Effluent Discharge Research Articles

Life-cycle analysis of environmental loads from household septic systems in Japan focusing on effluent water discharge

Abstract Various types of small-scale wastewater treatment systems are widely used in rural areas, and life-cycle assessment (LCA) should be performed to evaluate their environmental performance. In this study, septic systems were first classified into five categories based on their wastewater treatment performance. Effluent samples from actual systems were collected, and their water qualities were determined. A model to evaluate the environmental load from the septic systems using LCA methods was then established. The water-quality values obtained were input to the model, and the life-cycle environmental costs of the classified septic systems were calculated. The mean environmental load of the effluent during the operation stage was 37.6%, confirming that evaluation of an effluent discharge inventory using LCA, inspection, and water-quality monitoring to improve operations is critical for reducing the environmental load. The operation stage accounts for over 99% of the involved eutrophication, biological toxicity, and toxic chemicals, which are strongly related to the quality of the effluent. Evaluation of the effluent discharge inventory using LCA is of great significance, even for small-scale wastewater treatment systems. The set of procedures developed in this study can be used to calculate comprehensive environmental impacts at wastewater treatment plants.

Life cycle environmental impact assessment of slaughterhouse wastewater treatment

Slaughterhouses are significant industrial water users, ranking second highest in the livestock processing sector, and a potential pollution source for water bodies due to effluent discharge. This paper uses the wastewater composition of an actual slaughterhouse and models three alternative scenarios for the wastewater management; no treatment and discharge, primary treatment and discharge, and tertiary treatment followed by partial water reuse. All three scenarios are assessed in terms of their environmental performance following a Life Cycle Assessment, by using the Environmental Footprint 3.0 method. The results revealed that the best scenario for the slaughterhouse wastewater treatment is the third scenario with an overall footprint of 0.255 milliEcopoints (mPt), compared to 2.45 mPt and 1.31 mPt of the first and the second scenario, respectively.

Waste biomass derived highly-porous carbon material for toxic metal removal: Optimisation, mechanisms and environmental implications

Toxic elements, lead, and copper are often found in wastewater discharged from industries such as mining. The discharge of untreated effluent poses severe environmental challenges and sorption methods using agricultural waste materials are proposed as an efficient and cost-effective solution. For this research, activated sunflower material (ASM) was prepared from abundantly available agricultural sunflower waste residues and utilised to remove Pb2+ and Cu2+ ions from an aqueous medium. To begin, we examine variables that may have an impact on the adsorption process, such as pH, contact time, adsorbent dose, and initial concentration using Box-Behnken Design (BBD) to find optimal conditions. Maximum removal efficiency was found at a pH of 5, contact time of 180 min, and initial concentration of 50 mg/L for Pb2+ and 150 mg/L for Cu2+. Additionally, adsorbent dose differed by element, for Cu2+ it was 200 mg, whilst for Pb2+ it was 124 mg. Features of activated carbon such as morphology, elemental composition, textural properties, and surface functionalities were characterised using SEM-EDS, BET, FTIR, and XPS. The adsorption equilibrium data were analysed by Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. It was found that the obtained results for Pb2+ adsorption were better described with the Freundlich isotherm model. Maximum adsorption capacities for Pb2+ and Cu2+ were 91.8 mg/g and 20.5 mg/g, respectively. Furthermore, kinetic studies confirmed that the adsorption process followed a pseudo-first-order kinetic model for Pb2+, but for Cu2+ all applied kinetic models fitted experimental data with the same values of the correlation coefficient (R2 = 0.99). After comprehensive analysis using the methods mentioned above, ASM was tested for the removal of Cu2+ from mining wastewater sample, and the obtained removal efficiency was 98.6% ± 2.0%. The results of desorption experiments conducted, confirm that ASM has good potential to be reused for the purpose of removing Cu2+ from wastewater.

