Total Suspended Solids Concentrations Research Articles

Design, Development, and Performance Evaluation of Plastic-based Radial-flow Settling Unit for NFT Aquaponics

Highlights Inclusion of the designed radial flow settler to the aquaponic system helps to remove more than 80% TSS, which is on par with or better in comparison to the TSS removal efficiency of the existing models. Removing excess suspended solids in traditional aquaponic setups could help prevent biofilter choking and hence, water contamination further down the line. The developed radial flow is simple in design, cost-effective, and yet, efficient. Abstract. One cylindrical settler of capacity 200 L (Ø 0.6×0.7 m) with a center-bottom inlet has been designed and developed in High-Density Poly Ethylene (HDPE) under the All-India Co-ordinated Research Project on Plastic Engineering in Agriculture Structures & Environment Management (AICRP on PEASEM) center at ICAR-CIFA, Bhubaneswar for fitting to the developed Nutrient Film Technique (NFT) aquaponics system. The water flow into the settling unit comes from a single-drain fish culture tank with the outlet at the bottom-center with a downward slope of 1:22. The experiment was carried out for the evaluation of the efficiency of Total Suspended Solid (TSS) removal in the developed radial-flow settling unit. The performance is assessed in terms of capturing the suspended solids from the water of aquaculture operation with varying specific gravity (1=SG>2) as well as the skimming of the floating organic surfactants before entering into the biofilter. During the 90 days of study, a total of 60 water samples were collected from the outlet of the fish culture tank and the overflow of the settler, which were filtered through the standard 11 µm pore paper filter for further processing in the laboratory. The average TSS concentration removed was calculated to be 128.55 mg/L on dry weight basis and a mean efficiency of 80.06 ± 9.36% was observed in the experiment with a surface loading rate of 0.00103 m3/min-m2 of the radial flow settler. The right-angle submerged overflow of the settler helped in complete surfactant removal. Keywords: Aquaponics, NFT, Radial-flow, Specific gravity, Suspended solid.

Temporal detection of Total Suspended Solid (TSS) distribution in the southern area of Obi Island

The Halmahera Selatan Regency has many potential natural resources including mining potential, and nickel is one potential that can be found in Obi Island. The abundance of nickel in Obi Island also increases activities that cause various materials to enter the sea. The sediment materials entering the waters through land runoff are suspended sediment or Total Suspended Solids (TSS). Sentinel 2 satellite imageries could observed TSS concentration and its distribution in this research through visible and infrared channels. The distribution of TSS will be determined by using an algorithm, which uses the blue and green bands with corrected atmospheric reflectance format. Based on the data processing results, the distribution of TSS values in the southern area of Obi Island in 2023 was in the range of 4 - 874 mg/l that were divided into three groups of areas, represented by A area within the range of 4 – 874 mg/l, which describes the distribution of TSS in coastal areas without human settlements, B area within range of 4 - 237 mg/l which depicting TSS conditions at river estuaries, and group C area within range of 4 – 431 mg/l which illustrating TSS locations in coastal areas with human settlements.

A Comprehensive Assessment of the Quality of Supplied Drinking Water in Galyang Municipality of Syangja, Nepal

A thorough assessment on the municipally supplied water samples from Malunga and Galyang cities; two different places in the Syangja district focused on analyzing various water quality parameters. These parameters included pH value, alkalinity, electrical conductivity, turbidity/suspended solids, chloride contents, and the presence of acid and basic radicals (heavy metal ions).
 The results obtained from standard laboratory probes carried out on-site and at the chemistry laboratory of Amrit Campus, indicated that the pH value, alkalinity, electrical conductivity, chloride contents, and the presence of acid radicals (nitrate, sulfate, and chloride) and basic radicals (toxic heavy metal ions) in the water samples were all within the safe limits for potable water as suggested by both the National Drinking Water Quality Standards (NDWQS) of Nepal and the World Health Organization (WHO).
 However, it was disclosed that the total suspended solids in the water samples existed in higher concentrations, leading to coagulation and the formation of thin, flat, whitish lumps during long-term storage of the samples.
 Overall, while the study determined that the water samples concurred the safe limits for most parameters set by NDWQS and WHO, the higher concentration of total suspended solids during prolonged storage suggests a potential attention to be paid for the improvement of the quality.

