Development of inorganic and mixed matrix membranes for application in toxic dyes-contaminated industrial effluents with in-situ treatments.

Dyes are the most ubiquitous organic pollutants in industrial effluents. They are highly toxic to both plants and animals; thus, their removal is paramount to the sustainability of ecosystem. However, they have shown resistance to photolysis and various biological, physical, and chemical wastewater remediation processes. Membrane removal technology has been vital for the filtration/separation of the dyes. In comparison to polymeric membranes, inorganic and mixed matrix (MM) membranes have shown potentials to the removal of dyes. The inorganic and MM membranes are particularly effective due to their high porosity, enhanced stability, improved permeability, higher enhanced selectivity and good stability and resistance to harsh chemical and thermal conditions. They have shown prospects in filtration/separation, adsorption, and catalytic degradation of the dyes. This review highlighted the advantages of the inorganic and MM membranes for the various removal techniques for the treatments of the dyes. Methods for the membranes production have been reviewed. Their application for the filtration/separation and adsorption have been critically analyzed. Their application as support for advanced oxidation processes such as persulfate, photo-Fenton and photocatalytic degradations have been highlighted. The mechanisms underscoring the efficiency of the processes have been cited. Lastly, comments were given on the prospects and challenges of both inorganic and MM membranes towards removal of the dyes from industrial effluents.

Response of coastal phytoplankton to pollution from various sources in the coastal Bay of Bengal.

The coastal ocean receives nutrient pollutants from various sources, such as aerosols, municipal sewage, industrial effluents and groundwater discharge, with variable concentrations and stoichiometric ratios. The objective of this study is to examine the response of phytoplankton to these pollutants in the coastal water under silicate-rich and silicate-poor coastal waters. In order to achieve this, a microcosm experiment was conducted by adding the pollutants from various sources to the coastal waters during November and January, when the water column physicochemical characteristics are different. Low salinity and high silicate concentration were observed during November due to the influence of river discharge contrasting to that observed during January. Among the various sources of pollutants used, aerosols and industrial effluents did not contribute silicate whereas groundwater and municipal sewage contained high concentrations of silicate along with nitrate and phosphate during both the study periods. During November, an increase in phytoplankton biomass was noticed in all pollutant-added samples, except municipal sewage, due to the limitation of growth by nitrate. On the other hand, an increase in biomass and abundance of phytoplankton was observed in all pollutant-added samples, except for aerosol, during January. Increase in phytoplankton abundance associated with decrease in biomass was observed in aerosol-added sample due to co-limitation of silicate and phosphate during January. A significant response of Thalassiothrix sp. was observed for industrial effluent-added sample during November, whereas Chaetoceros sp. and Skeletonema sp. increased significantly during January. Higher increase in phytoplankton biomass was observed during November associated with higher availability of silicate in the coastal waters in January. Interestingly, an increase in the contribution of dinoflagellates was observed during January associated with low silicate in the coastal waters, suggesting that the concentration of silicate in the coastal waters determines the response of the phytoplankton group to pollutant inputs. This study suggested that silicate concentration in the coastal waters must be considered, in addition to the coastal currents, while computing dilution factors for the release of pollutants to the coastal ocean to avoid occurrence of unwanted phytoplankton blooms.

Removing Heavy Metals: Cutting-Edge Strategies and Advancements in Biosorption Technology.

