Total Suspended Solids Levels Research Articles

Mitigating environmental pollution from tofu industry wastewater: Case of Suyanto Tofu Factory, Mojokerto

Background: This research investigates the impact of tofu industry wastewater on water environments at Suyanto Tofu Factory, Mojokerto. The tofu industry generates liquid waste containing high pH, Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), and Chemical Oxygen Demand (COD), potentially polluting local rivers. Despite Suyanto Tofu Factory having wastewater treatment facilities, these are currently non-functional, underscoring the urgent need for designing new wastewater treatment installations. Methods: In this context, the study aims to determine the volume of wastewater produced, analyze the levels of BOD, COD, TSS, and pH in the wastewater, and design sustainable wastewater treatment facilities using a Constructed Wetland system. Findings: This method is expected to minimize the environmental impact of tofu wastewater, protect surrounding aquatic ecosystems, and comply with environmental regulations. By proposing sustainable solutions, the research aims to enhance awareness and management of wastewater in the tofu industry, offering technology solutions appropriate to local conditions. Conclusion: In conclusion, implementing effective and sustainable wastewater treatment installations is crucial to safeguard water quality and river ecosystems around Suyanto Tofu Factory. Novelty/Originality of this Study: By proposing a Constructed Wetland system for tofu industry wastewater treatment, this research introduces an innovative, sustainable solution tailored to local conditions, potentially revolutionizing waste management practices in small-scale food industries.

Assessment of temporal and spatial variations of water quality parameters in the Zarafshan River basin

AbstractRiver ecosystems in Central Asia face significant stress from environmental changes and pollution. This study assesses temporal and spatial variations in water quality parameters within the Zarafshan River Basin using retrospective data and field measurements. Water quality indicators, including electrical conductivity (EC), total suspended solids (TSS), ammonium nitrogen (N‐NH4), nitrite nitrogen (N‐NO2), nitrate nitrogen (N‐NO3), temperature (T), chemical oxygen demand (COD), dissolved oxygen (DO), and discharge, were analyzed using the Pearson's correlation coefficient and ANOVA, with the Mann–Kendall (MK) test detecting trends over time. Obtained results indicate significant seasonal effects with elevated TSS during summer, increasing sediment load and changing aquatic habitats. The strong inverse correlation (–0.89) between DO and N‐NH4 signifies ecological challenges particularly in low DO concentrations during summer (3.25 mg L–1). Long‐term analysis identifies Navoiazot chemical factory as a major pollution hotspot. Spatial analyses based on extended sampling have revealed the Siab and Dargom canals and Samarkand City as major pollution sources of elevated N‐NO2 and COD, respectively. Trends at various gauging stations (MK‐test) show increasing EC (τ = 0.72) and N‐NH4 (τ = 0.46) levels, with decreasing TSS, N‐NO3, T, and COD levels over time. Recommendations include targeted measures to reduce pollution at the Navoiazot factory and downstream, introducing sustainable agriculture practices, increasing public awareness for environmental conservation, and improving urban wastewater treatment to meet water quality requirements for different users.

Physicochemical and ecotoxicological approaches for Moknine Continental Sebkha in Tunisia.

Degradation of water quality is an emerging issue in many developing countries. In this context, industrial and domestic effluents heavily contaminate the coast of Moknine Continental Sebkha in Tunisia. The present study aimed to biomonitor the seawater quality of the Moknine Continental Sebkha coast using physicochemical and ecotoxicological approaches. The ecotoxicological assessment was performed using three species representing different trophic levels, namely Vibrio fischeri, Selenastrum capricornutum, and Lepidium sativum. In the physicochemical analysis such as BOD (biochemical oxygen demand), COD (chemical oxygen demand), TSS (total suspended solids), TOC (total organic carbon), NO3- (nitrate), AOX (adsorbable organic halogen), the recorded levels of pH and total suspended solids did not comply with the Tunisian standard (NT.09.11/1983). The ecotoxicological data confirmed that the tested water samples displayed toxicity to two test indicators L. sativum and S. capricornutum. A targeted chemical screening of the Moknine Continental Sebkha coast previously performed revealed the presence of total mercury, four phthalate acid esters, and one non-phthalate plasticizer, a fact that could explain the observed ecotoxicological effects and therefore might harm the biotic area and the health of the surrounding population.