Production of the Macroalgae Ulva lactuca Integrated with the Shrimp Penaeus vannamei in a Biofloc System: Effect of Total Suspended Solids and Nutrient Concentrations

This study focused on evaluating the effect of different concentrations of nutrients and total suspended solids on the removal rate of nutrients and biocompounds from the macroalgae U. lactuca in an integrated system with the shrimp Penaeus vannamei in biofloc. The experiment lasted 45 days and included five treatments with three replicates each, with percentages of 0 (control), 25, 50, 75, and 100% biofloc inoculum (73.3 ± 5.7 and 325.0 ± 21.2 mg L−1 initial nitrate and solids, respectively, in the 100% inoculum), from a shrimp farm, resulting in different concentrations of solids and nutrients. The macroalgae were introduced into 280 L tanks at a density of 0.88 kg m−2, along with 200 shrimp m−3. The algae were separated by a floating structure. Water quality parameters were measured, and the nutrient removal rate was evaluated. The treatment with 75% inoculum showed a removal rate of 55.0 ± 4.0 and 31.0 ± 10.0% of nitrate and phosphate, respectively. There was no difference in macroalgae growth between the treatments; however, macroalgae grown in 75% inoculum had higher protein, chlorophyll-a, and lower ash values compared with the control. The use of macroalgae in integrated production with shrimp under the conditions of the treatment with 75% biofloc inoculum proved to be viable and sustainable.

Roof runoff pollution control with operating time based on a field-scale assembled bioretention facility: Performance and microbial community dynamics

Bioretention facilities are essential, low-impact development measures to treat roof runoff pollution. To explore the effects of roof runoff pollution control and internal influencing mechanisms of field-scale bioretention facilities, a newly assembled bioretention facility (ABF) comprising volcanic rock and coconut coir was constructed. The results of the 21-month experiment showed that the peak concentrations of total suspended solids (TSS), ammonia nitrogen (NH4+–N), and chemical oxygen demand (COD) of roof runoff were 332.50 mg∙L−1, 3.46 mg∙L−1, and 122.33 mg∙L−1, respectively, indicating that the roof runoff was seriously polluted and needed urgent treatment. The removal rates of TSS, NH4+–N, and COD within the facility were 86.50 ± 7.31 %, 79.40 ± 19.28 %, and 51.84 ± 26.24 %, respectively. However, continuous and high-intensity rainfall decreased pollutant removal performance by weakening the adsorption effect of the media. Continuous pollutant input decreased the abundance of Arthrobacter and Hyphomicrobium within the media, and functional bacteria, such as KD4–96, Roseiflexaceae, Vicinamibacteraceae, and Gaiellales, played dominant roles in NH4+–N and COD removal to ensure the long-term stability of the facility. This study provides theoretical guidance and a practical basis for enhancing the application of ABF in mitigating roof runoff pollution.

Variation in urban snow quality indicated by three seasonal sampling surveys conducted in Luleå (Sweden) within a span of 27 years

Concentrations of total suspended solids (TSS), trace metals (Cu, Cd, Cr, Zn, Cd, Pb), Na and 16 US EPA priority PAHs in urban snow were studied in the City of Luleå in Northern Sweden. Snow was sampled at six central urban and suburban sites with various traffic intensities, in three sampling surveys (1994–95, 2002–03, 2020–21), repeated for three ages of the urban snow cover of 40, 80, and 120 days, respectively. The older data, from the 1994–95 and 2002–03 surveys, were obtained from the existing literature. The concentrations and mass loads of TSS and most trace metals studied (Zn, Cu, Pb, and Cd) varied with time. TSS, Zn, and Cu showed slightly higher concentrations and mass loads in the 2003 (TSS avg = 2300 μg/L, Zn avg = 620 μg/L and Cu avg = 250 μg/L) and 2021 (TSS avg = 1500 μg/L, Zn avg = 530 μg/L and Cu avg = 220 μg/L) sampling surveys, compared to the 1995 survey (TSS avg = 620 μg/L, Zn avg = 240 μg/L and Cu avg = 97 μg/L). However, no evident trend was observed between the 2003 and 2021 sampling surveys. The highest concentrations of Pb and Cd were observed in snow samples from the 1994–95 sampling survey (Pb max = 570 μg/L, Cd max = 4.6 μg/L). Results indicated higher concentrations of the pollutants studied in the city centre, compared to the residential suburbs, and in areas with heavier traffic, where concentrations of metals correlated well with traffic intensity. Fractionation analysis of trace metals indicated that Zn, Cu and Pb occurred mostly in the particulate-bound phase (>0.45 μm) containing the most of Zn, Cu, and Pb mass, at 80, 84 and 94% of the total, respectively. Over 50% of the dissolved phase of Zn and Cu was in the truly dissolved fraction (<3000 MWCO). Concentrations of PAHs also increased with traffic intensity, with pyrene being the most frequently detected PAH, likely because of the strength of sources and various physical processes influencing the snowbanks development and causing spatial and temporal variations in pollutant concentrations.

