Investigating the socioeconomic impacts of sewage spillages on businesses in the Umhlanga Rocks coastline area

Sewage spillage is fast becoming a significant concern in South Africa because of the deteriorating infrastructure and substandard service delivery. Thus, this study investigated the socioeconomic impacts of sewage spillages on businesses in the Umhlanga Rocks coastline area. A questionnaire with open and closed-ended questions was used to collect data from business owners in the affected area. One hundred business owners were handed questionnaires to complete, and 95 completed questionnaires were collected. The qualitative data from the questionnaires were analysed using thematic analysis, whereby line-by-line coding was manually completed using Excel. The quantitative data were analysed in R studio using numerous statistical tests, including the Shapiro-Wilk test, the Chi-square test, the Kruskal-Wallis test, Dunn's test, and Cohen's d test. The thematic analysis and statistical testing results showed that sewage spillages disrupted businesses significantly. Results indicated that businesses of different sizes experienced socioeconomic losses differently. Consequently, the results of this study have implications for business owners and communities living in the affected area. Moreover, findings have revealed practical strategies and interventions that may be used by micro- to medium-scale businesses to mitigate the socioeconomic impact of sewage spillages.

Contribution

The practical strategies revealed in this study contribute to reducing the vulnerability of communities and businesses to sewage spillages. Findings of the study have also been disseminated to the business owners and other relevant stakeholders to provide them with alternative solutions in 'softening the blow' caused by the spillages.

Recent Development of Metal-Organic Frameworks for Water Purification

Water contamination is an increasing concern to mankind because of the increasing amount of pollutants in aquatic ecosystems. To purify the polluted water, various techniques have been used to remove hazardous components. Unfortunately, traditional cleanup techniques with a low uptake capacity are unable to achieve water purification. Metal-organic frameworks (MOFs) have recently shown potential in effective water pollutant isolation in terms of selectivity and adsorption capacity over traditional porous materials. The high surface area and versatile functionality of MOFs allow for the development of new adsorbents. The development of MOFs in a range of water treatments in the recent five years will be highlighted in this review, along with assessments of the adsorption performance relevant to the particular task. Moreover, the outlook on future opportunities for water purification using MOFs is also provided.

Sorption of per- and poly-fluoroalkyl substances and their precursors on activated carbon under realistic drinking water conditions: Insights into sorbent variability and PFAS structural effects

Recent stringent drinking water quality standards create challenges for water utilities to meet these standards. Advanced treatment techniques will have to be applied on many drinking water production locations to meet these quality standards. This study investigated the sorption of per- and polyfluorinated-alkyl substances (PFAS) onto granular activated carbon (GAC). The study was performed at environmentally relevant PFAS concentrations and a realistic water-to-GAC ratio, providing a realism often overlooked in existing studies. Three different forms of GAC were evaluated, differing in micropore and mesopore structures. Tap water spiked with 5 ng/L of each of 31 PFAS was used in the sorption experiments, i.e. perfluorocarboxylic acids (C4-C12), perfluorosulfonic acids (PFSA, C5-C10) including linear and branched isomers, and three groups of PFAS precursors (per-/polyfluoroalkyl ether acids, sulfonamides, and sulfonamide acetic acids). The three studied GAC did not exhibit distinct differences in PFAS sorption. The removal of PFAS was below 50 % for most studied PFAS, except for the short-chain PFAS precursors. Sorption was affected by both the carbon chain length and functional groups for PFAS, while this was not observed for PFAS precursors. The presence of ether linkages and sulfonamide groups notably enhanced sorption. Linear and branched PFSA demonstrated similar sorption behavior, whereas branched isomers of the sulfonamide acetic acid precursors exhibited significantly higher sorption. This indicates that sorption was determined by both hydrophobic and electrostatic interactions. Given the relatively low PFAS removal by GAC under environmentally relevant test conditions, further improvements in sorbents are required to ensure that PFAS concentrations in produced drinking water comply with drinking water standards.