Analysis of total suspended solids in Lampuuk-Lhoknga Beach Waters, Aceh Besar, Indonesia

Research on total suspended solids in the waters of Lampuuk-Lhoknga Beach, Aceh Besar was conducted on March 16, 2023. Lampuuk-Lhoknga Beach is a beach that has high activity that affects the concentration level of total suspended solids which becomes a problem for waters if the concentration level is high. This study aims to analyze and calculate the concentration of total suspended solids in the waters of Lampuuk-Lhoknga Beach. This study used purposive sampling method by taking beach water samples from several predetermined stations. Water samples that have been taken are analyzed using the gravimetric method. Based on the results of the study, the concentration of total suspended solids at 10 stations (the northernmost, Station 1 to the southernmost, Station 10) ranged from 100 mg/l to 1500 mg/l. The lowest concentration result was found at Station 4 near the cliff, which was 100 mg/l, while the highest result was found at Station 5 near tourism activities, which was 1500 mg/l. The high concentration of total suspended solids is thought to be caused by high human activity in all fields ranging from marine tourism, culinary areas to industrial areas.

Eco-friendly green roof from biodegradable substrate for stormwater quality improvement

Currently, there is a significant surge of interest in green roof technology for construction buildings due to its numerous environmental benefits, such as stormwater management, energy efficiency, and enhanced urban biodiversity. However, the issue of potential pollutant release from green roof substrates into runoff water, causing water pollution, needs to be addressed. To tackle this concern, a lab-scale green roof model was assessed, utilizing a biodegradable substrate made from banana peels and eggshell waste (organic fertilizer). Three models were tested: a conventional green roof (control), a green roof with chemical fertilizer, and a green roof with organic fertilizer. Various water quality parameters, including pH, total suspended solids (TSS), nitrogen, phosphorus, and potassium (NPK), and chemical oxygen demand (COD), were evaluated. The results demonstrated the effectiveness of organic fertilizer in reducing TSS and COD levels, where the eco-friendly green roof with biodegradable substrate exhibited an impressive performance, achieving a higher COD removal percentage (78%) compared to the green roof with chemical fertilizer (50%). The utilization of organic fertilizer led to an enhancement in the quality of stormwater runoff, resulting in NPK removal percentages ranging from 17% to 25%. Additionally, the organic fertilizer fostered healthier vegetation growth, leading to a greater number of leaves compared to the chemical fertilizer. These findings highlight the potential of eco-friendly green roofs as a sustainable and effective tool for stormwater management, provided suitable substrate materials are employed.

Recommending Surface Water Quality Monitoring for the Nature Reserve Using Multivariate Statistical Methods

Lung Ngoc Hoang Nature Reserve has a crucial role in conserving and protecting the natural ecosystem and biodiversity in the Mekong Delta, Vietnam, and the local communities also receive great benefits from aquatic resources in this nature reserve. This study was conducted to assess water quality in the Lung Ngoc Hoang Nature Reserve and to provide important information for the monitoring program using multivariate statistical methods. Water samples were collected bimonthly from fifteen locations belonging to five functional zones of the nature reserve (i.e., buffer zone, main canal, administrative and service zone, ecological restoration zone, and strictly protected zone). The physiochemical properties of water samples were measured, including temperature, pH, electrical conductivity (EC), total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), sulfate (SO42-), iron (Fe2+), and aluminum (Al3+). The results showed that the levels of TSS, COD, and Fe2+ exceeded the Vietnamese standard on surface water quality, and the DO level was also far below the standard. Besides, the concentrations of TN, TP, and Al3+ in the nature reserve area showed the risk of eutrophication and negative effects on aquatic organisms. Problems of water quality were observed in the main canal and the administrative and service zones more than in the other zones. Cluster analysis (CA) suggested a reduction in the number of monitoring frequencies and locations to four months (i.e., January, April, July, and September) and twelve locations, respectively. This reduction allows for a decrease in the effort and cost of the monitoring program with adequate information to evaluate water quality. Moreover, principal component analysis (PCA) identified five principal components, which could explain 80.98% of the total variance of the initial dataset. Potential pollution sources were also recognized based on PCA, including the nature properties of sulfate-acid soils, livestock, fertilizer, and domestic activities. The findings of this study can enhance our understanding of water quality in the nature reserve area and the effectiveness of future monitoring programs. Doi: 10.28991/CEJ-SP2023-09-015 Full Text: PDF

