Water Quality Standards Research Articles

EVALUASI SISTEM DAN DAMPAK LINGKUNGAN PENGELOLAAN AIR TERPRODUKSI PADA SUMUR X1 PT MGBI LAPANGAN WUNUT

PT Minarak Gas Brantas Inc.'s operations in the Wunut Field involve the production of waste in various forms, primarily liquid waste, with produced water being the most significant type. Proper management of this produced water waste is crucial to prevent environmental pollution and ensure economic and environmental sustainability. The company manages this waste by reinjecting it into the reservoir to prevent groundwater contamination. To ensure the effectiveness of this reinjection process, they have created a groundwater flow pattern map (flow net) at three locations near the injection well: LP1 in Keduung Boto Village, LP2 in Candi Pari Village, and LP3 in Candi Pari Village, all in Sidoarjo Regency. This helps in understanding the potential spread of pollutants in the soil and underground water, aiding in environmental pollution monitoring and managment.The groundwater from this area is used for various human activities like bathing, cooking, and washing. However, based on water quality standards outlined in Ministry of Health Regulation No. 2 of 2023, the produced water from Well X-1 in the Wunut Field does not meet the required TDS (Total Dissolved Solids) content standards due to a decline in hydrocarbon fluid production, resulting in a separator efficiency of 74,86%. Additionally, lab tests and flow net results indicate that the TDS levels in LP1, LP2, and LP3 do not meet the sanitation and hygiene water quality standards, suggesting potential seepage in these locations that could contaminate groundwater. Keywords: Oil; Gas Produced Water; Gas Separator Eficiency; Groundwater Flow

Distribution of inorganic compositions of Japanese tap water: a nationwide survey in 2019–2024

A nationwide survey of inorganic components of tap water all over Japan was conducted from 2019 to 2024. In this survey, 1564 tap water samples were collected, and an additional 194 tap water samples were collected from 33 other countries. The water samples were analyzed for 27 dissolved inorganic components, with a primary focus on the distribution of major and trace components, including Ca, Mg, K, Na, Cl−, NO3−, SO42−, total-hardness, Al, Fe, Cu, Mn, and Zn. The Japanese tap water hardness was 50.5 ± 30.2 (± 1σ SD) mg/L, classified as soft water according to the World Health Organization (WHO) classification. The average content of each major component in Japanese tap water tended to be lower than those in other countries. Furthermore, Piper trilinear diagrams were used to categorize Japanese tap water types. The dominating water types were the Ca–HCO3 and mixed types, which had a nationwide distribution. Japanese tap water generally complied with Japanese and WHO drinking water criteria, with only 1% (17/1564 sites) of the samples exceeding water quality standards. Observations of water quality changes for 2 years at three household faucets revealed that fluctuations in major components and trace metals (Al, Fe, Cu, Mn, and Zn) varied in different patterns. This suggests that the behavior of trace metal elements is influenced by local infrastructure, such as supply pipes, distinct from the variability in source water quality.

Occurrence, transport and sources of metals and metalloids in the Bangpakong River in the eastern economic corridor area of Thailand

The occurrence of elements in river water is affected by various factors, including mobility, weathering and transport processes and anthropogenic contributions. A total of six water sampling campaigns were conducted from 2021 to 2022 to study the factors affecting the occurrence of twelve elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Se) in the Bangpakong River. The total concentrations of all the elements were within the levels set by the national surface water quality standard. Comparisons of dissolved elemental concentrations in the study area with the global average for dissolved elemental concentrations in pristine rivers indicated contamination with Al, As, Co, Mn, Zn and Se in the river water. Based on the percentage of each element in particulates to the total concentration, Al (80.6 %), Cr (71.9 %), Cu (69.9 %), Fe (95.6 %), Mn (76.6 %), Pb (74.7 %), and Zn (70.6 %) were mainly transported in the particulate phase in both the dry and wet seasons. However, As (65.5 %), Co (60.3 %), and Se (77.6 %) were mainly transported in the dissolved phase in both seasons. The ratios of the dissolved Se concentration in river water to the Se concentration in the Earth's crust indicated significant and high mobility, especially in downstream sites, likely due to Se leaching from alluvial sediments. Seawater intrusion is likely the cause of As and Zn contamination in the dry season. Weathering of rocks and soils likely causes Al, Co, and Mn contamination in the wet season. The anthropogenic sources of contamination include the discharge of Mn and Zn from fertilizers in agriculture and the use of formulated feed in aquaculture. Approximately 52.98, 25.23, 5.68 and 0.63 tons of Fe, Al, Mn and Zn, respectively, are estimated to be transported from the river into the Gulf of Thailand each year.

