Impact Water Quality Research Articles

Shift to remote learning degrades water quality in buildings

AbstractCommercial and institutional buildings now experience weeks and even months with below‐normal occupancy due to remote work/learning, which results in reduced water use and has the potential to adversely impact water quality. This study monitored the variations in water quality in multiple university buildings during several months of below‐normal occupancy followed by several months of normal occupancy. The levels of free chlorine, copper, and cellular ATP in water varied within buildings and between buildings. Using Wi‐Fi activity as a surrogate for building occupancy, the free chlorine concentration in water increased as Wi‐Fi counts increased. The copper concentration in building water was higher when the occupancy was below‐normal compared with normal occupancy, and the copper concentration decreased as Wi‐Fi counts increased. Throughout the study, flushing a fixture at the time of use decreased the concentrations of copper and cellular ATP and increased the concentration of free chlorine.

Establishing a Data Fusion Water Resources Risk Map Based on Aggregating Drinking Water Quality and Human Health Risk Indices

The Drinking Water Quality Index (DWQI) and the Human Health Risk Index (HHRI) are two of the most promising tools for assessing the health impact of water quality on humans. Each of these indices has its own ability to determine a specific level of safety for drinking, and their results may vary. This study aims to develop an aggregated index to identify vulnerable areas in relation to safe drinking water and, subsequently, risk areas for human health, particularly non-cancerous diseases, in the Maku–Bazargan–Poldasht area in NW Iran through the use of a data fusion technique. Nitrate (NO3−) and fluoride (F−) are the predominant contaminants that threaten the local population’s health. The DWQI revealed that the majority of the study sites had poor to improper quality for drinking water class. Health risk assessments showed an excessive potential for non-carcinogenic health risks because of high NO3− and F− exposure through drinking water. Children are at a higher risk for non-carcinogenic changes than adults, according to the total hazard index (THI; NO3− and F−), suggesting that locals have faced a lifetime risk of non-cancer changes as a consequence of their exposure to these pollutants. Using data fusion techniques can assist in developing a comprehensive water resources risk map for decision-making.

Analisis Islami Pemanfaatan Sumberdaya Air Dan Lahan Serta Kesejahteraan Keluarga Petani Di Kecamatan Lingsar Kabupaten Lombok Barat

This studi aims to determine and analyze farmers’ behavior regarding using water and land resources as well as their welfare viewed from Islamic economics and ecology perspective. This study employed a qualitative approach. This study was conducted in Ligsar West Lombok, using the researcher himself as the main instrument. The data where collected through participatory observation and in-depth interviews documented in the form of voice recordings, video recordings, and photographs. The participants were chosen using purposive and snowball. The stages of data analysis include reduction, displaying the data, and drawing conclusions. Th study found that most farmer are not frugl in using water because the assume water is available excessively in their neighborhood. Additionally, most farmers continuously plant similar crops, i.e. rice, on their land. They do it to maximize the use of their land. Moreover, most farmers burn straws after harvesting and clean the spray tanks and pesticide residues in the waterways, negatively impacting water quality and aquatic biota. In terms of welfare, it was found the most farmers are are not prosperous because the cannot fulfill their dharuriyyat needs (hifz-aql).On the other hand, the farmers live a good life (hayaatun tayyibah), as mentioned in the qur’an, an-Nahl (16:97), and the are qana’ah even though the live in simplicity.

A 22-Site Comparison of Land-Use Practices, E-coli and Enterococci Concentrations.

Land-use practices can greatly impact water quality. Escherichia (E.) coli and Enterococcus are accepted water quality indicators. However, surprisingly little research has been conducted comparing both organisms' population density relationships to land use practices and water quality. Stream water grab samples were collected monthly (n = 9 months) from 22 stream monitoring sites draining varying land use practice types in a representative mixed-land-use watershed of the northeastern United States. E. coli and enterococci colony forming units (CFU per 100 mL) were estimated (n = 396) and statistically analyzed relative to land use practices, hydroclimate, and pH, using a suite of methods, including correlation analysis, Principal Components Analysis (PCA), and Canonical Correspondence Analysis (CCA). Correlation analyses indicated significant (p < 0.05) relationships between fecal indicator bacteria concentrations, water quality metrics and land use practices but emphasized significant (p < 0.05) negative correlations between pH and instream enterococci concentrations. PCA and CCA results indicated consistent spatial differences between fecal indicator bacteria concentrations, pH, and land use/land cover characteristics. The study showed that pH could be considered an integrated proxy variable for past (legacy) and present land use practice influences. Results also bring to question the comparability of E-coli and enterococci relative to dominant land use practices and variations in pH and provide useful information that will help guide land use practice and water pollutant mitigation decision making.

