled microplastics’ spectra, which pointed out the high specificity of Raman spectroscopy in identifying the chemical composition of most common plastics.
Figure 3 showed the uneven distribution of microplastics in locations of Ho đưa ra Minh City. The microplastic amount was highest in residential areas, 45.89 ± 24.04 MPs/L in Bridge No. 1 (SG1 on the map, Figure 1) where floating rubbish from NL-TN canal was gathered, varied from 44.33 to lớn 58.57 MPs/L in Tau Hu Canal (SG8, SG9, SG1, SG11) belonging lớn Districts 6, 7, 8 và Tan Binh. Microplastics were found with a noticeably high abundance in some samples at the locations where the water environment was concentrated (dark color) with a higher number of visible floating garbage such as food boxes, clothing pieces & nylon bags. Among the repetition times, there were replicates obtaining a very high abundance of plastic debris, for instance, 160 MPs/L in Bridge No. 1 (SG1, Figure S1a), 110 MPs/L in Letter Y Bridge (SG10), 125 MPs/L in Lo Gom canal (SG10), & 220 MPs/L in Kenh Te Bridge (SG12). There was a dramatic decrease in the microplastic amount from the pollution sources to lớn Saigon River estuaries, for example, 23.92 ± 19.23 MPs/L in Bach Đang Wharf (SG7), & 27.33 ± 6.23 MPs/L in Khanh Hoi Bridge (SG15). Indeed, Tukey’s multiple tests showed significant statistical differences between Kenh Te Bridge và Khanh Hoi (Sig. = 0.005, Table S4), và Bach Dang Wharf (Sig. = 0.021, Table S4). There were no statistical differences between other locations.
These locations are grouped into four canals according lớn the geographical division of the Government. Nhieu Loc-Thi Nghe is a separate system inside HCMC flowing to Saigon River, while other canal systems connect HCMC with neighboring cities. Ben Nghe Canal (3.1 km) originates from the Lo Gom-Tau Hu Canal system (9 km), the Te Canal (KT, 4.5 km) is the continuation of the Doi Canal system (8.5 km). Đoi-Te and the Ben Nghe-Tau Hu canal basins join at the position of Nguyen Van Cu Bridge before flowing lớn Saigon River. Regarding the composition (Table 2), the percentages of plastic types were similar at close locations belonging to lớn each canal system. In general, nylon was the most abundant component, followed by polyester fibers. PE was also the second most frequently sorted in Ben Nghe & Te basins. In Nhieu Loc và Lo Gom basins, PE và PP were identified at the same proportions. Polystyrene was found with a higher percentage (around 12%) in the study of <56> but made up small percentages in our study. In fact, many fragments of PS food boxes were seen floating on surface waters while sampling, but they were regarded as macroplastics. Small-size particles in màu đen had a Raman band only at 1000 cm−1 of PS, which was not enough to assign them as PS microplastics. Physical processes, particularly wind blowing & water mixing influenced the sinking behavior of plastic debris, strongly affecting the presence of PS micro-size classes (57>.
Nhieu Loc-Thi Nghe canal system plays an important role in the city’s activities during its foundation và development. This 8.7-km long canal flowing through seven districts was the cleanest canal at the beginning of the reclamation of land in Southern Vietnam. It became the dirtiest canal in the 1970s mainly due khổng lồ the discharge of solid waste và wastewater from the slums on both sides of the banks. The water chất lượng in this canal has been significantly improved since 1993. It is now the cleanest canal in the city, thanks to lớn the largest canal clean-up programs (HCMC Environmental Sanitation Project) funded by the World ngân hàng and the đô thị Government <6>. Nonetheless, plastic pollution is still a concerning problem because plastic wastes can come from different sources such as direct dropping litter on land or at sea, blowing, leaching from landfills và losses during transport. According to lớn statistical data from Barnes et al. <58>, a large proportion of 40–80% of plastic garbage is from carrier bags, packaging, footwear, cigarette lighters & other domestic items. Indeed, in all urban canals, there is floating debris that comes from discarded wastes of tourists và residents, và natural vegetal waste, mainly water hyacinths drifting in from the không nên Gon River during high tides. The floating debris life cycle is specific to lớn each canal và not involved in solid waste management. The floating debris collection is very active in Nhieu Loc–Thi Nghe canal, conducted every day from 6 am to 6 pm. Indeed, the average values showed the lowest abundance of microplastics in this canal (Table 2), which is similar to the study of Lahens et al. <30>. The water unique of KT và TH-BN canal basins has been improved khổng lồ some extent thanks to HCMC Water Environment Improvement Project funded by the JICA <6>. Nonetheless, TH và LG canals flow along with the highest populated districts with many slum areas along the canals. The mismanaged wastewater management and ineffective floating debris collections in these districts led to higher pollution compared khổng lồ the Nhieu Loc canal <6>.