Production of bioelectricity from palm oil mill effluent through a dual chamber-microbial fuel cell system with the addition of Lactobacillus bulgaricus

Palm oil liquid waste has been successfully developed to produce bio-electricity with a dual chamber-microbial fuel cell system. This study utilized the Lactobacillus bulgaricus bacteria as a support for the substrate samples prepared in the anode chamber. Meanwhile, in the cathode chamber, KMnO4 electrolyte solution is used as an electroactive species that can capture electrons well. In addition, salt bridges fabricated from agar have a role as ion-exchange media in microbial fuel cells. The test results showed that the best performance was obtained in samples of palm oil wastewater with the addition of 10% Lactobacillus bulgaricus (LS/B-10) bacteria with current, voltage, and power density values of 0.9640 mA, 0.6760 V, and 248.04 mW/m2, respectively. The MFC system has also been proven to be able to reduce COD (Chemical Oxygen Demand) and TSS (Total Suspended Solid) levels, with the results of a reduction percentage of 42.6% and 7.2%, respectively, in the LS/B-10 variable treatment. All test results show that palm oil wastewater with the addition of Lactobacillus bulgaricus bacteria is promising for producing bioelectricity with a microbial fuel cell system.

The effectiveness of using coconut husk powder as an adsorbent to enhance the wastewater quality of the cepuk textile industry in Nusa Penida, Bali, Indonesia

Introduction: Tenun Cepuk (traditional woven) from Nusa Penida holds great potential as a traditional textile art form, cherished for its intricate patterns and cultural significance. However, the textile industry's wastewater, with its dye-related pollution, presents a significant environmental challenge that needs sustainable solutions. Coconut husk powder exhibits promising potential as an adsorbent for treating dye wastewater from the textile industry. Investigating the interplay between varying thicknesses and contact durations is crucial to maximizing coconut husk powder's adsorption capacity and efficiency for dye wastewater treatment. Method: This study, following an Experimental research design with a Posttest Only Control Group Design, aims to assess the impact of an intervention on the experimental group compared to the control group. Coconut fibers, sourced from Nusa Penida agriculture, serve as the adsorbent. Coconut powder is added to these tanks at thicknesses of 5 cm, 10 cm, and 15 cm. Subsequently, wastewater samples from the Cepuk weaving process are introduced into each experimental tank, along with a control group. The process is left for 24 and 72 hours as varying contact times. The adsorption results are subjected to analysis for parameters, including total suspended solids (TSS), total dissolved solids (TDS), five-day biochemical oxygen demand (BOD5), and chemical oxygen demand (COD) at the Panureksa Denpasar Laboratory. Results: The use of coconut husk powder as an adsorbent effectively lowers TDS, TSS, BOD5, and COD in Cepuk textile dye wastewater. The reduction depends on adsorbent thickness and contact time. Thicker adsorbents notably reduce TDS, TSS, BOD5, and COD, enhancing wastewater quality and environmental safety. A 15 cm-thick adsorbent effectively reduces TDS to permissible levels. Prolonged contact times also significantly lower levels. Conclusion: Coconut husk powder can be utilized to decrease TDS, TSS, BOD5, and COD levels in textile dye wastewater. Thickness and contact time significantly impact the enhancement of wastewater quality.

