Suspended Solids Research Articles

Dominance of Particulate Mercury in Stream Transport and Rapid Watershed Recovery from Wildfires in Northern California, USA.

Frequency and intensity of wildfires are expected to increase due to climate change, especially in areas with a long summer drought. Forests are a major sink for the global pollutant mercury (Hg), and fluvial transport of Hg from recently burned watersheds has not been widely investigated. Here, we examined two years of fluvial transport of Hg and its speciation (total Hg, methyl-Hg, particulate, and dissolved forms) under storm events and baseflow in two recently burned watersheds with different burned proportions and one nonburned reference watershed in the Coastal Ranges of northern California. We examined postfire storm-event transport of Hg and its methylated form (methyl-Hg), addressed the importance of the "initial runoff pulse" to postfire Hg fluvial transport and its predominant association with suspended solids, and elucidated potential sources of Hg exports from the burned landscapes using geochemical indicators, which suggested that ash materials were likely the significant sources of particulates in the first high-flow season postfire but not subsequently. The maximum total suspended solid and total Hg levels in the "first pulse" at the severely burned watershed were 442 and 46 times higher, respectively, than those at the reference watershed. Stream suspended solid and Hg levels declined substantially in the burned watersheds after just a few months of rainfall likely due to the rapid regrowth of vegetation commonly observed in postfire landscapes, implying that the wildfire effects on immediate Hg inputs from the burned landscape are at most transient in nature.

Water Quality Assessment using Selected Macroinvertebrate Based Indices and Water Quality Index of Sungai Air Hitam Selangor

A study was conducted from July to December 2022 at Sungai Air Hitam, a small tributary of the Selangor River located within the Tanjung Karang Sub-basin in Malaysia (coordinates: 3° 24' 27" N, 101° 25' 54" E to 3° 28' 14" N, 101° 26' 59" E). This confluence is situated near three major downstream water treatment plants. The study assessed six water quality parameters—pH, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), ammonia (NH3), and suspended solids (SS)—to calculate the Water Quality Index (WQI). Macroinvertebrates were sampled simultaneously using the dipping net method to obtain biotic indices for further evaluation of water quality. The results indicated that the WQI classified Sungai Air Hitam as Class III, with scores ranging from 56.9 to 64.6, suggesting the river is suitable for water supply and fisheries. However, the Biological Monitoring Working Party (BMWP) index categorized the water quality as poor, with scores between 30 and 42. Similarly, the Average Score Per Taxon (ASPT) ranged from 3.25 to 5.25, indicating pollution or environmental impact, while the Family Biotic Index (FBI) further classified the river as having poor to very poor water quality, with scores between 6.57 and 8.11. Overall, the study suggests that Sungai Air Hitam has experienced some degree of ecological degradation. These findings emphasize the need for continuous monitoring and remediation efforts to preserve and restore water quality.

Short-term forecasting of dissolved oxygen based on spatial-temporal attention mechanism and kernel-based loss function

Dissolved Oxygen (DO) is a fundamental indicator of the health of aquatic ecosystems. This study introduces a novel spatial-temporal attention model combined with Kernel Mean Squared Error loss function (STA-KMSE) for forecasting short-term DO. An attention-based Convolutional Neural Network (A-CNN) is used to incorporate the influence of upstream stations in the spatial module, a factor often overlooked in prior studies. The temporal module captures the influence of both previous hours and days using attention-based Long Short-Term Memory (A-LSTM), offering a more comprehensive temporal context. Our approach addresses the issue of outlier sensitivity and non-linear error patterns by utilizing the KMSE loss function, which improves the model's robustness and more effectively captures intricate variations in DO levels compared to the standard Mean Squared Error (MSE) commonly used in water quality modelling. The model is trained on an extensive dataset consisting of various water quality parameters collected from twenty locations along the Ganga River, its tributary, and nallahs spanning from 1 April 2017 to 30 April 2021. In terms of RMSE, STA-MSE outperforms A-CNN by 62.669 % and A-LSTM by 7.419 %. Compared to STA-MSE, the STA-KMSE shows an average reduction in RMSE by 3.067 % for one-step, 3.197 % for two-step, and 3.428 % for three-step forecasting. Experiments indicate better performance for river locations than for nallahs. SHapley Additive exPlanation (SHAP) analysis highlights pH and temperature as crucial factors for estimating DO in rivers, while level, temperature, conductivity, total suspended solids, pH, chlorine, and chemical oxygen demand are significant for nallahs.