This article explores recent advancements and innovative strategies in biosorption technology, with a particular focus on the removal of heavy metals, such as Cu(II), Pb(II), Cr(III), Cr(VI), Zn(II), and Ni(II), and a metalloid, As(V), from various sources. Detailed information on biosorbents, including their composition, structure, and performance metrics in heavy metal sorption, is presented. Specific attention is given to the numerical values of the adsorption capacities for each metal, showcasing the efficacy of biosorbents in removing Cu (up to 96.4%), Pb (up to 95%), Cr (up to 99.9%), Zn (up to 99%), Ni (up to 93.8%), and As (up to 92.9%) from wastewater and industrial effluents. In addition, the issue of biosorbent deactivation and failure over time is highlighted as it is crucial for the successful implementation of adsorption in practical applications. Such phenomena as blockage by other cations or chemical decomposition are reported, and chemical, thermal, and microwave treatments are indicated as effective regeneration techniques. Ongoing research should focus on the development of more resilient biosorbent materials, optimizing regeneration techniques, and exploring innovative approaches to improve the long-term performance and sustainability of biosorption technologies. The analysis showed that biosorption emerges as a promising strategy for alleviating pollutants in wastewater and industrial effluents, offering a sustainable and environmentally friendly approach to addressing water pollution challenges.

Exploring the synergistic effect of chromium (Cr) tolerant Pseudomonas aeruginosa and nano zero valent iron (nZVI) for suppressing Cr uptake in Aloe Vera.

Chromium (Cr) contamination of soil has substantially deteriorated soil health and has interfered with sustainable agricultural production worldwide and therefore, its remediation is inevitable. Inoculation of plant growth promoting rhizobacteria (PGPR) in association with nanotechnology has exerted broad based impacts in agriculture, and there is an urgent need to exploit their synergism in contaminated soils. Here, we investigated the effect of co-application of Cr-tolerant "Pseudomonas aeruginosa CKQ9" strain and nano zerovalent iron (nZVI) in improving the phytoremediation potential of aloe vera (Aloe barbadensis L.) under Cr contamination. Soil was contaminated by using potassium dichromate (K2Cr2O7) salt and 15 mg kg-1 contamination level in soil was maintained via spiking and exposure to Cr lasted throughout the duration of the experiment (120 days). We observed that the co-application alleviated the adverse impacts of Cr on aloe vera, and improved various plant attributes such as plant height, root area, number of leaves and gel contents by 51, 137, 67 and 49% respectively as compared to control treatment under Cr contamination. Similarly, significant boost in the activities of various antioxidants including catalase (124%), superoxide dismutase (87%), ascorbate peroxidase (36%), peroxidase (89%) and proline (34%) was pragmatic under contaminated soil conditions. In terms of soil Cr concentration and its plant uptake, co-application of P. aeruginosa and nZVI also reduced available Cr concentration in soil (50%), roots (77%) and leaves (84%), while simultaneously increasing the relative production index by 225% than un-inoculated control. Hence, integrating PGPR with nZVI can be an effective strategy for enhancing the phytoremediation potential of aloe vera.

Combined effect of PGPR and nanotechnology in the bioremediation of toxic contaminants is well reported in literature. Most of these reports comprise the use of hyperaccumulator plants for phytoextraction of heavy metals. However, phytostabilization potential of hyperaccumulators is still un-explored. Current study investigated the role of PGPR and Fe-NPs in suppressing the uptake of Cr in aloe vera, a hyperaccumulator plant.

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.

Metabolomics revealed disruptions in amino acid and antioxidant biochemistry in Daphnia magna exposed to industrial effluents associated with plastic and polymer production.

Industrial wastewater effluents are a major source of chemicals in aquatic environments, and many of these chemicals may negatively impact aquatic life. In this study, the crustacean Daphnia magna, a common model organism in ecotoxicity studies, was exposed for 48 h to nine different industrial effluent samples from manufacturing facilities associated with the production of plastics, polymers, and coating products at a range of dilutions: 10, 25, 50, 100% (undiluted). A targeted metabolomic-based approach using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantify polar metabolites from individual daphnids that survived the 48 h exposure. Multivariate analyses and metabolite changes revealed metabolic perturbations across all effluent samples studied, with non-monotonic responses and both up and downregulation relative to the unexposed control. Pathway analyses indicated the disruption of similar and distinct pathways, mostly connected to protein synthesis, amino acid metabolism, and antioxidant processes. Overall, we observed disruptions in Daphnia biochemistry that were similar across the effluent samples, but with unique features for each effluent sample. Additionally, non-monotonic heightened responses suggested additive and/or synergistic interactions between the chemicals within the industrial effluents. These findings demonstrate that targeted metabolomic approaches are a powerful tool for the biomonitoring of aquatic ecosystems in the context of complex mixtures, such as industrial wastewater effluents.