The average of MPs in our study (38.45 ± 24.93) was two orders of magnitude lower than the range of total microplastics reported by Lahens et al. <30> (172–519 fibers/L). The noticeable differences can be explained by different time periods, sampling techniques và analysis methods rather than the levels of plastic pollution in the studied regions as proposed by Enders et al. <15>. A few bundles of green fibers (Figure 2a) were detected in the state of being twisted together, thereby considered as “non-microplastics” due to lớn unclear shapes. Moreover, we found a large number of black particles whose images và spectra were difficult khổng lồ identify. Indeed, Raman analysis of black particles resulted in a considerably higher rejection rate, as suggested by Lenz et al. <59>. Hence, only black items with clearly homogenous shapes và identifiable structural characteristics were included in microplastic data, consequently leading khổng lồ small percentages (1.58–6.7%) of đen color.
The downstream of Saigon River merges with Dong Nai River to form Nha Be River and divides into two branches: Long Tau & Soai Rap Rivers, flowing to the East Sea (South trung quốc Sea) through Can Gio Mangrove. Plastic pollution sources, including direct dropping litter on land or at sea, blowing, leaching from landfills, & losses during transport, are mainly in the transition zone (from CT1 khổng lồ CT8 on the map). Nevertheless, its total microplastics (10.45 ± 3.67 MPs/L) are similar to the buffer zone (from CB1 lớn CB5 on the map) (10.75 ± 3.13 MPs/L), where human activities are more restricted. The geographical position is proposed lớn be the main reason. The transition zone consists of outer areas that are strongly affected by coastal features such as winds, waves, tides & river runoff, which makes microplastics dispersed & diluted unevenly <34>. Moreover, there are no clear geographical maritime boundaries between the zones because adjacent areas share the local canals & rivers.
Figure 4 indicates the distribution of plastic types in the zones of the Can Gio reserve. PE was the most abundant type in the transition & core zones, and almost all of it was in the size of fragments và particles. PET was the largest group in the size of fibers (35%) và fragments (35%) in the buffer zone but was the second-most dominant, mainly in fibrous khung (53.57%) in the transition zone and in both fibers (31.25%) and particles (31.25%) in the chip core zone. Fibers were found khổng lồ be abundant in the transition zone, especially in coastal locations. Can Gio 30 April Beach is the most attractive recreational beach, which is considered a vital pollution source, especially of polyamide fibers <60>. Fishing is the main income source of the local people, especially in Can Thanh. Zhu et al. <41> proposed that the origin of xanh nylon fibers is cables used in fishery activities. Moreover, fibers could originate from shipping <61>, especially at the intersection of main rivers—Đong Tranh và Long Tau, where large ships circulate every day. In addition khổng lồ plastics’ density at this location, the buoyancy effects of marine plastics in the water column were mediated by a high level of surface mixing caused by boat movement and seawater turbidity <34>. As a result, PET & PA dominated (26.53%), followed by PP (20.41%) and PE (10.2%).
In other words, microplastics were observed but in lesser numbers (7.48 ± 1.28 MPs/L) in the core zone (from CC1 khổng lồ CC3 on the map) although human domestic activities are strictly prohibited. This proves microplastics can be detected in areas far from pollution sources, & their abundance would depend on the proximity lớn urban sources. Microplastics, therefore, could be released from outer regions & float under the natural forces of water flows & accumulated in convergent zones <34>. The sediment of mangrove forests can be a suitable environment for microplastic storage because we found some trắng fragments and blue fibers similar to lớn ones in the seawater. The debris is difficult to detach from the sediment due to lớn the sticky characteristics of the sediment. Furthermore, pollutants retained in the vi xử lý core zone would be difficult lớn return to the marine environment because the waves are attenuated, and the water surface here remains calm <62>. Some studies reported the presence of microplastics in the mangrove sediment and roots <63>, but the role of mangroves as a filter of plastic debris for the seawater needs more investigation.