Treatment of digested blackwater using a submerged microfiltration membrane system or a drum filter

After energy recovery from blackwater via anaerobic digestion, technologies such as struvite precipitation and ammonia stripping can be used to enhance nutrient recovery. However, the presence of suspended solids, organics and metals, can negatively impact the nutrient recovery processes. This study examined the treatment of digested blackwater, applying either a ceramic microfiltration membrane or a drum filter, operating in parallel in a source-separated wastewater plant. The digestate as well as the permeates from the membrane and drum filter were sampled regularly and evaluated. In general, the ceramic membrane proved to be more efficient in improving the quality of digested blackwater in comparison to the drum filter. The ceramic membrane reduced total suspended solids to below the detection limit, while the drum filter achieved 74 % removal. The membrane removed 74 %, 85 % and 76 % of TOC, BOD7 and COD-Cr, respectively, higher than the corresponding treatment with the drum filter, which removed 41 %, 42 % and 34 %, respectively. No significant differences in phosphate and ammonium concentrations (P-value = 0.05), before and after both treatment methods were observed. The membrane removed particulate-bound metals (As, Cd, Cr, Cu, Ni, Pb and Zn) up to 25 %, 95 %, 87 %, 95 %, 66 %, 90 % and 98 %, respectively. The drum filter achieved lower removal for particulate-bound As, Cd, Ni, Pb and Zn for 25 %, 79 %, 44 %, 56 % and 86 %, respectively. The removal of metals is critical to maintain struvite purity and prevent the struvite contamination due to co-precipitate of these metals.

Potential Low-cost Treatment of Tannery Effluents from Industry by Adsorption on Activated Charcoal Derived from Olive Pomace

Tannery wastewater contains a significant amount of chemical compounds, including toxic substances. Due to the toxicity and negative environmental effects of these tannery effluents, mandatory treatment is necessary. The main objective of this study was to treat effluent from an artisanal tannery in the city of Fez (Morocco) using the adsorption process with activated charcoal derived from olive pomace. The physicochemical characterization of tanning water included several parameters, such as chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), suspended solids (SS), sulfate ions (SO42-), nitrate, and chromium Cr(VI). The analyses show that the adsorption process reduced nitrate by 57.54%, sulfate by 94.08%, TKN by 74.84%, COD by 68.18%, Cr by 91.27%, and Cr (VI) by 89.78%. The activated charcoal was characterized before and after tannery effluent treatment using various techniques, including FT-IR, SEM, and EDX. From the above, it can be inferred that using activated carbon made from olive pomace has the potential to reduce tannery effluent pollution parameters. This innovative approach demonstrates that competitive results can be achieved without sacrificing economic viability, thereby promoting sustainable practices in the treatment of industrial liquid waste and wastewater treatment plants.

High-rate Activated Sludge Process as a Pre-Treatment Alternative to Direct Filtration with Microfiltration/Ultrafiltration for Municipal Wastewater Reclamation to Produce Cooling Water

