Concentration Of Pollutants In Water Research Articles

Positivity and bound preserving well-balanced high order compact finite difference scheme for Ripa and pollutant transport model

We construct a fourth-order accurate compact finite difference scheme that is well-balanced, positivity-preserving of water height, and bound-preserving of temperature for Ripa and concentration for pollutant transport systems. The proposed scheme preserves the still-water steady state and the positivity of water height. It also maintains concentration bounds for pollutants across nonflat bottom topographies, regardless of the presence of a pollutant source. Our approach incorporates water height and pollutant concentration constraints within the same discretization, utilizing weak monotonicity and a simple bound-preserving limiter while preserving the well-balanced property. Through extensive numerical simulations encompassing Ripa and pollutant transport models, we demonstrate the effectiveness of our method, verifying its well-balanced property, high-order accuracy, positivity-preserving, and bound-preserving capabilities.

Evaluation of stormwater runoff pollutant distributions combined with land-use information in a regional karst aquifer in Texas, USA.

Fast urbanization can result in significant stormwater runoff pollution due to changes in land use. A 3-year study on the distribution and temporal variations of urban water pollutants in stormwater runoff was conducted, with a specific focus on the influence of land-use patterns in the recharge zone of a regional karst aquifer in Texas (Edwards Aquifer). The presence and concentration of various water pollutants including total suspended solids (TSS), total dissolved solids (TDS), nutrients (nitrite, nitrate, ammonia and phosphate), total carbon (TC) and total organic carbon (TOC), oil and grease (O&G), and eight heavy metals (Fe, Mg, Cu, Pb, Zn, Ni, Cr, Cd) were measured in stormwater samples collected from three bioswales. Results show that average TSS in site S1 (598.87mg/L) and S2 (628.69mg/L), COD in site S1 (103.97mg/L), phosphate in sites S1 (1.44mg/L) and S3 (0.65mg/L), and O&G (ranging from 50.63 to 84.32mg/L) in all three sites surpassed the national average (NSQD). While residential areas were identified as the main sources of nutrients, roads and parking lots were associated with heavy metals. Temporal variations indicated the effect of antecedent dry days on the concentrations of TSS and phosphate. Growing seasons as well as pet feces were associated with elevated nitrate concentrations in residential areas. Organic carbon was found overall higher during warmer months, while heavy metals during cooler months. The study also identified specific land-use practices that can be enhanced to mitigate stormwater pollution, such as the implementation of permeable pavements, rain gardens, and stricter waste disposal regulations. The results of this study offer valuable insights for enhancing stormwater management strategies to better mitigate stormwater pollution in urban regions.

Influence of earthworms on the mobility and bioavailability of metals, metalloids and radionuclides in historically contaminated soil

While soil characteristics such as pH, cation exchange capacity and organic matter are known to influence the mobility of pollutants in soil and the transfer to vegetation, far less attention has been paid to the possible non-trophic influence of organisms on pollutant transfer to other species. When pollutants are present in a bound unavailable form in the mineral or organic fraction, they can be made available through bio-weathering and decomposition of organic material. Within this study, the impact of earthworms on the mobility of metal(loid)s and radionuclides in soil and their transfer to vegetation was evaluated and the pathways through which earthworms work were studied. Soil from a Belgian field, historically contaminated with metal(loid)s and radionuclides, was used and microcosm systems were applied to mimic the natural interactions between soil, earthworms (Lumbricus terrestris) and vegetation (Lolium perenne). Metal and radionuclide concentrations were determined in soil, pore water and grass. In addition, soil pH, (chromophoric) dissolved organic matter, the ionic composition of pore water and the soil microbial activity were analysed. In general, earthworm presence significantly increased the concentration of most pollutants in soil pore water. This could be a direct consequence of decreased soil pH and increased humification. The latter also lead to higher nutrient concentrations in pore water that were depleted in the root zone due to high accumulation by plants. Indications were found for earthworm-induced effects on the soil microbial activity. The results show that earthworm activity can increase leaching of metal(loid)s and radionuclides and enhance dispersion into the environment and transfer to other biota and the food chain. Biologically induced release or remobilization of pollutants in the soil should therefore be considered in the context of risk assessment and site management strategies.

