Total Suspended Solids Concentrations Research Articles

Clarity tubes as effective citizen science tools for monitoring wastewater treatment works and rivers.

Improved freshwater resource management requires the implementation of widespread, effective, and timely water quality monitoring. Conventional monitoring methods are often inhibited by financial, infrastructural, and human capacity limitations, especially in developing regions. This study aimed to validate the citizen-scientist-operated transparency or clarity tube (hereafter "clarity tube") for measuring water clarity as a proxy for total suspended solids (TSS) concentration, a critical quality metric in river systems and wastewater treatment works (WWTW) effluent in Southern Africa. Clarity tubes provided a relatively accurate and precise proxy for TSS in riverine lotic systems and WWTW effluent, revealing significant inverse log-linear relationships between clarity and TSS with r2 = 0.715 and 0.503, respectively. We demonstrate that clarity-derived estimates of TSS concentration (TSScde) can be used to estimate WWTW compliance with WWTW effluent TSS concentration regulations. The measurements can then be used to engage with WWTW management, potentially affecting WWTW performance. Overall, these findings demonstrate the usefulness of clarity tubes as low-cost, accessible, and easy-to-use citizen science tools for high spatial and temporal resolution water quality monitoring, not only in rivers in Southern Africa but also in WWTW effluent for estimating compliance, with strong global relevance to the sustainable development goals (SDGs). Integr Environ Assess Manag 2024;00:1-10. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Particulate and water-mobilizable phosphorus from a watershed with a plain river network contributes equal amounts of algal available phosphorus to its downstream lake

This research was designed to estimate the contributions of phosphorus (P) in different factions from an upstream plain river network to algal growth in a downstream shallow eutrophic lake, Taihu Lake, in China. During three flow regimes, the P fractions in multiple phases (particulate, colloidal and dissolved phases) and their algal availabilities were assessed via bioassays with Dolichospermum flos-aquae as the test organism. The P partitioning patterns among multiple phases were strongly affected by the concentration of total suspended solids (TSS) that changed with the river flow regime, with stronger disturbance of sediments at lower water levels (low flow) and weaker disturbance of sediments at higher water levels (high flow) in the plain river network. The median TSS concentration across the river network decreased from 157.4 mg/L during low flow to 31.8 mg/L during high flow, and the median particulate P concentration decreased from 0.132 mg/L to 0.093 mg/L. The particulate P contributed equally to the amount of algal available P (AAP) as did the water-mobilizable P (colloidal plus dissolved phase) in the rivers flowing into Taihu Lake. The annual average concentrations of particulate algal available P (P-AAP), colloidal algal available P (C-AAP) and dissolved algal available P (D-AAP) were estimated to be 0.032 mg/L, 0.012 mg/L and 0.019 mg/L, respectively, during 2012–2018, accounting for 50.8 %, 19.0 % and 30.2 %, respectively, of the total AAP. At the watershed scale, controlling P drainage from downstream urbanized areas should be emphasized. Additionally, controlling sediment resuspension or reducing the TSS concentration in the inflowing rivers is important for decreasing the particulate P flux to downstream lakes.

Pollution by total suspended solids and its relationship with the liquid-solid flow of the lower basin of Usumacinta River in Tabasco, Mexico

Rivers are natural environments that collect water from basins and transport it in laminar flow to the sea. Gradual changes occur due to the erosion of the walls and the bottom of rivers and the deposition of solids that the current carries. In the Usumacinta River basin, there is a sinusoidal correlation between liquid and solid flow. The term solid flow refers to the amount of sediment in motion, gaining its name from the product between liquid flow and the concentration of suspended solids. 21 simple samples of surface water were taken from June to December 2017, in the municipalities of Tenosique, Emiliano Zapata and Jonuta, in the state of Tabasco, Mexico. The concentrations of total suspended solids exceed the maximum permissible limits of the NOM-001-SEMARNAT-1996 (Mexico), for urban public use. Moreover, according to CE-CCA-001/89 (Ecological Water Quality Criteria in Mexico), the surface water of the lower basin of the Usumacinta River is classified as polluted.

