Potentially toxic metals pollution in the Straits of Malacca warrants the development of rapid, simple and sensitive assays. Enzyme-based assays are excellent preliminary screening tools with near real-time potential. The heavy-metal assay based on the protease ficin was optimized for mercury detection using response surface methodology. The inhibitive assay is based on ficin action on the substrate casein and residual casein is determined using the Coomassie dye-binding assay. Toxic metals strongly inhibit this hydrolysis. A central composite design (CCD) was utilized to optimize the detection of toxic metals. The results show a marked improvement for the concentration causing 50% inhibition (IC50) for mercury, silver and copper. Compared to one-factor-at-a-time (OFAT) optimization, RSM gave an improvement of IC50 (mg/L) from 0.060 (95% CI, 0.030-0.080) to 0.017 (95% CI, 0.016-0.019), from 0.098 (95% CI, 0.077-0.127) to 0.028 (95% CI, 0.022-0.037) and from 0.040 (95% CI, 0.035-0.045) to 0.023 (95% CI, 0.020-0.027), for mercury, silver and copper, respectively. A near-real time monitoring of mercury concentration in the Straits of Malacca at one location in Port Klang was carried out over a 4 h interval for a total of 24 h and validated by instrumental analysis, with the result revealing an absence of mercury pollution in the sampling site.
Matched MeSH terms: Water Pollutants, Chemical/analysis
Mountain salts produced from the highland region in NE Sarawak have a market value and also provide basic income to the communities. During the salt-making process, microplastics (MPs) may enter into commercial table salts from various sources, which has not been explored yet. Hence, the current research investigates the presence of MPs in the rock salts produced from the highland saline water in two different locations (L1 and L2) in NE Sarawak. Among the brine water and rock salt samples analysed, the highest concentrations of MPs were detected from the salt samples. It has been revealed that both the water and salt samples have the highest concentration of MPs occurring within the size range of 1-1000 μm. Transparent MPs are the most common colour observed in both salt and water samples, followed by white, blue, red, and black. The most prevalent shapes of MPs are fibers, which account for almost 47% in water samples and 87% in salt samples. Based on the ATR-FTIR study, polyethylene (PE) is the most prevalent polymer observed in salt samples, followed by polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET). In water samples, PP is the most dominating polymer, followed by PE and PS. Through SEM microphotographs, fiber-type MPs have smooth surfaces, fragment-type MPs have rough edges, and sheet-type MPs have layered surfaces. EDX analysis revealed that carbon (C) and oxygen (O) are the most abundant elements, followed by aluminium (Al) and sodium (Na) in MPs. Based on the results, it is inferred that the MPs in the rock salts are mainly sourced from the different stages of salt-making production. This preliminary study shed light on the presence and characteristics of MPs in rock salts in this region. The research outcomes could support sustainable management plans to improve the salt quality and enhance the market value.
Matched MeSH terms: Water Pollutants, Chemical/analysis
Hydrogeochemical understanding of groundwater is essential for the effective management of groundwater. This study has been carried out to have concrete data for the seasonal variations in hydrogeochemistry of groundwater in central Tamilnadu forming a complex geological terrain with a varied lithology. A total of 244 groundwater samples were collected during four different seasons, viz, southwest monsoon (SWM), summer (SUM), postmonsoon (POM), and northeast monsoon (NEM) from bore wells. The physical parameters such as pH, temperature, TDS, ORP, humidity, and electrical conductivity (EC) were measured insitu, whereas major ions were analyzed in the lab adopting standard procedures. Overall, higher EC and NO3 values were observed and exceeded the WHO permissible limit irrespective of seasons, except for NO3 in SWM. Na and HCO3 are the dominant cation and anion in the groundwater irrespective of seasons. The highest average values of Na (65.06 mg L-1) and HCO3 (350.75 mg L-1) were noted during SWM. Statistical analysis was carried out to elucidate the hydrogeochemistry of the region. Initially, to understand the ionic relationship, correlation matrix was used followed by factor analysis for determination of major geochemical control and later factor scores were derived to understand the regional representations. An attempt has also been made to identify the samples influenced by multiple geochemical processes and to understand their spatial variation in the study period. Correlation of geochemical parameters reveals a excellent positive correlation between Ca and NO3 in SUM, SWM, and NEM due to the dominant of anthropogenic sources and minor influence of weathering process. Strongly loaded factor scores are found to be mostly in the following order POM > NEM > SWM > SUM. Principal component analysis of different seasons indicates the interplay of natural weathering and anthropogenic factors. Overall, the predominant geochemical processes in this region, irrespective of seasons are weathering and, ion exchange and anthropogenic activities.
