Biochemical Oxygen Research Articles

Influence of Organic Loading Rates on the Treatment Performance of Membrane Bioreactors Treating Saline Industrial Wastewater

This study investigated the efficacy of membrane bioreactor (MBR) technology in treating saline industrial wastewater, focusing on the impact of the organic loading rate (OLR) and the food-to-microorganism (F/M) ratio on treatment performance. This research utilized saline industrial wastewater from Al-Hasa, which had salinity levels ranging from 5000 to 6900 mg/L. It explored treatment processes at varying Chemical Oxygen Demand (COD) concentrations of 800, 1400, and 2000 mg/L, corresponding to an OLR of 0.80 ± 0.05, 1.41 ± 0.07, and 1.98 ± 0.12 g COD/L, respectively. The average F/M ratios used were 0.20, 0.36, and 0.50 g COD/g MLSS·d, maintaining a constant Sludge Residence Time (SRT) of 12 days, a hydraulic retention time (HRT) of 24 h (hrs.), and a flux of 10 L/m2·h. The MBR system demonstrated high COD removal efficiencies, averaging 95.7 ± 1.6%, 95.5 ± 0.4%, and 96.1 ± 0.3%, alongside Biochemical Oxygen Demand (BOD) removal rates of 98.3 ± 0.2%, 99.8 ± 0.1%, and 98.5 ± 0.1%, respectively. However, an increased OLR led to elevated residual COD and BOD levels in the treated effluent, with COD concentrations reaching 34.2 ± 12.8, 63.3 ± 5.9, and 76.5 ± 5.4 mg/L, respectively. This study also reveals a significant decline in ammonia and Total Kjeldahl Nitrogen (TKN) removal efficiencies as OLR increases, dropping from 96.1 ± 0.5% to 80.2 ± 0.9% for ammonia and from 83.8 ± 3.4% to 65.8 ± 2.3% for TKN. Furthermore, higher OLRs significantly contribute to membrane fouling and elevate the transmembrane pressure (TMP), indicating a direct correlation between OLRs and operational challenges in MBR systems. The findings suggest that for optimal performance within the Saudi disposal limits for industrial wastewater, the MBR system should operate at an F/M ratio of ≤0.33 g COD/g of Mixed Liquor Suspended Solid (MLSS)·d. This study underscores the critical role of the OLR and F/M ratio in treating saline industrial wastewater using MBR technology, providing valuable insights for enhancing treatment efficiency and compliance with environmental standards.

On the transition of liquid dispersion states and their physical-thermodynamic nature in the development of gas-condensate reservoirs in depletion mode

This work presents new results of physical and chemical analysis of samples from contaminated areas of the Absheron field. The advantages and disadvantages of the used and traditional methods of cleaning oil waste are shown. Modern methods have been used to determine the characteristics of oil sludge samples from the Balakhany, Ramana, Surakhany, Bibiheybet fields of the Absheron Peninsula: oil sludge composition, viscosity, density, water content, chemical composition, temperature, cutting size, toxicity, volume, pH level, turbidity, BOD (biological oxygen demand), TDS (total dissolved solids). The main properties of oil sludge from the fields of the Absheron Peninsula are analyzed and compared. Chromatographic analysis (Agilent 7820A GC) allowed us to separate the oil waste and mixtures of the studied samples into individual compounds and components. The separation and determination of the components of the waste mixture by gas chromatography consisted of three stages: 1) Introduction of the sample into the chromatograph, 2) Separation of the sample into individual components, 3) Determination of the compounds contained in the sample. An inductively coupled plasma mass spectrometer (Agilent 7500 cs) with reaction cell was used for the efficient determination of trace heavy metals in petroleum waste. The ion lens unit used in the Agilent 7500cs provided high sensitivity measurements. Thus, trace metals were detected in the samples. A vacuum distiller (Retort Oil and Water Kit RROW-50) was used to quantify liquid and solids in drilling mud. Comparison of our oil sludge analysis results with field data demonstrates the effectiveness of these methods in identifying the composition of oil sludge for obtaining target products. From the studied wastes of the oil industry, it is possible to obtain special additives and use them, for example, for asphalt concrete. The dependences of oil sludge evaporation (of the Balakhany, Ramana, Surakhany, Bibieybet deposits) on air temperature and thermal resistance of the waterproofing material of the oil storage facility have been studied. The evaporation of components also depends on the concentration of oil sludge. Based on our sample analyses, it has been shown that the combined use of physicochemical and chemical methods makes it possible to purify oil sludge to acceptable limits. The dependences of oil evaporation on air temperature and the thermal resistance of the waterproofing material of an oil tank on the concentration of oil sludge have been established.