Effect of varying hydrologic regime on seasonal total maximum daily loads (TDML) in an agricultural watershed

Rising hypoxia due to the eutrophication of riverine ecosystems is primarily caused by the transport of nutrients. The majority of existing TMDL models cannot be efficienty applied to represent nutrient concentrations in riverine ecosystems having varying flow regimes due to seasonal differences. Accurate TMDL assessment requires nutrient loads and suspended matter estimation under varying flow regimes with minimal uncertainty. Though a large database can enhance accuracy, it can be resource intensive. This study presents the design of an innovative modeling strategy to optimize the use of existing datasets to effectively represent streamflow-load dynamics while minimizing uncertainty. The study developed an approach to assess TMDLs using six different flux models and kriging techniques (i) to enhance the accuracy of nutrient load estimation under different hydrologic regimes (flow stratifications) and (ii) to derive an optimal modeling strategy and sampling scheme for minimizing uncertainty. The flux models account for uncertainty in load prediction across varying flow strata, and the deployment of multiple load calculation procedures. Further, the proposed flux approach allows the determination of load exceedance under different TMDL scenarios aimed at minimizing uncertainty to achieve reliable load predictions. The study employed a 10-year dataset (2009–2018) consisting of daily flow data (m3/sec) and weekly data (mg/L) for nitrogen (N), phosphorus (P) and total suspended solids (TSS) concentrations in three distinct agricultural sites in+ the Minnesota River Watershed. The outcomes were analyzed geospatially in a Geographic Information System (GIS) environment using the kriging interpolation technique. The study recommends (i) triple stratification of flows to obtain accurate load estimates, and (ii) an optimal sampling scheme for nitrogen and phosphorous with 30.6 % and 49.8 % datapoints from high flow strata. The study outcomes are expected to contribute to the planning of economically and technically sound combinations of best management practices (BMPs) required for achieving total maximum daily loads (TMDL) in a watershed.

Characterizing and optimizing adsorption for olive mill wastewater processing in Loukkos, Morocco.

The present research consists of studying the characterization and treatment of the olive mill wastewater (OMWW) resulting from the olive industries of the region of Loukkos, Morocco. According to the national plan for green Morocco, the annual volumes of OMWW discharges increase with the expansion of the areas of olive plantations compared to agricultural activities. The study of the organic, mineral, and microbiological composition of the obtained OMWW showed that they are rich in microbiological (FMAT, Let M., and B.L.), mineral (total Kjeldhal nitrogen, orthophosphate, total phosphorus, sodium, potassium, calcium, copper, iron, zinc, manganese, and lead ions), and organic (COD, BOD5, and polyphenols) micropollutants with very high percentages that are higher than the standards in force. The treatment used in this study is the combined process of aerated lagooning/adsorption using powdered activated carbon after optimization of the experimental parameters (mass concentration of activated carbon (AC) and agitation rapidity (Ar)) by experiment design method. The obtained physicochemical parameters, such as pH, total suspended solids (TSS), chemical oxygen demand (COD), rate of discoloration, and polyphenol content of raw OMWW, were 4.87, 0.63, 80.3, 0.8, and 1.45 g/l, respectively. The results of these parameters for the treated OMWW were obtained in the order of 6.10, 0.22, 28, 0.28, and 0.44 g/l for pH, TSS, COD, discoloration rate, and polyphenol content, respectively. These results show that the proposed treatment significantly reduced acidity, TSS, COD, discoloration rate, and polyphenol contents, with a performance of about 25.26, 65, 65.13, 65, and 69.65%, respectively. This indicates that there is significant performance in the processing of exploited OMWW.