Biological Responses of Oyster Crassostrea gasar Exposed to Different Concentrations of Biofloc

Oysters have the potential to be a part of more sustainable farming systems, such as multitrophic systems integrated into biofloc systems, due to their filtration activity, which enables them to act as organic consumers. However, the stress experienced by animals in a system with a high organic load can compromise their productive performance. The objective of this study was to evaluate the biological responses of Crassostrea gasar oysters when exposed to different concentrations of total suspended solids in biofloc systems. The oysters were exposed to four different concentrations of solids for 28 days. Hall effect sensors were installed on the outside of the shells to detect the movement of the oyster valves. Also, biochemical and histological analyses were conducted to assess the biological responses of the oysters to exposure to varying levels of solids. A difference in valve opening detected by the Hall sensors was observed from the second week of culture, indicating a relationship between shell closure and higher concentrations of suspended solids present in the system. In terms of biochemical analysis, a significant increase in lipid damage was observed in treatments with medium and high levels of total suspended solids compared with the control group. Conversely, no changes were observed in the gill structure of the oysters caused by the concentrations of suspended solids in the system when compared with the control. According to the analyses of gill activity and biochemistry, it is suggested that C. gasar should be cultured with total suspended solids at less than 200 mg/L. Oysters cultivated in a biofloc system keep their shells closed when subjected to high concentrations of total suspended solids; concentrations of total suspended solids below 200 mg/L do not induce oxidative stress, changes in behavior or histological alterations in C. gasar oysters cultivated in a biofloc system.

Monitoring Total Suspended Solids and Chlorophyll-a Concentrations in Turbid Waters: A Case Study of the Pearl River Estuary and Coast Using Machine Learning

Total suspended solids (TSS) and chlorophyll-a (Chl-a) are critical water quality parameters. Focusing on the Pearl River Estuary and its coastal waters, this study compared the performance of XGBoost- and BPNN-based algorithms in estimating TSS and Chl-a levels. The XGBoost-based algorithm demonstrated better performance and was then used to estimate TSS and Chl-a in the Pearl River Estuary and coastal waters from 2000 to 2021. According to our results, TSS and Chl-a were relatively high mainly in the northwest and low in the southeast. Furthermore, values were high in spring and summer and low in fall and winter, with high values emerging near the estuary of the Pearl River. In summer, a band zone with high Chl-a was observed from south of Yamen to south of Hong Kong. In terms of trends, TSS and Chl-a concentrations in the area around the Hong Kong–Zhuhai–Macao Bridge tended to decrease from 2000 to 2021. As the construction of the bridge began, changes in water flow caused by the bridge piers and artificial islands were influenced, the change in the rate of TSS in the west area of the bridge was greater than 0, and the TSS in the upstream area of the west side changed from decreasing to increasing trends. Concerning Chl-a concentrations, the change in the rate in the downstream area of the west side of the bridge was greater than 0. The study may provide a helpful example for similar estuarine and coastal waters in other coastal areas.

Acidifying remediation and microbial bioremediation decrease ammoniacal nitrogen, orthophosphates, and total suspended solids levels in intensive Nile tilapia farming under biofloc conditions

In biofloc technology (BFT) systems, the formation of bioflocs and accumulation of suspended solids are constant, which can cause impairments in water quality parameters and negatively impact the growth performance of farmed animals. We herein investigated two integrated solutions for intensive farming of Nile tilapia under BFT conditions. In this study, EUROGUARD® SOFT F60 (60% formic acid and 40% lignosulfonic acid) was used as the acidifying remediator, while ADD LIFE PRO BACIL ACQUA based on a mixture of Bacillus spp. was used as the microbial bioremediator. First, assays were conducted for in vitro inhibition tests of acidifying remediator against seven different strains of pathogenic bacteria. A dose-response test was performed for both acdifying bioremediator and microbial bioremediator. Then, an in vivo assay was conducted over four weeks. In 12 BFT units with a capacity of 250 L each, one group received the acidifying remediator at a concentration of 2.5 part per million (ppm), while another group received the bioremediator Bacillus spp. at a concentration of 0.10 g m−3 directly in tank water. A control group without aditives was also established, all in quadruplicate. The culture environment was evaluated daily by measuring dissolved oxygen, temperature, floc volume and weekly by measuring total ammonia nitrogen (TAN), ammoniacal nitrogen (N−NH3), nitrite (N-NO2), nitrate (N-NO3), alkalinity (CaCO3), orthophosphate (PO43−), electrical conductivity (μS−1), potential of hydrogen (pH) and total suspended solids (TSS). At the end of the period, in the in vivo assay, the bacterial community in the BFT, hematological parameters, and zootechnical performance of the tilapia were evaluated. In in vitro inhibition tests, the acidifying remediator inhibited the growth of all pathogenic bacteria evaluated. All concentrations reduced the count of filamentous bacteria, and the pH values were dose-dependent. Both in vivo treatments altered bacterial communities. Both treatment groups had lower concentrations of N-NH3, N-NO2 and N-NO3. PO43− content was lower in the acidifying remediator group. CaCO3 was higher in the treatment groups, while TSS was higher in the control group. Both remediation strategies were efficient in removing nitrogenous chemical compounds. However, the acidifying remediator concomitantly reduced N-NH3, N-NO2− and PO43− levels, becoming a powerful ally in the reduction of aquaculture effluents, as well as in the reduction of potentially pathogenic bacteria in tilapia culture.