Environmental proteomics as a useful methodology for early-stage detection of stress in anammox engineered systems.

Anammox bacteria are widely applied worldwide for denitrification of urban wastewater. Differently, their application in the case of industrial effluents has been more limited. Those frequently present high loads of contaminants, demanding an individual evaluation of their treatability by anammox technologies. Bioreactors setting up and recovery after contaminants-derived perturbations are slow. Also, toxicity is frequently not acute but cumulative, which causes negative macroscopic effects to appear only after medium or long-term operations. All these particularities lead to relevant economic and time losses. We hypothesized that contaminants cause changes at anammox proteome level before perturbations in the engineered systems are detectable by macroscopic analyses. In this study, we explored the usefulness of short-batch tests combined with environmental proteomics for the early detection of those changes. Copper was used as a model of stressor contaminant, and anammox granules were exposed to increasing copper concentrations including previously reported IC50 values. The proteomic results revealed that specific anammox proteins involved in stress response (bacterioferritin, universal stress protein, or superoxide dismutase) were overexpressed in as short a time as 28 h at the higher copper concentrations. Consequently, EPS production was also increased, as indicated by the alginate export family protein, polysaccharide biosynthesis protein, and sulfotransferase increased expression. The described workflow can be applied to detect early-stage stress biomarkers of the negative effect of other metals, organics, or even changes in physical-chemical parameters such as pH or temperature on anammox-engineered systems. On an industrial level, it can be of great value for decision-making, especially before dealing with new effluents on facilities, deriving important economic and time savings.

Evaluation of cyto-genotoxicity biomarkers, changes in histology and antioxidant defense system of Oreochromis niloticus induced by the industrial effluents.

Aquatic pollution mainly by industrial effluents has been a major concern since a few decades. The current study evaluated cyto-genotoxicity of industrial effluents on Oreochromis niloticus exposed to sublethal levels by hematotoxicity, blood biochemistry analysis, micronucleus assay, antioxidants and cerebral toxicity. The significant elevation in differential leukocytes of exposed fish was indicative of infections and compromised immune system. The acute and chronic industrial effluent exposure caused significant decline in aspartame transaminase (AST) and alanine transaminase (ALT) and renal function enzymes. Necrosis, hyperplastic growth, hypertrophy and toxicant accumulation exhibited cerebral toxicity potential of industrial toxicants. A significant decrease in antioxidants, GSH, SOD and catalase (0.14, 0.66 and 1549 unit/mg protein) in chronic exposure group in comparison to 0.18, 2.83, 7680 and 6200.8 values of GSH, SOD, GPx and CAT, respectively. Results showed that acute and chronic industrial effluent exposure caused genotoxicity with higher frequencies of formation of micronuclei and cytokaryotic fusion.

Bacterial nanocellulose and its application in heavy metals and dyes removal: a review.

This review discusses the application of bacterial nanocellulose (BNC) and modified BNC in treating wastewater containing heavy metals and dye contaminants. It also highlights the challenges and future perspectives of BNC and its composites. Untreated industrial effluents containing toxic heavy metals are systematically discharged into public waters. In particular, lead (Pb), copper (Cu), cadmium (Cd), nickel (Ni), zinc (Zn), and arsenic (As) are very harmful to human health and, in some cases, may lead to death. Several methods such as chemical precipitation, ion exchange, membrane filtration, coagulation, and Fenton oxidation are used to remove these heavy metals from the environment. However, these methods involve the use of numerous chemicals whilst producing high amount of toxic sludge. Meanwhile, the development of the adsorption-based technique has provided an alternative way of treating wastewater using BNC. Bacterial nanocellulose requires less energy for purification and has higher purity than plant cellulose. In general, the optimum growth parameters are crucial in BNC production. Even though native BNC can be used for the removal of heavy metals and dyes, the incorporation of other materials, such as polyethyleneimine, graphene oxide, calcium carbonate and polydopamine can improve sorption efficiencies.