The spatial organization of CAFOs and its relationship to water quality in the United States

• Applied Nearest Neighbor Index and Moran’s I to quantify the spatial pattern of AFOs. • Watersheds with higher AFO NNI were associated with elevated nutrient levels. • Clustering of smaller farms (less regulated) also corresponded to high nutrients. • Results help to inform management of AFOs and other pollutant sources. Large animal operations in the United States (US) have expanded in recent decades as a solution for meeting increasing food demand. These operations can release large amounts of organic matter and nutrients into the environment, potentially impacting water quality conditions of nearby waterbodies. Often referred to as animal feeding operations (AFOs) or CAFOs (concentrated AFOs) based on nomenclature in federal regulations, these operations are usually clustered in space, which may intensify the impacts observed. However, the influence of the known spatial aggregation of CAFOs on water quality conditions has not been evaluated. This study investigates the spatial organization of CAFOs and its relationship to water quality conditions. We hypothesized that watersheds with clustered CAFOs are likely to be associated with higher concentrations of Total Phosphorus (TP) and Total Nitrogen (TN) in the US. We gathered and digitized CAFO locations in 16 US states and used TP and TN concentration data to evaluate our hypothesis. We calculated the flow-weighted mean concentration of TN and TP from 2005 to 2014 and averaged those values per season. We used the nearest neighbor index (NNI) to determine the spatial pattern (i.e., clustering or dispersed) of CAFOs per watershed and its significance level. Additionally, for states with animal number information per farm, we performed a Local Moran’s I analysis to understand if the clustering of CAFOs with a low or high number of animals relates to the TP and TN concentrations of each nearest water quality station. Overall, we found that watersheds with significant clustering patterns were associated with higher TP and TN levels. Seasonally, this finding also held principally during spring and summer seasons, when manure tends to be land applied. Our Local Moran’s I analysis also revealed that the clustering of smaller and medium-sized farms, usually less regulated, is associated with elevated TP and TN concentrations. This reveals that the small, yet potentially unregulated farms could be highly impactful to the environment, which warrants further study. Given the lack of information on the influence of CAFO clustering (and other pollutant source clustering) on water quality and that most states do not regulate emitters based on this aspect, our outcomes advance the knowledge of how these entities may be driving changes to the environment. This study also brings insights into new water quality modeling approaches and supports future policy decisions.

Macroinvertebrates Assemblage Study: An attempt to Assess the Impact of Water Quality on Qua Iboe River Estuary, Akwa Ibom State, Nigeria

This study was conducted to access the water quality of Qua River Estuary, Akwa Ibom state, Nigeria by collecting water samples and macroinvertebrates using standard sampling procedures and analytical methods. The mean values of physicochemical parameters assessed in water samples gave the following ranges: DO (2.38 – 4.63 mg/l), water temperature (26.13 – 29.18 oC), turbidity (22.56 – 39.24 NTU),TDS (224.8 – 332.51 mg/l), pH (6.3 – 7.5 mg/l), salinity (3.13 – 4.84 ppt),BOD (1.13 – 3.64 mg/l), nitrate (2.45 – 6.72 mg/l), phosphate (2.12 – 5.93 mg/l) and Flow velocity (0.23 – 0.38 ms-1). ANOVA reveals significant variation in some parameters. A total of 308 individual species, comprising of three phyla and seven taxonomic groups of macro-invertebrate were identified. Arthropoda constituted the highest percentage composition (75.4%), followed by Mollusca (18.8%), and Annelida (5.8%). The dominant group was Decapoda (35.7%) and the least was Odonata accounted only for 1.9%. Station 5 has the highest number of individual’s species (112), station 3 had the least (43). Chironomus plumosus was the most occurring species, accounted for 19.2%. The result reveals that anthropogenic activities in the water system influence the abundance of aquatic biota; based on the macro-invertebrates identified, it shows that the water quality is moderately polluted owing to human activities.