THE INFLUENCE OF INDUSTRIAL EFFLUENT ON CHALLAWA RIVER WATER QUALITY

Water from River Challawa was assessed to test the influence of industrial effluent on the quality of water from the river. Sample collection was done in the month of June, 2023 at the end of dry season. At each sampling three (3) samples were collected to ensure accuracy by replication. A total of twenty-seven samples (27) were collected. Descriptive statistics was carried out on the data. The results obtained were compared with FEPA and WHO standards. A paired sample t-test was also carried out to test for any significant difference in the mean value of parameters upstream and downstream of points of discharge of effluents. Based on the findings of the research, it was concluded that, BOD, TDS and EC at the effluent point before and after have no any significant effect on the quality water from Challawa River. The findings of the study also revealed absence of lead and low concentration of zinc in the water. It was recommended that, the water from River Challawa can be used for irrigation with good management practices.

Differentiation of environment and wastewater treatment plants by core antibiotic resistance genes and aadA2 as indicators in South Korea

Antibiotic resistance is reportedly disseminated from wastewater treatment plants (WWTPs) into aquatic environments. In this study, it was hypothesized that discharge of effluent from WWTPs may influence resistome of the adjacent aquatic environment. Thus, we aimed at investigation of resistome in WWTPs and receiving waters, to observe the dynamics of resistome and to determine the indicators for consistent comparison of contamination level. In this study, twenty-seven samples of upstreams (n = 9), downstreams (n = 9), and effluents (n = 9) samples from nine WWTPs located in the Nakdong and Yeongsan Rivers, South Korea, were collected for four years, and a total of 343 antibiotic resistance genes (ARGs) were quantitatively amplified using SmartChip analysis. The five core ARGs (aadA, aadA2, aadA5, strB, and sul1) were commonly detected in all samples. Three (aadA, aadA2, aadA5) of the five core ARGs were significantly more abundant in the effluent than in the aquatic environment. Interestingly, the water sources of the aquatic environments and effluents could be differentiated based on the abundance of the five core ARGs. The decision-making tree model supported the classification of the two water sources: aquatic environments and effluents. Taken together, considering the ubiquitous presence of the five ARGs with significantly different abundance between water sources, core ARGs including aadA2 are recommended as indicator genes to monitor ARGs contamination by employing quantitative analysis in South Korea. Determination of indicators would help consistently evaluate contamination level by ARGs.

Radiological hazard assessment for human from nuclear power plant effluent released under normal operation scenario (hypothetical case study)

This paper presents an assessment of the radiological hazard for humans from nuclear power plant effluent released into a river under normal operation scenarios (NOS). A hypothetical case study was conducted to estimate the annual effective dose (AED) received by the general public due to the discharge of effluent from the nuclear power plant. The results indicate that the radiological hazard for humans from nuclear power plant effluent released under (NOS) is minimal. The estimated AED received by the general public was found to be below 0.1 mSv/year, which is well below the annual dose limit of 1 mSv/y set by the International Commission on Radiological Protection (ICRP). The excess lifetime cancer risk (ELCR) detected remained within acceptable limits. These results estimated that nuclear power can be a safe and reliable source of energy when operated in accordance with established safety protocols. The study revealed that the concentration of 137Cs in sediments was higher than that of other radionuclides studied, leading to increased potential hazards over time. Overall, this study provides valuable information on the radiological hazard associated with nuclear power plant effluent released into a river under (NOS), which can be useful in the development of radiation protection strategies for nuclear power plants and in the communication of the risks associated with nuclear power to the public.