Performances of constructed wetland system to treat whey and dairy wastewater during a macrophytes life cycle

Constructed wetlands system (CWs) have been proposed as an economical, efficient and sustainable wastewater treatment technology. The aim of this paper was to provide the first published data on the efficiency of CWs for dairy wastewater treatment in Tunisia. In most CWs, good organic, total suspended solids (TSS) and nutrient removal was measured.In order to evaluate the efficiency of this process, hybrid small-scale wetland system was designed containing three horizontal subsurface flow (HSSF) and one free water surface flow (FWS). A mixture of Reeds (Phragmites australis), Cattails (typha latifolia), and Papyrus (Cyperus papyrus) was planted.Several water quality parameters in both raw and treated wastewaters were monitored during the macrophytes life cycle. The average influent properties for 20% of whey are: TSS (3040mg/L), COD (5060mg O2/L), BOD5 (3020mg O2/L), TKN (79mgN/L) and TP (32,2mgP/L). Removal efficiencies of 99.6% for TSS, 80% for COD, 97% for BOD5, 90.4% for TKN and 99.6% for TP were observed. The results reveal temporal variations in system performance according to macrophyte growth rates. Reeds, Cattails and Papyrus start their life cycle at the beginning of the winter and continue growing in summer. The effluent pH, TSS, COD,BOD5, TKN and TP concentrations were in compliance with both irrigation reuse and discharge regulations.

The Conventional Oil-Water Separator as A Polluter Due to Lack of Maintenance – A Case Study

In addition to the common knowledge that lack of maintenance of conventional oil-water separators causes release of excessive amounts of oil in the effluent wastewater, this study has revealed that excessive amounts of other pollutants are released alongside the oil. The disappearance of fishes from a stream in the Niger Delta after the continual discharge of the wastewater of a company prompted this study. The company has a conventional oil-water separator but no maintenance was done on it, five months after commissioning. Research methods include sampling of the effluent wastewater for a period of two weeks (ten working days) and analysis of the wastewater for pH, oil & grease content, total suspended solids, total dissolved solids, sulfate and chloride contents. Results showed that the concentration of total dissolved solids was consistently less than the regulatory limit but much higher than the concentration obtained at the commissioning of the separator. Results showed that the oil & grease content, chloride, sulfate and total suspended solids concentrations were consistently higher than the regulatory limits and also much higher than the concentrations obtained at the commissioning of the separator. Results showed that the pH values of the effluent wastewater were consistently outside the optimum range for survival of aquatic life. Monthly maintenance of the separator and further treatment of its effluent wastewater were recommended for protection of the environment and public health.

The use of Carica papaya seeds as bio coagulant for laundry wastewater treatment

The study aims to analyze the effectiveness of wastewater treatment by using Carica papaya seeds as bio coagulants to diminish total suspended solids (TSS) and excess phosphate. This method has some advantages because it does not use chemical materials, is simple to apply, and is safe for the environment and human health. The wastewater samples were taken from an active laundry site in Palembang City, South Sumatra Province of Indonesia. The study found that the best dosage of coagulant was 3 g for the wastewater samples. The pH and BOD parameters showed slight changes after treatment, with pH 7.63–7.19 and 33–27 mg/L values, respectively. The TSS removal efficiency ranged from 9.3 to 15.6%, while the COD and phosphate removals were obtained from 11.7 to 39.3% and 56.3 to 68.4%, respectively. The treated TSS, COD, and phosphate concentrations have met the Indonesian domestic wastewater quality standard and environmental protection organization (EPO) guidelines. In addition, the statistical analysis and t-test showed significant differences (p < 0.05) for before and after treatment data of all parameters. The ANOVA test showed significant differences (p < 0.05) for all parameters among the three treatments. Overall, the study indicated that C. papaya seeds are promising materials that are eco-friendly and useful to treat laundry wastewater.

Monitoring the impacts of rainfall characteristics on sediment loss from road construction sites.