Wastewater Treatment Using Membrane Bioreactor Technologies: Removal of Phenolic Contaminants from Oil and Coal Refineries and Pharmaceutical Industries

Huge amounts of noxious chemicals from coal and petrochemical refineries and pharmaceutical industries are released into water bodies. These chemicals are highly toxic and cause adverse effects on both aquatic and terrestrial life. The removal of hazardous contaminants from industrial effluents is expensive and environmentally driven. The majority of the technologies applied nowadays for the removal of phenols and other contaminants are based on physio-chemical processes such as solvent extraction, chemical precipitation, and adsorption. The removal efficiency of toxic chemicals, especially phenols, is low with these technologies when the concentrations are very low. Furthermore, the major drawbacks of these technologies are the high operation costs and inadequate selectivity. To overcome these limitations, researchers are applying biological and membrane technologies together, which are gaining more attention because of their ease of use, high selectivity, and effectiveness. In the present review, the microbial degradation of phenolics in combination with intensified membrane bioreactors (MBRs) has been discussed. Important factors, including the origin and mode of phenols' biodegradation as well as the characteristics of the membrane bioreactors for the optimal removal of phenolic contaminants from industrial effluents are considered. The modifications of MBRs for the removal of phenols from various wastewater sources have also been addressed in this review article. The economic analysis on the cost and benefits of MBR technology compared with conventional wastewater treatments is discussed extensively.

Kinetics, isotherm, mechanism, and recyclability of novel nano-sized Ce4+-doped Ni-Al layered double hydroxide for defluoridation of aqueous solutions

Excessive fluoride removal from aqueous solutions is of utmost importance as it has an adverse impact on human health. This study investigates the defluoridation efficiency of a novel nano-sized Ce+4-doped Ni/Al layered double hydroxide (Ni-Al-Ce LDH) for aqueous solutions. The synthesized Ni-Al-Ce LDH exhibited a well-defined nanoscale plate-like morphology and a high surface area with an average size of 11.51 nm, which contributed to its enhanced fluoride adsorption capacity. XRD, SEM, HRTEM, and BET studies confirmed these characteristics. XPS analysis confirmed the presence of Ce4+ ions within the Ni-Al LDH. The experimental results indicated that the process of defluoridation followed a pseudo-second-order model of kinetics, suggesting a chemisorption mechanism. The fluoride adsorption isotherms demonstrated well fits to the Freundlich, Langmuir, and Jovanovic models, indicating both monolayer and multilayer fluoride adsorption on the Ce-doped Ni-Al LDH. The maximum adsorption capacity was found to be 238.27 mg/g (Langmuir) and 130.73 mg/g (Jovanovic) at pH 6.0 and 25 °C. The proposed mechanisms for fluoride adsorption on the LDH include ion exchange, surface complexation, hydrogen bonding, and ligand exchange. The Ni-Al-Ce LDH nanomaterial exhibited good recyclability, maintaining 71% of the fluoride adsorption efficiency even after four consecutive cycles. This study highlights the significant role of Ce doping in improving the performance of Ni-Al LDH as a defluoridation adsorbent.

Pollutants in aquatic system: a frontier perspective of emerging threat and strategies to solve the crisis for safe drinking water

Water is an indispensable natural resource and is the most vital substance for the existence of life on earth. However, due to anthropogenic activities, it is being polluted at an alarming rate which has led to serious concern about water shortage across the world. Moreover, toxic contaminants released into water bodies from various industrial and domestic activities negatively affect aquatic and terrestrial organisms and cause serious diseases such as cancer, renal problems, gastroenteritis, diarrhea, and nausea in humans. Therefore, water treatments that can eliminate toxins are very crucial. Unfortunately, pollution treatment remains a difficulty when four broad considerations are taken into account: effectiveness, reusability, environmental friendliness, and affordability. In this situation, protecting water from contamination or creating affordable remedial techniques has become a serious issue. Although traditional wastewater treatment technologies have existed since antiquity, they are both expensive and inefficient. Nowadays, advanced sustainable technical approaches are being created to replace traditional wastewater treatment processes. The present study reviews the sources, toxicity, and possible remediation techniques of the water contaminants.