Balneability of the Municipality of São Luis – MA and the Influence of Rainfall Occurrences as an Externality Factor

Objective: To analyze the bathing conditions, that is, the quality of the water intended for primary contact recreation on the beaches of Ponta D’areia, São Marcos, Calhau and Olho d’água located in the municipality of São Luís- Maranhão. Theoretical framework: This study was conducted based on theoretical reflections on environmental issues, the relationship between society and nature. Issues of water use for recreation, environmental policies regarding bathing and externalities that interfere with the quality of water for bathing and their impacts on the health of the population were analyzed. Method: To select beaches and water collection sites, the most intense flow of bathers and the risks of interference with water quality were taken into account. Data on bathing ability and average monthly precipitation were obtained to verify bathing conditions, in addition to information on effluent release points and urban drainage. Results and conclusion: It was observed that the main influence on the incidence of thermotolerant coliforms is the presence of sanitary effluents on beaches, this factor becomes visible in the rainy season and with the lack of sanitary infrastructure. Implications of the research: This research will contribute to public policy measures, helping decision-making to improve public and environmental health in the city of São Luís- MA. Originality/value: This study has socio-environmental and scientific value, as it relates bathing ability to externalities such as the lack of environmental sanitation and high rainfall in the region.

Effects of Rapid Thermal Cycling (Cold Shock) on Fish Health: Evidence from Controlled Laboratory Experiments, Behavior, and Telemetry

Powerplants frequently use river water for cooling, subsequently discharging warm effluent. Some of these plants can cycle on and off rapidly based on electricity demand, resulting in dramatic temperature fluctuations in the receiving waters. To understand the impacts on resident fish populations in the Upper Mississippi River, we (i) assessed the effects of rapid water cooling on three native fish species; (ii) investigated whether smallmouth bass (Micropterus dolomieu) behavior favored movement into thermal plumes when given a choice of cooler or ambient water; and (iii) tracked native M. dolomieu with acoustic tags and recorded core body temperature during the thermal cycling process of a steam electric powerplant. In cold shock experiments, mortality was associated with rapid temperature declines and dependent on the final (cold) holding temperature. The species or developmental stage of the tested organism did not affect survival. When given a choice between warm and ambient waters, M. dolomieu exhibited little inclination to acclimate to the warmer water and instead “self-regulated” by moving in and out of the warm water plume. This finding was supported by telemetry data on M. dolomieu. The core temperature of the fish never increased more than 2 °C above the ambient (upstream) Mississippi River temperature, even during warm effluent discharge.

Awareness of the effects of small-scale cassava mill effluent on the environment in Ika North East Local Government Area, Delta State, Nigeria.

The threat of environmental pollution in Nigeria, particularly in the Niger Delta region, cannot be solely ascribed to oil spillages; rather, it also encompasses the discharge of cassava mill effluent (CME), frequently disposed off in an unregulated manner. Existing studies on CME have focused on its potential environmental consequences on soil characteristics, microbial populations, and heavy metal levels. There is limited study on the awareness of the impact of CME on the environment. Thus, this study contributes to the literature on CME by examining the awareness of its effect on the environment in Ika North East Local Government Area of Delta State, Nigeria. The study used interviews, observation, and questionnaires administered to 399 respondents for data collection. A Student t-test, ANOVA, and Pearson's correlation were employed to analyse the data in Statistical Package for the Social Sciences. Results revealed limited awareness, with 51.3% unaware of CME's environmental impact. Slight, moderate, and extreme awareness were reported by 7.5%, 17.3%, and 23.8%, respectively. Gender's influence on awareness was insignificant, but age showed a significant influence (p < 0.05), while education, occupation, and income correlated positively with awareness (p < 0.001). The source of information significantly predicted awareness (r = -0.727, p < 0.001). It indicates that gender's influence on awareness might depend on education levels. Socio-economic factors are strongly related to awareness. Reliable information sources are vital for understanding CME's environmental impact. The study underscores the need for enhanced environmental education and reliable information dissemination to promote sustainable practices.