Exposed soils associated with active construction sites provide opportunities for erosion and sediment transport during storm events, introducing risks associated with excess sediment to downstream infrastructure and aquatic biota. A better understanding of the drivers of sediment transport in construction site runoff is needed to improve the design and performance of erosion and sediment control measures (ESCMs). Eleven monitoring locations on 3 active road construction sites in central Ohio were established to characterize runoff quality from points of concentrated flow during storm events. Grab samples were analyzed for total suspended solids (TSS), turbidity, and particle size distribution (PSD). Median TSS concentrations and turbidity levels across all samples were 626 mg/L (range 25-28,600 mg/L) and 759 NTU (range 22-33,000 NTU), respectively. The median PSD corresponded to a silty clay loam, mirroring the soil texture of much of Ohio's subsoils. TSS concentrations and turbidity were significantly positively correlated with the rainfall intensity 10 min prior to sample collection, suggesting that higher flow rates created greater shear stress on bare soil which resulted in more erosion. Conversely, rainfall duration was negatively correlated with particle size, indicating that prolonged moisture from rainfall promoted the dispersion of soil aggregates which mobilized smaller particles. Multivariable linear regression models revealed that higher rainfall intensities corresponded to higher turbidity values, while higher TSS concentrations were associated with higher rainfall intensities, depths, and durations. Results from this study highlight the importance of reducing raindrop impact and subsequent shear stress applied by concentrated flows through the use of ESCMs to limit sediment export from construction sites.

Evaluation of a self-cleaning larval rearing tank to improve production of two marine finfish species

The goal of this study was to test a commercial scale larval rearing tank with a self-cleaning mechanism to improve larval rearing success for marine fish. Four trials were conducted to compare the performance of a self-cleaning tank (SCT) to a control (CON) larval rearing tank. Two trials were conducted using California yellowtail (CYT; Seriola dorsalis) and two were conducted using white seabass (WSB; Atractoscion nobilis). Metrics collected for each trial included, larval growth, survival, bacterial colony counts (Vibrio spp.), total suspended solids concentrations, and labor (time spent siphoning the tanks). There were no differences in growth between tanks for either species. CYT survival in Trial 1 resulted in better survival in the CON tank (56.8%) than in the SCT (32.8%). WSB survival in both Trial 1 and 2 was higher in the SCT than in the CON tank (35.5% versus 26.9% and 15.8% versus 10.1%, respectively). We suspected that the cleaning arm was likely causing early mortality in both species (between 0 and 16 days post hatch; dph), therefore, Trial 2 involved only cycling the arm twice per day for one hour until the larvae were 16 dph. This modification yielded improved survival in the SCT (60.5%) than CON tank (47.1) but only for the CYT. Total suspended solids were higher in the CON tank for both species (up to 8.0 mg/L). Bacteriology results showed higher CFU counts for CYT in the CON tanks from 8 to 24 dph, and at 24 dph counts were higher in SCT. CFU counts were higher for WSB in the CON tank at 9 and 13 dph but otherwise there were no differences over time. Perhaps most notable was that the SCT tanks yielded a fourfold reduction in labor when compared to CON tanks due to more efficient siphoning.

Performance of wood waste biochar and food waste compost in a pilot-scale sustainable drainage system for stormwater treatment

Sustainable drainage system (SuDS) for stormwater reclamation has the potential to alleviate the water scarcity and environmental pollution issues. Laboratory studies have demonstrated that the capacity of SuDS to treat stormwater can be improved by integrating biochar and compost in the filter media, whereas their performance in scaled-up applications is less reported. This study examines the effectiveness of a pilot-scale SuDS, bioswale followed by bioretention, amended with wood waste biochar (1, 2, and 4 wt.%) and food waste compost (2 and 4 wt.%) to simultaneously remove multiple pollutants including nutrients, heavy metals, and trace organics from the simulated stormwater. Our results confirmed that SuDS modified with both biochar (2 wt.%) and compost (2 wt.%) displayed superior water quality improvement. The system exhibited high removal efficiency (> 70%) for total phosphorus and major metal species including Ni, Pb, Cd, Cr, Cu, and Zn. Total suspended solids concentration was approaching the detection limit in the effluent, thereby confirming its capability to reduce turbidity and particle-associated pollutants from stormwater. Co-application of biochar and compost also moderately immobilized trace organic contaminants such as 2,4-dichlorophenoxyacetic acid, diuron, and atrazine at field-relevant concentrations. Moreover, the soil amendments amplified the activities of enzymes including β-D-cellobiosidase and urease, suggesting that the improved soil conditions and health of microbial communities could possibly increase phyto and bioremediation of contaminants accumulated in the filter media. Overall, our pilot-scale demonstration confirmed that the co-application of biochar and compost in SuDS can provide a variety of benefits for soil/plant health and water quality.