Impact of Arieş River Contaminants on Algae and Plants

The Arieş River (Western Romania) represents one of the most important affluents of the Mureş River, with great significance in the Mureş Tisza basin. The environmental quality of the Arieş basin is significantly affected by both historic mining activities and contemporary impacts. Thus, an evaluation of the effects of the main contaminants found in water (organochlorine pesticides-OCPs, monocyclic aromatic hydrocarbons-MAHs, polycyclic aromatic hydrocarbons-PAHs, and metals) on cyanobacteria and plants was performed. Among OCPs, hexachlorocyclohexane isomers, dichlorodiphenyltrichloroethane, and derivatives were detected in plants while admissible concentrations were detected in water. Among MAHs, high levels of benzene were detected both in water and in plants. The levels of PAHs exceeded the allowable values in all samples. Increased concentrations of metals in water were found only at Baia de Arieş, but in plants, all metal concentrations were high. The pH, nitrates, nitrites, and phosphates, as well as metals, pesticides, and aromatic hydrocarbons, influenced the physiological characteristics of algae, test plants, and aquatic plants exposed to various compounds dissolved in water. Considering that the Arieş River basin is the site of intense past mining activities, these data provide information about the impact on water quality as a consequence of pollution events.

Environmental pollutants and their effects on human health

Numerous environmental contaminants significantly contribute to human disease, affecting climate change and public and individual health, resulting in increased mortality and morbidity. Because of the scarcity of information regarding pollution exposure from less developed nations with inadequate waste management, higher levels of poverty, and limited adoption of new technology, the relationship between pollutants and health effects needs to be investigated more. A similar situation is present in many developed countries, where solutions are only discovered after the harm has already been done and the necessity for safeguards has subsided. The connection between environmental toxins and health needs to be better understood due to difficulties in quantifying exposure levels and a lack of systematic monitoring. Different pollutants are to blame for both chronic and acute disorders. Additionally, research becomes challenging when disease problems are seen after prolonged exposure. This review aims to discuss the present understanding of the association between environmental toxins and human health in bridging this knowledge gap. The genesis of cancer and the impact of various environmental pollutants on the human body's cardiovascular, respiratory, reproductive, prenatal, and neural health are discussed in this overview.

The Adsorption Efficiency of Regenerable Chitosan-TiO2 Composite Films in Removing 2,4-Dinitrophenol from Water

In this work, the great performance of chitosan-based films blended with TiO₂ (CH/TiO₂) is presented to adsorb the hazardous pollutant 2,4-dinitrophenol (DNP) from water. The DNP was successfully removed, with a high adsorption %: CH/TiO₂ exhibited a maximum adsorption capacity of 900 mg/g. For pursuing the proposed aim, UV-Vis spectroscopy was considered a powerful tool for monitoring the presence of DNP in purposely contaminated water. Swelling measurements were employed to infer more information about the interactions between chitosan and DNP, demonstrating the presence of electrostatic forces, deeply investigated by performing adsorption measurements by changing DNP solutions' ionic strength and pH values. The thermodynamics, adsorption isotherms, and kinetics were also studied, suggesting the DNP adsorption's heterogeneous character onto chitosan films. The applicability of pseudo-first- and pseudo-second-order kinetic equations confirmed the finding, further detailed by the Weber-Morris model. Finally, the adsorbent regeneration was exploited, and the possibility of inducing DNP desorption was investigated. For this purpose, suitable experiments were conducted using a saline solution that induced the DNP release, favoring the adsorbent reuse. In particular, 10 adsorption/desorption cycles were performed, evidencing the great ability of this material that does not lose its efficiency. As an alternative approach, the pollutant photodegradation by using Advanced Oxidation Processes, allowed by the presence of TiO₂, was preliminary investigated, opening a novel horizon in the use of chitosan-based materials for environmental applications.

Porous Materials for Water Purification

Water pollution is a growing threat to humanity due to the pervasiveness of contaminants in water bodies. Significant efforts have been made to separate these hazardous components to purify polluted water through various methods. However, conventional remediation methods suffer from limitations such as low uptake capacity or selectivity, and current water quality standards cannot be met. Recently, advanced porous materials (APMs) have shown promise in improved segregation of contaminants compared to traditional porous materials in uptake capacity and selectivity. These materials feature merits of high surface area and versatile functionality, rendering them ideal platforms for the design of novel adsorbents. This Review summarizes the development and employment of APMs in a variety of water treatments accompanied by assessments of task-specific adsorption performance. Finally, we discuss our perspectives on future opportunities for APMs in water purification.