Figure 5 demonstrates remarkable changes in the relative abundance of microplastics from Ho-Chi-Minh đô thị (HCMC, Saigon urban canals/rivers) through Can Gio Mangrove (Can Gio seawater) to the East Sea (Soai Rap Estuary, from Long Tau Estuary to ghen Rai Gulf, và White Tiger Oilfield). Mangroves involve a special soil that accumulates carbon, nutrients and sediments as an “enhancer of sedimentation” <64>. Sediments deposited into mangroves come from allochthonous sediments (external sources lượt thích terrestrial or oceanic sources), and autochthonous sources (re-suspended sediments) <65>. Microplastics can be transported from the oceanic environment khổng lồ the mangrove and accumulated in the sediment layers in a similar way as in the aquatic environment <13>. This is considered one of the main reasons for the low number of microplastics within the Can Gio reserve. Indeed, the decrease in the amount of plastic debris highlights the feasible role of the mangrove in retaining contaminants including microplastics.
The Tukey’s thử nghiệm showed a statistical difference in total MPs between Binh Khanh ferry (CT1) with ganh Rai Gulf (ES3) (Sig. = 0.03, Table S3) và with Soai Rap estuary (Sig. = 0.03, Table S3). Tukey’s thử nghiệm showed a statistical difference in total MPs between Binh Khanh ferry with ghen Rai Gulf (Sig. = 0.03, Table S3), và with Soai Rap estuary (Sig. = 0.03, Table S3); between Rach Đon Bridge (Can Gio buffer zone, CB1) và Ganh Rai Gulf (Sig. = 0.014, Table S3). The comparison tests indeed showed some statistical difference between Saigon urban canals with Can Gio Mangrove & the East Sea, for example, Bui Huu Nghia Bridge (SG5) with transition zone (C1-Sig. = 0.01, C2-Sig. = 0.038, C3-Sig. = 0.018, Table S4), with downstream of Soai Rap River (ES2) (Sig. = 0.004, Table S4), downstream of Long Tau River (ES1) (Sig. = 0.036, Table S4), ghen tuông Rai Gulf (ES3) (Sig. = 0.001, Table S4) & White Tiger Oilfield (ES4) (Sig. = 0.011, Table S4).
The pollution sources concentrate in HCMC, & therefore the MPs amount there was highest (nearly 40 items/L) and decreased gradually khổng lồ the estuary areas. The number of microplastics in the Saigon river-estuarine system of our study falls into the range of concentrations reported by Strady et al. <31>, which was 22 to 251 MPs/L. At the intersection of HCMC và Can Gio (Binh Khanh Ferry), the microplastic concentration decreased lớn below trăng tròn MPs/L. The average abundance of MPs was around 10 MPs/L within Can Gio reserve, which was in the range of microplastics in Three Gorges Reservoir in china (1.597–12.611 MPs/L) <66>, Taihu Lake in china (3.4–25.8 MPs/L) <33>. This comparison could be made owing lớn the similarity of the position of Can Gio và Taihu in terms of geographical location & human activities. Nevertheless, Taihu Lake has become one of the most severely polluted lakes in đài loan trung quốc due to lớn the development of the local economy và industry & the presence of three wastewater treatment plants, but, in contrast, Can Gio is strictly protected by the government & UNESCO. Microplastics have eventually reached the East Sea, but in a smaller amount, from 3.1 ± 1.6 khổng lồ 4.7 ± 3.2 MPs/L.
The total microplastics in ghen Rai Gulf were much lesser than in the Jinhae Bay, South Korea (88 ± 68 MPs/L) <22>, but equivalent to lớn the Hudson River (USA) khổng lồ some extent (0.625–2.45 fibers/L) <67>. Microplastics in ghen tuông Rai (ES3) are predicted khổng lồ come from terrestrial & sea-based sources. The latter source is supposed lớn be maritime transport <68,69>, because the sampling sites are around the intersection of cargo ships & vessels carrying imported-exported fuels và gases. However, it is still not well understood what is the main reason for the presence of plastic debris in this area. According to lớn Browne, <70>, the source of maritime shipping is much smaller than land-based sources. In fact, microfibers accounted for a larger percentage than micro-particles (Table 3), which is attributed khổng lồ textile sources from the mainland. All of the investigated plastic types were encountered from the ocean surface to lớn the depths of 3 m in the sampling locations of tị Rai Bay. PE dominated the sea surface, whilst PA, PET, & PVC were predominant in the sub-surface samples, 2 m và 3 m, respectively. They are subject to lớn distribution more in the deeper seawater levels since their densities (up khổng lồ 1.14, 1.3–1.5 và 1.15–1.70 g/cm3, respectively) were higher than seawater (1.023 g/cm3 in measured average) <43,71,72>. PS was found in the sub-surface seawater with a higher abundance despite its similar mật độ trùng lặp từ khóa to the seawater. Hence, it can be seen that the vertical distribution of microplastics depends on not only the density of virgin polymers. Their distribution is also affected by the disturbance caused by the actions of internal wave & oceanic circulation modes in the seawater <73> since any abrasion, cracking và pitting of the surface can increase the density <43>.