Matched MeSH terms: Water Pollutants, Chemical/analysis*
The assessment of surface water quality is often laborious, expensive and tedious, as well as impractical, especially for the developing and middle-income countries in the ASEAN region. The application of the water quality index (WQI), which depends on several independent key parameters, has great potential and is a useful tool in this region. Therefore, this study aims to find out the spatial variability of various water quality parameters in geographical information system (GIS) environment and perform a comparative study among the ASEAN WQI systems. At present, there are four ASEAN countries which have implemented the WQI system to evaluate their surface water quality, which are (i) Own WQI system-Malaysia, Thailand and Vietnam-and (ii) Adopted WQI system: Indonesia. A spatial distribution of 12 water quality parameters in the Selangor river basin, Malaysia, was plotted and then applied into the different ASEAN WQI systems. The WQI values obtained from the different WQI systems have an appreciable difference, even for the same water samples due to the disparity in the parameter selection and the standards among them. WQI systems which consider all biophysicochemical parameters provide a consistent evaluation (Very Poor), but the system which either considers physicochemical or biochemical parameters gives a relatively lenient evaluation (Fair-Poor). The Selangor river basin is stressed and impacted by all physical, biological and chemical parameters caused by both the aridity of the climate and anthropogenic activities. Therefore, it is crucial to include all these aspects into the evaluation and corresponding actions should be taken.
Matched MeSH terms: Water Pollutants, Chemical/analysis*
The present study was performed to analyze the bioaccumulation of heavy metals, biochemical constituents, antioxidants, and metabolic enzymes in the crab Scylla serrata from different regions of Tuticorin, Southeast Coast of India. The study area consists of Threspuram and Harbour Beach which were polluted environments due to the discharge of industrial effluents and domestic sewage into them. Punnakayal, which is a low-polluted environment where the in-situ culture of S. serrata is carried out by local fish farmers, was selected as well. The results revealed that the level of heavy metals, biochemical constituents, antioxidants, and metabolic enzymes were significantly high in the crabs collected from Threspuram and Harbour Beach compared to the crabs collected from Punnakayal. This study indicates that crabs from polluted environments have significant heavy metals bioaccumulation which leads to elevated antioxidants and metabolic enzyme levels. This implies that the crabs are under oxidative and metabolic stress.
Matched MeSH terms: Water Pollutants, Chemical/analysis*
The current study aimed to develop a suitable molecular marker [Linear alkylbenzenes (LABs)] approach for pollution determination in mangrove oysters of peninsular Malaysia. C. belcheri species were collected from rivers of Merbok, Perai, Klang, Muar and PulauMerambong (An Island). The LABs were extracted from C. belcheri and determined using GC-MS. The LABs indices which included I/E, L/S and C13/C12 were applied to describe the sources and biodegradation of LABs. The results revealed that the maximum concentrations were detected in oysters from Klang (27.91 ng g-1dw), while the lowest concentrations were detected in oysters from Merbok (8.12 ng g-1dw). Moreover, I/E ratios varied between 2.83 and 6.40, indicating the secondary treatment effluents being discharged to coastal zones. The results of this study suggested that the oysters absorbed LABs mainly in dissolved phase. Therefore, mangrove oysters are a good biosensor for LABs contamination in the aquatic environment.