Industries use reclaimed water for their makeup water requirements of cooling towers to decrease their water footprints. Makeup water quality depends on the type of cooling tower design; however, total suspended solids (TSS), biological oxygen demand (BOD5), fecal coliform, pH, total dissolved solids (TDS), some ions (sulphate, chloride, ammonium) and heavy metals (aluminum, silica, manganese, iron) are important parameters to prevent contamination, scaling, and corrosion. In the first part of this study, cooling water production from municipal wastewater was experimentally investigated, in the second part of this study cost of treatment alternatives was estimated. Six different treatment configurations (C1: microfiltration (MF)+nanofiltration (NF); C2: ultrafiltration (UF)+NF; C3: high-rate activated sludge (HRAS)+NF; C4: MF+reverse osmosis (RO); S5: UF+RO; C6: HRAS+RO) were analyzed. Thanks to the high treatment performances of NF and RO membranes, reclaimed water in each scenario met the suggested cooling water quality. The effluent of the HRAS process showed the worst effluent quality in terms of turbidity (42.1±2.6 NTU of turbidity) compared to MF and UF direct filtration (turbidity of DMF permeates were below 5 NTU). However, since HRAS process is less costly than direct membrane filtration (DMF) via MF or UF membranes, the lowest treatment cost was achieved with the C3 (HRAS+NF) treatment configuration (0.52 €/m3 reclaimed water). This study demonstrates that the HRAS+NF configuration can produce water suitable for cooling tower makeup, highlighting its potential as a sustainable solution to reduce water footprints and promote water circularity in industries.

Statistical analysis of water quality and cyclone impacts along the south Odisha coast, east coast of India

Water quality along south Odisha coast (25km stretch), east coast of India was studied collecting monthly samples at 10 different sampling stations from June 2008 to March 2011 and June 2012 to May 2017. The samples were analysed for salinity, dissolved oxygen (DO), total suspended solids (TSS) and pH. In addition, river discharge, siltation, rainfall and wind speed data were also collected from 2008 to 2017 at the study region and their impacts on coastal water quality were assessed along with the impacts of cyclonic storms. Anomalies of water quality parameters and their seasonal variability were assessed. Spatio-temporal variation of these parameters and multivariate statistical techniques such as factor analysis, correlation coefficient and, descriptive statistics were applied to the observed datasets. Results indicate that, salinity is positively correlated with wind speed at 0.05 significance level while negatively correlated with river discharge. TSS is positively correlated with siltation at 0.01 significance level. DO values are also positively correlated with strong wind speed. Nutrient driven primary production helps pH to be higher at Rushikulya river mouth during monsoon and post-monsoon as compared to at all other stations. Throughout the year, the study environment remains alkaline. Due to impacts of cyclonic storms, water quality parameters show significant reduction in salinity and enhancement in TSS, DO and pH during the post-cyclone period while the seasonal trend is maintained during the pre-cyclone period. Factor analysis reveals the factors controlling the hydrographic behaviour of seawater. The spatial variation in coastal water quality is very high and dominates over the temporal variation. Importance of coastal water quality assessment in relation to coastal ecosystem and disaster is discussed.

Phytotreatment of tofu effluent using water lettuce (Pistia stratiotes) and potential of biogas production from resultant biomass

Tofu effluent contains a high concentration of organic materials, nutrients, suspended solids and is also low in pH. This research was aimed at applying phytotreatment using floating plant species of Pistia stratiotes to polish tofu effluent before final discharge into water bodies while also producing biogas from the resultant biomass after treatment. A range-finding test (RFT) was conducted to determine the initial concentration to be treated and resulted in 10 % tofu effluent. Phytotreatment was conducted for a period of 14 days, focusing on the removal of organic matter and nutrient contents. After 14 days of treatment, P. stratiotes were able to remove total suspended solids (TSS) by 88 %, ammonia by 42.3 %, phosphate by 50 %, chemical oxygen demand (COD) by 84 %, and biological oxygen demand (BOD) by 95 %, significantly higher as compared to control. Phytotreatment was able to stabilize pH to a neutral value, and P. stratiotes were able to transfer oxygen from air to the rhizosphere area. The maximum daily production of biogas using the plant's biomass was higher as compared to the control; however, the overall biogas accumulation was significantly lower during the 45 days of observation. Further biomass pretreatment was suggested before digestion to obtain higher biogas production since the cellulose, hemicellulose, and lignin content inside the plant biomass were subjected to being hardly degraded by the anaerobic microorganisms.