As seen in Table 3, the majority of microplastics were fibers with various kích cỡ fractions. There was a surprising similarity in their colors in most environments. Trắng was always most predominant in all shapes of plastic types, particularly 18.1% for fibers. Pink (red), blue, purple and gray were popular colors of fibers (Figure 2), 15.7%, 14.4%, 12.4% and 10.2%, respectively. đen accounted for 7.6% of fibers. However, the đen was seen with purple or blue instead of completely black as activated carbon. These colors were also commonly found in fibers in the Northeast Atlantic Ocean (blue, black, red) <34>, Jinhae Bay, South Korea (green, blue, red) <22>, Qatar (blue, white) <74> và the Hudson River-USA (blue, black, red) <67>. The results showed that the distribution of plastic types was not much different by depth in the water column. PE dominated in the surface samples, PET & PA were predominant in the sub-surface samples. PE, PP & many PET fragments were attributed khổng lồ the breakdown products of plastic items, especially single-use water bottles & tableware. In ganh Rai, Soai Rap and White Tiger seawater, pink fibers were dominated by PET (Figure 2e), while xanh was more frequently observed in pa fibers (Figure 2d). In the water of Saigon canals, some parts of several colored fibers appeared brown, which showed the contamination of colored substances on the surface of microplastics in the environment.
Fibers were also commonly encountered in Can Gio reserve. However, their percentage (21–22%) was still lower than that of fragments (33–36%) (Table 3). The kích cỡ of plastic debris in this mangrove varied from 15 μm to lớn 53.38 μm, so smaller than those in Saigon urban canals (from 15 μm to 197.5 μm). Similarly, microfibers were only 60 μm maximum (53.43 μm on average) in the mangrove but were up to 561.23 μm (122.76 μm on average) in Saigon canal systems. The shape of fibers in locations of Can Gio & East Sea (Figure 2b–e) looked similar, that is, single colored fibers, which suggests that microfibers have dispersed in the marine environment. Differently, bundles of microfibers (Figure 2a) were quite often found in only Saigon urban canals. The small size fraction (25–50 μm) is quite common in the mangrove systems as also reported in the mangrove sediment of the Maowei Sea <63> and in Singapore’s coastal mangrove ecosystem <75>. The high percentages of small plastic fragments revealed that mangrove systems might accelerate plastic decomposition and accumulation. This, therefore, can promote harmful effects of plastic debris on the mangrove benthos lớn some extent.
Investigating microplastics in the aquatic environment is a time-consuming procedure of multiple steps, including sampling, separation, qualification & quantification. Raman scattering microscopy is a powerful tool lớn assess the microplastics in a water matrix with high specificity & low interference of water molecules. This study found that microplastic concentration decreased gradually from the urban waterborne (30–250 MPs/L) khổng lồ estuaries (10–20 MPs/L) và to the sea (3–5 MPs/L), which highlights the dispersion of microplastics in the marine environment. The data showed the variability in morphology và plastic composition of marine microplastics. Polyethylene, polyester and polyamide were predominant polymers of marine debris in the estuary location of Southern Vietnam. The findings indicated that the presence of marine plastic debris was associated with not only proximity lớn land-based sources, population density, but also natural water circulation in the sea. Nonetheless, it is a practical challenge lớn determine the exact sources and fate of microplastics in the coastal và marine environment because they are distributed randomly throughout the water column, especially in the sea surface microlayer. Finally, the prevalence of very small microplastics in fibrous và non-fibrous forms in the seawater warns the risks of microplastic pollution in UNESCO Can Gio Mangrove Biosphere Reserve, which suggests that appropriate actions should be taken in time to protect the reserve and marine environment of Vietnam.