TARGETED SCREENING OF PHENOLIC TOXICANTS IN WATERS AND BOTTOM SEDIMENTS OF THE MIDDLE REACHES OF THE DON RIVER

The targeted screening of 11 phenolic toxicants (phenol, chlorophenols, 2,4-dichlorophenoxyacetic acid, octylphenol, nonylphenol, bisphenol A) has been carried out over river water and bottom sediments (BS) in the middle reaches of the Don river within the boundaries of the Voronezh Region. Three sampling points were selected for quantitative chemical analysis: in the zone affected by the discharge of sewage treatment plants of a large city (Voronezh), in the district centre (the city of Liski), and in an area with insignificant anthropogenic influence. The concentrations of phenolic compounds were determined using gas chromatography - mass spectrometry (GC-MS), the analytes were preconcentrated on a magnetic sorbent functionalised with aminated hypercrosslinked polystyrene. Sampling was carried out four times a year, taking into account seasonal climatic fluctuations and precipitation. The maximum concentrations were established in the spring for 2,4-dichlorophenoxyacetic acid (1022 ng/L) and 2,4-dichlorophenol (557 ng/L). In bottom sediments, the highest concentrations are achieved for alkylphenols: 1.99 and 7.84 μg/g for octylphenol and nonylphenol, respectively. Bisphenol A has not been found in detectable amounts in waters, however, a significant concentration of this compound has been found in bottom sediments: 3.18 μg/kg. The bottom sediments were also determined to contain 2,4,5-trichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol. The maximum concentrations of phenolic pollutants in river water are usually observed in spring during high water and after heavy rainfall. Phenol concentrations in bottom sediments are less susceptible to seasonal fluctuations. The hydrophobicity of substances and an increase in their stability against degradation significantly affect their accumulation in BS.

Assessment of Human Errors in the Determination of the Concentration of Water Pollutants

Assessment of Human Errors in the Determination of the Concentration of Water Pollutants

Geospatial insights into groundwater contamination from urban and industrial effluents in Faisalabad

Groundwater remains the most dependable resource for various essential uses such as drinking, cleansing, agricultural irrigation, and industrial applications. In urban areas, the dependency on groundwater to meet water demands is significant. However, this resource faces threats from overuse and poor management, leading to a degradation in quality primarily due to the unchecked release of industrial and household wastes. The escalation of industrial activities and rapid urban growth have amplified the volume of wastewater, adversely affecting the purity of freshwater sources within aquifers. This investigation focuses on evaluating the impact of industrial and urban effluents on groundwater quality in the city of Faisalabad. The main contributors to groundwater pollution include the indiscriminate disposal of industrial and urban effluents through unlined drains and the extensive application of chemical agents in agriculture, such as fertilizers, and pesticides. To understand the physiochemical properties of both, drain and groundwater, samples were collected at various distances 50 m, 100 m, and 150 m from drain outlets. This study utilized Geographic Information Systems (GIS) to accurately map and analyze the distribution and impact of contaminants. Parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness, bicarbonates, calcium and magnesium hardness, and chloride levels were examined. The findings indicated that contaminant levels were highest in drain water and increased in concentration the closer they were to the drainage sources, with the exception of pH levels. All samples exceeded the World Health Organization's (WHO) safe limits, deeming them unfit for use. This finding indicates widespread contamination, posing significant public health risks and highlighting the urgent need for improved waste management and water treatment practices in Faisalabad. It underscores the critical importance of implementing effective pollution control measures to safeguard public health and ensure water security in the region. However, a notable correlation was observed between the concentration of pollutants in drain water and key indicators such as EC, TDS, total hardness, and magnesium hardness, highlighting their role in deteriorating aquifer water quality. Moreover, groundwater samples collected 50 m from drains exhibited the highest pollutant concentrations compared to those taken further away, at 100 m and 150 m distances.