Prevalence and Control of Pseudomonas aeruginosa in Tourist Facilities across the Canary Islands, Spain.

Pseudomonas aeruginosa is a common pathogen associated with recreational water facilities and poses risks to public health. However, data on the prevalence of P. aeruginosa in tourist destinations like the Canary Islands, Spain, remain limited. We assessed P. aeruginosa prevalence in 23 tourist facilities from 2016 to 2019. Compliance with water quality standards was evaluated, and 3962 samples were collected and analyzed. We examined different types of recreational water installations, including outer swimming pools, whirlpools, and cold wells. Of the sampled facilities, 31.2% did not comply with the current legislation's parametric values, mainly due to inadequate disinfectant levels, water temperature, and P. aeruginosa presence. The prevalence of P. aeruginosa was 4.8%, comparable to some European countries but lower than others. Cold wells displayed the highest non-compliance rate (89.2%) and yet exhibited a lower P. aeruginosa prevalence (1.9%) than outer swimming pools and whirlpools. Children's presence did not significantly impact P. aeruginosa contamination. Chlorine-based disinfectants are more effective than bromine-based ones in controlling P. aeruginosa. Regional variability in contamination was observed, with Fuerteventura showing lower colonization rates. Disinfectant levels play a critical role in P. aeruginosa control, and maintaining adequate levels is essential, particularly in bromine-treated installations. Our findings provide valuable insights into the prevalence and distribution of P. aeruginosa in recreational waters within tourist facilities. Tailored strategies are needed to ensure water safety in different Spanish regions. Continued monitoring and assessment, combined with artificial intelligence and machine learning, will enable the implementation of targeted interventions to protect the health of recreational water users.

Physicochemical and microbiological assessment of multi‐village drinking water source in diarrheal hotspot areas of north Shoa zone, Amhara region, Ethiopia

AbstractQuality water is essential to people's health and social and economic well‐being. Evaluation of the quality of the water sources provides benchmark data on quality status and insights into the development of further protective measures. A laboratory‐based cross‐sectional study design was conducted in the diarrheal hotspot area of the North Shewa zone. The contamination risks of water sources were assessed using the World Health Organization (WHO) sanitary inspection checklist. A grab water sample was collected from 138 multi‐village drinking water sources according to WHO guidelines. The collected sample was processed for physicochemical and microbiological analysis. Data were recorded and analyzed using SPSS version 25 software. The inspection survey indicated there was no proper handling of the water sources. The water temperature range was between 7 and 32°C, while the turbidity values ranged from 1.8 to 6 NTU. Electrical conductivity, pH, and total dissolved solutes were 100% within the acceptable limits of WHO and the Ethiopian Ministry of Health (EMoH) water quality guidelines. However, only (77/138, 55.79%) and (101/138, 73.29%) drinking water sources were within the acceptable range of temperature and turbidity, respectively. The mean bacteriological counts in multi‐village drinking water sources were a mean value of 72.14, 29.78, 21.09, and 15.64 for TMC, TCC, FC, and FSC, respectively. A total of (19/138, 13.8%) drinking water samples were positive for total coliform (Tc) and/or fecal coliforms (Fc). The remaining (119/138, 86.2%) water samples were bacteriologically potable. The physicochemical quality of the drinking water sources was consistent with WHO and national water quality standards, except that turbidity exceeded the acceptable range. The results also showed that some water sources were contaminated with fecal and total coliform, which was supported by an inspection survey in which most water sources were poorly protected. These research findings can serve as a valuable evidence base for informing policy decisions and guiding practical interventions aimed at ensuring access to safe drinking water in diarrheal hotspot areas.