Bioactive carbohydrate from potato peels: A sweet inducer that mediate resistance against powdery mildew disease of cucumber through phytohormonal alterations

Large volumes of nutritive wastes are generated by food industries, which can be used in the production of bioactive compounds of commercial values. The waste generated by potato chips industries contains high quantities of insoluble starch, high concentrations of total suspended solids and chemical oxygen demand, or environmental issues. In this study, the starch extracted from the potato peels was subjected to bioconversion of isomaltose-oligosaccharide by enzymatic method and further eluted isomatlose by liquid chromatography-mass spectrometry. The structural elucidation of isomaltose was confirmed by 1H NMR and 13C NMR spectroscopy. The purified isomaltose displayed excellent in vitro antifungal action against Erysiphe cichoracearum and Fusarium oxysporum at concentrations 1.0 and 2.5 mg/ml, respectively. Notably, cucumber-seeds primed with isomaltose (2.5 and 5.0 mg/mL) concentrations recorded a significant improvement of germination (91.5 and 89 %) and vigor (2210.93 and 2015.7) over the untreated control. Subsequently, the isomaltose-primed cucumber plants challenged with powdery mildew pathogen showed enhanced protection of 63% in comparison with pathogen alone-induced plants. This enhanced growth parameters and induced resistance in cucumber may be fairly contributed by the upregulation of phytohormone levels in primed plants observed in this study. Taken together, this study is unique in the use of bioactive isomaltose from potato peels, which could enable us to minimize the agro-industrial wastes and most importantly could help to develop new formulations for sustainable crop protection strategies.

Landsat observations of total suspended solids concentrations in the Pearl River Estuary, China, over the past 36 years

Information on long-term trends in total suspended solids (TSS) is critical for assessing aquatic ecosystems. However, the long-term patterns of TSS concentration (CTSS) and its latent drivers have not been well investigated. In this study, we developed and validated three semi-analysis algorithms for deriving CTSS using Landsat images. Subsequently, the long-term trends in CTSS in the Pearl River Estuary (PRE) from 1987 to 2022 and the driving factors were clarified. The developed algorithms yielded excellent performance in estimating CTSS, with mean absolute percentage errors <25% and root mean square errors of <13 mg/L. Long-term Landsat observations showed an overall decreasing trend and significant spatiotemporal dynamics of the CTSS in the PRE from 1987 to 2022. The analysis of driving factors suggested that industrial sewage, cropland, forests and grasslands, and built-up land were the four potential driving forces that explained 87.81% of the long-term variation in CTSS. This study not only provides 36-year recorded datasets of CTSS in estuary water, but also offers new insights into the complex mechanisms that regulate CTSS spatiotemporal dynamics for water resource management.

Application of biofloc technology in the larval rearing of zebrafish (Danio rerio)

The aim of this study was to investigate the different strategies of biofloc addition to zebrafish (Danio rerio) larviculture, and evaluate their growth and biochemical parameters. Three treatments were used: addition of 200 mL biofloc once at the start of the assay (O1), addition of 100 mL biofloc every seven days (1W), and addition of 100 mL biofloc every four days (2W). The 1W and 2W treatments also received 200 mL biofloc at the start of the assay. Regarding water quality, the only difference was the total suspended solid concentration, because the 2W treatment had a higher concentration in the final assay (127.6 ± 24.3 mg L-1). The final weight, survival rate, and juvenile percentile did not show statistical differences among the treatments. However, the O1 treatment exhibited a higher total length (11.93 ± 0.45 mm) than those in the 2W treatment. The juveniles in the 2W treatment exhibited lower nonprotein thiols and higher TBARS concentrations than those in the other treatments. Thus, the biofloc system can be a viable alternative to zebrafish larviculture without the use of conventional live food, and the addition of biofloc once (O1) at the beginning of larval rearing achieves good growth and survival results.

Comparison of Total Suspended Solids (TSS) in the estuary of the Bengawan Solo Gresik River using satellite image data

Comparison of Total Suspended Solids (TSS) in Muara Bengawan Solo Gresik River Using Satellite Image Data. The estuary of the Bengawan Solo River, which is in Ujung Pangkah District, has undergone many changes every year. This is influenced by several factors, one of which is the process of settling (sedimentation) from the transport of material carried by river water along the watershed (DAS). Based on this background, efforts are needed to monitor the distribution of Total Suspended Solid (TSS) in the Bengawan Solo Gresik river estuary. The aim of this study is to determine the distribution of Total Suspended Solid (TSS) over 5 years to find the right formula to model the impact of this change, which can be addressed in the future. The method developed below is remote sensing technology with Landsat 8 satellite image data extracting digital number values that are converted into reflectance values to then find the optimal mathematical model algorithm with parameters from Total Suspended Solid (TSS). From the research that has been done, the following results are obtained: the red band reflectance has the best relationship value with TSS In Situ with an R square value of 0.0450. and the appropriate algorithm model for estimating TSS concentrations is the Linear model with the equation Y = 1311.3x + 447.93.