Foliar architecture differentially restrains metal sequestration capacity in wheat grains (Triticum aestivum L.) grown in hyper-chloride-contaminated soils.

Anthropogenic activities, such as industrial wastewater and use of water softeners, cause hyper-accumulation of Cl- in water sources and soils. Currently, industries have no sustainable method to remove these Cl- ions from wastewater. This study was conducted to evaluate the integrative responses of wheat cultivated in five industrial effluent-affected areas (S2-S6) by investigating soil characters and bioaccumulation of metals in wheat plants and grains. The S4 site (near the second chloride outlet) exhibited a higher concentration of CO2, SO2, NO2, Cl-, Cd, Mn, Ni, Cr, and Zn. Soil from S6 (sewage wastewater downstream getting mixed with chloride-contaminated water) had a minimum level of nutrients (Na, K, and Ca), maximum metals (Cd, Fe, Pb, Mn), and reduction in plant biomass. In site S2 (sewage wastewater upstream of the chloride factory), a higher level of minerals and metals was noted in the roots. Maximum metals in grains occurred in S6 with higher organic osmolytes. The sequestration capacity of metals in leaves was also increased by alterations in anatomical traits. Results indicated that metals and hyper-Cl- concentration employed a negative influence on the plants because of poor soil quality, extremely damaged microstructures leading to reduced yield, poor grain quality, and excessive translocation from roots to wheat grains. These findings revealed that contaminated plants used as either green forage or hay are noxious to animals and if used as grain for feed or humans can lead to serious health hazards.

A critical review on the removal of toxic pollutants from contaminated water using magnetic hybrids.

The persistence of organic/inorganic pollutants in the water has become a serious environmental issue. Among the different pollutants, dyes and heavy metal pollution in waterways are viewed as a global ecological problem that can have an impact on humans, plants, and animals. The necessity to develop a sustainable and environmentally acceptable approach to remove these toxic contaminants from the ecosystem has been raised. In the past two decades, rapid industrialization and anthropogenic activities in developed countries have aggravated environmental pollution. Industrial effluents that are discharged directly into the natural environment taint the water, which has a consequence for the water resources. Magnetic nanohybrids are broadly investigated materials used in the adsorption and photocatalytic degradation of poisonous pollutants present across water effluents. In the present review, the toxic health effects of heavy metals and dyes from the water environment have been discussed. This paper reviews the role of magnetic nanohybrids in the removal of pollutants from the water environment, providing an adequate point of view on their new advances regarding their qualities, connection methodologies, execution, and their scale-up difficulties.

Spring water quality monitoring using multiple bioindicators from multiple collection sites.

The aim of this study was to examine the water quality of the Extrema River spring in a Brazilian Cerrado area. Three collection sites (P1 - P3) were sampled in the dry and rainy seasons, which are close to industries from different sectors. In the physicochemical analysis, a decrease in dissolved oxygen levels (<5 mg/L) and pH (< 6) at P3 was detected. An increase in heterotrophic bacteria count was recorded at all sites (> 500 colonies/ml). In ecotoxicological analyses, P2 and P3 exhibited toxicity using Vibrio fischeri (> 20%). In evaluating toxicity, the reduction in seed germination was significant utilizing Lactuca sativa at all locations and with Allium cepa only at P2; rootlet length was decreased at P3 on L. sativa and at all sites with A. cepa. In contrast, loss of membrane integrity and mitochondrial function of meristems was adversely affected at all locations using both L. sativa and A. cepa assays. Principal components analysis (PCA) approach indicated that seasonality apparently did not markedly interfere with the obtained data, but it is important to include more collection locations to be evaluated with multiple bioindicators in the spring region. Our data indicate the urgent need for more rigorous programs to monitor the discharge of effluents into water springs.