Study on Nutrients Concentration Trends in Tukad Badung River Toward Nutrient Recovery Potential

This study addresses the urgent concern of water quality degradation resulting from untreated domestic wastewater discharge, with a specific focus on nutrient trends within an aquatic ecosystem. The investigation centres on ammonium (NH4 +) as a significant contaminant sourced from residual foods, hygiene practices, and fertilizers, known for its association with eutrophication—characterized by excessive algae growth and oxygen depletion. The study aims to offer comprehensive insights by meticulously analysing water quality parameters across six distinct sampling points. Data collection encompassed total suspended solids (TSS), ammonia (NH4 +), nitrite (NO2 −), nitrate (NO3 −), total phosphate (PO4 −), and total nitrogen (TN). Notable variations were observed: TSS concentrations ranged from 9.00 mg/L to 20.00 mg/L, NH4 + concentrations spanned 0.00 mg/L to 1.96 mg/L, NO2- and NO3 − levels varied from 0.00 mg/L to 0.16 mg/L and 1.19 mg/L to 1.91 mg/L, respectively, PO4 3- content ranged from 0.01 mg/L to 0.65 mg/L, and TN concentrations fluctuated between 1.36 mg/L and 3.31 mg/L. These findings underscore the complexity of water quality dynamics and highlight the need for integrated management strategies to mitigate nutrient pollution’s impact on aquatic ecosystems.

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.

Deep learning-based total suspended solids concentration classification of stream water surface images captured by mobile phone.

The continuous monitoring of total suspended solids (TSS) in streams plays an important role in the management of hydrological processes, and TSS is also a decisive parameter in the control of pollution in streams. Determination of TSS involves both a costly and time-consuming process. For this reason, there is a need to determine TSS more quickly, easily reliably, and economically. In this study, it is aimed to classify TSS concentration by using stream water surface images recorded with a mobile phone. For this purpose, the sampling studies carried out in the Lower Değirmendere Stream Watershed (Trabzon, northeast of Turkey) between June 2020 and May 2021, and the images of the stream water surface were taken and recorded with a mobile phone simultaneously with the sampling studies. The stream water surface images and TSS concentration were divided into four classification group, namely clear, turbid, very turbid, and extremely turbid and processed with deep learning method. More than 5500 stream water surface images and TSS concentration data were divided into groups as 70% training and the rest of test. This study uses eight convolutional neural network (CNN) models, including a custom CNN model designed for image classification, along with pre-existing architectures such as VGG-16, VGG-19, Inception-V3, Xception, DenseNet-121, MobileNet, and NASNet-mobile. The results revealed that the most effective ensemble model formation strategy was stacking with an accuracy rate of 87%, followed by weighted averaging, averaging, and majority voting. As a result, with the image of the stream water surface via the mobile phone camera, it can be easily determined which class the current TSS concentration belongs to instantly.

Towards a generic solution to onsite wastewater treatment

Decentralized wastewater treatment, specifically onsite treatment, is fundamental to recent wastewater management paradigms. However, onsite solutions often produce inadequate effluent quality for reuse and are ineffective in removing organic micropollutants (OMPs). This study suggests a multistep onsite system for treating wastewater in varying conditions. The system comprises biological treatment in a recirculating vertical-flow bioreactor (RVFB) followed by ozonation and ultrafiltration. The system was constructed on a farm in the Israeli Negev desert and tested year-round for its effluent quality and removal of two model OMPs. Additionally, laboratory-scale experiments were conducted to understand the field data. The system has demonstrated stable performance over varying climate conditions and wastewater qualities during one year of operation. The RVFB reduced the total suspended solid (TSS) concentration by up to 96 %, the dissolved organic carbon by up to 88 %, and the biodegradable OMP, Ibuprofen, by approximately 82 %. Ozonation had limited impact on effluent quality, most likely due to low ozone concentrations, but interestingly efficiently reduced Carbamazepine, a recalcitrant OMP, by around 87 %. Additionally, the laboratory experiments using the farm's wastewater demonstrated the ozone's potential efficiency in improving effluent quality. The final membrane filtration treatment step fully removed the residual TSS and E. coli, achieving effluent quality that meets the standards for wastewater reuse. The membrane exhibited stable performance over one month without chemical cleaning, probably due to the pre-ozonation step. Overall, this study highlights the potential of the suggested system to effectively treat diverse wastewater types and produce high-quality effluent suitable for reuse.