Matched MeSH terms: Water Pollutants, Chemical/analysis*
Brunei Bay is one of the most important marine environments of East Malaysia (South China Sea), covering many productive ecosystems with activities including fisheries, tourism, and main shipping lanes for petroleum transfers. Evaluation of the sources and distributions of steroids in the surface sedimentary organic matter was carried out by gas chromatography-mass spectrometry (GC-MS). The concentrations of the total identified sterols (TIS) ranged between 0.81 and 12.69 μg g-1 dry weight, and the total sterones were between 0.11 and 5.66 μg g-1 dry weight. The coprostanol level was comparatively low (<0.10 μg g-1), and the multi-biomarker proxies indicated that the region did not exhibit significant contamination from sewage effluents. Principal component analysis (PCA) revealed the coastal environment of the study area was dominated by allochthonous (mainly terrestrial) organic matter input.
Matched MeSH terms: Water Pollutants, Chemical/analysis*
In pursuit of advancing photocatalysts for superior performance in water treatment and clean energy generation, researchers are increasingly focusing on layered double hydroxides (LDHs) which have garnered significant attention due to their customizable properties, morphologies, distinctive 2D layered structure and flexible options for modifying anions and cations. No review has previously delved specifically into ZnCr and NiCr LDH-based photocatalysts and therefore, this review highlights the recent surge in ZnCr and NiCr-based LDHs as potential photocatalysts for their applications in water purification and renewable energy generation. The structural and fundamental characteristics of layered double hydroxides and especially ZnCr-LDHs and NiCr-LDHs are outlined. Further, the various synthesis techniques for the preparation of ZnCr-LDHs, NiCr-LDHs and their composite and heterostructure materials have been briefly discussed. The applicability of ZnCr-LDH and NiCr-LDH based photocatalysts in tackling significant issues in water treatment and sustainable energy generation is the main emphasis of this review. It focuses on photocatalytic degradation of organic pollutants in wastewater, elucidating the principles and advancements for enhancing the efficiency of these materials. It also explores their role in H2 production through water splitting, conversion of CO2 into valuable fuels and NH3 synthesis from N2, shedding light on their potential for clean energy solutions. The insights presented herein offer valuable guidance for researchers working towards sustainable solutions for environmental remediation and renewable energy generation.
Matched MeSH terms: Water Pollutants, Chemical/analysis
Phosphorus (P) plays an important role in regulating primary production in estuarine environments. However, knowledge of the P-functional gene composition of microbial communities and the mechanisms of microbial adaptation to changes in available P in estuaries remain limited. This study coupling 16 s rDNA and metagenomics sequencing was conducted to reveal the relationship between P cycling functional genes, microbial interactions, and P availability in the Jiulong River Estuary. The results showed that the relative abundance of P cycling functions genes was highest in winter, and lowest in summer. Spatially, the total relative abundance of P cycling functions genes was higher in the riverward than that in the seaward. P cycling functional microbial interactions and P cycling gene coupling were strongest in summer and in the seaward. Changes in both temperature and salinity had significant direct and indirect effects on P cycling function, and the influence of salinity on P cycling function was greater than that on the microbial community in the estuary. Salinity had significant direct negative effects on inorganic P-solubilization (IP), organic P-mineralization (OP), and P uptake and transport functions (PT). Whereas, salinity had a significant positive effect on P-starvation response regulation (PR) function. Thus, salinity and microbial communities regulate the soluble reactive phosphate concentrations in estuarine environments by strengthening internal coupling among P cycling functions, promoting PR function, and facilitating PT gene expression. PR is the most important predictors, PR, PT, and PR-PT together explained 38.56 % of the overall soluble reactive phosphorus (SRP) variation. Over 66 % of the explained SRP variations can be predicted by the PR, PT, and PR-PT functional genes. This finding improves the knowledge base of the microbial processes for P cycling and provides a foundation for eutrophication management strategies in the estuary.