Effect of Integrated Landscape Characteristics Around Chaohu Lake on River Water Quality Based on Watershed Units

Considering the impact of differences in watershed characteristics on river water quality, with the Chaohu Lake Basin as the research object, based on the data of water quality, meteorology, topography, soil, and remote sensing images of the river monitoring points from October 2019 to September 2020, the watershed unit at each monitoring point was divided through digital terrain analysis, and the comprehensive landscape characteristics based on the watershed unit were explored through the comprehensive use of correlation analysis, redundancy analysis, and multiple regression analysis to investigate the influence of comprehensive landscape characteristics based on watershed units (including land use, climate, topography, soil, etc.) on the water quality of rivers around Chaohu Lake. The results showed that:① the water quality of rivers around Chaohu Lake had large spatial differences, with the main pollutants being total nitrogen and ammonia nitrogen. Most of the rivers had total nitrogen concentrations exceeding the Class V water quality standards, and the areas with serious nitrogen and phosphorus pollution were concentrated in the urban area of Hefei and the surrounding rivers, as well as in the middle and lower reaches of the Fengle and Hangbu Rivers. ② The comprehensive landscape characteristics of the watershed unit had a significant impact on the river water quality. Among them, the proportion of built-up land, the density of patches, the dispersion and juxtaposition index, and the Shannon diversity index were positively correlated with the water quality indicators, whereas the proportion of forest and grassland and the spreading index were negatively correlated with the water quality indicators. ③ In different seasons, the effect of the integrated landscape characteristics of the watershed unit on river water quality was stronger in the wet season than in the dry season, which was mainly caused by the difference in precipitation in the dry and wet seasons.

The Impact of Pit Latrines on the Pollution of Groundwater in the District of Rwamagana, Rwanda

The composition and condition of a water body change over time and across different locations due to internal and external factors. In many rural and peri- urban communities in Rwamagana, the lack of treated water has increased reliance on groundwater for various household and community needs. Groundwater sources are essential for meeting the water demand in these regions. An investigation was carried out in the Rwamagana district of the eastern province of Rwanda to evaluate the influence of pit latrines on groundwater quality. The research examined the water quality of four boreholes with hand pumps and 18 improved springs located near pit latrines. The evaluation specifically looked at total coliforms (TC), electrical conductivity (EC), turbidity, and pH. The proximity of the pit latrines to the boreholes or springs was considered in order to determine the presence of fecal coliforms in the groundwater, with the goal of establishing a minimum safe distance between the pit latrines and water sources. The physicochemical indicators of the water samples met the drinking water quality criteria set by the World Health Organization (WHO). However, the levels of biological contaminants exceeded the WHO's drinking water quality standards. The highest coliform counts detected in the study were 99cfu/100ml of water. The research findings suggest a clear relationship between fecal microbes from pit latrines and their impact on groundwater quality, with the contamination effect extending up to 322.4m for improved springs and 266.2m for boreholes with hand pumps.

Impact of Agricultural Practices on Nitrate Pollution in Groundwater in India

Purpose: The aim of the study was to examine impact of agricultural practices on nitrate pollution in groundwater in India Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: a significant environmental concern with far-reaching implications for human health, ecosystem integrity, and water resource management. It is evident that agricultural activities such as fertilizer application, irrigation methods, and land management practices play a pivotal role in exacerbating nitrate contamination of groundwater. The studies highlighted the complex interactions between agricultural activities and hydrological processes, elucidating the pathways through which nitrates migrate from soil to groundwater. Unique Contribution to Theory, Practice and Policy: Diffuse Pollution Theory, Hydrological Connectivity Theory & Sustainable Agriculture Theory may be used to anchor future studies on impact of agricultural practices on nitrate pollution in groundwater in India. Encourage the adoption of sustainable agricultural practices that minimize nitrate pollution while maintaining agricultural productivity. This includes promoting precision agriculture techniques, cover cropping, and integrated nutrient management systems to optimize fertilizer use and reduce nitrate leaching. Strengthen regulations and enforcement mechanisms to limit nitrate pollution from agricultural activities. This may include setting stringent water quality standards for nitrate concentrations in groundwater and implementing monitoring programs to assess compliance.

