scholarly journals Occurrence and Polymer Types of Microplastics from Surface Sediments of Molawin Watershed of the Makiling Forest Reserve, Los Baños, Laguna, Philippines

2020 ◽  
Vol 19 (1) ◽  
pp. 57-67
Author(s):  
Jomel S. Limbago ◽  
◽  
Marion Michael A. Bacabac ◽  
Dawn Rosarie M. Fajardo ◽  
Camille Rose T. Mueda ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Environmental Science ◽  
Surface Sediments ◽  
River Sediment ◽  
Size Range ◽  
Dry Weight ◽  
Freshwater Ecosystems ◽  
Forest Reserve ◽  
Sediment Samples ◽  
Density Separation

Microplastic pollution is an emerging topic in environmental science. However, information about its prevalence in the freshwater ecosystems is still scarce. This study quantified and identified microplastic form and polymer types from surface sediments of the Molawin River. Sediment samples were collected from the upstream, midstream, and downstream stations of the river. Isolation of microplastics was performed through a modified granulometric approach, density separation, and filtration. Stereoscopic microscopy and Fourier-transform infrared spectroscopy (FTIR) were conducted to quantify and describe microplastics and identify the polymer types based on the infrared spectrum of absorption, respectively. The highest concentration of microplastics was found in the downstream station, with an average number of 97±12 items/100 g and 47.33±11.39 items/100 g sediment dry weight in the bank and channel, respectively. The isolated microplastics were dominated by ≥100 to ≤200 μm size range. Based on stereoscopic microscopy, microfragments and microfibers were the most common microplastic type, while polyethylene (PE) and polypropylene (PP) were the polymer types identified based on FTIR analyses. This study revealed the presence of microplastics and confirmed the microplastics polymers present in the Molawin Watershed of Makiling Forest Reserve.

scholarly journals Distribution and sources of n-alkanes in surface sediments of Taihu Lake, China

2016 ◽  
Vol 42 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Yunlong Yu ◽  
Yuanyuan Li ◽  
Zhigang Guo ◽  
Hua Zou
Keyword(s):  
Surface Sediment ◽  
Surface Sediments ◽  
Taihu Lake ◽  
Higher Plants ◽  
Complex Mixture ◽  
Dry Weight ◽  
Short Chain ◽  
Sediment Samples ◽  
Total Concentrations ◽  
Long Chain

Abstract The last study on n-alkanes in surface sediments of Taihu Lake was in 2000, only 13 surface sediment samples were analysed, in order to have a comprehensive and up-to-date understanding of n-alkanes in the surface sediments of Taihu Lake, 41 surface sediment samples were analyzed by GC-MS. C10 to C37 were detected, the total concentrations of n-alkanes ranged from 2109 ng g−1 to 9096 ng g−1 (dry weight). There was strong odd carbon predominance in long chain n-alkanes and even carbon predominance in short chain n-alkanes. When this finding was combined with the analysis results of wax n-alkanes (WaxCn), carbon preference index (CPI), unresolved complex mixture (UCM), hopanes and steranes, it was considered that the long chain n-alkanes were mainly from terrigenous higher plants, and that the short chain n-alkanes mainly originated from bacteria and algae in the lake, compared with previous studies, there were no obvious anthropogenic petrogenic inputs. Terrestrial and aquatic hydrocarbons ratio (TAR) and C21−/C25+ indicated that terrigenous input was higher than aquatic sources and the nearshore n-alkanes were mainly from land-derived sources. Moreover, the distribution of short chain n-alkanes presented a relatively uniform pattern, while the long chain n-alkanes presented a trend that concentrations dropped from nearshore places to the middle of lake.