Fabrications of Electrospun Mesoporous TiO2 Nanofibers with Various Amounts of PVP and Photocatalytic Properties on Methylene Blue (MB) Photodegradation

The superior chemical and electrical properties of TiO₂ are considered to be suitable material for various applications, such as photoelectrodes, photocatalysts, and semiconductor gas sensors; however, it is difficult to commercialize the applications due to their low photoelectric conversion efficiency. Various solutions have been suggested and among them, the increase of active sites through surface modification is one of the most studied methods. A porous nanostructure with a large specific surface area is an attractive solution to increasing active sites, and in the electrospinning process, mesoporous nanofibers can be obtained by controlling the composition of the precursor solution. This study successfully carried out surface modification of TiO₂ nanofibers by mixing polyvinylpyrrolidone with different molecular weights and using diisopropyl azodicarboxylate (DIPA). The morphology and crystallographic properties of the TiO₂ samples were analyzed using a field emission electron microscope and X-ray diffraction method. The specific surface area and pore properties of the nanofiber samples were compared using the Brunauer-Emmett-Teller method. The TiO₂ nanofibers fabricated by the precursor with K-30 polyvinyl pyrrolidone and diisopropyl azodicarboxylate were more porous than the TiO₂ nanofibers without them. The modified nanofibers with K-30 and DIPA had a photocatalytic efficiency of 150% compared to TiO₂ nanofibers. Their X-ray diffraction patterns revealed anatase peaks. The average crystallite size of the modified nanofibers was calculated to be 6.27-9.27 nm, and the specific surface area was 23.5-27.4 m²/g, which was more than 150% larger than the 17.2 m²/g of ordinary TiO₂ nanofibers.

A critical review of oil spills in the Niger Delta aquatic environment: causes, impacts, and bioremediation assessment

The Niger Delta region in South-South Nigeria, on Africa's West Coast, is densely populated. The region, which contains a substantial stock of crude oil and natural gas, has been nicknamed "the engine room" for Nigeria's economic development and progress. It is responsible for up to 90% of the country's economic growth (or gross domestic product/GDP). The region has multiple ecosystems, such as the aquatic environment, that are critical to the survival of the area's various habitats and living species. However, the same region has witnessed unjustifiable environmental pollution arising from oil activities over the years of exploration and production which has orchestrated negative consequences on the Niger Delta ecosystem. This has led to extended negative consequences on natural resources, which also have detrimental repercussions psychologically, ecologically, socially, economically, and physically which, in turn, impacts the overall health of the affected individuals. This write-up provides an overview of the major drivers of the oil leakage in Nigeria's Niger Delta ecosystem as well as the major impacts on the environment. It will also analyze numerous means of remediation in use and extend such for a more inclusive and productive option. Moreover, this review offers key measures that may help to maintain long-term policies for reducing adverse implications and increasing the living standard for the Niger Delta area's affected communities.

Ecological River Health Assessment Using Multi-Metric Models in an Asian Temperate Region with Land Use/Land Cover as the Primary Factor Regulating Nutrients, Organic Matter, and Fish Composition

This study was performed to determine the ecological health of a temperate river over nine years (2011−2019); it also analyzed the trophic structure and linkage of nutrients (nitrogen [N] and phosphorus [P]), sestonic chlorophyll-a (CHL-a), and the top trophic fish in the Asian monsoon region. Water chemistry, trophic indicators, and tolerance guilds were primarily influenced by land use and land cover (LULC); the magnitude of variation was also related to geographic elevation, artificial physical barriers (weirs), and point sources. Levels of nutrients, organic matter, and CHL-a largely influenced by the intensity of the monsoon seasonality for a particular LULC and stream order. Mann−Kendall tests based on a long-term annual dataset showed that annual organic matter and CHL-a increased over time because of longer hydraulic residence time after weir construction. The results of empirical nutrient models suggested that P was the key determinant for algal growth (CHL-a); the strong P-limitation was supported by N:P ratios > 17 in ambient waters. Linear regression models and canonical correspondence analysis (CCA) were used to determine the influences of LULC and water quality on the trophic/tolerance linkages, fish community compositions and structures, and river health. Tolerant species had a positive functional relationship with nutrient enrichment through total phosphorus (TP) (R2 = 0.55, p < 0.05) and total nitrogen (TN) (R2 = 0.57, p < 0.05), organic pollution in terms of biological oxygen demand (BOD) (R2 = 0.41, p < 0.05) and chemical oxygen demand (COD) (R2 = 0.49, p < 0.05), and algal growth (R2 = 0.47, p < 0.05); sensitive species exhibited the opposite pattern. The degradation of river health, based on the multi-metric index of biotic integrity (IBI) model, was evident in the downriver region (“fair−poor” condition) and was supported by the quantitative fish community index (QFCI) model. The outcomes suggested that the degradation and variation of ecological river health, trophic linkages of water chemistry (N, P)-algal biomass-fish, were largely controlled by the land use pattern and construction of physical barriers in relation to the Asian monsoon.