PENINGKATAN MUTU AIR SUMUR SIAP MINUM MELALUI FILTRASI DENGAN BIAYA EKONOMIS

Water is one of important substance for human being. Good water for daily needs has to be clean, no colour and odorless. Other than that for consumtion good water also has to contain important minerals needed by human body. The villagers of Kampung Melayu RW 01 Kelurahan Setokok , Kecamatan Bulang uses rain water and digging well to get water for their daily needs. This water does not meet basic requirements for daily needs. In community service activity programme in 2020, the students of Mechanical Engineering of Engineering Faculty Uniba conducted education for the villagers on the importance of clean water for life and how to get it at low cost. The education focused on technical matter to get clean water by filtration system. Filtration method uses plastic bottle, gravel, cotton, charcoal and water tubing to purify water. After purification by filtration system water meets all requirements as stated in Indonesian Goverment Law Number 20 year 1990 on water quality standard. Keyword: filtration, purification, standard water.

Performance evaluation of the compact water treatment system pilot project at Timah Tasoh Water Treatment Plant, Perlis, Malaysia

Abstract Clean water is crucial to ensuring the well-being of people. The Package Timah Tasoh Water Treatment Plant (WTP) is designed to support the existing conventional plant in coping with the growing demand for clean water. The package plant used the Compact Water Treatment System, classified as a Category B in the Suruhanjaya Perkhidmatan Air Negara (SPAN) guidelines; thus, this performance monitoring research was conducted prior to product registration. The plant consists of aeration, flocculation, clarification, and filtration processes. The performance of this package plant was monitored through comparative and efficiency analysis of removal parameters and carried out over a period of six (6) months. Twelve (12) water quality parameters were selected, including turbidity, pH, total dissolved solids (TDS), colour, ammonia, residual chlorine, aluminium, iron (Fe), manganese (Mn), fluoride, standard total coliform, and E. coli with sampling water of RW, SW, FW, and TW, which was then assessed alongside the drinking water quality standards set by Ministry of Health (MOH). As a result, eight key parameters such as pH, turbidity, colour, TDS, iron, aluminium, manganese, and ammonia were meeting the MOH drinking water quality standards in over 94 % of cases. The remaining parameters are chlorine residual, fluoride, E. coli and standard total coliform were in non-compliance due to the inoperability of disinfection and fluoridisation processes. Most of the significant parameters deduced a better performance in terms of removal efficiency (> 60 %) consistently, except for TDS, throughout the monitoring activity.

Analysis of Sea and River Water Quality Standards Due to Operations and Domestic Activities in the Sanur Port Area, Bali