The University of West Florida Campus Ecosystem Study: Spatial and Temporal Variation in Water Quality at Thompson Bayou

Much of our understanding of factors influencing stream chemistry comes from studies of montane forests, whereas far less work has focused on streams of coastal areas that integrate a homogeneous, flat topography and interactions with the bodies of water into which they drain, especially involving tidal fluxes. Fewer still do so in the context of an urban interface, especially that of a college campus. This study assessed the water quality of Thompson Bayou, a freshwater stream entering the University of West Florida campus in a wetland after flowing through the urban property with impacted water quality. We measured temperature, pH, dissolved O2 (DO), and specific conductivity (SC) for one year at eight sites along Thompson Bayou from campus to the Escambia River. All variables, except temperature, varied spatially, with consistent increases in DO and SC toward the river of 10% and 75%, respectively. Variables exhibited temporal patterns of significant seasonal variation, especially temperature, increasing from a January minimum of 14 °C to a summer maximum of 28 °C. These results suggest that, in general, the biogeochemistry of coastal streams such as Thompson Bayou can be influenced by numerous factors, including (1) wetland processes, (2) interactions of the stream channel with forested uplands, and (3) tidal fluxes.

Endogenous, Regime-Switching Hedonic Estimation of Commercial Waterway Water Quality Impact on Home Values in the Alabama Black Belt

We are the first researchers to investigate the impact of the water quality of a commercial marine waterway on the housing market. We use housing data for properties in proximity to the major waterways and minor tributaries of the Gulf Intracoastal Waterway in the Alabama Black Belt. Research shows a positive relationship between water quality and the value of waterfront properties. We use waterway impairment as a proxy to measure water quality to conduct a counterfactual analysis based on a unique endogenous regime-switching hedonic price model. We find significant empirical evidence that properties in proximity to the Black Belt’s major waterways could depreciate by approximately 22% compared to the counterfactual case of properties located on or near minor tributaries. A possible implication might be that homeowners prefer properties on or near minor tributaries of the Alabama Black Belt because of perceptions that the water quality is better than on major commercial waterways.