A Sustainable Decision Support System for Drinking Water Systems: Resiliency Improvement against Cyanide Contamination

Maintaining drinking water quality is considered important in building sustainable cities and societies. On the other hand, water insecurity is an obstacle to achieving sustainable development goals based on the issues of threatening human health and well-being and global peace. One of the dangers threatening water sources is cyanide contamination due to industrial wastewater leakage or sabotage. The present study investigates and provides potential strategies to remove cyanide contamination by chlorination. In this regard, the main novelty is to propose a sustainable decision support system for the dirking water system in a case study in Iran. First, three scenarios have been defined with low ([CN−] = 2.5 mg L−1), medium ([CN−] = 5 mg L−1), and high ([CN−] = 7.5 mg L−1) levels of contamination. Then, the optimal chlorine dosage has been suggested as 2.9 mg L−1, 4.7 mg L−1, and 6.1 mg L−1, respectively, for these three scenarios. In the next step, the residual cyanide was modelled with mathematical approaches, which revealed that the Gaussian distribution has the best performance accordingly. The main methodology was developing a hybrid approach based on the Gaussian model and the genetic algorithm. The outcomes of statistical evaluations illustrated that both injected chlorine and initial cyanide load have the greatest effects on residual cyanide ions. Finally, the proposed hybrid algorithm is characterized by the multilayer perceptron algorithm, which can forecast residual cyanide anion with a regression coefficient greater than 0.99 as a soft sensor. The output can demonstrate a strong positive relationship between residual cyanide- (RCN−) and injected chlorine. The main finding is that the proposed sustainable decision support system with our hybrid algorithm improves the resiliency levels of the considered drinking water system against cyanide treatments.

Performance Assessment of Natural Wastewater Treatment Plants by Multivariate Statistical Models: A Case Study

Waste stabilization ponds (WSPs) as natural wastewater treatment plants are commonly utilized for wastewater treatment due to their simple design, low cost, and low-skilled operator requirements. Large-scale studies assessing the performance of WSPs using multivariate statistical models are scarce. Therefore, this study was conducted to assess the performance of 16 full-scale WSPs regarding physicochemical parameters, algae, bacterial indicators, and pathogens (e.g., Cryptosporidium, Entamoeba histolytica) by using multivariate statistical models. The principal component analysis revealed that the chemical pollutants were removed significantly (p < 0.001) through the treatment stages of 16 WSPs, indicating that the treatment stages made a substantial change in the environmental parameters. The non-multidimensional scale analysis revealed that the treatment stages restructured the bacterial indicators significantly (p < 0.001) in the WSPs, implying that the bacterial indicators were removed with the progress of the treatment processes. The algal community exhibited a distinct pattern between the geographical location (i.e., upper WSPs versus lower WSPs) and different treatment stages (p < 0.001). Four out of the sixteen WSPs did not comply with the Egyptian ministerial decree 48/1982 for discharge in agriculture drainage; three of these stations are in lower Egypt (M.K., Al-Adlia, and Ezbet El-Borg), and one is in upper Egypt (Armant). The continuous monitoring of WSPs for compliance with regulatory guidelines with the aid of multivariate statistical models should be routinely performed.

Environmental health impacts and controlling measures of anthropogenic activities on groundwater quality in Southwestern Nigeria

Groundwater is the major source of drinking water in virtually all the regions of Nigeria, including the southwestern region. It is an indispensable source of drinking water that many individuals are dependent upon for daily activities in Nigeria. However, the spontaneous rise in various forms of industrialization and other anthropogenic activities of man within the southwestern region has immensely polluted these water sources. This calls for tremendous and actionable concern because of the health implications associated with the intake of contaminated water. This study aims to thoroughly disentangle the major impacts of anthropogenic activities on the quality of groundwater in the southwestern region of Nigeria through extensive reviews of literature and conceptualization of scientific and research data on the field. Unlike previous reviews, the major sources of groundwater pollution in the region were discussed extensively to set the tone for the x-raying of the subject. The study also showed major long-standing pollution cases in the region with graphical, tabular, and pictorial illustrations of some of the groundwater parameters and at the same time proposed controlling measures to enable eidetic understanding of the concepts and contribution to knowledge. In the last part of the work, we recommend improving the existing groundwater assessment techniques in Southwestern Nigeria. Regular monitoring of groundwater in Nigeria should also be encouraged to establish its quality status.