Spatiotemporal Changes in the Quantity and Quality of Water in the Xiao Bei Mainstream of the Yellow River and Characteristics of Pollutant Fluxes

The Xiao Bei mainstream, located in the middle reaches of the Yellow River, plays a vital role in regulating the quality of river water. Our study leveraged 73 years of hydrological data (1951–2023) to investigate long-term runoff trends and seasonal variations in the Xiao Bei mainstream and its two key tributaries, the Wei and Fen Rivers. The results indicated a significant decline in runoff over time, with notable interannual fluctuations and an uneven distribution of runoff within the year. The Wei and Fen Rivers contributed 19.75% and 3.59% of the total runoff to the mainstream, respectively. Field monitoring was conducted at 11 locations along the investigated reach of Xiao Bei, assessing eight water quality parameters (temperature, pH, dissolved oxygen (DO), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP), permanganate index (CODMn), and 5-day biochemical oxygen demand (BOD5)). Our long-term results showed that the water quality of the Xiao Bei mainstream during the monitoring period was generally classified as Class III. Water quality parameters at the confluence points of the Wei and Fen Rivers with the Yellow River were higher compared with the mainstream. After these tributaries merged into the mainstream, local sections show increased concentrations, with the water quality parameters exhibiting spatial fluctuations. Considering the mass flux process of transmission of the quantity and quality of water, the annual NH3-N inputs from the Fen and Wei Rivers to the Yellow River accounted for 11.5% and 67.1%, respectively, and TP inputs accounted for 6.8% and 66.18%. These findings underscore the critical pollutant load from tributaries, highlighting the urgent need for effective pollution management strategies targeting these tributaries to improve the overall water quality of the Yellow River. This study sheds light on the spatiotemporal changes in runoff, water quality, and pollutant flux in the Xiao Bei mainstream and its tributaries, providing valuable insights to enhance the protection and management of the Yellow River’s water environment.

Household Waste Water Treatment using Activated Charcoal: An Effective and Sustainable Approach

Effective household wastewater management is crucial for environmental sustainability and public health, especially in areas with limited advanced treatment infrastructure. This study explores the use of activated charcoal as a cost-effective and efficient method for treating household wastewater. Known for its high adsorption capacity, activated charcoal was evaluated for its ability to remove key contaminants from wastewater collected from residential sources such as kitchens, bathrooms, and laundry areas. The research utilized both batch adsorption tests and column filtration experiments. In the batch tests, wastewater samples were treated with varying doses of activated charcoal (2, 5, 10, and 15 g/L) over different contact times (30 minutes to 4 hours). The results showed that activated charcoal effectively reduced Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), and Biological Oxygen Demand (BOD), with average reductions of 75%, 65%, and 70%, respectively. Additionally, activated charcoal demonstrated significant effectiveness in removing heavy metals and organic compounds, with removal efficiencies ranging from 60% to 80% depending on the contaminant type and operational conditions. The optimal treatment conditions were found to be a dosage of 10 g/L and a contact time of 2 hours. Future research could focus on optimizing regeneration processes and exploring hybrid systems that combine activated charcoal with other treatment technologies to further enhance performance.