Matched MeSH terms: Water Pollutants, Chemical/analysis
Every year, the global production of plastic waste reaches a staggering 400 million metric tons (Mt), precipitating adverse consequences for the environment, food safety, and biodiversity as it degrades into microplastics (MPs). The multifaceted nature of MP pollution, coupled with its intricate physiological impacts, underscores the pressing need for comprehensive policies and legislative frameworks. Such measures, alongside advancements in technology, hold promise in averting ecological catastrophe in the oceans. Mandated legislation represents a pivotal step towards restoring oceanic health and securing the well-being of the planet. This work offers an overview of the policy hurdles, legislative initiatives, and prospective strategies for addressing global pollution due to MP. Additionally, this work explores innovative approaches that yield fresh insights into combating plastic pollution across various sectors. Emphasizing the importance of a global plastics treaty, the article underscores its potential to galvanize collaborative efforts in mitigating MP pollution's deleterious effects on marine ecosystems. Successful implementation of such a treaty could revolutionize the plastics economy, steering it towards a circular, less polluting model operating within planetary boundaries. Failure to act decisively risks exacerbating the scourge of MP pollution and its attendant repercussions on both humanity and the environment. Central to this endeavor are the formulation, content, and execution of the treaty itself, which demand careful consideration. While recognizing that a global plastics treaty is not a panacea, it serves as a mechanism for enhancing plastics governance and elevating global ambitions towards achieving zero plastic pollution by 2040. Adopting a life cycle approach to plastic management allows for a nuanced understanding of possible trade-offs between environmental impact and economic growth, guiding the selection of optimal solutions with socio-economic implications in mind. By embracing a comprehensive strategy that integrates legislative measures and technological innovations, we can substantially reduce the influx of marine plastic litter at its sources, safeguarding the oceans for future generations.
Matched MeSH terms: Water Pollutants, Chemical/analysis
Stormwater runoff is a leading cause of nitrogen (N) transport to water bodies and hence one means of water quality deterioration. Stormwater runoff was monitored in an urban residential catchment (drainage area: 3.89 hectares) in Florida, United States to investigate the concentrations, forms, and sources of N. Runoff samples were collected over 22 storm events (May to September 2016) at the end of a stormwater pipe that delivers runoff from the catchment to the stormwater pond. Various N forms such as ammonium (NH4-N), nitrate (NOx-N), dissolved organic nitrogen (DON), and particulate organic nitrogen (PON) were determined and isotopic characterization tools were used to infer sources of NO3-N and PON in collected runoff samples. The DON was the dominant N form in runoff (47%) followed by PON (22%), NOx-N (17%), and NH4-N (14%). Three N forms (NOx-N, NH4-N, and PON) were positively correlated with total rainfall and antecedent dry period, suggesting longer dry periods and higher rainfall amounts are significant drivers for transport of these N forms. Whereas DON was positively correlated to only rainfall intensity indicating that higher intensity rain may flush out DON from soils and cause leaching of DON from particulates present in the residential catchment. We discovered, using stable isotopes of NO3-, a shifting pattern of NO3- sources from atmospheric deposition to inorganic N fertilizers in events with higher and longer duration of rainfall. The stable isotopes of PON confirmed that plant material (oak detritus, grass clippings) were the primary sources of PON in stormwater runoff. Our results demonstrate that practices targeting both inorganic and organic N are needed to control N transport from residential catchments to receiving waters.