Analysis of Total Suspended Solid Algorithm on Tuban Coast with 2 Channel Approach of Visible Light Wavelength Satellite Image

Satellite image channels have been widely used by researchers from various countries to map and analyze variables that have a lot of influence on ecosystem changes including the total suspended solid levels scattered on the coast. The use of 1 channel in satellite images provides many results with various good correlations, but in this study, we want to try to use a 2-channel approach to get more optimal results from total suspended solid mapping. The area of interest for research is the Tuban coastline which has a fairly flat and not hilly coastal morphology so that sea currents that carry solids have characteristics in their growth over time. The method used to construct the algorithm of these 2 channels is the use of reflectance values of visible light wavelengths in blue, green and red channels. The results obtained from the calculation of the 2-channel algorithm show a fairly good suitability and correlation, especially in the comparison of the blue channel with the red channel with an R2 value of 0.76 so that it can be used as a reference to monitor total suspended solids as well as a comparison for the calculation of 1 channel. The conclusion obtained is that the channels from satellite images have their own characteristics in providing reflectance values for objects on earth so that with the right combination of channels will be able to obtain accurate results in mapping total suspended solids.

The benefits of restoring urban lakes in the tropics.

Lake restoration in developing economies, particularly in the tropics, is a major challenge given the severe levels of pollution from untreated wastewater and the warm climate conducive to microbial and algal growth. Restoration goals are often ill-defined or unachievable. Here we describe the successes that can be achieved through a control, compared with intervention case study of the two urban lakes in Bengaluru, India, one of the world's largest and fastest growing mega-cities. The unrestored control, Bellandur Lake, was severely polluted by 231 million litres per day (MLD) of untreated wastewater. The restoration site, Jakkur Lake, receives 10 MLD of treated wastewater and also receives some tertiary treatment by circulating the effluent through a constructed wetland before it enters the lake. The water quality of Bellandur Lake can only be described as extremely bad. Organic pollution levels in the main inflow were high (BOD5 of 199mg/l, faecal coliforms 6.9 Log MPN/100ml, total suspended solids (TSS) of 285mg/l) leading to the complete deoxygenation of lake even at the surface. The levels exceeded use-base standards for bathing water and fisheries. The high levels of organic pollution and low oxygen conditions also led to extreme levels of methane emissions that occasionally led to the lake surface catching fire. Total nitrogen (TN) and total phosphorus (TP) concentrations in the lake were extremely high (47mg/l and 6.3mg/l) respectively with low Secchi depth (SD). Despite the high nutrient levels, very little phytoplankton growth occurred (chlorophyll-a of 0mg/l), most likely due to the high TSS loads which restricted light availability. In comparison, the wastewater treatment and wetland at Jakkur Lake markedly reduced organic pollution of the main inflow (BOD5 of 32mg/l, faecal coliforms 4.1 Log MPN/100ml, TSS of 48mg/l). Levels of coliforms in the lake were above the standards for bathing waters. Total nitrogen (TN) and total phosphorus (TP) concentrations in the lake reduced (10.5mg/l, 2.4mg/l) but still classify the lake as extremely hypereutrophic. The lower TSS levels did, however, enable dense phytoplankton blooms to develop (max chlorophyll-a of 600 µg/l) which are in part responsible for the higher levels of dissolved oxygen in the lake water, albeit and as expected with large diurnal fluctuations. The comparison highlights the benefits that standard wastewater treatment provides to restore urban tropical lakes in context of rapidly urbanising catchments, and even though Jakkur Lake is by no means fully restored, it sustains water quality that allow propagation of fisheries and shore-based recreation. It also greatly contributes to greenhouse gas emission reductions. Further restoration measures are likely needed for urban tropical lakes, particularly to tackle pollutant loads in monsoon periods, but restoring community pride in the uses of a lake is an important milestone of the restoration efforts.