Application of multi index comprehensive evaluation method in the selection of wastewater treatment processes

The study comprehensively evaluates various wastewater treatment processes by using Grey Relational Analysis (GRA) and Analytic Hierarchy Process (AHP) to identify the optimal method for wastewater treatment. To conduct this evaluation, six key indicators were identified and used for assessment: five-day biochemical oxygen demand (BOD5) removal rate, chemical oxygen demand (COD) removal rate, ammonia nitrogen removal rate, total nitrogen removal rate, total phosphorus removal rate, and suspended solid removal rate. Initially, GRA was employed to calculate the grey relational degree of each treatment process based on the weights of the indicators, and the treatment processes were then ranked and analyzed according to these degrees. Subsequently, AHP was applied to construct a judgment matrix, determine the weights of each indicator, and ensure the matrix's rationality through consistency testing. The study reveals significant differences in the performance of various wastewater treatment processes among the indicators, with the Modified A2/O+AO process showing the highest comprehensive performance in the evaluation. The findings provide a scientific basis for improving efficiency, reducing pollution, and guiding policy and technological development.

Assessment and monitoring of leather effluent discharge from Dewas and Ranipet and their computational approach.

The swift pace of industrialization, urbanization, and burgeoning populations propel the surge in demand for manufactured goods and infrastructure. The wastewater produced during leather processing comprises a cocktail of organic and inorganic chemical contaminants that have the potential to affect the environment. This study focuses on conducting a comparative physico-chemical, analytical,in vitro, and in silicotoxicity assessment and monitoring of leather effluent discharged from two different areas, namely, Dewas and Ranipet. The physicochemical analysis of collected effluents revealed higher levels of biochemical oxygen demand, chemical oxygen demand, total dissolved solids, total suspended solids, and heavy metals than the permissible limit fixed by the Central Pollution Control Board (CPCB). The X-ray powder diffraction analysis of both samples identified the existence of crystalline and amorphous phases. The functional composition of compounds was identified through the analysis of Fourier-Transform Infrared Spectroscopy, which revealed the existence of C-H, O-H, N-H, C = O, C=C, and C≡C stretching vibrations. A variety of compound derivatives, including amines, organic acids, organometallic compounds, alcohols, hydrocarbons, esters, aldehydes, ketones, aromatic, and organogermanium, were identified by Gas Chromatography-Mass Spectrometry. An assessment and monitoring of the phytotoxicity of effluent on the germination of Vigna radiata seeds reveals that (100%) of both Dewas and Ranipet leather effluents inhibited seed germination by 33.34% and 100%. The incorporation of Absorption-Distribution-Metabolism-Excretion-Toxicity (ADMET) analysis improved comprehension of the toxicity profiles of the GC-MS-identified compounds. Moreover, the result of docking studies revealed that cytochrome P450 showed the highest binding affinity towards 1,3-benzodioxol-2-one, hexahydro-cis with an affinity score of - 7.1kcal/mol. The overall research revealed that the leather effluents from Dewas and Ranipet exhibit significant toxicity, highlighting the necessity of better wastewater management. In the future, innovative treatment methods and environmental friendly processes can be developed to minimize the detrimental effects of leather effluents.

Ecological quality of the Jucusbamaba River, a high Andean urban river in northeastern Peru

The Jucusbamaba River, located in the northeastern region of Peru, flows through two towns that use its waters for agricultural activities. However, these activities generate waste discharged back into the river, which is additionally polluted by untreated domestic wastewater discharges. The main objective was to evaluate the ecological quality of this lotic system, analyzing biotic and abiotic parameters during two seasons. The biotic parameters included microinvertebrates and fecal coliforms, while the abiotic parameters encompassed temperature, pH, dissolved oxygen, electrical conductivity, turbidity, total dissolved solids, and biochemical oxygen demand. Six sampling points were established where physicochemical and microbiological parameters were analyzed. Simultaneously, quantitative sampling of macroinvertebrates was carried out at the same points to evaluate their diversity using Shannon- Wiener, Margalef and Simpson indices. The Andean Biotic Index (ABI) and the Biotic Family Index (FBI) were calculated to determine the ecological quality of the river using macroinvertebrates. Finally, the spatio-temporal variation of macroinvertebrate composition and physicochemical and microbiological parameters were analyzed. Very high concentrations of BOD, total dissolved solids, and electrical conductivity were obtained in the dry season, while in the rainy season, they were pH, dissolved oxygen, and turbidity. 12548 individuals from 6 classes, 11 orders, and 26 families were collected. The greatest richness of macroinvertebrate families was found at points 1 and 2, with Trichoptera, Ephemeroptera and Plecoptera individuals predominating. There was evidence of temporal variation in physicochemical and microbiological parameters, as well as in macroinvertebrate composition. It was concluded that the ecological quality of the Jucusbamba River decreases as it follows its course due to anthropic disturbances. This research can be used to develop management plans, awareness-raising, and sanitation measures to ensure the protection and conservation of the Jucusbamaba River.