Matched MeSH terms: Water Pollutants, Chemical/analysis*
The aim of this study is to uncover the multifaceted environmental threats posed by Oil Spill Water Pollution (OSWP) originating from tanker terminals situated in the Qeshm and Hormozgan regions of Iran. In this region, water pollution arises from diverse sources, mostly from ruptured pipelines, corroded valves, unforeseen accidents, and aging facilities. The Qeshm Canal and Qeshm Tanker Terminal emerged as pivotal sites for investigation within this study. The focus is directed towards pinpointing vulnerable areas at risk of water contamination and delving into the intricate pathways and impacts associated with oil spills. Utilizing the sophisticated modeling capabilities of the National Oceanic and Atmospheric Administration's (NOAA) GNOME model, the research explores various scenarios extrapolated from seasonal atmospheric and oceanic data through 2022. The findings show the OSWP hazard zones located northeast of Qeshm. Notably, the wind and currents greatly affect how OSWPs are destined and dispersed. This underscores the intricate interplay between environmental factors and spill dynamics. In essence, this study not only sheds light on the imminent environmental threats posed by OSWP but also underscores the critical need for proactive measures and comprehensive strategies to mitigate the adverse impacts on marine ecosystems and coastal communities.
Matched MeSH terms: Water Pollutants, Chemical/analysis
Alkylphenols and most pesticides, especially organochlorine pesticides are endocrine-disrupting chemicals and they usually mimic the female hormone, estrogen. Using these chemicals in our environment would eventually lead us to consume them somehow in the food web. Several rivers in the State of Selangor, Malaysia were selected to monitor the level of alkylphenols and pesticides contamination for several months. The compounds were extracted from the water samples using liquid-liquid extraction method with dichloromethane and ethyl acetate as the extracting solvents. The alkylphenols and pesticides were analyzed by selected ion monitoring (SIM) mode using the quadrapole detector in Shimadzu QP-5000 gas chromatograph-mass spectrometer (GCMS). Recovery of most alkylphenols and pesticides were in the range of 50% to 120%. Trace amounts of the compounds were detected in the river water samples, mainly in the range of parts per trillion. This technique of monitoring the levels of endocrine-disruptors in river water is consistent and cost effective.
Matched MeSH terms: Water Pollutants, Chemical/analysis
To assess the sources, levels, spatial distributions and exposure to human health, the concentration of heavy metals Pb, Cu, Mn, Zn, and Fe in the sand/sediment of the Parki Beach area of Anowara, Chattogram, Bangladesh are determined using Atomic Absorption Spectroscopy (AAS) for the first time. A total of 40 surface and subsurface sand and sediment samples were collected from 20 different sampling points along the 15 km long Parki Beach area, Bangladesh. Average concentrations of Pb, Cu, Mn, Zn and Fe in surface samples are 14.60, 10.10, 283, 407 and 25,256 mg/kg respectively and 9.95, 4.20, 193, 156.6 and 24,404 mg/kg for sub-surface samples, respectively, which shows that the values are higher in surface samples than those in sub-surface samples. According to the Consensus-Based Sediment Quality Guidelines (CBSQG), the northern part of the beach becomes moderately polluted by Mn and Fe, and a smaller area of the southern part is highly polluted by Zn. The average Contamination Factor (CF) of Zn was greater than 1(CF > 1), while the CF of other metals was less than 1(CF
Matched MeSH terms: Water Pollutants, Chemical/analysis
The accumulation of plastic waste from various sources into marine and inland water is considered a global problem due to its serious impacts on aquatic ecosystems and human health. In the past decade, remote sensing has played an important role in monitoring of plastic pollution in marine and inland water sources and has achieved a series of research results in this field. In this study, a comprehensive review was conducted on the development, opportunities, and challenges of datasets and methods in Marine and Inland Water Plastics Remote Sensing (MIWPRS) monitoring over the past decade, based on the Web of Science (WOS) core database. The results indicated that compared with traditional methods, remote sensing has attracted the attention of scholars due to its advantages. Since 2014, the number of related publications has been increasing year by year, especially in China and the United States, which have achieved tremendous development. The MIWPRS research focus mostly on the use of different satellite remote sensing data and related algorithms to obtain the distribution of plastics in marine and inland water. However, it faces the challenge of lacking subsequent systematic impact assessment models and key pollution prevention measures. In terms of data acquisition, there is a lack of continuous observation models due to the fluidity of marine and inland water. Therefore, MIWPRS has great development opportunities in developing specialized sensors and combining multi-source data with interdisciplinary knowledge such as artificial intelligence (AI) and GIS. It is necessary for us to improve the seasonal migration model of plastics in water and promote the development of MIWPRS towards broader and deeper fields.