Water Quality Impacts of the Energy–Water Nexus

digitalData = {"site":{"ip":"196.51.238.233","environment":"LIVE","website":"ngwa.onlinelibrary.wiley.com","websiteCode":"ngwa","serverDate":"2023-02-20"},"identities":[{"type":"SmartGroupUser","uuid":"b238ab85-6bb4-49e4-84ca-a0d9f3ee5a35"},{"type":"InstitutionUser","uuid":"dd40e26c-3e96-4e9f-9382-5d13a2a401f3","customerRecords":[{"customerDomain":"ALM-CU","customerNumber":"EAL57933332"}]},{"type":"RegionUser","uuid":"3c5060a1-6620-438f-862b-902a4d4cd4ac"},{"type":"BasicGroup","uuid":"e623deab-c83b-41e3-84a2-d9f1d46c5f17"},{"type":"SmartGroupUser","uuid":"b7acda8c-ce18-451b-a68d-e14b72f9b5b8"},{"type":"RegionUser","uuid":"79ad3272-fe6f-4ef7-b463-5204f4509918"},{"type":"BasicGroup","uuid":"197fe835-5b5f-4f4e-b8e9-a74d68491a84"},{"type":"SmartGroupUser","uuid":"b2dbfe27-ecae-4bb6-bb0d-d75e5caa3762"},{"type":"SmartGroupUser","uuid":"da88d808-3f7b-4bde-9210-10862b6d121b"},{"type":"SmartGroupUser","uuid":"8c72a733-117a-4bc9-a682-13475f13e6a3"}],"publication":{"item":{"title":"Water Quality Impacts of the <fc>Energy–Water</fc> Nexus","doi":"10.1111/gwat.13251","access":"no","earliestDate":"2022-09-16","formats":["Full text","PDF","References","AM pdf"],"topics":[{"taxonomyUri":"embo-article-types","topicLabel":"Review","topicUri":"review"},{"taxonomyUri":"global-subject-codes","topicLabel":"Groundwater & Hydrogeology","topicUri":"es71"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydrological Sciences","topicUri":"es70"},{"taxonomyUri":"global-subject-codes","topicLabel":"CIVIL ENGINEERING & CONSTRUCTION","topicUri":"ce"},{"taxonomyUri":"global-subject-codes","topicLabel":"EARTH SCIENCE","topicUri":"es"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydraulic / Water Engineering","topicUri":"ce31"},{"taxonomyUri":"global-subject-codes","topicLabel":"Water Resources","topicUri":"ce42"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydrology (Civil Engineering)","topicUri":"ce30"},{"taxonomyUri":"global-subject-codes","topicLabel":"Environmental Engineering","topicUri":"ce40"}]},"group":{"title":"","doi":"10.1111/gwat.v61.1","access":"no","volume":"61","issue":"1","coverDate":"2023-01-01","topics":[{"taxonomyUri":"global-subject-codes","topicLabel":"Groundwater & Hydrogeology","topicUri":"es71"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydrological Sciences","topicUri":"es70"},{"taxonomyUri":"global-subject-codes","topicLabel":"CIVIL ENGINEERING & CONSTRUCTION","topicUri":"ce"},{"taxonomyUri":"global-subject-codes","topicLabel":"EARTH SCIENCE","topicUri":"es"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydraulic / Water Engineering","topicUri":"ce31"},{"taxonomyUri":"global-subject-codes","topicLabel":"Water Resources","topicUri":"ce42"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydrology (Civil Engineering)","topicUri":"ce30"},{"taxonomyUri":"global-subject-codes","topicLabel":"Environmental Engineering","topicUri":"ce40"}]},"series":{"title":"Groundwater","doi":"10.1111/(ISSN)1745-6584","access":"no","code":"17456584","issn":"0017-467X","eissn":"1745-6584","topics":[{"taxonomyUri":"gpt-sitename","topicLabel":"wly.civ.eng.con_000034","topicUri":"wly.civ.eng.con_000034"},{"taxonomyUri":"global-subject-codes","topicLabel":"Groundwater & Hydrogeology","topicUri":"es71"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydrological Sciences","topicUri":"es70"},{"taxonomyUri":"global-subject-codes","topicLabel":"CIVIL ENGINEERING & CONSTRUCTION","topicUri":"ce"},{"taxonomyUri":"global-subject-codes","topicLabel":"EARTH SCIENCE","topicUri":"es"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydraulic / Water Engineering","topicUri":"ce31"},{"taxonomyUri":"global-subject-codes","topicLabel":"Water Resources","topicUri":"ce42"},{"taxonomyUri":"global-subject-codes","topicLabel":"Hydrology (Civil Engineering)","topicUri":"ce30"},{"taxonomyUri":"global-subject-codes","topicLabel":"Environmental Engineering","topicUri":"ce40"},{"taxonomyUri":"gpt-zonename","topicLabel":"ground-water_GWAT","topicUri":"ground-water_gwat"}]}},"page":{"subPage":"Abstract","page":"Article/Chapter View","pageGroup":"Publication Pages","title":"title","errorCode":200}}

Spectral characteristic of the waters with different sizes of particles: impact of water quality and land-use type.

Natural colloids (NCs) are heterogeneous mixtures of particles in the aquatic environments that are strongly influenced by land use and water quality between terrestrial and aquatic environments. However, the relevant study paid little attention to the difference among the waters with different sizes of particles (e.g., suspended particulate matter (SPM), NCs, and the truly soluble substances). In this study, the spectral properties of these different waters were investigated from different land-use types in the Yuan River basin, China. Results of the UV-visible absorption spectral showed that with the particle size increased, the aromaticity, chromophoric dissolved organic matter, and humification degree of organic matter increased, while the condensation degree decreased. Data analysis from the fluorescence indices indicated that the source and the autochthonous feature of the truly soluble substances differed from that of NCs and SPM, whereas the protein-like component was mainly combined with the relatively larger size of particles (i.e., SPM and NCs), especially the downstream. Although the spectral characteristics of the water samples were strongly influenced by the water quality (> 45%), the land-use type might be the real potential impactor. Furthermore, the influence of land-use type on the spectral properties differed between the large and small scale of the buffer strips and between the mainstream and the tributaries. And this effect was more significant on the fluorescence properties in the mainstream and the spectral properties for NCs than for SPM. The study helps to understand the biogeochemical effects of the waters with different particle sizes.