Assessment of Long-Term Surface Water Quality in Mekong River Estuaries Using A Comprehensive Water Pollution Index

Surface water quality (SWQ) has been degraded in the Mekong River Basin under increasing pressures of population growth, economic development, and global climate change. This study employed the comprehensive water pollution index (CWPI) to assess the spatio-temporal variation of SWQ in the downstream Mekong River estuaries. Eight water quality parameters were measured between 2005 and 2021 at 21 sampling sites downstream of the Mekong River. These parameters included total suspended solids (TSS), biological oxygen demand (BOD5), chemical oxygen demand (COD), ammonia (N-NH4+), nitrate (N-NO3-), phosphate (P-PO43-), iron (Fe), and total coliform. Most of the monitoring locations in the estuaries of Ham Luong, Cua Dai, Ba Lai, and Co Chien exhibited slightly to moderately polluted conditions, as indicated by the CWPI values ranging from 0.67-2.91, 0.41-2.20, 0.27-3.02, and 0.37-2.95, respectively. TSS and Fe concentrations consistently exceeded the allowable limits, while the majority of values for N-NH4+, N-NO3-, P-PO43-, and coliform remained within acceptable thresholds. Additionally, parameters indicative of organic pollution, namely BOD5 and COD, displayed a noticeable upward trend between 2005 and 2021. SWQ exhibited significant spatial and temporal variations with TSS, organic matter, nutrients, and iron being the main areas of concern. These findings can provide guidance to policymakers involved in the assessment and enhancement of water quality in the presence of pollutant compounds that lead to a decline in water quality.

FROM ABUNDANCE TO ADVERSITY: UNDERSTANDING THE CHANGING DYNAMICS OF LAKE ALAU'S WATER QUALITY

Lake Alau, a critical water resource in the region, was subject to an extensive water quality assessment with the aim of assessing the impact of human activities on the physico-chemical parameters of Lake Alau, with a specific focus on water quality potentials of the Lake. The study spanned over a year, capturing variations in several physicochemical parameters using standard laboratory techniques. The data were computed and analysed using ANOVA. The findings reveal that the lake generally maintains water quality within permissible limits for aquatic ecosystems. The physical parameters of the lake, including Temperature, Total Solids (TS), Total Dissolved Solids (TDS), and Total Suspended Solids (TSS), were within the range of a productive lake, but higher concentrations of TDS (365.68g/L) and TSS (171.95g/L) might have altered the ecological balance of the lake. The chemical parameters, including pH, biochemical oxygen demand (BOD), Chemical Oxygen Demand (COD), Nitrite, Nitrate, and Phosphate, were within the permissible limit for a productive lake, supporting the biological parameters of the lake However, phosphate concentrations exceed 0.1mg/l which is the limit for drinking water. The observed variations underscore the lake's vulnerability to human activities and seasonal changes. Despite some concerns, Lake Alau remains suitable for aquatic life, with certain water quality management practices recommended to maintain its intergrity.

Concentration of suspended solids in superintensive culture of the Pacific white shrimpLitopenaeus vannameiwith biofloc technology (BFT): A review

AbstractMicrobial flocs (bioflocs) present in the water of intensive culture tanks are formed by a variety of microorganisms and other kinds of particulate organic matter, such as faeces and uneaten feed. During shrimp culture, biofloc concentrations increase. It has been reported that some level of control over biofloc levels, which can be quantified by the concentration of total suspended solids (TSS), is necessary for the adequate performance of the system. Some authors suggest that TSS concentrations below 600 mg L−1are more appropriate for the superintensive culture of the Pacific white shrimpLitopenaeus vannameiin biofloc technology (BFT). However, subsequent research results contradict some of the arguments supporting the suggested solids limits, for example, the impact of increased solids on gill obstruction and subsequent shrimp survival. Recent studies have also shown the relationship between the control of solids and other important aspects of the system not considered so far, such as the control of opportunistic bacteria. Therefore, this topic seems worthy of revisiting, and it will be helpful to find new guidance toward understanding the levels of bioflocs that should be kept inL. vannameiculture tanks. In this review, we addressed the reasons that led to the establishment and limitations of the current biofloc levels forL. vannameiculture. The effects of maintaining low and high levels of bioflocs on both shrimp performance and the culture system are also analysed. Finally, perspectives on the management of biofloc levels are discussed, highlighting the advantages and disadvantages of each proposed strategy.