Amyloid fibril–bacterial cellulose nanohybrid membrane cartridge for efficient removal of heavy metal from industrial wastewater

ABSTRACT Worldwide, the harmful ion contamination of water has become a serious problem because of unregulated industry, energy production, and mining, which greatly increase the concentration of pollutants in water. The novel membranes through adsorbent self-assembly, such as protein amyloids, were explored for wastewater treatment. Herein, we report amyloid fibril (AF)-embedded bacterial cellulose nanohybrid membrane for efficient removal of heavy metal from industrial effluent. AFs are synthesized by heat treatment using bovine serum albumin and embedded with bacterial cellulose nanomembrane (BCN). The AF-embedded BCN (AF/BCN) was characterized using microscopy and spectroscopic methods. In addition, the well-ordered multi-layered AF/BCN filtration assembly was fabricated in the commercial cartridge and validated for the removal of heavy metals (Pb2+ and Hg2+) from wastewater and treatment of industrial wastewater sample containing heavy metals. Our multi-layered filtration assembly removed Hg2+ and Pb2+ with efficiency of 95 and 78.34%, respectively. A computational study using molecular docking has also been performed for the identification of metal entrapment sites. Moreover, our AF/BCN filtration assembly showed high regeneration capacity up to four cycles. The isotherm model also revealed a strong fit and good adsorption behaviour. This makes potential filtration assembly for low-cost, high-efficiency for the removal of heavy metal from wastewater.

Karakterisasi Air Hasil Filtrasi Instalasi Pengolahan Air Sederhana Berdasarkan Variasi Waktu Filtrasi dan Ketebalan Media Arang Ampas Teh

The increase in population and the development of the industrial sector have resulted in water pollution and a decrease in the quality of clean water. Water treatment with filtration method is an effort to reduce the concentration of pollutants in water using adsorbents. This study aims to test the quality of water filtration results using a simple water treatment plant with tea grounds as the adsorbent. The media used in the simple water treatment plant are coconut fiber, zeolite sand, silica sand, tea grounds, gravel, and sponge. The water quality parameters tested were TDS (Total Dissolved Solid) analysis, pH analysis, organoleptic analysis, total hardness analysis, fixed hardness, temporary hardness and COD analysis. The independent variables in this study were the thickness of tea pulp media (0 cm, 3 cm, 5 cm, and 7 cm) and filtration time (20 minutes, 40 minutes, and 60 minutes). The results showed that the combination of tea pulp media height and process time had no significant effect on TDS, pH, hardness, COD, and organoleptic values. The optimum condition of tea pulp media height and process time with filtration-adsorption process for pH characteristics is in the treatment of 0 cm charcoal height, on the characteristics of total hardness and fixed hardness is in the treatment of 0 cm charcoal height and 20 minutes process time, while the optimum condition of temporary hardness is in the treatment of 7 cm charcoal height and 20 minutes process time.

Assessing water quality of the Saigon River under the impact of industrial wastewater incidents

The Saigon River, as its economic potential and clusters and industrial parks evolve, is threatened by a high potential for water pollution. The objective is to evaluate the water quality (BOD5 and COD) under the influence of industrial wastewater incidents in the Saigon River using MIKE 21FM model. The results of model calibration and validation have high reliability with NSE values larger than 0.65 for the flow simulation and percentage error values less than 25% for the water quality simulation. Subsequently, the study proceeds to develop hypothetical scenarios in case untreated wastewater from industrial parks is charged directly into the Saigon River with actual discharge volumes of 15,811 m3/day and 30,000 m3/day. The results indicated that when an incident occurs at a location 1.3 km upstream from the Hoa Phu pumping station with a discharge volume of 15,811 m3/day, that has the most consequential impact, in terms of time and concentration of water pollutants on the pumping station. Specifically, the water quality at the pumping station area experiences a remarkable decrease after one and three hours of incidents in the dry and rainy seasons, respectively. In general, the impacts of industrial wastewater incidents vary depending on their location. An incident beneath the Hoa Phu pumping station on the Saigon River is expected to have a faster impact on the raw water source during the dry season compared to the rainy season.

Limiting Factors of Simultaneous Measurement Method for Turbidity and Total Suspended Solids Based on Image Processing Approaches

Image processing is one of the computational approaches that can be applied to measure fluctuations in surface water pollutant concentrations. Identifying factors that can affect and become a limitation in the development of image processing-based simultaneous measurement methods is the focus of the discussion in this article. Nineteen variables have been identified from the three-factor categories of hardware configuration, software settings, and the measured suspension characteristics. Measurements were made on thirty images extracted from video captured with a USB Mechanic-DX-230 camera with a 23-megapixel resolution Panasonic CMOS sensor equipped with a macro lens in 130X magnification on the S-EYE-1.6.0.11 interface. Image frame extraction was performed with VirtualDub2 build 4428/release, followed by digital image processing and analysis with ImageJ 1.46r. The lens’s focal length to the sample cell is 5 cm, setting the brightness parameter minimum of 90 and maximum of 255 and minimum threshold settings of 209 and maximum of 255, which is a controlled factor to achieve the best repeatability rate. It is indicated by a relative standard deviation of up to 6% in the measurement chamber with a dark background. Complying with the stated factors is essential to ensure measurement results’ reliability and validity.