Water Quality and Anthropogenic Impact Assessment Using Macroinvertebrates as Bioindicators in a Stream Ecosystem

Water Quality and Anthropogenic Impact Assessment Using Macroinvertebrates as Bioindicators in a Stream Ecosystem

A global review of beaver dam impacts: Stream conservation implications across biomes.

Beaver are recolonizing previously occupied regions, expanding into new territories, and increasingly being introduced and protected for stream conservation and restoration across numerous biomes. However, beaver dam effects on the physical, chemical, and biological characteristics of streams may vary within and among biomes. A comprehensive review of these impacts is lacking. The goals of this review were to: 1) summarize the distribution of studies by biome on beaver dam effects related to channel morphology, hydrology, water quality, and aquatic biota, as well as on beaver habitat selection, 2) summarize the extent to which beaver dam impacts have been consistent within and among biomes, and 3) share testable hypotheses regarding beaver impacts within understudied biomes. We quantify the directionality of beaver dam impacts from 267 peer-reviewed studies. Results show that the majority of studies have been completed within temperate forest environments and that many biomes are understudied. Across biomes, beaver preferred sites for dam development characterized by relatively low gradients and unconfined reaches with small drainage areas. Overall, parameters related to stream morphology and hydrology showed relatively consistent responses to beaver dams within and among biomes, yet water quality and biotic responses were variable among biomes. Responses also varied by parameter within water quality and biotic impact categories. The findings of this study can be useful for stream conservation and restoration efforts that introduce or protect beaver. Additional studies are needed within arid and cold biomes historically occupied by beaver and in novel biomes where beaver populations are currently expanding.

Source water vulnerability to elevated total dissolved solids within a mixed-use Appalachian River basin

The upper Monongahela River basin in West Virginia represents a watershed wherein historic land use activities, including coal mining, conventional oil and gas development, and residential and urban development have contributed to elevated total dissolved solids (TDS) concentrations within surface and source waters with widespread exceedance of the 500 mg/L secondary drinking water standard for TDS. Our research was designed to characterize spatial variability in and sources of elevated and assess vulnerability of surface and source waters to additional TDS sources and loading. We compiled 3439 unique water quality sampling records throughout the study area over a ten-year period and applied boosted regression tree (BRT) analysis to model log[x]-transformed TDS as a function of landscape attributes across the 885 sampled NHD catchments. We predicted (i.e., elevated TDS and reduced dilution capacity) and observed (i.e., increased variability in TDS and temporary exceedances of 500 mg/L) elevated vulnerability of source waters, with vulnerability being largely driven by a few dominant contributors of TDS throughout the stream network. Notably, seven 12-digit hydrologic unit code (HUC) inflows to the Monongahela River and its vulnerable tributaries were predicted to require a combined 6,664,879 m3 of water (i.e., chemical footprint) to dilute TDS concentrations below 500 mg/L from July through September. Our results provide insights into how the mixed land uses containing extractive industries can impact water quality and demonstrates the importance of both spatial and temporal processes in controlling vulnerability of source waters to water pollution.

Application of modified clay in intensive mariculture pond: Impacts on nutrients and phytoplankton

Nutrients and phytoplankton associated with mariculture development are important concerns globally, as they can significantly impact water quality and aquaculture yield. Currently, there is still insufficient information regarding the variations in nutrients and phytoplankton community of intensive mariculture systems, and effective treatment is lacking. Here, based on consecutive daily monitoring of two Litopenaeus vannamei ponds from July to October, the dynamic variations in nutrients and phytoplankton were elucidated. In addition, modified clay (MC) method was adopted to regulate the nutrients and phytoplankton community. The temporal variations in organic and inorganic nutrients presented fluctuating upward trends. Notably, organic nutrients were the dominant species, with average proportions of TON/P in TN/P were as high as 75.29% and 87.36%, respectively. Furthermore, a marked increase in the ratios of dinoflagellates to diatoms abundance were also observed in the control pond, concurrently with dominant organic nutrients, ascending N/P ratio and decreasing Si/N and Si/P ratios. In the MC-regulated pond, MC reduced the contents of both organic and inorganic nutrients. Furthermore, a distinct change pattern of dominant phytoplankton community occurred, with green algae becoming the most abundant phytoplankton in the MC-regulated pond. This study can provide new insights into an effective treatment for managing water quality and maintaining sustainable mariculture development.