Land use and Occupation and Water Quality of the Meia Ponte River

Purpose: The present study aimed to study the catchment basin of the Meia Ponte River, analyzing land use and occupation, verifying whether permanent preservation areas are being preserved and which activities predominate in the region. Theoretical framework: Inadequate land use and the release of effluents can harm the quality and quantity of water available for use. Therefore, the sustainable exploitation of natural resources is necessary, combining economic development and environmental preservation. Methods: Physicochemical analyzes were carried out, evaluating the following parameters: pH, turbidity, color, temperature, biochemical oxygen demand (COD) and total phosphorus. The location chosen to carry out the collections was the water collection point for public supply from the Meia Ponte River. In addition to data obtained by the mapbiomas program using QGIS software. To delimit the basin, data from the Goiás geographic information system (SIEG) was used. Results and conclusion: The results showed that more than 60% of the basin area studied was pasture area, showing that there is degradation in the basin and satellite images showed that there are also areas of APP that are not properly preserved. Furthermore, water collections during the rainy season showed a high turbidity value, indicating that solids are being transported into the water body. Research implications: The main contributions are related to the eutrophication process and the environmental impacts caused by human actions. Originality/value: Verification of the impacts of human actions on land use and occupation on water quality in the Meia Ponte river region.

Fifty-Year Review of Effluent Discharge Trends to the Southern California Bight from Large Municipal Wastewater Treatment Facilities from 1971 to 2020

Historically, Southern California’s four largest publicly owned treatment works (POTWs) were major sources of contaminants in the Southern California Bight (SCB), home to over 22 million residents and diverse marine life. This study conducted a fifty-year review (1971–2020) to assess these facilities’ performance in protecting human and aquatic life. We analyzed effluent discharge flow, total annual mass emissions into SCB, and the rate of change of mass emissions in five ten-year timeframes. Results show a significant decrease in contaminant concentrations (43% to 99%) from 1971 to 2020, with most reaching historically low levels. Despite a growing population, effluent volume decreased by 23%, reflecting successful local water conservation and recycling efforts. Some constituents experienced temporary increases that later decreased. Overall, the decline in mass emissions for all constituents over fifty years highlights the POTWs’ efforts to treat effluent and reduce their impact on the SCB’s ecosystem.

Impact of wastewater reuse on contaminants of emerging concern in an effluent-dominated river

Contaminants of emerging concern such as pharmaceuticals, personal care products, per- and polyfluoroalkyl substances, and plasticizers, are ubiquitous in effluent-dominated rivers and have potential adverse effects on humans and aquatic life. Demands on water supply have prompted conservation and water reuse measures, impacting the discharge in these rivers, yet the effects of these management decisions on water quality are largely intuited and not quantified. This research examines how changes in water reuse practices will impact concentrations of contaminants of emerging concern, specifically carbamazepine, diclofenac, galaxolide, gemfibrozil, 4-nonylphenol, and perfluorooctane sulfonic acid (PFOS), in the effluent-dominated Los Angeles River (Los Angeles County, California). A water quality module was added to a calibrated hydrologic model of the system and parametrized with observed water quality monitoring data in EPA SWMM. Results indicate that water reuse (i.e., reduced effluent flow) will consistently improve in-stream water quality for all compounds studied except PFOS. However, the improvements are often not substantial enough to mitigate high concentrations directly downstream of treated effluent discharge points. Concentrations of these pharmaceuticals are substantially reduced through attenuation as dilution and degradation occur downstream, though the rate of this attenuation is variable and based on the contaminant. In contrast, concentrations of PFOS increase under some wastewater reuse scenarios and decrease under others but remain below the recommended environmental screening levels. Our work also highlights that management decisions regarding water quantity should integrate water quality modeling to help identify priority monitoring locations and constituents.