Solar light driven enhanced in photocatalytic activity of novel Gd incorporated ZnO/SnO2 heterogeneous nanocomposites

The Gd-doped ZnO/SnO2 nanocomposites with various atomic percentages (0, 0.5, 0.8, and 1.2 at%) of gadolinium (coded as GdZS0, GdZS1, GdZS2, and GdZS3) was synthesis via the sol–gel method and explored for photodegradation against dye solutions exposing solar light irradiation. The synthesized nanocomposites were characterized employing the XRD, FTIR, FE-SEM, Raman spectroscopy, BET analysis and UV–Vis spectrophotometer. The FE-SEM results indicated that the formation of nanoparticles to nanoflowers covered with Gd ions was observed with an increased doping concentration of Gd. The optical bandgap was evaluated and found in the range of 3.21–3.27 eV for GdZS nanocomposites. The GdZS nano-photocatalysts were investigated against the degradation of different organic dyes and GdZS3 shows the highest degradation efficiencies of 99.3%, 98.3% and 99.4% towards MO, MB and RhB dyes, respectively at neutral pH in aqueous media. Before and after photodegradation. Biological oxygen demand and chemical oxygen demand tests to make estimations of mineralization. The investigations are very promising for the degradation process in rare earth doped metal oxide nanocomposites. A plausible photodegradation mechanism of synthesized nanocomposites under investigation has also been proposed.

Assessment of water quality and identification of priority areas for intervention in Guanabara Bay basin, Rio de Janeiro, Brazil, using nonparametric and multivariate statistical methods.

The Guanabara Bay hydrographic region (GBHR) has served as a central hub for human settlement and resource utilization throughout Brazil's history. However, the region's high population density and intense industrial activity have come at a cost, leading to a significant decline in water quality. This work aimed to identify homogeneous regions in GBHR according to water quality parameters in dry and rainy periods. The following water quality monitoring variables were monitored at 49 gauge stations: total phosphorus (TP), nitrate (NO3-), dissolved oxygen (DO), hydrogenionic potential (pH), turbidity (Turb), thermotolerant coliforms (TCol), total dissolved solids (TDS), biochemical oxygen demand (BOD), water temperature (Tw), and air temperature (Ta). The statistical analysis consisted of determining principal components, cluster analysis, seasonal differences, and Spearman's correlation. The water quality parameter correlations were not expressively influenced by seasonality, but there are differences in the concentrations of these parameters in the dry and rainy periods. In the dry period, urban pressure on water quality is mainly due to fecal coliforms. The resulting clusters delimited areas under urban, agricultural, and forestry influence. Clusters located in areas with high demographic density showed high concentrations of TCol and TP, while clusters influenced by forestry and agriculture had better water quality. In the rainy season, clusters with urban influence showed problems with TCol and TP, in addition to some characteristics in each group, such as high TDS, NO3-, and BOD. Forested areas showed high DO, and clusters under agricultural influence had higher concentrations of TCol, BOD, and NO3- concerning forested regions. The troubling state of sanitation in GBHR occurs in metropolitan regions due to lack of a formal sanitation system.