Mobility of Be, Bi, F, Ga, Ge and W in Surface Water and the Water Quality Impact on Epilithic Diatoms Downstream of the Historical Yxsjöberg Mine Site, Sweden

There is a potential risk that the geochemical cycles of several critical metals will be affected when mining of these metals increases to meet the demand of green technology. The geochemistry of Be, Bi, Ga, Ge, and W, herewith called CM5, is lacking, yet is necessary to ensure responsible mine waste and water management. Beryllium, Bi, and W are all considered immobile, but in previous studies of skarn tailings in Yxsjöberg, Sweden, all three elements were mobilized. The tailings are enriched in CM5, together with pyrrhotite, calcite, and fluorite. The mobility and environmental impact of CM5 and F in surface waters downstream of the Yxsjöberg mine site, Sweden, were studied using monthly water samples from seven locations and analysis of diatoms at five of these locations. Bismuth, Ge, and W were present at low concentrations, transported in the particulate phase, and likely settled in the sediments hundreds of meters from the tailings. Beryllium and F were present at high concentrations and dominantly transported in the dissolved phase. At these pH conditions (5.6), Be should form insoluble hydroxides; however, elevated concentrations of dissolved Be were observed more than 5 km from the mine site. Diatoms downstream of the mine site were negatively affected by the mine drainage. The release of low quality neutral mine drainage will continue for hundreds of years if remediation actions are not undertaken since only a small portion of the tailings have weathered during 50–100 years of storage.

Development of Web-based Geographic Information System for Water Quality Monitoring of Watershed in Malang

Human activity and climate change significantly impact water quality, especially in Malang's watershed. This research aims to develop a web-based Geographic Information System (Web- GIS) for water quality monitoring in that watershed. The water quality data had been collected from Enviromental Office of Malang District and Malang City. Water quality in this application was determined using the STORET method, comparing water quality data to water quality standards according to Government regulation so that the water quality status at each monitoring point will be known. The total 57 monitoring points are visualized spatially in this application based on the sampling location plotted by Global Positioning System (GPS). The longitude and latitude coordinates of the monitoring location had been converted in GeoJSON using Quantum GIS (QGIS) software. Google Map API key was used to display a sampling location map on the website. Web-GIS application was tested functionally using a black box, compatibility, and usability testing. Based on the testing results, it worked correctly on Chrome, Edge, Mozilla, and Opera browsers for PC/Laptops and also for browsers on Android smartphones version 4 and above. The application could be appropriately used and efficiently based on usability testing results.

Distribution and assessment of the environmental risk of heavy metals in Aguada Blanca reservoir, Peru

Sediments containing high concentrations of heavy metals in reservoirs, lakes and rivers, can resuspend into aquatic environments and negatively impact water quality. The concentrations of 10 elements were studied in surface sediments and water from the Aguada Blanca Reservoir, Peru, an important water source to 1,080,000 people in the arid province of Arequipa. Sediment and water samples were collected from nine points in 2019. The enrichment, accumulation, ecological risk and distribution of metals in sediment were determined, and the information on heavy metals in water was used to assess the quality of the aquatic system. Spatially, heavy metals showed variations throughout the study area, with an increase for most elements near the deepest part of the reservoir. The average concentration of Cd in sediment was 4 times higher than the natural background. In water, As was the only element that exceeded Peruvian regulations (As &gt; 10 μg L-1). The Enrichment Factor (EF) and Geoaccumulation Index (Igeo) of metals in sediment presented the following order: Cd&gt; As&gt; Pb&gt; Zn&gt; Cu&gt; Ni&gt; Cr, with Ni and Cr being the only elements that did not present enrichment. The most considerable Igeo was Cd (1.21 ± 1.45), presenting a classification of moderately to heavily contaminated. The integrated potential ecological risk (RI) of Cd presented high values in 5 points of the reservoir. The information developed will assist in establishing effective control strategies for the quality of the aquatic system.&#x0D; Keywords: heavy metals, reservoir, sediments, water quality.