Seasonal fluctuations and diversity of Ingoldian mycobiota in two water bodies receiving different effluents at Assiut Governorate (Upper Egypt).

In the current study, fifty-eight Ingoldain fungal species assignable to forty-one genera were recovered from two water bodies receiving the treated sewage and the effluents of oils and soaps factory at Assiut Governorate (Upper Egypt), of which Anguillospora, Amniculicola, Flagellospora, and Mycocentrospora were the most prevalent genera. The most widespread identified species were Anguillospora furtive, Amniculicola longissima and Flagellospora fusarioides. Forty-three species were identified for the first time in Egypt. The most Ingoldain taxa were estimated for El-Zinnar canal, with the highest recorded taxa in winter. Whereas, the highest dominance of Ingoldian fungi was estimated for the El-Ibrahimia canal. The highest Simpson and Shannon diversity indexes were estimated for El-Zinnar canal samples recording 0.9683 and 3.741, respectively. The poorest water sites with Ingoldian fungi were those exposed directly to either treated sewage or industrial effluents, with which relatively higher values of water conductivity, cations and anions. Water temperature was the main abiotic factor driving the seasonal occurrence of Ingoldian fungi. It is interesting to isolate some Ingoldian fungal species from the stressful water sites receiving the effluents which provide valuable insights regarding their adaptation, predictive and putative role as bioindicators and their potentiality in pollutants degradation, organic decomposition, and transformation of xenobiotic compounds.

Solar light driven degradation of textile dye contaminants for wastewater treatment - studies of novel polycationic selenide photocatalyst and process optimization by response surface methodology desirability factor.

The unplanned anthropogenic activities and raced industrial revolution detrimentally causes serious threat to terrestrial and aquatic life. A high discharge of wastewater from industries using dyes affects living organisms and the environment. This paper presents studies on polycationic selenides (PCS) synthesized by hydrothermal methods for photocatalytic degradation of dyes. The synthesized PCS were confirmed by various characterization techniques such as FTIR, SEM, EDX, UV/Vis, and XRD. The FTIR spectra revealed characteristic band at 843, 548 cm-1, and 417 cm-1 due to the M - Se stretching and intrinsic stretching vibrations, respectively. The optical bandgap of polycationic selenide lies in the visible light region (2.36 eV). The SEM images showed that PCS has a spherical shape with an average crystallite size of 29.23 nm calculated from XRD data using Scherer's equation. The PCS has a point of zero charge (PZC) at pH 7. The efficiency of synthesized PCS photocatalyst was confirmed in terms of its activity towards Eosin (EY) and Crystal violet (CV) dyes mineralization. The photocatalytic degradation for EY and CV dyes at optimum conditions was 99.47% and 99.31% and followed second order reactions kinetics with 1.4314 and 0.551 rate constant, respectively. The polynomial quadratic model is the best-fitted response surface methodology (RSM) model having a maximum desirability factors value and significant terms, with R2 (0.9994) and adj R2 values (1.0).

The reliability of evaporation ponds as a final basin for industrial effluent: Demonstration of an environmental risk management methodology.