Total Suspended Solids in Teluk Awur, Jepara using Red Reflectance from Landsat-8

The coastal waters of Teluk Awur, Jepara are affected by human activities such as aquaculture, tourism, agriculture, and settlements. The number of human activities on land will contribute to high suspended solids (TSS) entering coastal waters by run-off. The high TSS in coastal areas will affect the entry of light intensity, disrupting the photosynthesis process and ecosystem. This study compares TSS values based on Landsat images using several TSS algorithms such as Wirasatriya, Budhiman, Ajiperwata, and Parwati algorithms and the algorithm resulting from the July 2023 field data calibration against red reflectance. The algorithm's performance from calibration has a smaller error value with RMSE = 8.51, MAPE = 25.77%, and Bias = 7.52. TSS estimation from Landsat 8 satellite imagery has a range of values of 30.56 - 62.55 mg/L (average 35.60 mg/L), while field measurements of TSS values are 22.40 - 64.52 mg/L (average 32.69 mg/L). This research will be valuable information for using the right Landsat-8 algorithm for temporal and sustainable TSS monitoring. It can be used in abrasion monitoring and management in the Teluk Awur coastal waters of Jepara.

The ADDRESS of a grain: Sediment particle tracking as an approach to assessing ecosystem quality in dammed reservoirs

The study integrates hydrodynamic modelling and geospatial analysis methods to describe the dynamic transport and sedimentation conditions of suspended solids (SS) in large lowland reservoirs. The method was tested on a dam reservoir on the Vistula River (Poland). Stochastic particle tracking was used with a Lagrangian approach, then geostatistical analyses to interpret the simulation results.It is shown that, excluding the backwater, SS sedimentation is greatest in distal parts of the reservoir's lacustrine and river sections. The reservoir retains an average of 79 % of inflowing SS. The primary process affecting the sedimentation of SS is a dam-wards increasing fineness of settling grains. Hydrodynamic simulation results showed deposition of clay fraction to also be possible in the reservoir's upper part, even during floods. Moreover, sand grains entered the dam even during very low flows. Interpretation of Particle Tracking Model (PTM) simulation results and geostatistical modelling reveals that the submerged bed of the pre-dam river still has a transport function, while fine SS accumulates in slow-flowing areas outside it. The anastomosing pre-dam riverbed still influences flow conditions and SS deposition in the upper and middle reservoir. PTM modelling and geostatistical analyses determined the influence of hydrodynamic conditions on the spatial variability of SS sedimentation in terms of the quantity and grain-size distribution of sedimenting matter.An original indicator (ADDRESS [A]; Accumulation or Discharge of Dam REservoir Suspended Solids) was developed determining the ability of polymictic reservoirs to either retain SS of different diameters or allow them through the reservoir to be discharged through the dam. The indicator quickly and simply determines particle behaviour under given hydrological conditions. Information on whether all or only some of grains of specific diameters will flow through the dam is important for explaining many natural processes affecting the reservoir ecosystem and the river ecosystem below the dam.

Seasonal Dynamics of Caligus clemensi Infestation in European Seabass and Flathead Grey Mullet Integrating Morphological, Molecular, Immunological, and Environmental Perspectives