Modified dry bean pod waste (Phaseolus vulgaris) as a biosorbent for fluorescein removal from aqueous media: Batch and fixed bed studies

This study presents the use of dry bean pods as a solid phase for fluorescein removal from water. The non-pretreated solid phase did not display any sorption properties for the chosen dye. However, interesting sorption properties were observed following a chemical derivative treatment with nitric acid. The study was carried out using both batch and column approaches. Regarding the batch study, all parameters that influence sorption capacity, such, as pH, adsorbent mass, ionic strength, temperature and contact time, were evaluated. A sorptive capacity of 36.80 mg g^-1 was obtained in the optimized condition. In the fixed column bed study, the influence of particle size, flow rate and initial concentration of the dye were evaluated through breakthrough curves and a sorptive capacity of 4.35 mg g^-1 was obtained. Thermodynamic studies revealed that the adsorption is exothermic and spontaneous. Four different models, Langmuir, Freundlich, Temkin and Redlich-Patterson, were employed. The Akaike information criterion (AIC) was employed to rank the best equilibrium model, which was determined as the Freundlich isotherm. The method was applied to a real sample and the same removal rate was obtained, thus indicating its suitability to wastewater treatment.

Hybrid metal organic frameworks as an Exotic material for the photocatalytic degradation of pollutants present in wastewater: A review

In this world, water is considered as the Elixir for all living creatures. Human life rolls with water, and every activity depends upon water. Worldwide water resources are being contaminated due to the elevation in the population count, industrialization and urbanization. Ejection of chemicals by industries and domestic sewages remains the major reason in the destruction of natural water resources. Contaminated water with harmful microbes, chemical dyes, pesticides, and carcinogens are the root cause of many diseases and deaths of living species. In this scenario, researchers engaged in producing ultra components to remove the contaminants. Metal organic frameworks (MOF) are the desired combination of organic and inorganic materials to achieve the required target. MOFs possess unique characteristics like tunable internal structure, porosity, crystallinity and high surface area which enable them for energy and environmental application. For the past years, MOFs are concentrated more as a photocatalyst in the treatment of polluted water. These research studies discuss the improvement of photocatalytic performance of MOF by the incorporation of metals, metal coupled with nanoparticles like polymers, graphene, etc., into it to achieve the enhanced photocatalytic activity by scavenging entire chemicals and harmful microbes to retain the quality of water. The target of this review article is to focus on the state of the art research work on MOFs in photocatalytic water treatment technique.

Longitudinal Chemical Gradients and the Functional Responses of Nutrients, Organic Matter, and Other Parameters to the Land Use Pattern and Monsoon Intensity

River water quality degradation is one of the hottest environmental issues worldwide. Therefore, monitoring water quality longitudinally and temporally is crucial for effective water management and contamination control. The main aim of this study was to assess the longitudinal variations in water quality in the mainstream of the Han River, Korea, from 2015 to 2019. The trophic state classification (TSC), microbial pollution indicator (MPI), and river pollution index (RPI) were calculated to characterize river water quality and revealed more serious pollution toward the downstream zone (Dz) due to agricultural and urban-dominated areas. The biodegradability index (BI) indicated that non-biodegradable organic pollutants are increasing in the water body from the urban and animal wastewater treatment plants. Nutrients, organic matter contents, total suspended solids, ionic factors, and algal chlorophyll were higher in the Dz than in any other zones and were markedly influenced by the summer monsoon. Empirical analysis showed that nutrients and organic matter had positive linear functional relations with agricultural and urban coverage and negative linear relations with forest coverage. The pollutant-transport function suggested that suspended solids act as TP and TN carriers. Regression analysis indicated that TP (R2 = 0.47) has more positive functional relations with algal growth than TN (R2 = 0.22). Our findings suggest that a combination of empirical models and pollution indices might be utilized to assess river water quality and that the resulting information could aid policymakers in managing the Han River.

Does aquatic sediment pollution result in contaminated food sources?