Matched MeSH terms: Water Pollutants, Chemical/analysis
Plastic resin pellets collected at Minh Chau island and Ba Lat estuary between 2007 and 2014 in Vietnam were analyzed for dichloro-diphenyl-trichloroethanes (DDTs), polychlorinated biphenyls (PCBs) and hexachlorocyclohexanes (HCHs). The study was carried out as part of the International Pellet Watch program for monitoring the global distribution of persistent organic pollutants (POPs). Higher levels of DDTs compared to PCBs indicated agricultural inputs rather than industrial discharges in the region. Most POP concentrations on both beaches decreased over the period, with the exception of HCH isomers. Though the concentration of DDTs showed a drastic decline on both beaches between 2007/2008 and 2014, DDTs accounted for 60-80% of total DDTs, suggesting that there is still a fresh input of these chemicals in the region. This study strongly recommends further investigations to track temporal and spatial patterns of POP levels in the marine environment using plastic resin pellets.
Matched MeSH terms: Water Pollutants, Chemical/analysis*
Sediment is a great indicator for assessing coastal mercury contamination. This work profiled the magnitude of mercury pollution in the tropical estuaries and coastal sediments of the Strait of Malacca. Mercury was extracted through the ultrasound-assisted mercury extraction method and analyzed using the flow injection mercury system. The mean concentration of mercury in the sediment samples was 61.43 ± 23.25 μg/kg, ranging from 16.55 ± 0.61 to 114.02 ± 1.54 μg/kg. Geoaccumulation index revealed that a total of 13% of sampling sites were moderately enriched with mercury. The northern part of the Strait of Malacca had the highest mean mercury (Hg) concentration (76.36 ± 27.25 μg/kg), followed by the southern (64.59 ± 16.09 μg/kg) and central (39.33 ± 12.91 μg/kg) parts. Sediment mercury concentration in the current study was lower than other regions like Japan, China, Indian, east Mediterranean, and Taiwan. When compared to the Canadian interim marine and freshwater sediment, China's soil interim environmental guidelines, mercury contamination in the Strait of Malacca was found to be below these permissible limits. Sediment organic matter content was found to have significant correlation with sediment mercury concentration. This study could provide the latest benchmark of mercury pollution and prove beneficial to future pollution studies in relation to monitoring works in tropical estuaries and coastal sediments.
Matched MeSH terms: Water Pollutants, Chemical/analysis*
The content of 12 elements in Cambodian dried striped snakehead fish was determined using inductively coupled plasma mass spectrometry. The present study compares the level of the trace toxic metals and nutritional trace elements in the fish processed using solar drying system (SDS) and open sun drying (OSD). The skin of SDS fish has lower level of As, Pb, and Cd compared to the OSD sample. As such, the flesh of the fish accumulated higher amount of toxic metals during OSD compared to SDS. However, arsenic was detected in both samples within the safe limit. The nutritional elements (Fe, Mn, Mg, Se, Mo, Cu, Ni, and Cr) were higher in the skin sample SDS fish compared to OSD fish. These beneficial metals were not accumulated in the flesh sample SDS fish demonstrating lower level compared to drying under conventional system. The reddish coloration of the SDS fish was due to the presence of high Cu content in both the skin and flesh samples which possibly account for no mold formation 5 days after packaging. As conclusion, drying of Cambodian C. striata using solar-assisted system has proven higher content of the nutritious elements compared to using the conventional system despite only slight difference in the toxic metals level between the two systems.
Matched MeSH terms: Water Pollutants, Chemical/analysis*