Reprocessing and Resource Utilization of Landfill Sludge—A Case Study in a Chinese Megacity

In the past, due to improper sludge treatment technology and the absence of treatment standards, some municipal sludge was simply dewatered and then sent to landfills, occupying a significant amount of land and posing a serious threat of secondary pollution. To free up land in the landfill area for the expansion of a large-scale wastewater treatment plant (WWTP) in Shanghai, in this study, we conducted comprehensive pilot research on the entire chain of landfill sludge reprocessing and resource utilization. Both the combination of polyferric silicate sulfate (PFSS) and polyetheramine (PEA) and the combination of polyaluminum silicate (PAS) and polyetheramine (PEA) were used for sludge conditioning before dewatering, resulting in dewatered sludge with approximately 60% moisture content. The combined process involved coagulation and sedimentation, flocculation, and oxidation to treat the leachate generated during dewatering. The treatment process successfully met the specified water pollutant discharge concentration limits for the leachate, with the concentration of ammonia nitrogen in the effluent as low as 15.6 mg/L. Co-incineration in a power plant and modification were applied to stabilize and harmlessly dispose of the dewatered sludge. The coal-generating system ran stably, and no obvious problems were observed in the blending process. In the modification experiment, adding 5% to 7% of the solidifying agent increased the sludge bearing ratio by 53% and 57%, respectively. This process effectively reduced levels of fecal coliforms and heavy metals in the sludge but had a less noticeable effect on organic matter content. The modified sludge proved suitable for use as backfill material in construction areas without requirements for organic matter. The results of this study provide valuable insights for a completed full-scale landfill sludge reclamation and land resource release project.

Highly salt resistant composite based protonated g-C3N4@rGO/biochar for photocatalytic degradation of organic dyes through simultaneous solar steam-electricity generation

Solar steam generation (SSG) is a promising solar energy harvesting technique for addressing global freshwater scarcity. However, the high materials cost, salt accumulation, and concentration of pollutants in the brine after SSG hindered their practical applications. Herein, the recycled sawdust waste was used as a cost-effective evaporator and decorated with protonated carbon nitride and reduced graphene oxide (rGO) which was termed as P-g-C3N4 @ rGO/DB. The g-C3N4 was protonated with sulfuric acid giving P-g-C3N4, which has high salt resistance via the Donnan exclusion mechanism. Besides, P-g-C3N4 as a metal-free semiconductor with a mild band gap (2.7 eV) was utilized for the photocatalytic degradation of the organic dyes under solar illumination to prevent the concentration of pollutants in water after desalination. Coupling rGO as electron acceptors inhibits the e−/h+ pairs recombination and traps the organic dyes on the surface of the evaporator increasing the photocatalytic degradation efficiency. The composite exhibited an excellent evaporation rate of 1.98 kg m−2 h−1 with 97.2 % solar to steam conversion efficiency as well as superior photocatalytic degradation of RhB dye under 1 sun illumination. Finally, the evaporator was coupled with a thermoelectric module achieving the maximum electricity cogeneration of 13.69 mW/m2.