This case study investigates the seasonal prevalence, morphological characteristics, molecular identity, host immune response, and environmental factors influencing Caligus clemensi infestations in farmed European seabass and flathead grey mullet at a single marine fish farm. A total of 600 fish (400 seabass, 200 mullet) were examined over one year, revealing seasonal fluctuations in parasite prevalence and intensity. C. clemensi infestation peaked in winter for seabass (75% prevalence) and spring for grey mullet (80% prevalence), with notable declines in summer and autumn for both species. Morphological analysis confirmed C. clemensi as the causative agent, exhibiting sexual dimorphism and characteristic features including a quadrilateral cephalothorax and disk-shaped lunules. Molecular characterization of the 18S rRNA gene corroborated the morphological identification, with phylogenetic analysis revealing a well-supported monophyletic clade for C. clemensi within the family Caligidae. Quantitative real-time PCR demonstrated significantly elevated interleukin-1β (IL-1β) expression in infected fish, indicating a robust inflammatory response. Grey mullet and seabass exhibited high IL-1β upregulation. Histopathological examination revealed severe gill tissue damage, vascular changes, and hepatic steatosis in infected fish. Water quality analysis identified several parameters exceeding permissible limits, including total suspended solids (4800-5100 mg/L), total dissolved solids (32000 mg/L), sulfates (2300 mg/L), and chlorides (18000 mg/L). These elevated levels, likely associated with nearby oil production and refining activities, created conditions conducive to parasite proliferation. The high total suspended solids might provide substrates for C. clemensi settlement and attachment, while increased dissolved ions could stress fish and reduce their parasite resistance. This multidisciplinary case study revealed complex host-parasite interactions between C. clemensi and farmed marine fish, highlighting the need for improved water quality and targeted parasite control to enhance aquaculture sustainability in the Suez Canal region.

Insight into the effect of Tubificidae on dynamic membrane reactor: Membrane fouling mitigation and Tubificidae-ASM3-dynamic membrane coupled model

To gain insights into the effects of Tubificidae on dynamic membrane sequencing batch reactor (DMSBR), 4 identical DMSBRs were operated with different Tubificidae densities (i.e., 0, 1, 2, 3 g ww/L). Experimental results showed that Tubificidae had a minimal effect on carbon and nitrogen removal but varied effluent turbidity and sludge characteristics. An appropriate density (2 g ww/L) of Tubificidae significantly decreased effluent turbidity and mitigated membrane fouling, which was attributed to the minimized mixed liquor suspended solids (MLSS) and the maximized particle size. A Tubificidae-ASM3-dynamic membrane coupled model was developed by combining the biological model with the dynamic membrane resistance model, incorporating the extracellular polymeric substances (EPS) to characterize its contribution to membrane pore fouling, and introducing an inhibitory function to limit the unrestricted growth of membrane resistance. The model can be considered as a first attempt to describe the observed Tubificidae effects on dynamic membrane reactor.

Spatial Distribution of Calanoida in Freshwater Ecosystems and Their Application as a Food Web Assessment Index

Calanoida is a representative oligo-mesotrophic indicator species, frequently used as an index for assessing lake ecosystems’ health. Additionally, they function as trophic intermediates in the food web, connecting primary producers and higher consumers within lake ecosystems’ food chains. However, research cases that present the implications of habitat environment assessments, such as ecosystem structure and water quality, represented by these taxa remain insufficient. In this study, we conducted research across 49 lakes in South Korea, analyzing the occurrence characteristics of Calanoida and examining the correlations between Calanoida abundance and water quality parameters and the morphological-based functional groups of phytoplankton. Calanoida were more frequently observed in lakes characterized by greater size, increased depth, and reduced levels of anthropogenic land use. Furthermore, Calanoida occurrence was more probable in environments characterized by lower electrical conductivity and suspended solids concentrations. Their presence was also associated with conditions where Large mucilaginous phytoplankton (MBFG7), which includes cyanobacteria, and Large filamentous phytoplankton (MBFG3) were prevalent. An analysis of the environmental factors influencing the increase in Calanoida abundance revealed an inverse relationship between their abundance and water quality factors, including nutrient levels. This trend was observed consistently across all genera. Additionally, Calanoida were observed to maintain a high abundance in environments where the presence of the Large mucilaginous phytoplankton group (MBFG7) was relatively high. In contrast, Cyclopoida exhibited varying occurrence characteristics by genus in response to different water quality factors. Based on these results, we suggest that Calanoida, commonly used as an indicator of mesotrophic conditions, can also serve as a valuable indicator for evaluating the functionality of the food web. While Calanoida struggle to inhabit environments characterized by degraded water quality, they demonstrate the ability to adapt and persist in environments containing large, mucilaginous, or filamentous phytoplankton species that are typically challenging for other zooplankton to graze.