CURRENT CONTAMINATION OF PERSISTENT ORGANOCHLORINES IN THIVAI RIVER SEDIMENTS, SOUTHERN VIETNAM

2021 ◽  
Vol 36 (06) ◽  
Author(s):  
NGOC VINH NGUYEN ◽  
LUIZ FELIPPE DE ALENCASTRO
Keyword(s):  
River Basin ◽  
River Sediment ◽  
River Sediments ◽  
Dry Weight ◽  
Gas Chromatography Mass Spectrometry ◽  
Reference Sites ◽  
Sediment Samples ◽  
Southern Vietnam ◽  
Highly Sensitive ◽  
The World

This report presents the development an highly sensitive, stable and reliable OCs analyzing method with GC/MS (gas chromatography/mass spectrometry) and results of OCs (organochlorines) levels in sediments of Thivai River basin. The method recovery ranges from 72% to 129% and meets the requirement for OCs analyzing. 18 composite sediment samples were taken from 18 sites along Thivai river basin from upstream (Formosa Plant sewer mouth –  Lo Ren canal) to downstream (confluence of Thi Vai and Go Gia rivers). The analytical results show that OCs concentration in Thi Vai river sediment (max 1.73 ng/g dry weight) is not higher than those of the reference sites and other river basins in Vietnam and in the world.

Estimation of Organochlorine Pesticides and Dioxin-Like PCBs in Surface Sediments from Baihua Lake

2011 ◽  
Vol 233-235 ◽  
pp. 2988-2993 ◽  
Author(s):  
Jin Luo ◽  
Li Ya Fu ◽  
Ji Wei Hu ◽  
Zheng Wen Yu ◽  
Chun Liu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Polychlorinated Biphenyls ◽  
Organochlorine Pesticides ◽  
Surface Sediment ◽  
Surface Sediments ◽  
Dry Weight ◽  
Selected Ion Monitoring ◽  
Sediment Samples ◽  
Sampling Locations

The concentration of eight organochlorine pesticides (OCPs) and twelve dioxin-like polychlorinated biphenyls (dl-PCBs) were estimated in nine surface sediment samples from Baihua Lake. Gas chromatography with mass spectrometry (GC-MS) was applied using selected ion monitoring (SIM) mode for the quantification of the OCPs and for the qualification of the dl-PCBs. The results showed that the concentrations of DDTs varied from 1.04 to 36.74 ng g-1(dry weight) in these sampling locations, and that of HCHs was in the range from 0.57 to 8.90 ng g-1. In addition, PCB167 and PCB169 were detected in several sediment samples.

The Correlation of Sediments Characteristics with Organochlorine Pesticides (OCPs) in Surface Sediments of Nansi Lake, China

2013 ◽  
Vol 726-731 ◽  
pp. 926-930 ◽  
Author(s):  
Gui Zhai Zhang ◽  
Zhao Ke Pan ◽  
Jing Li ◽  
Xiao Ming Li
Keyword(s):  
Particle Size ◽  
Organochlorine Pesticides ◽  
Surface Sediment ◽  
Surface Sediments ◽  
Dry Weight ◽  
Organic Content ◽  
Soluble Salt ◽  
Sediment Characteristics ◽  
Nansi Lake ◽  
Sediment Samples

The correlations of sediment characters[total organic content (TOC), particle size, soluble salt] with organochlorine pesticides (OCPs) in seven surface sediment samples of Nansi lake were discussed. Organochlorine pesticides(OCPs) in seven surface sediment samples of Nansi lake were analyzed by GC／ECD(Gas chromatography with electrochemical detection). The result showed that OCPs content was 2.9-6.91ng/g dw (dry weight).The concentrations of organochlorine pesticides (OCPs) failed to correlate with sediment characteristics (TOC, particle size and soluble salt).

Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments of the Brisbane River (Australia) – Preliminary Results

1989 ◽  
Vol 21 (2) ◽  
pp. 161-165 ◽  
Author(s):  
S. I. Kayal ◽  
D. W. Connell
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
River Estuary ◽  
Dry Weight ◽  
Weight Basis ◽  
Sediment Samples ◽  
Preliminary Results ◽  
Treated Sewage ◽  
Polycyclic Aromatic ◽  
Petroleum Refineries

Results of the analysis of twenty-three composite sediment samples revealed that PAHs are widely distributed in the Brisbane River estuary. Mean concentrations for individual compounds, on a dry weight basis, ranged from 0.03 µg/g for dibenz [ah] anthracene to 2.34 µg/g for fluoranthene. Observed PAH assemblages were rich in compounds having pyrolytic origins. However, the presence of petroleum derived compounds was indicative of the importance of petroleum as a PAH source in the estuary. Petroleum refineries, a coal loading terminal and a major treated sewage outfall located at the mouth were not indicated as major contributing sources of PAH pollution in the estuary.

Determination of denudation rates by the measurement of meteoric 10Be in Guadiana river sediment samples (Spain) by low-energy AMS

2018 ◽  
Vol 189 ◽  
pp. 227-235 ◽  
Author(s):  
S. Padilla ◽  
J.M. López-Gutiérrez ◽  
D.M.R. Sampath ◽  
T. Boski ◽  
J.M. Nieto ◽  
...  
Keyword(s):  
River Sediment ◽  
Low Energy ◽  
Sediment Samples ◽  
Denudation Rates

Litter decomposition and nutrient release in a tropical rainforest, Southern Bakundu Forest Reserve, Cameroon

1995 ◽  
Vol 11 (3) ◽  
pp. 333-350 ◽  
Author(s):  
Nicholas C. Songwe ◽  
D. U. U. Okali ◽  
F. E. Fasehun
Keyword(s):  
Forest Floor ◽  
Tropical Rainforest ◽  
Great Influence ◽  
Wood Decay ◽  
Nutrient Release ◽  
Dry Weight ◽  
Nitrogen And Phosphorus ◽  
Forest Reserve ◽  
Ceiba Pentandra ◽  
Terminalia Superba

ABSTRACTDecomposition of litter on the forest floor and of leaves of five species, Celtis zenkeri, Cola lepidota, Desbordesia glaucescens, Ceiba pentandra and Terminalia superba in nylon mesh bags, as well as wood decay were studied in the tropical rainforest at Southern Bakundu Forest Reserve, Cameroon.The rate of loss of dry matter was fastest in Celtis zenkeri which was significantly different from the other species, while potassium was the most rapidly released element from all species with more than 50% being released in the first two months of the experiment. Nitrogen and phosphorus showed initial increases in bagged leaf litter independent of dry weight losses and while nitrogen was later released phosphorus continued to increase reaching 2–3 times the initial concentration. Decomposition constant (k) of litter on the forest floor was found to be 2.23 whereas the mean decomposition constants of the different species were as follows: Celtis zenkeri 4.18, Cola lepidota 2.18, Desbordesia glaucescens 1.60 and Ceiba pentandra 2.16 for the two experiments.Termites were found to have a very great influence on the decay of the wood of Terminalia superba with decay due to micro-organisms being negligible.

scholarly journals Sediment Sources and Dispersion on the Western Sunda Shelf, Malay Peninsula, Southern South China Sea

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2823
Author(s):  
Yanguang Liu ◽  
Chuanshun Li ◽  
Ramlan Bin Omar ◽  
Xuefa Shi ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Surface Sediment ◽  
Surface Sediments ◽  
The Other ◽  
Coarse Grained ◽  
Malay Peninsula ◽  
Sediment Sources ◽  
Southern South China Sea ◽  
Sunda Shelf ◽  
Sediment Samples