Simultaneous removal of nitrogen and phosphorus nutrients from secondary effluent by magnetic resin containing two types of quaternary ammonium adsorption sites: Preparation, characterization, and application

The direct discharge of secondary effluent (SE) from wastewater treatment plants without proper nitrogen and phosphorus treatments can result in the eutrophication of landscape water bodies. The primary objective of advanced treatment should focus on the removal of NO3− and PO43− as the optimal approach. In this study, magnetic resin microspheres known as MGE (derived from the initials of the three organic monomers used, namely methyl methacrylate, glycidyl methacrylate, and 3,4-epoxy-1-butene) were successfully prepared through suspension polymerization. MGE incorporated two types of sites specifically designed for the removal of anionic nitrogen and phosphorus nutrients. The removal of NO3−, PO43−, and humic acid (HA) by MGE fit well with the pseudo-second-order kinetic and Freundlich adsorption isotherm models (R2 = 0.884–0.993 and 0.918–0.969, respectively). The removal efficiencies of ultraviolet absorbance at 254 nm, total nitrogen, total phosphorus, NO3−, PO43−, and total fluorescence in SE by MGE were 50.4 %, 20.9 %, 27.1 %, 21.5 %, 30.2 %, and 42.0 %, respectively, which were significantly higher than those achieved by commercially available MIEX® and D201. The molecular dynamic simulation results indicated that the increased removal of NH4+ by resin after adsorption of HA can be attributed to the aggregation effect of HA and NH4+ caused by H-bonds. The nitrogen and phosphorus indicators of the MGE effluent met the GB/T 18921-2019 water quality standard for scenic environmental use in China. MGE exhibited exceptional adsorption capacity and rapid achievement of adsorption equilibrium, making it a potential adsorbent for the removal of anionic nitrogen and phosphorus nutrients in engineering applications.

Proposal of a Model for Water Usage: Revenue Estimation in Brazil Hydrographic Basin

In order to improve the quality of aquatic ecosystems, a water collection instrument was established in the National Water Resources Policy (PNRH), with the purpose of collecting and allocating resources to the management of water systems, as well as stimulating the conscious and efficient use of water, with the direct finality of reducing the rates of waste and pollution of water sources. This instrument guided the definition of the objective from the present research, which is to estimate the collection of the Pianco-Piranhas-Açu Basin, located between the State of Paraiba and Rio Grande do Norte, to be calculated with a mathematical model of collection by the multiple water uses that consider volumes consumed, captured and for the discharge of effluents. To do so, it was analysed the main collection models adopted in Brazil to finally define the best algorithmic basis. Analysing the results, it was observed that the planned resources still do not provide a sustainable application of the real situation of the analysed basin, requiring further research to better understand the peculiarities of the region, given that the estimated collection is insufficient to provide the necessary infrastructure for Pianco-Piranhas-Açu (Brazil) river’s basin management system. Therefore, this situation serves to alert public water management bodies about the modelling to be used and the urgency of implementing the charging instrument, given that it could improve the quality of the hydrographic basin studied.

Multivariate statistical analysis to assess the surface water quality of a snow and glacier-fed river: A case from Alaknanda River basin.

The water quality of Himalayan rivers has declined due to human activities, untreated effluent discharge, and poor sewage and drainage systems. The current study aimed to assess the water quality of these rivers using multivariate statistical analysis throughout four seasons. The analyses of 44 surface water samples taken during the monsoon, winter, spring, and summer seasons are well within the ranges acceptable for drinking and domestic use after the sedimentation. The suspended soils and turbidity are highly correlated and affect the water quality index (WQI). The WQI of headwater streams is good during low water flow seasons and poor during high water flow seasons. This is due to the number of melting glaciers and suspended solids/turbidity. Principal component analysis shows that in all the seasons, human activities such as road-cutting projects across the river and natural causes such as intense rainfall and melting of moraine-filled glaciers both impact the WQI. The findings of this study provide important information for future research and policy decisions aimed at improving the water quality of the Himalayan rivers.