Forecasting regeneration parameters of free-floating biocarriers in an aeration tank

A mathematical model was developed to describe the efficiency of air regeneration used for immobilised biofilm on free-floating biocarriers “FB Bio-850”. For this purpose, a physical model of an aeration tank bioreactor was developed, forming the basis for this study. The use of biocarriers contributes to decreasing the concentration of water pollutants that pose a threat to humans and the environment when released into the surface or groundwater without adequate treatment. This increases the efficiency of the aeration tanks, accelerates the oxidation of pollutants and ensures high-quality water purification. In addition, biocarriers increase the performance of the biological treatment plant, promote the resilience of biological structures to abrupt discharges of pollutants and facilitate the nitrification process. Carrying out such studies on an industrial aerated facility poses significant technical challenges. The model aerated tank and the experimental setup provided the flexibility to vary the intensity of the air medium-bubble regeneration for free-floating biocarriers, regeneration time, and the specific gravity of the biocarriers across a broad range, along with controlling the concentration of free-floating sludge. The correlation between the efficiency of regeneration of the plastic carriers “FB Bio-850” and the following technical parameters was established, including the regeneration time of the biocarriers, the loading mass and the intensity of the fine bubble aeration of the water-sludge mixture. A mathematical model of the efficiency of air regeneration was developed, reflecting the influence of all the above parameters. The obtained predictive matrix for efficiency values was used to develop a geometric model of the efficiency surface. This model provides an optimal selection of technological parameters for air regeneration of immobilised biofilm in a biological wastewater treatment aeration tank bioreactor, ensuring a sufficiently high regeneration efficiency.

Pollution characteristics and risk assessment of endocrine-disrupting chemicals in surface water of national (freshwater) aquatic germplasm resource reserves in Guangdong Province.

The distribution, composition, and risk assessment of 8 EDCs in the surface water of 14 national aquatic germplasm resource reserves (freshwater) were investigated during dry and wet seasons. Bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) were the main contributors of the 8 EDCs. The concentrations of phenolic pollutants in surface water during the dry season were higher than those in the wet season. However, no significant seasonal differences were found among the steroid hormones. According to the evaluation of estrogenic activity (EEQ > 1.0), E2 and EE2 were the main contributors to estrogenic activity. EDC mixtures posed a higher risk to crustaceans and fish (RQ > 1.0) and a moderate to high risk to algae (RQ > 0.1). Fish were the most sensitive aquatic organisms. In the study areas, EE2, E1, BPA, NP, and E2 had a higher risk than the other three compounds and should be controlled as a priority.

Successful Water Quality Improvement Practices of a Campus’s River in Ningbo Based on Water Replenishment and Circulation Since Year 2017

Rivers play a critical role in regional water quality, but from time to time concentration of surface water pollutants can easily exceed both national and local water standards. This study debates the feasibility and effectiveness of utilizing the natural treatment potential of flowing river water by replenishing treated sewage effluent and forced circulating. The research combines field experiments and laboratory analyses to assess the impact of this approach on water quality. Theoretical simulation with one-dimension modeling recommended by China’s national standard of “Code of Practice for Computation on Allowable Permitted Assimilative Capacity of Water Bodies” (GB/T 25173-2010) indicates that the target campus river water’s cycle flowing contributes to the further removal of key pollutants from treated sewage, resulting in the improvement of campus river’s water quality downstream along its forced circulation. NH3-N and CODMn levels of the campus’s river water were notably reduced and met the planning water qualities as expected.

Statistically Analyzed Heavy Metal Removal Efficiency of Silica-Coated Cu0.50Mg0.50Fe2O4 Magnetic Adsorbent for Wastewater Treatment.

Even low concentrations of pollutants in water, particularly heavy metals, can significantly affect the ecosystem and human health. Adsorption has been determined to be one of the most effective techniques of removing pollution from wastewater among the various strategies. To remove heavy metals such as Zn2+ and Pb2+, we prepared a silica-coated CuMgFe2O4 magnetic adsorbent using sol-gel method and tested it for wastewater treatment. X-ray diffraction investigation validated the creation of cubic spinel structure, while morphological analysis showed that silica coating reduces the particle size but boosts the surface roughness of the nanoparticles and also reduces the agglomeration between particles. UV-visible spectroscopy indicates a rise in bandgap and magnetic characteristics analysis indicates low values of magnetization due to silica coating. The kinetic and isotherm parameters for heavy metal ions adsorption onto silica-coated Cu0.50Mg0.50Fe2O4 nanoparticles are calculated by applying pseudo-first-order, pseudo-second-order, Langmuir and Freundlich models. Adsorption kinetics revealed that the pseudo-second-order and Langmuir models are the best fit to explain adsorption kinetics. Synthesized adsorbent revealed 92% and 97% removal efficiencies for Zn2+ and Pb2+ ions, respectively.