Brycon amazonicus larviculture cannibalism is reduced in biofloc systems

This study evaluated matrinxã Brycon amazonicus larviculture performance at different total suspended solid (TSS) concentrations in a biofloc technology (BFT) system, for 5 and 10 days. Larvae 24 h after hatching were used at a stocking density of 10 larvae L−1 for 10 days in four treatments: clear water (CW – control, 100% water renewal per day and no bioflocs), and three TSS concentrations in BFT systems: Low BFT (BFTL) - up to 200 mg L−1, Medium BFT (BFTM) - 200 to 350 mg L−1 and High BFT (BFTH) - 350 to 500 mg L−1. The matrinxã larvae were fed artemia nauplii until the 5th day and artemia nauplii plus mash feed containing 55% crude protein from the 6th to the 10 th day. Water quality, performance, morphology, and type II cannibalism (complete larvae ingestion) (n = 30) were evaluated after 5 and 10 days. Water quality, although altered, remained within the appropriate matrinxã limits in all treatments, with about a 90% water consumption decrease observed in the BFT systems. The BFT treatments resulted in larval survival increases of over 170% compared to the CW group, at 5 (p < 0.05) and 10 (p < 0.05) days of rearing, with CW = 31.4 and 17.9%; BFTL = 81.5 and 39.4%; BFTM = 88.9 and 59.9% and BFTH = 87 and 53.5% respectively. Larvae growth (p < 0.05) and morphological development (p < 0.05) at 5 days were lower in the BFTH treatment, due to the presence of more developed cannibalistic larvae compared to the other treatments, evidencing greater predation capacity. Cannibalism was observed after 5 and 10 days in all treatments, except for the BFTH group at 5 days and BFTM group at 10 days, proving the influence of high TSS levels and, consequently, turbidity, in reducing this behavior. The findings reported herein indicate matrinxã larviculture BFT system efficiency and suggest the use of TSS concentrations between 200 and 350 mg L−1 as an alternative to reduce cannibal behavior and increase matrinxã productivity, in addition to maintaining good quality and reducing water use.

Anthropogenic activities and COVID-19 effects on natural water bodies: Arroyo Seco’s case

Concerns about pollution in Arroyo Seco, an important natural water body in the Monterrey Metropolitan Area, have been reported due to possible wastewater discharges and solid waste mismanagement, turning the river into a potential public health hazard in the context of the COVID-19 pandemic. As a result, a volunteer clean-up campaign denominated “Arroyo Vivo” has been promoted by Distrito Tec and the Campana-Altamira initiative. To aid in the efforts, ammonium, nitrates, nitrites, and sulfate concentrations, total solids, and total organic matter were measured in parallel with SARS-CoV-2 detection and quantification in river water samples. Compared with applicable regulations (NOM-001-SEMARNAT-2021, NOM-127-SSA1-2021), total suspended solid levels (55-365 mg/L) were found above the maximum limit (84 mg/L), while ammonium (0.0175-0.198 mg/L), nitrite (0.0585-0.169 mg/L), nitrate (1.065-3.285 mg/L), sulfate (91.2-111 mg/L), and chemical oxygen demand (16.95-43.1 mg/L) were consistently below the maximum limits (0.50, 0.90, 11.00, 84.00, 400.00, and 100.00 mg/L, respectively), showing that no large-scale wastewater discharges had taken place in Arroyo Seco. However, SARS-CoV-2 genetic material was detected at three sampling sites, indicating some degree of sewage leakage and inadequate management of solid waste containing respiratory fluids of infected patients. While reports indicate that water bodies are not sources of SARS-CoV-2 infection in surrounding populations, it proves that waste disposal policies must be enforced more strictly to ensure water quality and environmental protection towards sustainable development. Nonetheless, continued efforts to screen concerning contaminants are still needed to fully assess the environmental status of the stream and propose relevant public policy.