The development of an area has impacts, both positive and negative impacts. The positive impact is in the form of regional economic growth, employment and development of the surrounding regions. The negative impact is the disruption of the environmental ecosystem and a decrease in environmental quality due to waste generated from development operations, in the form of solid waste (garbage) and liquid waste. The increasing pollution load is also caused by public awareness and business activities in upstream areas that do not manage waste properly, which ultimately leads to all of the waste accumulating in water bodies and causing changes in water quality standards. Sanur Port, which is one of the development centers in its operations, is very vulnerable to environmental pollution impacts. The pollution mechanism originates from activities around Sanur Port and domestic activities which are discharged into rivers and seas in the Sanur area. This research aims to analyze the quality of river water and sea water caused by activities around Sanur Port and community activities based on Decree of the Minister of Environment Number 51 of 2004 and determine the pollution index. Water quality standards use Bali Governor Regulation no. 16 of 2016 concerning Environmental Quality Standards and Quality Standard Criteria for Environmental Damage. This research uses a quantitative approach by collecting primary data from direct observations in the field and secondary data based on previous research reports and government reports. The research results show that TDS in the rainy season tends to be lower than in the dry season, both in the results of testing samples of Abianbase river water, the results of testing samples of sea water in front of the Mak Beng Restaurant and sea water samples in the Sanur Port Pool. In front of Mak Beng, ammonia levels during the rainy season are higher than during the dry season. Ammonia levels in the Abianbase River and sea water in front of Sanur port are lower during the rainy season compared to the dry season. The presence of Coliform bacteria and E. coli shows a tendency to decrease during the rainy season. This decrease is thought to be caused by leaching by rainwater entering marine waters and retailing and changes in ocean currents during the rainy season.

Water Quality River Estuary of Batang Hari, Musi Banyuasin District, the Province of South Sumatera

This study aims to determine the water quality of the estuary of the Batangharileko River based on factors of physics, chemistry and biology. The results showed that the water quality of the estuary of the Batangharileko River by physical factors already meets the criteria of raw water for class I, II , III and IV. While chemical parameters already meet the criteria class III water quality standards. Water Appropriation Category I is for the raw water of drinking water, class II for facilities/infrastructure recreation and freshwater fish breeding, class III for fishery cultivation and watering the plants, the Group IV for watering plants. Biological parameters in this case is the abundance, diversity index and dominance index, Batangharileko River estuary has undergone minor contamination although physiologically not appear on macrozoobenthos life

Evaluation of treated wastewater quality from Cap-falcon plant for agriculture irrigation

Wastewater reuse is a useful tool for minimizing the amount of wastewater discharged into the environment. However, it is associated with threats to the environment and public health; consequently, effluent quality assessment is essential prior to reuse. The aim of this study is to assess the physicochemical and microbiological quality of treated wastewater from Cap Falcon wastewater treatment plant for reuse in irrigation. The suitability of treated wastewater from Cap Falcon plant for irrigation was assessed based on its composition and Algerian irrigation water quality standards. The average biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) values decrease from 316 mg/L to 21 mg/L with a mean removal efficiency of 93.0% and from 659 to 40 mg/L with removal efficiency of 93.7% respectively. For total suspended solids (TSS), the concentration at the inlet of the treatment plant is very high but reduces greatly after biological treatment with a removal efficiency over 94.5%. The physico-chemical analyses of treated wastewater samples from the storage reservoir indicated that pH varied from 6.81 to 8.20 with an average value of 7.43, which is slightly alkaline in nature. Electrical conductivity is one of the criteria used to evaluate the suitability of water for agricultural use; the average value was found less than 1500 μS/cm, indicating that the treated wastewater is considered as suitable for irrigation use. On the other hand, microbiological analyses indicate that faecal coliforms are high compared with Algerian water quality reuse standards. Furthermore, the overall quality of tertiary treated wastewater was analyzed by calculating the water quality index. The calculated index for the physicochemical and microbiological parameters was 96, which corresponds to a water quality type “very poor” signifying that this effluent can only be used for restricted irrigation practices.

Low Cost Water Purification: Harnessing Adsorbents for Sustainable Treatment Solutions

Water is essential for life, yet millions lack access to clean drinking water. Low-cost treatment methods are crucial to ensure equitable access to safe water and prevent waterborne diseases in underserved communities. The study devised a 12-liter water filter utilizing pebbles, sand, and adsorbents biochar of Julifora, cashew nut shell and rice husk. Results demonstrated the filter's effectiveness in sustaining pH levels while reducing chloride, fluoride, hardness and alkalinity. Particularly noteworthy was the capacity of cashew nut biochar to efficiently adsorb chloride, fluoride, hardness and alkalinity as 27%, 37%, 38% and 43% respectively. This indicates its promising role as an adsorbent for water purification. The findings underscore the potential of the designed filter in improving drinking water quality by mitigating contaminants. Further refinement and optimization of the filter could enhance its efficacy in meeting stringent water quality standards, addressing the pressing need for accessible and safe drinking water globally.