A new diatom-based multimetric index (MMI-D) for ecological health monitoring in the Tropical Rift Valley Lake (Lake Hawassa, Ethiopia)

Multimetric assessment is one of the important tools for diagnosing, detecting and measuring impairment in ecosystem function in lentic ecosystems. It enhances detection capabilities across a broader variety of stressors and offers a more complete picture of ecological conditions than single metrics or biological indicators. In this context, a diatom-based multimetric index (MMI-D) has been developed to evaluate the ecological health of Lake Hawassa. Physicochemical and benthic diatom sampling was conducted at nine sites along the lakeshore, representing varying levels of human disturbance, from February to November in2015 and 2016. The sampling sites were classified a priori into three categories: minimally disturbed (three sites), moderately disturbed (three sites) and highly disturbed (three sites). This classification, was based on a clustering analysis using the percent disturbance score (PDS). Of the 24-diatom candidate metrics, only ten were chosen as core metrics for the development of MMI-D, based on redundancy analysis, reaction to environmental conditions, percent discriminatory efficiency (%DE) and box plots. The newly established MMI-D clearly distinguished between reference and non-reference sites, and between the lake’s three clusters. The MMI-D’s performance was validated using independent data sets from lakes Hawassa and Ziway and it demonstrated the best capability for discrimination between different disturbance levels. MMI-D 2-stage Least Squares (2SLS) regression analysis revealed an inverse but robust connection with the PDS, indicating its responsiveness to Lake Hawassa habitat quality degradation (n = 9, R 2 = 0.921, p < 0.001). The MMI-D revealed a high %DE (95.1%) and a negative but significant connection with nutrients, total suspended solids (TSS), and turbidity (R 2 > 0.6; p < 0.05). Generally, it can be concluded that this index is a powerful tool that could assist endusers by providing a practical method for measuring the ecological quality of Lake Hawassa.

Long term performance of Nature-Based Solutions as decentralized wastewater treatment: a case study of a retail store in southern Italy

The aim of this study is to evaluate the removal efficiency and the hydraulic behavior of the 10-year-old hybrid treatment wetland (TW) system treating effluents of the IKEA® store of Catania (Eastern Sicily, Italy), under Mediterranean semi-arid climate conditions. The system is placed downstream to the conventional wastewater (WW) treatment of the store, that includes a sequential batch reactor (SBR) followed by a horizontal subsurface treatment wetland (HF) unit and two vertical subsurface flow treatment wetlands (VF1 and VF2) units. The assessment of chemical, physical, and microbiological parameters in treated WW was carried out through regular monitoring activities, occurring approximately on a monthly basis, over a 8-year period spanning from 2016 to 2023. Up to 72 samples were collected for the following parameters measurements: total suspended solids (TSS), BOD5, COD, total phosphorus (TP), ammonia (as NH4), nitrate (as NO3-N), nitrite (as NO2-N), total nitrogen (TN) and E. coli. Hydraulic conductivity at saturation (Ks) measurements and tracer tests were conducted to evaluate the extent of clogging and to characterize the hydraulic behavior within the HF unit. Results obtained during the entire monitoring period show the following mean and standard errors (±) removal efficiency ranges (%): TN 21(±11)-80(±9); TSS 18(±42)-95(±3); COD 28(±23)-93(±2); BOD5 31(±10)-85(±44); TP 14(±6)-49(±19); NH4 50(±50)-95(±3); E. coli was abated with a mean range of 3.3(±0.2)-4.8(±0.4) Ulog reduction, reaching not detectable values in most samples analyzed since 2018. The efficacy of the treatment system is assessed in the context of both national and European regulatory frameworks governing effluent discharge and water reuse standards. Ks values and tracer test results agree in showing the progressive clogging of the HF unit influencing the hydraulic behavior of the unit giving useful on the management of TWs in Mediterranean area. Finally, the performance results also indicate that the overall treatment is not affected by the HF unit clogging.