The following supporting information can be downloaded at: https://www.uia.edu.vn/article/10.3390/microplastics1030038/s1. The spectra of microplastic types investigated in the manuscript (Figure S1), pictures & sample information taken in the field trips (Figure S2, Table S1), as well as statistical analysis tables (Tables S2–S4), are included in the supplementary materials published online alongside the manuscript.
Conceptualization, V.T.K.K.; Data curation, V.T.K.K.; Formal analysis, V.T.K.K., D.V.L. Và H.A.L.; Investigation, V.T.K.K.; Methodology, V.T.K.K.; Project administration, C.D.; Software, D.V.L.; Supervision, C.D. Và A.R.F.; Validation, H.A.L., A.R.F. Và C.D.; Visualization, D.V.L. & H.A.L.; Writing—original draft, V.T.K.K.; Writing—review & editing, D.V.L., H.A.L., A.R.F. And C.D. All authors have read and agreed khổng lồ the published version of the manuscript.
This work was supported by the German Academic Exchange Service (DAAD) for MSc. V.T.K.K. (Scholarship program: Sustainable Water Management 2018). This research received no external funding for article processing charges (APC). The first tác giả (
Data are contained within the article or Supplementary Material. The data presented in this study are available in this DOI’s article after the manuscript is accepted.
The authors would like to thank Cao Van Tuan và the assistant Le Thi Thanh Thuy (Ho-Chi-Minh đô thị Urban Environment Co., Ltd.—CITENCO) for the boat sampling trips along the Saigon urban canals. We thank Ta Chau Phu and Phan Minh Chi—lecturers of Ho-Chi-Minh Cadre Academy for their sampling in Can Gio mangrove; Nguyen đưa ra Trinh và his navigator colleagues of Sao Mai Port Operating Company for the sampling trip to ganh Rai Gulf, Soai Rap at the East Sea. We thank Vo Thi Thien Kim (student at University of Medicine Pham Ngoc Thach), Pham Thi ước ao Dao (Nhan Dan Gia Dinh Hospital), Vo Duy Khoa (Nguyen Tri Phuong Hospital), Nguyen Huy Phuc (student at Industrial University of Ho đưa ra Minh City) & Vo Duy Hoang Kim (student at Vo Thi Sau High School) for their assistance in sampling trips & interview campaigns.
Abbreviations
| The Abbreviations of Plastic Types | |
| MPs | Microplastics, total microplastics |
| PE | Poly-Ethylene |
| LDPE | Low-Density Polyethylene |
| MDPE | Medium-Density Polyethylene |
| HDPE | High-Density Polyethylene |
| PP | Poly-Propylene |
| PS | Poly-Styrene |
| PVC | Poly-Vinyl Chloride |
| PET (PETE) | Poly-Ethylene Terephthalate |
| PA | Poly-Amides, Nylon |
| PMMA | Poly Methyl Metacrylate |
| Geographic Terms & Abbreviations | |
| SG, HCMC | Hồ Chí Minh City, “Saigon” was also used alternatively |
| NL-TN | Nhiêu Lộc–Thị Nghè canal in Saigon city |
| BN | Bến Nghé canal in Saigon city |
| KT | Tẻ canal in Saigon city |
| LG | Lò Gốm canal in Saigon city |
| CG | Cần Giờ—a coastal suburban district of Ho chi Minh City, UNESCO Can Gio Mangrove Biosphere Reserve |
| East Sea | East Sea, a name of Vietnamese people for South trung quốc Sea |
| CT | Can Gio Mangrove–Transition zone |
| CB | Can Gio Mangrove–Buffer zone |
| CC | Can Gio Mangrove–Core zone |
References
Figure 1.Geographical maps of Vietnam, study areas & sampling locations. SG stands for Saigon, another name of Ho-Chi-Minh City, CT stands for Can Gio Mangrove—Transition zone, CB stands for Can Gio Mangrove—Buffer zone, CC stands for Can Gio Mangrove—Core zone, ES stands for East Sea, a name by the Vietnamese people for South đài loan trung quốc Sea. The detailed location names are found in Table S1 in Supplementary Materials.
Figure 1.Geographical bản đồ of Vietnam, study areas & sampling locations. SG stands for Saigon, another name of Ho-Chi-Minh City, CT stands for Can Gio Mangrove—Transition zone, CB stands for Can Gio Mangrove—Buffer zone, CC stands for Can Gio Mangrove—Core zone, ES stands for East Sea, a name by the Vietnamese people for South đài loan trung quốc Sea. The detailed location names are found in Table S1 in Supplementary Materials.