Recycling leachate nanofiltration concentrate and preparing a novel and low-cost absorbent dried gel by graft polymerization

Leachate nanofiltration concentrate (LNC), characterized by its complex composition and recalcitrant contaminants, poses a significant environmental challenge. This study explores the synthesis of absorbent gels via free radical polymerization, utilizing LNC as the solvent. Employing urea as the modified material, acrylic acid (AA) as the monomer, N, N′-Methylenebisacrylamide (MBA) as the cross-linking agent, and potassium persulfate (KPS) as the initiator, the resulting gel is stable below 180 °C. It demonstrates an impressive absorbency (Q) exceeding 14.50 g/g with key gel synthesis conditions optimized via response surface methodology (RSM). Subsequent application of the prepared LNC gel in LNC treatment via low-temperature evaporation achieves remarkable pollutant removal, meeting relevant water quality standards. This gel-based LNC treatment method achieves notable reductions in carbon emission and cost to 39.2 kgCO2/kgCOD and 3.4 $/kgCOD, respectively. This study provides a cost-effective and environment-friendly approach for LNC reutilization, and exemplifies the concept of utilizing waste to treat waste, thereby mitigating environmental impact of LNC and advancing gel technology in environmental remediation.

Chemical-Saving Potential for Membrane Bioreactor (MBR) Processes Based on Long-Term Pilot Trials.

Membrane bioreactors (MBRs) have gained attraction in municipal wastewater treatment because of their capacity to meet strict water quality standards and support water reuse. Despite this, their operational sustainability is often compromised by high resource consumption, especially regarding the use of chemicals for membrane cleaning. This study explores innovative membrane-cleaning strategies to enhance the sustainability of MBR processes. Through long-term pilot trials at Stockholm's largest wastewater treatment plant, this study showed that alternative cleaning strategies can reduce chemical use by up to 75% without sacrificing treatment performance. The results further suggest that these alternative strategies could result in cost reductions of up to 70% and a reduction in environmental impacts by as much as 95% for certain indicators. Given that MBRs play a crucial role in addressing increasing treatment demands and advancing circular water management, the outcomes of this study are beneficial for the broader adoption of MBR processes. These results also have implications for existing installations, offering a pathway to more sustainable wastewater treatment. Moreover, the presented cleaning strategies provide significant opportunities for lowering operational costs and reducing the environmental footprint of new and existing MBR installations.

Sustainable management of small-town water supply in Nepal: improvement through the multi-stage training mechanism

ABSTRACT In Nepal, a project to sustain a safe water supply for small towns was executed in 68 towns, each with distinctive water sources and topographical situations. This project adopted two approaches to establish a standardized capacity development process for small-town water supplies. The first approach, the Management Model, consists of standard operating procedures (SOPs) and business planning. The second approach, termed the Support Model, entails a comprehensive system for training, monitoring, and evaluating water supply management. Throughout the project, a total of 31 SOPs pertaining to operation, maintenance, and facility rehabilitation manuals were developed. Moreover, four courses consisting of training, basic and on-site training, and interactive workshops were conducted. Consequently, the data deficiency rate reduced significantly by 61%, while 87% of water samples met water quality standards. In contrast, the operating ratio and water production rates improved by 17 and 29%, respectively. The materials produced from these models are expected to contribute to small-town water supply systems beyond the pilot sites. This is due to the versatility of the model for future applications. Although the project was effectively implemented, continuous support for small-town water supply by the Government of Nepal is needed for future sustainability.

Water quality evaluation based on water quality index and multiple linear regression: A research on Hanyuan Lake in southern Sichuan Province, China.