Enhancing the anaerobic sludge characteristics and inorganic impurities removal from synthesis wastewater through integration of electrocoagulation process with up-flow anaerobic sludge blanket reactor.

The present study investigated effects of coupling electrocoagulation (EC) process with an anaerobic digestion bioreactor, namely up-flow anaerobic sludge blanket (UASB), for the synthetic wastewater treatment. The EC-UASB mode of operation consisted of one anode and two cathodes subjected to an intermittent electrical current (10 min ON/30 min OFF) with current density of 1.5 mA/cm2. In light of this integration, the concentration ofmixed liquor suspended solids and mixed liquor volatile suspended solids within anaerobic granular sludge (AGS) increased by 20.0 ± 1.4% and 12.8 ± 0.8%, respectively. The results of sludge volume index, loosely and tightly bound extracellular polymeric substances and their constituents (protein and carbohydrate) revealed that through this integration the quality of AGS has been improved. Furthermore, results of scanning electron microscopy and Fourier-transform infrared spectroscopy showed alteration in the morphology and functional groups of AGS, respectively. Additionally, this combination has demonstrated promising results in terms of performance improvement by increasing the removal efficiency of total dissolved solids by 12.1 ± 0.3% and reducing the ionic pollution in treated wastewater. However, the integration of the EC system within the UASB resulted in energy consumption and operating cost of 1.33 kWh/m3 and 0.099 USD/m3, respectively.

Complex landscape, instream and anthropogenic environmental features drive genetic and morphological structuring amongst brown trout (Salmo trutta) populations in a dendritic river system

Abstract Untangling the patterns and proximate drivers of intraspecific genetic and phenotypic structuring informs our understanding of the evolutionary processes shaping diversity. This study investigated morphological and genetic structuring of brown trout (Salmo trutta L.) populations across varying spatial scales in a single, complex, dendritic river catchment and examined the potential natural and anthropogenic environmental features driving this structuring. Morphometric and hierarchical genetic structuring analyses of fish from 22 sampling sites in the River Foyle catchment, Ireland (~ 4500km2) identified 19 morphologically distinct groups and 15 genetically distinct populations, separated by river distances ranging from 0.4 km to 188 km. Isolation by Distance was the main factor shaping both genetic and morphological divergence, indicating that strong philopatry is one of the major drivers of the observed population structuring in this system. However, both natural and anthropogenic environmental variables also explained pairwise genetic and morphological differences between sampling sites. Thus, the pairwise differences in the area of woodland in the upstream catchment, water phosphorus concentration, biological oxygen demand, catchment slope, urban area in upstream catchment, altitude, site specific percentage of canopy cover and dissolved oxygen concentration in the river channel were correlated with genetic divergence. The pairwise differences in the concentration of suspended solids, the extent of bankside overhang, the composition of bedrock, boulder and cobble substrates, watercourse width, catchment slope and site altitude were correlated with between-site morphological differences. We hypothesise that local differential selection pressures comprising both natural environmental variation and variation resulting from anthropogenic effects, in combination with strong philopatry and random genetic processes drive the clearly defined genetic and phenotypic patterns described here.

Using Dominant Phytoplankton as Assessment of Water Quality: Water Resource Case Studies of University in Chatuchak District

The use of dominant phytoplankton as a water quality indicator was studied. Samples from 6 stations (S1-S6) were collected. From the study, 6 divisions of 34 genera of phytoplankton, i.e. Euglenophyta, Chlorophyta, Bacillariophyta, Chromophyta, and Pyrrhophyta were found, and the significant phytoplankton genera were Euglena, Phacus, and Tetraedron. By analysing water quality assessment in terms of scores by AARL-SPP Score using these three dominant genera, it was found that stations S1–S4 had a moderate level of water quality and stations S5–S6 had a moderate-polluted level of water quality. When the relationship between phytoplankton species and the water quality parameters were analysed by stepwise multiple regression analysis, the results showed that the prominent genus Merismopedia of Cyanophyta (Blue-green algae), correlated with transparency, salinity, chlorophyll a, and soluble phosphate while the genus Oscillatoria correlated with the total suspended solids, Chlorophyll a content, transparency, pH, temperature, and ammonia-nitrogen. The correlation indicates the high rate of phytoplankton growth was due to reduced water quality. According to water quality standards for surface water, the water quality was classified in Category 3.