Coupling numerical models of deltaic wetlands with AirSWOT, UAVSAR, and AVIRIS-NG remote sensing data

Abstract. Coastal marsh survival relies on the ability to increase elevation and offset sea level rise. It is therefore important to realistically model sediment fluxes between marshes, tidal channels, and bays as sediment availability controls accretion. Traditionally, numerical models have been calibrated and validated using in situ measurements at a few locations within the domain of interest. These datasets typically provide temporal information but lack spatial variability. This paper explores the potential of coupling numerical models with high-resolution remote sensing imagery. Products from three sensors from the NASA Delta-X airborne mission are used. Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) provides vertical water level change on the marshland and was used to adjust the bathymetry and calibrate water fluxes over the marsh. AirSWOT yields water surface elevation within bays, lakes, and channels, and was used to calibrate the Chezy bottom friction coefficient. Finally, imagery from AVIRIS-NG provides maps of total suspended solids (TSS) concentration that were used to calibrate sediment parameters of settling velocity and critical shear stress for erosion. Three numerical models were developed at different locations along coastal Louisiana using Delft3D. The coupling enabled a spatial evaluation of model performance that was not possible using simple point measurements. Overall, the study shows that calibration of numerical models and their general performance will greatly benefit from remote sensing.

Effects of Aquatic Plant Coverage on Diversity and Resource Use Efficiency of Phytoplankton in Urban Wetlands: A Case Study in Jinan, China.

With the acceleration of urbanization, biodiversity and ecosystem functions of urban wetlands are facing serious challenges. The loss of aquatic plants in urban wetlands is becoming more frequent and intense due to human activities; nevertheless, the effects of aquatic plants on wetland ecosystems have received less attention. Therefore, we conducted field investigations across 10 urban wetlands in Jinan, Shandong Province, as a case in North China to examine the relationships between aquatic plant coverage and phytoplankton diversity, as well as resource use efficiency (RUE) in urban wetlands. Multivariate regression and partial least squares structural equation modeling (PLS-SEM) were used to analyze the water quality, phytoplankton diversity, and RUE. The results demonstrate that the increase in aquatic plant coverage significantly reduced the concentration of total nitrogen and suspended solids' concentrations and significantly increased the phytoplankton diversity (e.g., species richness and functional diversity). The aquatic plant coverage significantly affected the composition of phytoplankton functional groups; for example, functional groups that had adapted to still-water and low-light conditions became dominant. Furthermore, the increase in phytoplankton diversity improved phytoplankton RUE, highlighting the importance of aquatic plants in maintaining wetland ecosystem functions. This study may provide a scientific basis for the management strategy of aquatic plants in urban wetlands, emphasizing the key role of appropriate aquatic plant cover in maintaining the ecological stability and ecosystem service functions of wetlands.

The Effect of Vegetation Density on The Total Suspended Solid (TSS) Concentration in The Aquatic Area of Pomalaa District

Analysis of the influence of vegetation density levels on the concentration of Total Suspended Solids (TSS) in aquatic areas is crucial in the Pomalaa District, an area characterized by extensive mining activities. This research aims to examine changes in vegetation density conditions and analyze the influence of vegetation density levels on TSS concentrations in the aquatic region. Changes in vegetation density conditions are analyzed through multi-temporal remote sensing image processing using the NDVI method. The TSS concentration is analyzed using the gravimetric method. Meanwhile, the influence of vegetation density level on TSS concentration is analyzed using the Pearson correlation coefficient equation. The results of the research show that there has been an increase in the area with very low levels of vegetation density and a decrease in the area with high levels of vegetation density in the period 2014 to 2023. The calculated results of TSS concentrations at the research location are 78 mg/l to 111 mg/l. The correlation analysis shows that the broader the area with very low vegetation density, the higher the TSS concentration in the aquatic environment. Additionally, the larger the area with high vegetation density, the lower the TSS concentration value of the water at the research locations.