Distance and weightage-based identification of most critical and vulnerable locations of surface water pollution in Kabul river tributaries

Water plays a key role in the economic growth of an agricultural country. Pakistan is a farming country that uses almost 90% of its water resources for agriculture. Khyber Pakhtunkhwa (KPK) province of Pakistan has extensive surface water resources. In addition to using groundwater resources for irrigation, large parts of its flat plains are irrigated with the Kabul River surface water. Due to large population growth and unregulated small/local scale industries in the region, surface water quality deteriorates with time, which affects people's health when polluted surface water is used for irrigation purposes. This research investigates the surface water quality of Kabul River's different tributaries. It identifies the most critical and vulnerable locations regarding water quality using the weightage-based identification method and distance-based iteration method, respectively. The Bara River exhibited the most critical location, surpassing the threshold values by a considerable margin in at least seven water quality parameters. The maximum seven critical values determined against the Bara River using the weightage-based method, i.e., 17.5, 5.95, 7.35, 27.65, 1.75, 0.35, and 10.45 for total alkalinity, sodium, total hardness, magnesium, total suspended solids, biological oxygen demand (BOD), and turbidity. The Khairabad station, where the Kabul River meets the Indus River, was identified as vulnerable due to elevated levels of total suspended solids, hardness, sulfate, sodium, and magnesium using distance-based methods. The locations, i.e. Adezai, Jindi, Pabbi, and Warsak Dam, appeared critical and vulnerable due to the prevalence of small-scale industries on their bank and high population densities. All the results are finally compared with the interpolated values over the entire region using Kriging interpolation to identify critical and vulnerable areas accurately. The results from the distance and weightage-based methods aligned with the physical reality on the ground further validate the results. The critical and vulnerable locations required immediate attention and preventive measures to address the deteriorating water quality parameters by installing monitoring stations and treatment plants to stop further contamination of the particular parameter.

Spatial and Temporal Dynamics of Key Water Quality Parameters in a Thermal Stratified Lake Ecosystem: The Case Study of Lake Mead

Lake Mead located in the Arizona–Nevada region of the Mohave Dessert is a unique and complex water system whose flow follows that of a warm monomictic lake. Although monomictic lakes experience thermal stratification for almost the entire year with a period of complete mixing, the lake on occasion deviates from this phenomenon, undergoing incomplete turnovers categorized with light stratifications every other year. The prolonged drought and growing anthropogenic activities have the potential to considerably impact the quality of the lake. Lake Mead and by extension the Boulder Basin receive cooler flow from the Colorado River and flow with varying temperatures from the Las Vegas Wash (LVW), which impacts its stratification and complete turnovers. This study analyzes four key water quality parameters (WQPs), namely, total dissolved solids (TDS), total suspended solids (TSS), temperature, and dissolved oxygen (DO), using statistical and spatial analyses to understand their variations in light of the lake stratifications and turnovers to further maintain its overall quality and sustainability. The study also evaluates the impacts of hydrological variables including in and out flows, storage, evaporation, and water surface elevation on the WQPs. The results produced from the analysis show significant levels of TDS, TSS, and temperature from the LVW and Las Vegas Bay regions compared with the Boulder Basin. LVW is the main channel for conveying effluents from several wastewater treatment facilities into the lake. We observed an increase in the levels of TDS, TSS, and temperature water quality in the epilimnion compared with the other layers of the lake. The metalimnion and the hypolimnion layer, however, showed reduced DO due to depletion by algal blooms. We observed statistically significant differences in the WQPs throughout various months, but not in the case for season and year, an indication of relatively consistent variability throughout each season and year. We also observed a no clear trend of influence of outflows and inflows on TDS, temperature, and DO. TSS concentrations in the lake, however, remained constant, irrespective of the inflows and outflows, possibly due to the settling of the sediments and the reservoir capacity.