Integration of Sentinel-2A Imagery and Laboratory Measurements for Estuarine Pb and TSS Concentration Monitoring in Suwung, Denpasar City, Indonesia

Research has been carried out on integrating the results of Sentinel-2A and laboratory image data measurements in the form of a mathematical model that can be used to estimate the concentration and spatial distribution of Pb and Total Suspended Solid (TSS) of the Suwung estuary, Denpasar city, Bali, Indonesia. Integration is carried out using the regression method and correlation of the pixel value measurement results of the Sentinel-2A and laboratory images. Pixel values in Sentinel-2A image data which represent TSS concentrations are obtained by applying the TSS algorithm and Pb pixel values through Sentinel-2A band matching. The number of samples tested was 30 which were taken and measured at predetermined coordinate points. There are differences in the results of concentration measurements, both Pb and TSS obtained from laboratory measurements with Sentinel-2A pixel values. The integration results obtained in the form of a mathematical model in this research are for Pb, it is p=33.757q – 1.1345 and for TSS it is y=1.0213x – 0.2921. The variables p and y are the results of laboratory measurements, while the variables q and x are the results of measuring the Sentinel-2A pixel values. The spatial distribution of Pb detected was mostly on the west side and a small part on the east and north. For TSS, most of it is upstream in the north, while a small part is in the south and east.

Impacts of acute and chronic suspended solids exposure on juvenile freshwater mussels

Construction activities may affect adjacent water systems by introducing increased levels of suspended solids into the water body and may subsequently affect the survival and growth of freshwater mussels. We tested three sediment types from sites in Missouri, including Spring River sediment (SRS), Osage River bank clay soil (ORC), and quarried limestone from Columbia (LMT). We prepared series of suspensions of each sediment with total suspended solids concentrations ranging from 0 to 5000 mg/L. Juveniles from three mussel species, Fatmucket (Lampsilis siliquoidea), Arkansas Brokenray (Lampsilis reeveiana), and Washboard (Megalonaias nervosa) were exposed to these suspensions in both acute (96-h) and chronic (28-d) tests. No clear impact on survival was observed from the acute or chronic exposures, but chronic test showed that juvenile mussels' growth was strongly affected. Interestingly, growth was enhanced at lower levels of SRS and ORC (≤500 mg/L, p < 0.05), and the juvenile mussels exposed to 500 mg/L SRS exhibited approximately 60 % more dry weight than those reared in the control. LMT did not enhance growth. Growth was slowed by high concentrations (>1000 mg/L) of all three sediments, implying that high suspended solids levels could reduce survival in the long term. Our findings may help to inform regulations and guidelines for construction activities to minimize adverse effects on juvenile mussels.

An Alternative Model to Estimate Total Suspended Solids Concentrations using Landsat 8 Imagery in Indonesia

A regular monitoring program of water quality is generally performed using a direct measurement method, which requires substantial efforts and resources. These issues can be minimised using several options, one of which is Landsat 8 (L8). This imagery has been broadly used to measure several water quality parameters, especially Total Suspended Solids (TSS) concentrations, even in Indonesia. This paper will compare several models from previous studies and a modified model generated using data from various sites. The comparison is based on their competencies to estimate TSS concentrations. The competencies are determined by the coefficient of correlation (r), correlation of determination (R2), and residual standard error (RSE) parameters as these three parameters are strongly correlated, generally applied, and provide distinctive determinations. The best model should have the highest r and R2 values, while the RSE value should be the lowest. The results imply that TSS model 4 generated in this study provides comparable results with TSS model 1, which has been generally used in Indonesia and provided favourable results. Thus, it can be an alternative model to estimate TSS concentrations in Indonesia.

An Alternative Model to Estimate Total Suspended Solids Concentrations using Landsat 8 Imagery in Indonesia

A regular monitoring program of water quality is generally performed using a direct measurement method, which requires substantial efforts and resources. These issues can be minimised using several options, one of which is Landsat 8 (L8). This imagery has been broadly used to measure several water quality parameters, especially Total Suspended Solids (TSS) concentrations, even in Indonesia. This paper will compare several models from previous studies and a modified model generated using data from various sites. The comparison is based on their competencies to estimate TSS concentrations. The competencies are determined by the coefficient of correlation (r), correlation of determination (R2), and residual standard error (RSE) parameters as these three parameters are strongly correlated, generally applied, and provide distinctive determinations. The best model should have the highest r and R2 values, while the RSE value should be the lowest. The results imply that TSS model 4 generated in this study provides comparable results with TSS model 1, which has been generally used in Indonesia and provided favourable results. Thus, it can be an alternative model to estimate TSS concentrations in Indonesia.