Machine learning-based prediction of effluent total suspended solids in a wastewater treatment plant using different feature selection approaches: A comparative study

Accurately predicting the characteristics of effluent, discharged from wastewater treatment plants (WWTPs) is crucial for reducing sampling requirements, labor, costs, and environmental pollution. Machine learning (ML) techniques can be effective in achieving this goal. To optimize ML-based models, various feature selection (FS) methods are employed. This study aims to investigate the impact of six FS methods (categorized as Wrapper, Filter, and Embedded methods) on the accuracy of three supervised ML algorithms in predicting total suspended solids (TSS) concentration in the effluent of a municipal wastewater treatment plant. Based on the features proposed by each FS method, five distinct scenarios were defined. Within each scenario, three ML algorithms, namely artificial neural network-multi layer perceptron (ANN-MLP), K-nearest neighbors (KNN), and adaptive boosting (AdaBoost) were applied. The features utilized for predicting TSS concentration in the WWTP effluent included BOD5, COD, TSS, TN, NH3 in the influent, and BOD5, COD, residual Cl2, NO3, TN, NH4 in the effluent. To construct the models, the dataset was randomly divided into training and testing subsets, and K-fold cross-validation was employed to control overfitting and underfitting. The evaluation metrics that are used are root mean squared error (RMSE), mean absolute error (MAE), and correlation coefficient (R2). The most efficient scenario was identified as Scenario IV, with the Sequential Backward Selection FS method. The features selected by this method were CODe, BOD5e, BOD5i, TNi. Furthermore, the ANN-MLP algorithm demonstrated the best performance, achieving the highest R2 value. This algorithm exhibited acceptable performance in both the training and testing subsets (R2 = 0.78 and R2 = 0.8, respectively).

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.

Modelling of ocean currents and distribution of total suspended solids in Citarum River estuary

The Citarum River is an important river in West Java, which empties into the Java Sea carrying large suspended sediment concentrations. The purpose of this study is to examine the interaction of current patterns and distribution of total suspended solids (TSS) in the Northwest and Southeast Monsoons using hydrodynamic Modelling. The flow model and TSS used were 2-dimensional models with the OpenFlows FLOOD software. The ocean tide model results were validated using the Root Mean Square Error (RMSE) method with a value of 0.10. The current velocity in the West and East monsoons ranges from 0.07 - 0.35 m/s. Currents flow north and northeast during high-tide conditions and move south and southwest during low-tide conditions in both seasons. The movement of TSS was influenced by the current patterns. The highest concentration of TSS is in the Northwest Monsoon at low tide, which was in the range of 560–575 mg/L. The lowest TSS concentration was in the Southeast Monsoon during high tide conditions, ranging from 80 to 120 mg/L. The high concentration of TSS in the Northwest Monsoon was influenced by higher rainfall, with an average in January and only 23.2 mm/day while in the Southeast Monsoon it is only 7.8 mm/day.

Influence of effluent particles and particle-bound micropollutants on the removal of micropollutants and UVA254 in wastewater effluent ozonation

This study systematically investigated the influence of effluent particles and activated sludge (AS) particles on the removal of micropollutants via wastewater effluent ozonation within typical effluent total suspended solids (TSS) concentrations. A series of batch experiments revealed that particle concentrations up to 30 mg/L had a minor impact on the removal of organic micropollutants (OMPs) in the aqueous phase. Moreover, the reduction of UV absorbance at 254 nm (UVA254) was negatively correlated to the level of particle concentration at ozone doses higher than 0.5 gO3/gDOC. It indicates that UVA254 abatement was more sensitive to the presence of particles compared to OMP removal. Organic micropollutants (OMPs) sorbed on effluent particles and sludge particles were extracted before and after ozonation. OMP sorption in effluent particles was 2–5 times higher than that in sludge particles. During the ozonation of raw secondary effluent, particle-bound micropollutants were removed comparably to the micropollutants in the aqueous phase. This suggests that the boundary layer surrounding the particle didn’t affect the removal of OMPs in the particle phase. Furthermore, the removal of existing OMPs (irbesartan, sulfamethoxazole, and metoprolol) in the effluent was used to assess the ozone and •OH exposure. In water samples with and without particles, the elimination of OMPs could be reliably predicted (R² > 0.95) by calculated ozone and •OH exposures.