The sediment pollution of the aquatic environment by waste due to anthropogenic activity is of an increasing concern. The contaminants coming from the aquatic environment can enter the aquatic food chain and accumulate in the tissues of fish and shellfish used for human consumption. The aim of this study was to sum up the current level of knowledge concerning the pollution of aquatic sediments and its transfer to aquatic foods as well as to indicate whether such contamination has the potential to affect the health and welfare of aquatic organisms as well as the quality and safety of the species intended for human consumption. Based on the results of scientific studies, the European Food Safety Authority, and the Rapid Alert System for Food and Feed, contamination of fish and seafood occurs predominantly through their diet and the levels of bioaccumulative contaminants are higher in fish which rank higher in the food chain. Contamination of aquatic habitats can not only significantly affect behavior, development, and welfare of aquatic organisms, but it can also affect the safety of fish and seafood for human consumption.

Cellulose for the effective decontamination of water pollution

The widespread industrialization, urbanization, and technological development have triggered the daily release of considerable amounts of pollutants, specifically in aquatic environments. Previous research and work-studies indicate the existence of defined properties, such as low cost, non-toxicity, biodegradability, reusability, and easy synthesis, preparation or extraction, which make a material an ideal agent for the remediation of water or the environment. Therefore, the scientific community has focused on the development and study of several novels, environmentally friendly, and cost-effective materials. Cellulose is the most abundant natural polymer encountered worldwide. Thereby, due to the unique biological properties that this biopolymer possesses, it has emerged as a potential candidate to replace synthetic materials for practical bioremediation of contaminated water. Furthermore, the presence of hydroxyl groups on its surface makes this biopolymer highly malleable, thus significantly enhancing its physicochemical properties by using a wide variety of functional groups and modification methods. The present review describes the different biopolymers useful for remediation of environmental pollution, explores in more detail the characteristics of cellulose and its promising applications in the decontamination of water pollution, and pays special attention to the removal of heavy metal ions, dyes, and hydrophobic organic compounds.

Biomonitoring of Heavy Metal Pollution Using Acanthocephalans Parasite in Ecosystem: An Updated Overview

As a result of the global industrial revolution, contamination of the ecosystem by heavy metals has given rise to one of the most important ecological and organismic problems, particularly human, early developmental stages of fish and animal life. The bioaccumulation of heavy metals in fish tissues can be influenced by several factors, including metal concentration, exposure time, method of metal ingestion and environmental conditions, such as water temperature. Upon recognizing the danger of contamination from heavy metals and the effects on the ecosystem that support life on earth, new ways of monitoring and controlling this pollution, besides the practical ones, had to be found. Diverse living organisms, such as insects, fish, planktons, livestock and bacteria can be used as bioindicators for monitoring the health of the natural ecosystem of the environment. Parasites have attracted intense interest from parasitic ecologists, because of the variety of different ways in which they respond to human activity contamination as prospective indices of environmental quality. Previous studies showed that fish intestinal helminths might consider potential bioindicators for heavy metal contamination in aquatic creatures. In particular, cestodes and acanthocephalans have an increased capacity to accumulate heavy metals, where, for example, metal concentrations in acanthocephalans were several thousand times higher than in host tissues. On the other hand, parasitic infestation in fish could induce significant damage to the physiologic and biochemical processes inside the fish body. It may encourage serious impairment to the physiologic and general health status of fish. Thus, this review aimed to highlight the role of heavy metal accumulation, fish histopathological signs and parasitic infestation in monitoring the ecosystem pollutions and their relationship with each other.

Plasma-assisted advanced oxidation process by a multi-hole dielectric barrier discharge in water and its application to wastewater treatment

Advanced oxidation process (AOP) is a promising technology to decolorize and reduce organic contaminants in water. It is carried out using hydroxyl radicals (^•OH) with an oxidizing potential of 2.80 V. Non-thermal plasma can directly generate ^•OH while maintaining a low temperature, and O₃, H₂O_2, and UV light are also generated; these are necessary for AOP. In this study, we developed a multi-hole dielectric barrier discharge (DBD) system capable of generating radicals and active species in water for assisting AOP. We confirmed the optimized operating conditions based on critical parameters, including electrical and optical properties and O₃ concentration. Furthermore, we described the plasma-based AOP through experimental results. We performed wastewater treatment using the multi-hole DBD: turbidity, BOD, and COD, were reduced by 60%, 40%, and 60%, respectively, after 20 min of treatment. Finally, 99.99% of Escherichia coli were eliminated after plasma treatment.