Assessing the effects of Water hyacinth proliferation on biochemical oxygen demand with operational land imager data

The rapid proliferation of water hyacinth (Eichhornia crassipes) in water bodies poses a significant threat to ecosystems and communities that rely on these resources. While this plant can offer certain benefits, its excessive growth can lead to detrimental ecological and social impacts. This study aimed to assess the relationship between water hyacinth coverage and Biochemical Oxygen Demand (BOD) levels in the Sonso Lagoon, Colombia, using Landsat 8 satellite imagery and in-situ measurements. Water hyacinth coverage was classified and quantified from Landsat 8 images. These data were then correlated with BOD levels obtained through periodic monitoring of the lagoon. The analysis revealed a strong negative correlation (ρ=−0.83; p−value<0.05**) between water hyacinth coverage and BOD, demonstrating the plant's impact on water quality. A predictive model was developed to estimate BOD levels based on satellite-derived water hyacinth data. The integration of remote sensing and in-situ measurements offers an effective strategy for monitoring water hyacinth proliferation and its ecological consequences. The proposed approach enables rapid assessment of water quality parameters, facilitating timely implementation of mitigation and control measures. This methodology can be extended to quantify other invasive aquatic plant species and their impacts on aquatic ecosystems.

Productivity and competitive dominance of freshwater filamentous macroalgal cultivars for nutrient bioremediation of primary municipal wastewater

ABSTRACT Algal bioremediation using macroalgae is a promising approach to wastewater treatment. This study compared the productivity and bioremediation performance of the freshwater filamentous algal cultivars; Klebsormidium flaccidum, Oedogonium calcareum, and Oedogonium sp., in primary municipal wastewater in outdoor high-rate filamentous algal pond mesocosms. K. flaccidum had the highest biomass productivity (3.09 g dry weight m−2 day−1 ± 0.20 SE) and bioremediation performance, reducing total ammoniacal-N by 51% to 14.80 mg L−1 (± 0.81 SE), nitrate-N by 59% to 0.30 mg L−1 (± 0.02 SE), and dissolved reactive phosphorous by 15% to 3.52 mg L−1 (± 0.07 SE). This cultivar achieved the greatest reductions in total suspended solids (54%), carbonaceous biochemical oxygen demand (93%), and chemical oxygen demand (74%). K. flaccidum and Oedogonium sp. reduced Escherichia coli by 98%. Competitive dominance of K. flaccidum and Oedogonium sp. was assessed in bicultures at three stocking densities. By day 12, K. flaccidum's proportion increased from 50 to 64% (± 6.1 SE) and 73% (± 5.0 SE) at a stocking density of 0.25 g and 0.5 g FW L−1, respectively. Based on superior biomass productivity, bioremediation performance, and competitive dominance, K. flaccidum was identified as a target cultivar for bioremediation of primary municipal wastewater.

Ecological restoration amplifies riverine fish catch of Gudusia chapra (Hamilton, 1822): an impact study in the river Ganga using multivariate statistical tools and water quality indices.

Fish residing in the aquatic ecosystem are considered the best ecological indicator for monitoring environmental habitat. To evaluate the changes that occurred due to relative restoration in the ecological habitat, a study was conducted in the freshwater zone of the river Ganga between Buxar, Bihar, and Ballia, Uttar Pradesh, between July 2021 and July 2022. In the monitoring, the physico-chemical condition, as well as the food and feeding habits of the fish Gudusia chapra, were monitored with the help of various pollution evaluating indices, namely, the algal pollution index (API) for planktons, the comprehensive pollution index (CPI-WQI), and the National Sanitation Foundation Water Quality Indices (NSF-WQI) for water. The study showed that the relative restoration facilitated the amplification of the fish catch from 5.60 to 98.98% in two consecutive years. The reduction in the API (15 to 4) as well as CPI (0.80 to 0.72) during both years signified the reduction of the pollution status of the river in the region. The NSF-WQI also decreased from 88.27 to 79.27 from 2021 to 2022. The electivity index for the fish showed that fish preferred the groups Cyanobacteria, Rotifera, and Copepoda. The multivariate, as well as univariate analyses, revealed that the fish G. chapra is significantly influenced by multiple abiotic as well as biotic variables, among which the major contributors are riverine velocity, transparency, conductivity, pH, dissolved oxygen, total alkalinity, carbonate, bicarbonate, salinity, total hardness, calcium, silicate, and biochemical oxygen demand.