The Content of Pollutants in the Melt Water of the Snow Polygon (Yuzhno-Sakhalinsk)

The results of monitoring the dynamics of the release of pollutants into the environment with meltwater from the snow landfill were presented. The concentrations of pollutants in water at the beginning and end of the active melting period were identified. The concentrations of pollutants were found to exceed background values for heavy metals. The concentrations of pollutants in meltwater at the beginning and end of the period of active melting were analyzed. At the end of the period, a decrease in the concentration of most pollutants was detected, with the exception of some of them, such as Fe, the concentration of which was 17 times higher, which is associated with the high iron content in the waste layer of the landfill. A significant increase in the concentration of pollutants was detected at the site of sedimentation of sludge in the swamp ditch.

A Review on Pollutants Found in Drinking Water in Sub-Sahara African Rural Communities: Detection and Potential Low-cost Remediation Methods

Water is the most essential substance that supports various life mechanisms. It is a fundamental and necessary requirement for mankind and all other living creatures on the planet. Therefore, daily drinking water should be clean, readily available, sufficient, and free from harmful substances. However, in many rural areas, most sources of drinking water are assumed to be safe for human consumption, but this is not always the case. This work aims to provide a review of pollutants found in the drinking water of Sub-Saharan rural communities and explore potential low-cost remediation methods. The assessment of water pollutants and their remediation methods has been the primary focus of research for several years. Additionally, the World Health Organisation has established various minimum standards regarding the concentration of common pollutants in water. This review presents the major sources of water, the origin of contaminants, the different types of pollutants, and remediation methods to enhance the current knowledge in the field of rural drinking water contaminants.

Tracing surface water pollution in China’s supply chain

Decades of economic growth in China were enabled by rapid industrialization with insufficient water quality controls. Previous studies have traced water pollution discharges or grey water footprint using the multi-regional input–output (MRIO) model. However, there is a research gap in understanding the relation between surface water pollutant concentrations and final consumption of local and external basins. Here, we present the first national analysis to map surface water quality degradation in watersheds embedded in China’s supply chains. To do this, we developed a basin-specific relationship between surface water pollution concentration and discharge, and combined it with the MRIO model to trace the water pollution of different basins through the trade of products and services. We find that ∼50% chemical oxygen demand (COD) and ∼46% ammonium nitrogen (NH4+-N) discharges from production processes can be traced to consumer demands beyond the basin where the pollution was initially released. 0.3–2.2 mg/L COD and 0.03–0.31 mg/L NH4+-N water quality degradation (the range indicates pollution concentration in different basins) can be attributed to final consumption of commodities from other basins in China. International consumers contributed to increased degradation of water quality (0.43 mg/L COD in Huai River Basin and 0.07 mg/L NH4+-N in Hai River Basin). High pollution concentrations were often concentrated in dry North China, because water scarce basins in this region are more susceptible to human pollution loadings. Basins outsourcing water pollution were mainly developed economies that outsourced production and subsequent water quality impairments to other basins. This study highlights the interactions between water quality and supply chains.

Assessing the impacts of fine sediment removal on endogenous pollution release and microbial community structure in the shallow lakes

Resuspension is a crucial process for releasing endogenous pollution from shallow lakes into the overlying water. Fine particle sediment, which has a higher contamination risk and longer residence time, is the primary target for controlling endogenous pollution. To this end, a study coupling aqueous biogeochemistry, electrochemistry, and DNA sequencing was conducted to investigate the remediation effect and microbial mechanism of sediment elution in shallow eutrophic water. The results indicated that sediment elution can effectively remove some fine particles in situ. Furthermore, sediment elution can inhibit the release of ammonium nitrogen and total dissolved phosphorous into the overlying water from sediment resuspension in the early stage, resulting in reductions of 41.44 %–50.45 % and 67.81 %–72.41 %, respectively. Additionally, sediment elution greatly decreased the concentration of nitrogen and phosphorus pollutants in pore water. The microbial community structure was also substantially altered, with an increase in the relative abundance of aerobic and facultative aerobic microorganisms. Redundancy analysis, PICRUSt function prediction, and the correlation analysis revealed that loss on ignition was the primary factor responsible for driving changes in microbial community structure and function in sediment. Overall, the findings provide novel insights into treating endogenous pollution in shallow eutrophication water.