Thirty-nine surface sediment samples collected from the western Sunda Shelf off the Malay Peninsula (WSSMP) in the southern South China Sea (SCS) were analysed for grain size, major and trace elemental compositions, and light/heavy mineral contents to trace the sediment sources and their transport mechanisms in the study area. In the WSSMP, the surface sediments are relatively poorly sorted but transportable. A principal component analysis of 37 elements and grain size fractions indicates that the surface sediments can be grouped into four major assemblages in the study area. Integrating with the light/heavy minerals data in the 63–125 μm fractions of the surface sediment samples, to better trace the sediment sources of the coarse-grained components in the marine environment, the study area can be further divided into four sediment provinces. Province I is located in the northwestern part of the study area. The concentrations of TiO2, Na2O, garnet, siderite, and glauconite in Province I were higher than in the other provinces. The main sediment source for this province originated from the Kelantan River and the Gulf of Thailand transported by the northeastern monsoon current. Province II is located offshore of the Pahang and Endau Rivers. The percentages of TiO2, rare earth elements, Al2O3, quartz, plagioclase, hypersthene, and magnetite in the surface sediments were typically higher in this province than in the other provinces. The Pahang and Endau rivers provide most of the sediments to this province, which are transported by southward coastal currents. Province III is located in the northeastern and eastern parts of the study area, where the coarse-grained sediment fraction had relatively high hornblende and biotite contents. Sediments in this province are mostly transported from the Mekong River during the northeastern monsoon. The other parts of the study area belong to Province IV, where the surface sediment elemental and mineral concentrations were mostly between those of the other three provinces. Therefore, we suggest that Province IV has a mixed source due to inputs from the surrounding rivers.

Reconstructing provenance changes in sediments supplying the South East African margin

2021 ◽  
Author(s):  
Ellie Pryor ◽  
Ian Hall ◽  
Morten Andersen ◽  
Daniel Babin ◽  
Yue (Merry) Cai ◽  
...  
Keyword(s):  
South African ◽  
Marine Sediment ◽  
River Sediment ◽  
Middle Stone Age ◽  
Source Rocks ◽  
Drainage Basins ◽  
Sediment Samples ◽  
Terrigenous Sediment ◽  
Geological Unit ◽  
Spatial Coverage

<div> <p>Sediment provenance is of key importance for understanding transport history and characterising sediment source regions in the marine and terrestrial environment. Radiogenic isotopes are widely used to identify inland and coastal sediment origins. They document changes in detrital terrigenous sediment fluxes which can be related to continental hydrological variability. Understanding sediment sources to the ocean is a pre-requisite before interpreting past climate archives in marine sediment cores.</p> </div><div> <p><span>South African coastal drainage basins are composed of various geological units, each reflected by different radiogenic isotope signals in the sediment. In addition to the age and nature of their source rocks, the sediment type influences this radiogenic signature.</span></p> </div><div> <p><span>Here, we present a review of the present-day radiogenic isotopic fingerprints of South African river catchments signals from new river sediment samples with the aim to gain a broad spatial coverage of the source rocks in the region and their relative contributions of terrigenous sediment delivered to the ocean. This information will be applied to marine sediment core MD20-3591 (36° 43.707 S; 22° 9.151 E, water depth 2464m), located offshore South Africa which has the potential to record both Agulhas Current and terrestrial variability. The core site receives a significant amount of terrigenous material from the African continents via riverine input. During the last glacial period, these rivers flowed across the continental shelf within a subdued incised valley. The Gourritz River catchment drains the Cape Supergroup and Karoo Supergroup, typical of these southern drainage basins, whereas the eastern Cape rivers drain the Karoo Supergroup geological unit which is capped by the Drakensberg basalts.</span></p> </div><div> <p><span>We are using the knowledge gained from these new South African terrestrial river sediment samples to identify the sources and transport pathways of the terrigenous sediments in MD20-3591. Of particular interest is the sensitivity of the radiogenic isotopic signatures to grain size variabilities and how this relationship can help to define local or distal sediments. These records will allow us to explore variability in regional hydroclimate in relation to the abundant archaeological evidence of cultural and technological innovations of Middle Stone Age humans in southern Africa.</span></p> </div>

Determination of NSAIDs in river sediment samples

2006 ◽  
Vol 387 (4) ◽  
pp. 1337-1342 ◽  
Author(s):  
Jan Antonić ◽  
Ester Heath
Keyword(s):  
River Sediment ◽  
Sediment Samples
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