Biotic and Abiotic Components of The River

This study offers a comprehensive analysis of the physico-chemical parameters of the Sarodha Dam in Kabirdham, Chhattisgarh, over three distinct periods: pre-autumn, autumn, and post-autumn of 2007. Key parameters examined include temperature, velocity, total solids, total suspended solids, total dissolved solids, turbidity, pH levels, dissolved oxygen content, free CO2 concentration, biochemical oxygen demand (BOD), chemical oxygen demand (COD), alkalinity, chlorides, sulphate levels, and fish species identification. The research identified 36 distinct fish species within the dam, underscoring the biodiversity present. Historically, water has been a crucial resource for human survival and development, with rivers playing a vital role globally. However, pollution from sewage and industrial effluents threatens these vital water bodies, leading to significant environmental and health issues. Despite advances in water treatment, urban piped water often remains contaminated, resulting in waterborne diseases such as jaundice, cholera, typhoid, and gastroenteritis. Pollution impacts rivers through chemical degradation and disruption of ecosystems, highlighting the need for interdisciplinary approaches to monitor and manage water quality effectively.

Winkler Titration Assessment of Biochemical Oxygen Demand (BOD5) in Oka Creek, Toru-Orua, Bayelsa State

Aim: The aim of study was to investigate the Biochemical Oxygen Demand (BOD) levels in water samples from the Oka Creek. Study Design: Qualitative study design. Place and Duration of Study: Water samples were collected from the Oka Creek, located in Toru-Orua in Sagbama Local Government Area, Bayelsa State, Nigeria. The study lasted for twenty days. Methods: Water samples were collected from four different locations and depths in the Oka Creek, Toru-Orua, Sagbama Local Government Area of Bayelsa State, Nigeria, at various times. Each sample was transferred into 250 ml bottles labeled L1, L2, L3, and L4. The temperatures of the samples were recorded before transporting them to the chemistry laboratory for treatment. Winkler titration method was employed in analyzing the samples. Results: Location L1 recorded the highest BOD value, 28.38 ppm, measured at sunset (25 °C), from a relatively stagnant region. The high BOD at this location is attributed to minimal photosynthetic activity and significant oxygen consumption by microorganisms. In contrast, L2, collected from the same region at 35 °C during peak sunlight, exhibited a BOD value of 21.76 ppm. The lower BOD at L2 is due to increased photosynthetic activity. These high values suggest significant sludge deposits, domestic sewage and agricultural runoffs, which could lead to oxygen depletion and negatively impact aquatic life. Sample L3, taken from a deeper, stagnant region at sunset (25 °C), recorded a BOD value of 4.50 ppm. This moderate BOD level suggests the presence of moderate sludge deposits and agricultural runoff, but higher water flow speed helped mitigate these effects. Location L4, with the lowest BOD value of 3.74 ppm, was collected during peak sunlight (35 °C). Deeper location and high water flow speed contributed to reduced BOD levels, indicating better water quality and a healthier aquatic environment. Conclusion: The BOD values at L1 and L2 (28.38 ppm and 21.76 ppm) exceed acceptable limits for fish growth. Conversely, BOD values at L3 and L4 (4.50 ppm and 3.74 ppm) fall within acceptable limits, suggesting healthier aquatic environment, as evidenced by the yearly bountiful fish harvests in these sections of the Oka Creek.

Biodegradation of poly(butylene adipate terephthalate) and poly(vinyl alcohol) within aquatic pathway