Cascading effects of trace metals enrichment on phytoplankton communities of the River Ganga in South Asia

Globally freshwater ecosystems and associated biota including phytoplankton communities are at extreme risk from trace metal pollution originating from geogenic as well as from anthropogenic sources such as release of untreated industrial effluents. In the present study influence of iron- and arsenic-enrichments on structure and metabolism of phytoplankton communities of River Ganga, one of the largest rivers of South Asia, was assessed under laboratory-based microcosm experiments. Surface water samples were collected and subsequently enriched with higher than recommended concentrations of iron (10 mg/L) and arsenic (10 μg/L). The set-up comprised of nine containers of 25 L volume with three containers each for iron- and arsenic-enrichment and was maintained for 30 days. Trace metal enrichment rapidly changed the phytoplankton community structure and chemistry of nutrients uptake. Iron-enrichment prompted diatom blooms comprising of Thalassiosira, succeeded by green algae Coelastrum. Arsenic-enrichment maintained cyanobacteria for longer time-spans compared to the control and iron-enriched containers but significantly lesser abundance of diatoms. Variations in community composition was also reflected in nutrient uptake rates with silicate release in the arsenic-enriched containers at the end of the experiment. Changes in macronutrient dynamics also altered genus growth rates wherein both iron- and arsenic appeared to lower the death rate of Thalassosira but stimulated growth of other genera including Skeletonema and Pandorina. Iron appeared to influence lesser number of genera compared to arsenic which altered growth rates of both diatoms and green algae. This consequently influenced the gross primary productivity values which lowered both in the iron- and arsenic-enriched containers compared to the control owing to decrease in phytoplankton diversity. Iron appeared to drive phytoplankton communities toward a less general and more specialized composition with high abundance of selective species comprising of small diatoms such as Thalassiosira, whereas arsenic appears to select for green algal enrichment in freshwater ecosystems.

Distribution of Antibiotic Resistance in a Mixed-Use Watershed and the Impact of Wastewater Treatment Plants on Antibiotic Resistance in Surface Water.

The aquatic environment has been recognized as a source of antibiotic resistance (AR) that factors into the One Health approach to combat AR. To provide much needed data on AR in the environment, a comprehensive survey of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs), and antibiotic residues was conducted in a mixed-use watershed and wastewater treatment plants (WWTPs) within the watershed to evaluate these contaminants in surface water. A culture-based approach was used to determine prevalence and diversity of ARB in surface water. Low levels of AR Salmonella (9.6%) and Escherichia coli (6.5%) were detected, while all Enterococcus were resistant to at least one tested antibiotic. Fewer than 20% of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (17.3%) and carbapenem-resistant Enterobacteriaceae (CRE) (7.7%) were recovered. Six ARGs were detected using qPCR, primarily the erythromycin-resistance gene, ermB. Of the 26 antibiotics measured, almost all water samples (98.7%) had detectable levels of antibiotics. Analysis of wastewater samples from three WWTPs showed that WWTPs did not completely remove AR contaminants. ARGs and antibiotics were detected in all the WWTP effluent discharges, indicating that WWTPs are the source of AR contaminants in receiving water. However, no significant difference in ARGs and antibiotics between the upstream and downstream water suggests that there are other sources of AR contamination. The widespread occurrence and abundance of medically important antibiotics, bacteria resistant to antibiotics used for human and veterinary purposes, and the genes associated with resistance to these antibiotics, may potentially pose risks to the local populations exposed to these water sources.

Application of alternative organic wetland media for acid mine drainage treatment: Insights on reformations of microbial community structure