Figure 2.Non-microplastics and microplastics extracted from the marine environment of Southern Vietnam: non-microplastic fibers (a); microplastics in Saigon urban canals (b), Can Gio (c), ganh Rai (d), white Tiger oilfield (e).
Figure 2.Non-microplastics & microplastics extracted from the marine environment of Southern Vietnam: non-microplastic fibers (a); microplastics in Saigon urban canals (b), Can Gio (c), ghen Rai (d), white Tiger oilfield (e).
Figure 3.Total microplastics in Saigon urban canal systems. NL-TN Canal System is from Bridge No.1 to Bach Đang Wharf; Tau Hu (TH) Canal System is from Lo Gom lớn Letter Y Bridge; Te Canal (KT) is from Nguyen Van Cu Bridge khổng lồ Tan Thuan Bridge; Ben Nghe Canal (BN) is from Nguyen Van Cu Bridge lớn Khanh Hoi Bridge. The names of locations (from left lớn right) in Figure 3 are abbreviated as SG1, SG2, SG3, SG4, SG5, SG6, SG7, SG8, SG9, SG10, SG11, SG12, SG13, SG14 and SG15 in the maps (Figure 1).
Figure 3.Total microplastics in Saigon urban canal systems. NL-TN Canal System is from Bridge No.1 lớn Bach Đang Wharf; Tau Hu (TH) Canal System is from Lo Gom to Letter Y Bridge; Te Canal (KT) is from Nguyen Van Cu Bridge lớn Tan Thuan Bridge; Ben Nghe Canal (BN) is from Nguyen Van Cu Bridge khổng lồ Khanh Hoi Bridge. The names of locations (from left lớn right) in Figure 3 are abbreviated as SG1, SG2, SG3, SG4, SG5, SG6, SG7, SG8, SG9, SG10, SG11, SG12, SG13, SG14 and SG15 in the maps (Figure 1).
Figure 5.The decrease in microplastic concentration from Saigon lớn the East Sea through UNESCO Can Gio Mangrove Biosphere Reserve. Binh Khanh ferry is the intersection of HCMC và Can Gio; The confluence of Soai Rap River is the natural border of Can Gio with Mekong Delta; ghen tuông Rai Gulf is the confluence of Long Tau River; white Tiger Oilfield is in the East Sea belonging to lớn Đong Nai thành phố (not HCMC).
Figure 5.The decrease in microplastic concentration from Saigon khổng lồ the East Sea through UNESCO Can Gio Mangrove Biosphere Reserve. Binh Khanh ferry is the intersection of HCMC and Can Gio; The confluence of Soai Rap River is the natural border of Can Gio with Mekong Delta; ghen tuông Rai Gulf is the confluence of Long Tau River; white Tiger Oilfield is in the East Sea belonging khổng lồ Đong Nai city (not HCMC).
Table 1.Raman band assignments of standard plastics và sampled microplastics (Figure S1 in Supplementary Materials).
Table 1.Raman band assignments of standard plastics and sampled microplastics (Figure S1 in Supplementary Materials).