Physicochemical wastewater treatment improvement by hydrodynamic cavitation nanobubbles

Hydrodynamic nanobubble aeration is proposed as an innovative approach to enhancing physicochemical wastewater treatment. Integrating a novel cavitation system to replace conventional aeration significantly improves standard oxygen transfer efficiency and energy consumption. The changes in size and surface charge of air, oxygen (O2), ozone (O3), and chitosan nanobubbles were studied as a function of the reactor diameter. Interestingly, it was found that increasing the radial dispersion length had no significant effect on the measured parameters. Flotation, Coagulation-flocculation (CF), and Advanced Oxidation (AOPs) processes of municipal wastewater comparing convective air and O3 NBs aeration were carried out at pilot plant scale. The use of O3 NBs in the flotation process improves 160 % the suspended solids removal compared to the air-NBs- process. The CF process was evaluated by adding a chitosan dose to the convective processes and monitoring the water quality parameters in real-time. The results demonstrated that the interaction of chitosan with O3 NBs eliminates more than 80 % of the initial chemical oxygen demand (COD). Finally, the AOP carried out with O3 NBs reaches a removal efficiency of 99.8 % total suspended solids and 90 % COD. This modular system presents a practical and efficient alternative for removing municipal and industrial wastewater contaminants.

Anaerobic membrane bioreactor (AnMBR) with external ultrafiltration membrane for the treatment of sugar beet vinasse.

Vinasse, a by-product of ethanol production, is generated at significant rates. While rich in nutrients such as calcium, magnesium, and potassium, its high solids, organic matter, acidity, and sulfate content pose challenges when disposed directly on soil, necessitating treatment. Anaerobic digestion is a viable solution, reducing organic pollution while recovering energy in the form of biogas, aligning with the biorefinery concept. Traditionally, sludge bed reactors and anaerobic contact reactors are utilized for vinasse processing, with sludge granulation being vital for treatment success. However, challenges such as sludge wash-out due to recalcitrant compounds, high solids concentration in the influent, low pH, salinity, and temperature hinder granule formation. Anaerobic membrane bioreactors (AnMBR) offer an alternative, simplifying treatment by integrating intensified pre- and post-treatment units. Due to complete sludge retention, AnMBRs achieve high COD removal efficiencies, yielding a suspended solids-free and largely disinfected effluent. Therefore, AnMBRs show promise for vinasse treatment, eliminating the need for sludge granulation and producing nutrient-rich effluent with minimal residual organics and suspended solids. In this study, an AnMBR equipped with an inside-out external crossflow ultrafiltration membrane was proposed for the treatment of vinasse. The AnMBR reached a COD removal efficiency of 95% ± 2.6% and produced 0.3 CH4 L.g COD removed -1 working at organic loading rates of 8g COD. L-1 d-1 and membrane fluxes of 10 LMH. At organic loading rates of 10g COD. L-1 d-1 and fluxes of 12 and 14 LMH, the COD removal efficiency decreased to 77% ± 11% and 73% ± 7.9%, respectively. The AnMBR technology represents an innovation for wastewater treatment, however, more research using the cross-flow configuration and different types of effluents is needed. Literature studies that address the treatment of sugar beet or sugarcane vinasse using AnMBR are still scarce. This study explored the potentials of AnMBR technology for vinasse treatment and contributes to the dissemination of this technology, opening new possibilities for vinasse processing.