The natural radioactivity in drinking water by gross alpha and beta measurements and radiological quality assessment

The aim of this study is to investigate the radiological quality of drinking waters consumed in Nevşehir province which is the most important tourism destination of the Cappadocia region. The activity concentration of gross α- and β-emitting from natural radionuclides (238U, 234U, 230Th, 226Ra, 210Po, 232Th and 210Pb, 228Ra and 40K) in 21 tap water samples supplied by municipal pipelines were analyzed by using a gas proportional α/β counter. The average activity concentrations of the gross α and gross β in tap water samples were found as 88 ± 10 mBq L−1 and 305 ± 32 mBq L−1, respectively. The average natural activity concentrations of α- and β-emitting radionuclides in tap water samples are below the limit values recommended by the Turkish regulation and WHO. For all samples, except for one sample, the gross β activity concentrations are higher than the corresponding gross α concentrations. The average annual effective radiation dose (AERD) due to the ingestion of these water samples was estimated to be 43, 60 and 124 μSv year−1 for infants, children, and adults, respectively. The average of AERD estimated for adults is 24 % higher than the dose limit of 100 μSv year−1. The activity concentration results reveal that tap water samples are acceptable for human consumption in accordance with the Turkish regulation and WHO recommendations for drinking water.

Optimization of Macroalgal Density and Salinity for Nutrient Removal by Caulerpa lentillifera from Aquaculture Effluent

Determining the optimum levels of macroalgal density and salinity for removing aquaculture effluent has gained increasing research interest in recent years because of the growing concerns over environmental sustainability. Here, we determined the effects of macroalgal density and salinity on the uptake of NO2−, NO3−, NH3, and PO43− by Caulerpa lentillifera from the effluent of Poecilia latipinna using spectrophotometry. Laboratory experiments were conducted to measure nutrient uptake at five different macroalgal density levels (10, 20, 30, 40, and 50 g/L) and three salinity levels (20, 30, and 40 ppt) with and without aeration. Quadratic regression analysis revealed significant nonlinear and linear effects of macroalgal density on the uptake of NO2−, NO3−, NH3, and PO43−, where the maximum uptake was predicted to occur at the macroalgal densities of 31.6, 33.3, 50.0, and 20.0 g/L, respectively. Likewise, the effects of salinity on the uptake of NO2−, NO3−, NH3, and PO43− were significant and nonlinear where the maximum uptake was predicted to occur at the salinity levels of 29.1, 30.7, 29.5, and 29.5 ppt, respectively. The result of the effects of aeration was mixed but somewhat indicated a positive effect on the nutrient uptake within the 24 h period. Our results could help aquaculturists to minimize the excessive nutrients by C. lentillifera from aquaculture effluent while achieving long-term sustainable aquaculture production.

Groundwater quality assessment of the Takelsa phreatic aquifer (Northeastern Tunisia) using geochemical and statistical methods: implications for aquifer management and end-users

The Takelsa phreatic aquifer (Northeastern Tunisia) is an important source of fresh water for different economic sectors in the region that are strongly dependent on groundwater resources but, the aquifer is showing increasing signs of groundwater quality degradation like many other regions in the Mediterranean Basin. By integrating geochemical and multivariate statistical investigation methods, this research aims to identify the main geochemical processes and anthropogenic activities that are responsible for regional groundwater quality evolution, identifying the origins of salinity and nutrients, and their implications for groundwater use forcropirrigation and drinking water supply in order to improve aquifer management practices. The results show that groundwater facies vary from Ca-Mg-SO₄ to Na-Cl water type and that mineralization is strongly controlled by mineral dissolution and cation exchange. The isotopic analyses indicate that groundwater is recharged by rainwater infiltration at higher altitudes and that a cumulative evaporative effect may contribute to local increase of salt content in groundwater. The Water Quality Index (WQI) used to determine the suitability of the Takelsa groundwater for drinking purposes reveals that just half of the groundwater points sampled show good to excellent quality for human consumption. The groundwater quality is also limited for irrigation purposes due to anthropogenic activities existing throughout the region. As groundwater in the studied region is crucial for irrigation and human supply, the identified groundwater quality problems and the identification of the main processes responsible for them should contribute to improve the infrastructure and managementpractices to allow the region to sustainable exploit the available groundwater resources.