Understanding the environmental fate of biodegradable plastics in aquatic systems is crucial, given the alarming amount of plastic waste and microplastic particles transported through aquatic pathways. In particular, there is a need to analyze the biodegradation of commercialized biodegradable plastics upon release from wastewater treatment plants into natural aquatic systems. This study investigates the biodegradation behaviors of poly(butylene adipate terephthalate) (PBAT) and poly(vinyl alcohol) (PVA) in wastewater, freshwater, and seawater. Biodegradation of PBAT and PVA assessed through biochemical oxygen demand (BOD) experiments and microcosm tests revealed that the type of aquatic system governs the biodegradation behaviors of each plastic, with the highest biodegradation rate achieved in wastewater for both PBAT and PVA (25.6 and 32.2 % in 30 d, respectively). Plastic release pathway from wastewater into other aquatic systems simulated by sequential incubation in different microcosms suggested that PBAT exposed to wastewater and freshwater before reaching seawater was more prone to degradation than when directly exposed to seawater. On the other hand, PVA displayed comparable biodegradation rate regardless of whether it was directly exposed to seawater or had passed through other environments beforehand. Metagenome amplicon sequencing of 16S rRNA genes revealed distinct community shifts dependent on the type of plastics in changing environments along the simulated aquatic pathway. Several bacterial species putatively implicated in the biodegradation of PBAT and PVA are discussed. Our findings underscore the significant influence of pollution routes on the biodegradation of PBAT and PVA, highlighting the potential for wastewater treatment to facilitate rapid degradation compared to direct exposure to pristine aquatic environments.

Impacts of fish pond effluent on the water quality of an afrotropical stream: a comprehensive evaluation using the water quality index

This study highlights the importance of managing fishpond effluent to minimize its impact on aquatic environments. Fish effluents are a major concern worldwide in aquatic environments. It also provides information on the impacts of effluents on the water quality index of streams when released into aquatic environments. Streams and fishponds were sampled bimonthly for two annual cycles, covering different sampling stations both upstream and downstream of the fishpond effluents at 50-m intervals. Water quality parameters associated with in situ conditions were determined in the field. In the laboratory, other physicochemical parameters were determined via proper standard protocols. The results of the study revealed that water quality parameters such as turbidity, total suspended solids, total solids, conductivity, total dissolved solids, dissolved oxygen, biological oxygen demand and organic matter recorded in water samples collected from 50 m upstream at the point of effluent discharge were significantly (p < 0.05) different from those recorded at other sampling stations. The WQI value of the discharge point was higher than the WQI recorded in both the upstream and downstream sections of the stream. The findings of this study showed that the point of discharge of fishpond effluents is particularly concerning for the receiving stream compared with other sampling points. This localized area has experienced marked deterioration in water quality, posing significant threats to the health and biodiversity of aquatic ecosystems. The effluent's impact, though slight when dispersed in the receiving waterbody, underscores the necessity for adequate management practices to mitigate its adverse effects. Effective strategies, including regular monitoring, effluent treatment, and sustainable pond management, are imperative to ensure the long-term health and resilience of the aquatic environment.

The effect of inoculum source of different pollution levels on the performances of microbial fuel cell biosensors

Selection of inoculum sources is a key factor in constructing microbial fuel cells (MFCs), and the property of inoculum sources is greatly affected by the degree of environmental pollution. However, limited attention has been paid to how these differences affect the response of MFC biosensors. Here the effects of inoculum sources with varying pollution levels on the performances of constructed MFCs were evaluated, and the microbial communities were analyzed before and after inoculation. The results showed significant differences in the detection of biochemical oxygen demand (BOD) and toxicity (Cu2+) among the five groups of MFC biosensors. Combined with the data of the microbial community, the results indicated that the increase rate of the initial start-up voltage is related to the abundance of original electroactive bacteria (EAB) in the inoculum source. The higher the abundance of EAB, the faster increase rate in the initial start-up voltage and the shorter start-up time. The difference in the detection range of the BOD should be related to the ability of the microbial communities to withstand the organic shock loads. The microbial community's tolerance to Cu2+ was affected by the original water quality of the inoculum source. The high metal ion content leads to low sensitivity of MFC biosensor to Cu2+ ion. Enterobacteriaceae were abundant in all the five groups of MFCs, indicating that the dominant bacteria can be enriched in MFC anode biofilms with the inoculum sources of different pollution levels. The microbial community compositions of the anode biofilms were affected by the inoculum sources of different pollution levels, which in turn resulted in the differences in MFCs performances.