This study aims to understand the changes in the water quality of Hanyuan Lake and to show these changes over time. In this study, monthly sampling was conducted at three sampling sites in Hanyuan Lake, and water samples were measured for water quality indicators in the laboratory according to the methods specified in the Environmental Quality Standards for Surface Water (GB3838-2002). Based on the monitoring data from January to December 2019, the WQI comprehensive evaluation method was used to conduct multiple linear stepwise regression analysis, extract key indicators, and establish the WQImin model. The results show that according to the WQI comprehensive evaluation method, the WQI values of Hanyuan Lake are all above 90, and the grade is excellent. The overall water quality of Hanyuan Lake is excellent, and most of the water quality indexes reach the Class I standard in the Environmental Quality Standards for Surface Water (GB3838-2002). WQImin1 (R2 = 0.86, p < 0.001, PE = 4.28) as the best WQImin model. In this study, a model with fewer parameters was established by multiple linear regression method, which is conducive to better monitoring of water quality at monitoring stations while saving costs. PRACTITIONER POINTS: According to the WQI comprehensive evaluation method, the WQI values of Hanyuan Lake are all above 90, the rating is excellent. From January 2019 to September 2020, the monthly change trend of each section is roughly the same, showing a trend of first decreasing, then rising, then decreasing, and finally rising and flattening. The WQImin model was developed to completely describe the change in the water body.

Freshwater water quality criteria for phthalate esters and recommendations for the revision of the water quality standards

With increasing urbanization and rapid industrialization, more and more environmental problems have arisen. Phthalates (PAEs) are the foremost and most widespread plasticizers and are readily emitted from these manufactured products into the environment. PAEs act as endocrine-disrupting chemicals (EDCs) and can have serious impacts on aquatic organisms as well as human health. In this study, the water quality criteria (WQC) of five PAEs (dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP)) for freshwater aquatic organisms were developed using a species sensitivity distribution (SSD) and a toxicity percentage ranking (TPR) approach. The results showed that long-term water quality criteria (LWQC) of PAEs using the SSD method could be 13.7, 11.1, 2.8, 7.8, and 0.53 μg/L, respectively. Criteria continuous concentrations (CCC) of PAEs were derived using the TPR method and determined to be 28.4, 13.1, 1.3, 2.5, and 1.6 μg/L, respectively. The five PAEs are commonly measured in China surface waters at concentrations between ng/L and μg/L. DBP, DEHP, and di-n-octyl phthalate (DnOP) were the most frequently detected PAEs, with occurrence rates ranging from 67% to 100%. The ecological risk assessment results of PAEs showed a decreasing order of risk at the national level, DEHP, DBP, DMP, DEP, DnOP. The results of this study will be of great benefit to China and other countries in revising water quality standards for the conservation of aquatic species.

Polymer foam fabricated via surfactant foaming method enables high-performance solar interfacial evaporation

Solar interfacial evaporation is considered as a low energy consumption, low cost, and sustainable desalination technology. However, its practical application is still limited by complex preparation processes and low photothermal conversion efficiency. In this work, we report novel polymer foam (Agar/SA/GO-Ag composite foam). It is prepared by simple and convenient surfactant foaming and in-situ reduction methods and consists of graphene oxide (GO) and silver nanoparticles (Ag NPs) (photothermal conversion medium) as well as Agar and sodium alginate (SA) (basic skeleton) for use in solar-powered interfacial evaporation systems. The prepared foam has excellent wettability and achieves 96.7% light absorption in the full spectrum range. A high evaporation rate of 2.55 kg·m−2·h−1 and a high evaporation efficiency of 97.3% were obtained under the conditions of simulated sunlight (1.0 kW·m−2). Moreover, the foam exhibits good reusability in a 10-cycle test without obvious attenuation in evaporation performance. Foam is used for seawater desalination and wastewater purification, and the treated water meets the water quality standards of the World Health Organization (WHO) and the United States Environmental Protection Agency (USEPA). In short, this work demonstrates a sustainable strategy for low-cost and efficient solar-powered clean water production.