Effectiveness of Green Mussel Shells as a Natural Coagulant for Domestic Wastewater Treatment

Coagulation is one of the wastewater treatment processes. Aluminum sulfate is usually used as a chemical coagulant. On the other way, the use of alum can cause a new problem that was the inorganic residues produced are carcinogenic and can harm the environment and human health. Then people try to use natural materials such as chitosan as the coagulant. Chitosan can be produced from the skin of marine animals such as green mussels. This study aimed to determine the effectiveness of natural coagulant green mussel shells. The research method was an experimental study by testing the effectiveness of green mussel shells as a natural coagulant with one group post design. This research used small dose of chitosan that is 0,15 g/l until 0,4 g/l to know which one is the most effective to reduce turbidity and suspended solid. The sample in this study was domestic wastewater. The parameters were total suspended solids (TSS) and turbidity. The data were analyzed by the ANOVA test. The result showed that both TSS and turbidity were decreased by about 100% (14 mg/l to 0,65 mg/l) for optimum decreasing of TSS parameter and 73% (2.38 NTU to 0 NTU) for turbidity parameters. The optimal dose of natural coagulant green mussel shells for domestic wastewater was 0,4 g/l. The ANOVA test showed that there was an effect of green mussel shells coagulant dose on TSS and turbidity level (p-value = 0,000). The potential of using these green mussel shells as a coagulant is indeed very high. However, it takes a combination with other natural ingredients to make an effective and safe coagulant.&#x0D;

Integrated multitrophic culture of shrimp Litopenaeus vannamei and tilapia Oreochromis niloticus in biofloc system: A pilot scale study

Shrimp production in biofloc systems generates excess organic matter that must be removed from the system. Due to its ability to consume natural productivity, the integration of tilapia in shrimp culture could help to reduce the levels of total suspended solids in the biofloc system. The present study aimed to evaluate two stocking densities of tilapia in an integrated culture with shrimp Litopenaeus vannamei reared in a pilot-scale biofloc system. Two stocking densities of tilapia were tested, 35 and 65 fish m-3 in a recirculating system with 10 m3 tanks for shrimp culture and 4 m3 for tilapia culture with water recirculation of 965.66 ± 92.83 L h-1 during 78 days. The initial weight of shrimp was 0.9±0.1 g and of tilapia was 7.1±3.2 g. Shrimps were fed according to the feeding table and fish were underfed to stimulate bioflocs consumption. Selected water quality parameters were monitored during the trial. Tilapia densities did not affect shrimp growth (11.5±1.9 g and 10.1±0.7 g for 35 and 65 fish m-3 treatments, respectively). The tilapia presented a FCR lower than 1, proving that bioflocs were consumed by fish. The clarification time was shorter when compared to other studies with shrimp monoculture. Between the treatments, a reduction of 10 hours in the system clarification occurred when lower fish stocking density was used. The results demonstrate the feasibility of integrated shrimp and tilapia culture on a pilot scale, without compromising shrimp productivity.

Extensibility of a Machine Learning Model for Stormwater Basin Design and Retrofit Optimization Through a User-Friendly Web Application

To sequester particulate matter (PM) and chemical loads, stormwater basins are a common infrastructure component of transportation land use systems in a planning/design or a retrofit phase. Basin design relies on residence time (RT), capacity–inflow ratio (CIR), and continuous stirred-tank reactor (CSTR) concepts to provide presumptive guidance for load reduction. For example, 14-day (or 21-day) RT is presumed to provide load reduction for total suspended solids (TSS) (e.g., commonly 80%), and for total phosphorus (TP) (e.g., commonly 60%). Despite such guidance, most existing basins are impaired—not meeting presumptive guidance, whether for TSS, nutrients, or chemicals (e.g., metals). RT guidance results in high initial basin design costs (land and construction). For impaired basin retrofit, RT guidance generates a significantly higher cost (area/volume increase), if such a retrofit is even feasible considering proximate infrastructure constraints. This study presents a computational fluid dynamics (CFD)-machine learning (ML) augmented web application, DeepXtorm, for cost–benefit optimization of basin design and retrofit. DeepXtorm is examined against basin costs from as-built data, RT, CIR, and CSTR (deployed in the Storm Water Management Model [SWMM]) over a range of load reduction levels of TSS (60%–90%) and TP (40%–60%). For a given load reduction requirement, DeepXtorm demonstrates up to an order of magnitude (or more) lower basin cost compared with RT, CIR, and CSTR models, and greater than an order of magnitude compared with as-built cost data. DeepXtorm represents a more robust and cost-effective tool for stormwater basin design and retrofit.