Vegetation health and its relationship with Organic Pollution of the Santa Rosa Wetland, Chancay – Lima, 2023 [Salud de la vegetación y su relación con la Contaminación Orgánica del Humedal Santa Rosa, Chancay – Lima, 2023

The present research aimed to: Determine the Health of Vegetation and its relationship with Organic Pollution of the Santa Rosa Wetland, located in the district of Chancay, in the year 2023. The study is of a mixed type, with a descriptive level by analyzing satellite images to determine the Normalized Difference Vegetation Index (NDVI), with an experimental design, by taking water samples and analyzing them in the laboratory to identify the levels of organic material pollution. Results: From the satellite image analysis, it was determined that the NDVI decreased in 2023, (value of 0.132) between the months of June to October, and in the water quality analysis, the parameters of chemical oxygen demand were measured, with results ranging from 48.50 to 100.50 mg/L, total suspended solids from 30 to 31 mg/L, and biochemical oxygen demand between 19.34 to 33.50 mg/L, indicating that there is pollution (DS. N° 004-2017-MINAM). At the same time, the results were reaffirmed by measuring the extent of the vegetation with a supervised classification analysis of the satellite images, obtaining that the vegetation of the wetland (duckweed and water lentil) increased from 66.08% to 86.64% between the months of June to October. According to the obtained data, it is concluded that there is a relationship between both variables; if pollution decreases the vigor of the indicator plants also decreases as they act biologically as phytoremediators.

Comparative Analysis of Water Quality Index (WQI) from Selected Water Bodies in Different Regions of Southeast Nigeria

This study was carried out to compare the water quality index of selected water bodies in Okigwe, Imo State, Nigeria. Water samples were collected from two streams, Ihiku and Iyiechu (upstream and downstream) and the experimental research was used for this study. Several physico-chemical characteristics were analyzed in line with W.H.O, USEPA, S.O.N. The results obtained from the physico- chemical parameters ranged as follows: air shade temperature (23.3-25.0), pH (5.7-6.8), Electrical conductivity (15.5-20.4), Total hardness (33-40.5), Alkalinity (55.5-70.8), Biological Oxygen Demand (2.6-5.0), Dissolved Oxygen (6.5-8.0), Sulphate (1.8-5.7), phosphate (5.2-7.0) and silica (0.66-0.78). The result showed that there were variations in the concentration as a result of anthropogenic activities of man. The water quality index was also checked and compared to standards. The Pearson’s Correlation Moment was performed at 0.01% level. The result showed that values obtained were statistically significant. However, adequate treatment facilities that purify sewage prior to discharge or disposal should be adopted.

Performance evaluation of integrated Upflow Anaerobic Sludge Blanket reactor with trickling filter used for municipal wastewater treatment and effluent reuse potential for agriculture

Effluent reuse is a rapidly growing field of research where assessing the quality of effluent is one of the focus areas. This research examines the viability of using wastewater in agriculture by testing an integrated Upflow Anaerobic Sludge Blanket (UASB) reactor with a trickling filter (TF) system during the dry season. Compliance monitoring was conducted for 30 days from May 11 to June 9 of 2021. Samples were collected, handled, and analyzed following standard wastewater analysis procedures for biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), volatile suspended solids (VSS), cations, anions, heavy metals, E. coli, and helminth egg. The UASB-TF system in Kality wastewater treatment performed well in removing COD, BOD5, and TSS with average removal rates of 80.5%, 82.9%, and 80.9%, respectively, compared well with similar treatment configurations. The effluent quality satisfied the national inland discharge limit with a residual concentration of 125.1 mg/L for COD, 61.7 mg/L for BOD5 and 85.8 mg/L for TSS. On the other hand, high concentrations of chromium, nitrate-nitrogen, and helminth egg count restricted effluent reuse for agricultural purposes due to high health risks and environmental contamination. We found out that discharging industrial sewage into the domestic sewer network could inhibit microbial growth and affect the biological treatment processes. Furthermore, adopting integrated treatment systems in developing countries might face operational challenges and monitoring nitrate, helminth egg, and heavy metals would help provide timely operational feedback. An appropriate tertiary treatment unit—constructed wetlands or polishing ponds—is therefore needed to be introduced to ensure effluent reuse for agricultural purposes.