Acid mine drainage (AMD) discharge, particularly from the North Eastern Coalfield (NEC), Assam, has been a major persistent ecological threat. A lab-scale constructed wetland (CW) deriving organic wastes as the wetland media was implemented to treat high acidity (724 mg L–1 as CaCO3) AMD loaded with sulfate (1000–1300 mg L–1). Metal contents in mine wastewater comprised iron, aluminium, manganese, zinc, cobalt, nickel and chromium as 104, 25, 6.2, 5.1, 1.1, 1.1 and 1.1 mg L–1, respectively. CW operated continuously at a hydraulic loading rate (HLR) of 0.03 m3 m–2 d–1 for 282 days. Effluent water quality was monitored, and resulting shifts in microbial diversity were identified. Results demonstrated 771 mg L–1 (as CaCO3) alkalinity in effluent and metal removal (87–100%), except Co and Mn, which surpassed effluent discharge criteria. Further, the high-throughput sequencing results revealed significant reformations in bacterial assemblages throughout the operational period. Proteobacteria (45%) and Bacteroidetes (26%) represented the major bacterial groups at the start-up of CW, which later declined due to the elimination of aerobic strains under anaerobic conditions. Additionally, methanogenic archaea suppressed greatly due to the competition from sulfate and iron-reducers. An increase in the relative abundances of key functional bacteria (Firmicutes, Bacteroidetes, Actinobacteria and Acidobacteria) in the treatment phase indicated stable operation. Sulfate reduction (62%) was partial, evidenced by the prominence of sulfate-reducing bacteria (SRB) (Thermodesulfobium, Syntrophobacter, Desulfomonile and Desulfovibrio). This study offers insights into the microbial dynamics within an organic-media-amended CW, which directly influences AMD treatment.

Fabrication of visible-light induced fluorine doped bismuth oxide (Bi2O3-xFx) photocatalyst in degrading textile dyes from wastewater

Discharge of unused and untreated dye effluents into the environment by the textile industries is a major issue. In this wastewater, the methylene blue (MB) and methyl orange (MO) remain in a dissolved state along with various pollutants at different levels. To remove these dyes, visible light (λ ​≥ ​420 ​nm) active F (fluorine) doped bismuth oxide (Bi2O3-xFx) photocatalyst was synthesized through facile sol-gel method utilizing bismuth oxide (Bi2O3) and hydrofluoric acid (HF). Bi2O3-xFx demonstrated enhanced photocatalytic activity to decompose methylene blue (MB) and methyl orange (MO) under visible light. The F content in Bi2O3-xFx composite was optimized to 0.94 atom % with respect to organics decomposition. The study showed that enhanced photocatalytic activity of Bi2O3-xFx was ascribed due to participation of photo-induced electron (e¯)-hole (h+) in photocatalysis. The existence of hole (h+) and the generated °OH radical was experimentally confirmed in aqueous medium. The formation mechanism of these reactive species was explained on the basis of relative energy band position of Bi2O3-xFx and a detail photocatalytic decomposition reaction mechanism was proposed.

Assessment of organic pollutants in petroleum refinery wastewater by LC-MS analyzer

The release of toxic and hazardous effluents from petroleum refining companies seriously threatens the poisoning of water bodies. Thus, it is necessary to determine an accurate treatment process by understanding the nature of wastewater. This work uses Liquid Chromatography-Mass Spectroscopy (LCMS), including LC-Tandem MS (LCMS/MS), ion trap (IT), and quadrupole-time-of-flight (Q-TOF) to comprehend the composition of petroleum refinery effluent. Many polar metabolites available, even as a trace fraction, can be found using advanced LCMS with defined molecular structure, which may or may not be itemized in CAS. Based on the number of carbon atoms (C1-C48), chemical reactivity (saturated, unsaturated, and aromatics), and functional group (hydrocarbons containing oxygen only and other minerals along with oxygen), substances are identified. Using LCMS/MS, 170 organic components, 77.10% negative and 22.90% positive metabolites, are quantified. A range of carbon between C8 and C48 is identified as having 6.50% C8-C12, 30% C13-C17, and 63.50% C18-C48. Higher molecular mass hydrocarbons from C22-C48 are less soluble in water and are more positively polarized, while C8-C21 hydrocarbons are more soluble under negative polarity. The principal ingredient is documented as consisting primarily of aromatic chemicals (72.30%), the majority of which are found as harmful metabolites. Further, 83% of the hydrocarbons are acknowledged to contain solely oxygen compared to other minerals in petroleum effluents. Overall, it was concluded that the direct discharge of petroleum refinery effluents without treatment may cause various health and environmental issues.