| Polystyrene(PS) | 1612.87 | 1604.24 | phenyl ring stretch <47,48> |
| 1015.03 | 1001.75 | C–C in-plane ring deformation +,C–H out-of-plane deformation <47> | |
| 622.43 | 621.1 | in-plane ring deformation <47,48> | |
| Poly(methyl methacrylate) (PMMA) | 1679.85 | 1723.71 | C–O–C symmetric stretch <47> |
| 1512.1 | 1447.51 | –CH2– deformation <48> | |
| 1154.13 | 1181.31 | C–C–C–C stretch <48> | |
| 835.31 | 808.67 | C=O stretch <47> | |
| Polypropylene(PP) | 2886.5 | 2889.14 | –CH3 stretch <49> |
| 1451.79 | 1458.89 | –CH2– deformation <48> | |
| 1325.16 | 1328.97 | C–C stretch <49> | |
| 1150.51 | 1153.82 | –CH3 rock <49> | |
| 805.23 | 808.67 | –CH2– rock <48> | |
| Polyethylene(LDPE) | 2928.9 | 2884.5 | –CH2– stretch <50> |
| 1442.63 | 1441.9 | –CH2– wag <50> | |
| 1293.13 | 1296.25 | –CH2– twist <50> | |
| 1172.35 | 1124.36 | C–C stretch <50> | |
| 1069.69 | 1060.97 | C–C stretch <50> | |
| Polyamide-6,nylon-6(PA-6) | 2895.67 | 2900.2 | –CH2– stretch <51> |
| 1680.05 | 1633.39 | unknown group <51> | |
| 1440.22 | 1441.9 | –CH2– <51,52> | |
| 1383.02 | 1430.49 | –CH2– bend <51,52> | |
| 1094.93 | 928.73 | –CH2– twist <52> | |
| Poly-ethylene terephthalate(PET) | 1753.59 | 1725.34 | C=O stretch <53,54> |
| 1602.3 | 1614.52 |  | |
| 1302.58 | 1288.21 | C–C | |
| 846.1 | 855.4 | C=C <53> | |
| 693.92 | 628.46 |  | |
| Polyvinyl chloride(PVC) | 2892.78 | 2852.09 | C–H stretch <55> |
| 1436.72 | 1430.19 | –CH2– bend <51,55> | |
| 1360.33 | 1319.11 | unknown group <55> | |
| 693.92 | 632.64 | C–Cl |
| Total microplastics (MPs/L) | 35.58 ± 4.75 | 45.19 ± 10.30 | 33.83 ± 10.54 | 43.41 ± 7.93 |
| PE (%) | 14.35 | 12.23 | 14.68 | 17.41 |
| PP (%) | 13.48 | 12.66 | 11.51 | 11.34 |
| PET (%) | 21.74 | 18.34 | 8.73 | 7.283 |
| PVC (%) | 5.65 | 6.11 | 11.51 | 4.86 |
| PS (%) | 3.04 | 2.18 | 4.76 | 1.21 |
| PA (%) | 22.17 | 23.58 | 14.68 | 17.41 |
| PMMA (%) | 1.31 | 0.87 | 0.79 | 1.21 |
| Unidentifed (%) | 18.26 | 24.02 | 33.33 | 39.27 |
Table 3.Comparisons of parameters of microplastics in Saigon urban canals, Can Gio Reserve và East Sea.
Table 3.Comparisons of parameters of microplastics in Saigon urban canals, Can Gio Reserve and East Sea.
| Plastic compositions | PA > PET > PE > PP > PVC > PS > PMMA | PET > PE > pa > PP > PVC > PS > PMMA | PE > PP > PET > pa > PVC = PS > PMMA | PET > PE > page authority > PP > PVC ≥ PS > PMMA | PET > pa > PP > PE > PVC > PS = PMMA |
| Common shapes (%) | Fiber: 35.4Fragment: 20.6 | Fiber: 27.7Fragment: 34.2 | Fiber: 31.3Particle: 21.8 | Fiber: 42.4Particle: 20.14 | Fiber: 44.1Particle: 26.5 |
| Common colors | white > gray > brown > green > pink | white > gray > blue > pink > brown | white > pink > blue > purple > yellow | white > xanh > pink > gray > green | white > gray > pink > xanh > purple |
| Size range (μm) | Fiber: 14.1–561.2Non-fibers: 15.7–188.4 | Fiber: 25–60Non-fibers: 14–53.4 | Fiber: 19.7–58.3Non-fibers: 21.9–94.5 | Fiber: 25–436.9Non-fibers: 23.5–265 | Fiber: 36.1–184.7Non-fibers: 22–92 |
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Khuyen, V.T.K.; Le, D.V.; Le, H.A.; Fischer, A.R.; Dornack, C. Assessing Microplastic Prevalence and Dispersion from Saigon Urban Canals via Can Gio Mangrove Reserve to lớn East Sea by Raman Scattering Microscopy. Microplastics 2022, 1, 536-553.https://doi.org/10.3390/microplastics1030038
AMA Style
Khuyen VTK, Le DV, Le HA, Fischer AR, Dornack C. Assessing Microplastic Prevalence & Dispersion from Saigon Urban Canals via Can Gio Mangrove Reserve to East Sea by Raman Scattering Microscopy. Microplastics. 2022; 1(3):536-553.https://doi.org/10.3390/microplastics1030038
Chicago/Turabian StyleKhuyen, Vo Thi Kim, Dinh Vu Le, Hung Anh Le, Axel René Fischer, và Christina Dornack. 2022. "Assessing Microplastic Prevalence & Dispersion from Saigon Urban Canals via Can Gio Mangrove Reserve khổng lồ East Sea by Raman Scattering Microscopy"