Biomediated nanosized ZnS using Ulva fasciata and Citrus japonica: A new bio-photocatalyst for textile wastewater treatment

The aquatic ecosystems face excessive stress and depletion due to many pollutants impacting water quality. Biosynthesis of nanoparticles (NPs) using the green route represents a cost-effectively and eco-friendly approach, with significant applicability in various fields. In this regard, ZnS-NPs with improved photocatalytic and antimicrobial activities were biosynthesized for the first time from Ulva fasciata and Citrus japonica aqueous extracts. Biosynthesized ZnS-NPs were characterized and compared with chemically synthesized ones using UV–Vis spectroscopy, FTIR, TEM, XRD, and EDAX. TEM micrographs and XRD confirmed the formation of polygonal and spherical-shaped ZnS blend sphalerite nanocrystals with an average diameter between 7 and 31 nm. The optical properties of the produced ZnS-NPs showed higher band-gap energy of 5.63 eV and 4.76 eV for chemically and biosynthesized ZnS-NPs, respectively, as compared to ZnS macromolecules (3.77 eV). Biosynthesized ZnS-NPs showed excellent photocatalytic activity toward textile wastewater and two organic dyes (crystal violet and safranin), with significant degradation efficiency of 82–96.8, 82.5–98.12, and 84–95.9%, respectively. Biosynthesized ZnS-NPs showed high stability up to three subsequent cycles of photodegradation and exhibited promising antimicrobial activity against different Gram-positive and Gram-negative bacteria and Candida albicans. Biosynthesized ZnS-NPs have a less cytotoxic effect (IC50 > 300 μg/mL) than chemically synthesized ZnS-NPs (IC50 88 μg/mL) on human skin fibroblast normal cell lines. The photocatalytic efficiency of the biosynthesized ZnS-NPs has some advantages, such as non-toxic products, cost-effectiveness, and antimicrobial activity, which give them superiority to be used as a safe bio-photocatalyst for water treatment.Graphical abstract

Transcriptome Analysis Reveals the Algicidal Mechanism of Brevibacillus laterosporus against Microcystis aeruginosa through Multiple Metabolic Pathways.

It is widely accepted that eutrophication has played an important role in the formation of harmful cyanobacterial blooms in recent decades, which impacts water quality and ecological environment and causes huge economic losses. Algicidal bacteria have a promising application prospect in controlling cyanobacterial blooms in aquaculture water. Here, the process of the algicidal bacterium Brevibacillus laterosporus strain Bl-zj acting on Microcystis aeruginosa was explored using transcriptome analysis to elucidate the algicidal mechanism. The results of the co-culture of bacterium and alga showed a strong alga-lysing effect of B. laterosporus against M. aeruginosa with an extreme morphology deformation of the algal cells. A total of 2744 differentially expressed genes of B. laterosporus were identified, which were mainly involved in the metabolism of amino acid, carbohydrate, and lipid. In the co-cultured group, the expression of genes mainly enriched in valine, leucine and isoleucine degradation, and fatty acid degradation were significantly increased. However, the expression of the genes related to ribosome were mainly inhibited. Transcriptome analysis showed that B. laterosporus obtained ATP and energy by the degradation of valine, leucine, isoleucine, and fatty acids, and destroyed algal cells by efflux pump transporters, secretion of hydrolytic enzymes, antibiotics, proteases, and other secondary metabolites, resulting in algal death and achieving the algicidal effect.

Phosphate Uptake by Precipitation in Model Animal Wastewaters: Adjusting Ionic Strength and Ionic Composition to Maximize Phosphorus Removal

While phosphorus is a limited resource that is essential for agriculture, its release to the environment adversely impacts water quality. At the same time, animal wastewaters contain significant quantities of phosphorus and nitrogen that can be recovered for beneficial use. Phosphorus uptake experiments were performed with magnesium-treated corn-cob char and with magnesium silicate prepared using silicate from rice straw at pH 8 and 9. The concentration of dissolved phosphorus as a function of total added ammonium chloride (NH4Cl) was determined, and chemical equilibrium modeling was used to investigate the concentration trends of dissolved and mineral species. According to chemical equilibrium modeling, carbonate alkalinity exerted a significant magnesium demand, with approximately half of all added magnesium forming magnesite (MgCO3(s)). As total added NH4Cl increased, excess Cl− complexed with dissolved Mg2+ in competition with orthophosphate, freeing orthophosphate to precipitate, mainly as the mineral struvite (NH4MgPO4·6H2O(s)). As the concentration of added NH4Cl increased by a factor of ten, measured concentrations of dissolved phosphorus decreased by a factor of ten, meaning that ionic composition has the potential to significantly impact the amount of phosphorus that can be recovered from wastewaters for beneficial use.