Recognizing and assessing environmental risk are key components of every industry management strategy. Projects need to make sure that a detailed environmental risk management strategy is applied by methodically recognizing and addressing threats from internal and external influences to comply with regulatory standards for environmental preservation and safeguarding. This study's goal is to use a novel technique to assess the impact of environmental risks related to the use of evaporation ponds as final basins for industrial effluents. It employs qualitative and statistical methodologies to identify areas where engineering and managerial safeguards' structure, functioning, and lines of defense have flaws that might result in an ecologically hazardous occurrence. Additionally, it will offer a risk evaluation based on the gravity of the impact and the likelihood that the environmental occurrence would happen by using evaporation ponds to store industrial effluents. While the environmental threat would be entirely removed, it must be capable of reducing it to ALARP. The environmental risk assessment matrix will serve as a key factor in determining whether the environmental risk level linked with an evaporation pond is acceptable, as determined by the likelihood and impacts. The result of this research allows industrial units to recognize and control potential environmental risks associated with effluents by practically implementing a new environmental risk matrix based on several environmental and ecological effects with probability factors.•This study aims to assist industrial operators, especially power plants, manage environmental risk by combining ALARP concepts with other factors to evaluate risk acceptance and tolerance levels.•The Physico-chemical characteristics of effluent collected in the evaporation pond reveal that evaporation has a deleterious impact on such industrial effluent, as evidenced by a large increase in various effluent properties, some of which exceed the limit values.•A risk evaluation found that effluent collected in the evaporation pond has a detrimental negative impact on industrial effluents. This was evidenced by a significant rise in associated activities. This could increase the expense of operating and managing evaporation ponds, which could harm the ecosystem.

Stem powder and its active carbon of Arachis hypogaea plant for lead (II) removal: application to treat battery-based industrial effluents.

Stem powder and its active carbon of Arachis hypogaea plant are identified to have strong adsorptivity for lead ions. The bio-sorbents are characterized by conventional methods including XRD and FTIR analysis. These biomaterials are investigated for their maximum adsorption for lead ions by optimizing the extraction conditions. The maximum removal is observed in the pH range of 6-7 for both sorbents. With stem powders, the removal is 76.0% from a simulated lead solution of concentration: 20.0 mg/L with 1.5 g/L of the sorbent and at an equilibration time of 2.0 h. With the active carbon, the maximum extraction of: 86.0% is observed at pH: 6.5 with 1.0 g/L of the sorbent after an equilibration time of 1.5 h. The sorption capacities are 32.0 mg/g for stem powders, and 40.5 mg/g for active carbon. Many co-ions have marginal interference. Spent adsorbents can be recycled after regeneration. Thermodynamic investigations reveal the spontaneity and endothermic nature of adsorption. High ΔH values viz., 26.45 kJ/mole for AHSP and 46.40 kJ/mole for AHSAC, confirm the bonding of Pb2+ ions with the sorbents is either "ion-exchange" and/or a sort of "complex formation." The disorder at the solid and liquid boundary is indicated by high positive ΔS values and it is a favorable condition for good Pb2+ adsorption. On analysis of different kinetic and isotherm models, the sorption of Pb2+ ions follows Pseudo-2nd order and Langmuir models. This confirms the mono-layer adsorption of Pb2+ ions on the humongous surface of the sorbent. The adsorbents are successfully applied to treat industrial effluent samples.

In the present investigation, stem powder and its active carbon of Arachis hypogaea plant are identified to have strong adsorptivity for highly toxic lead ions. Successful methodologies are developed for the maximum extraction of lead ions from industrial wastewater at a convenient nearly neutral pH. The adsorption capacities are as high as: 32.0 mg/g for stem powders and 40.5 mg/g for active carbon. The sorbents are characterized and the sorption mechanism is investigated. The novelty of the present investigation is that highly toxic lead ions can be easily removed from polluted water by using simple bio-adsorbents by adopting convenient procedures.

Strategies for microbial bioremediation of environmental pollutants from industrial wastewater: A sustainable approach.

Heavy metals are hazardous and bring about critical exposure risks to humans and animals, even at low concentrations. An assortment of approaches has been attempted to remove the water contaminants and keep up with water quality, for that microbial bioremediation is a promising way to mitigate these pollutants from the contaminated water. The flexibility of microorganisms to eliminate a toxic pollutant creates bioremediation an innovation that can be applied in various water and soil conditions. This review insight into the sources, occurrence of toxic heavy metals, and their hazardous human exposure risk. In this review, significant attention to microbial bioremediation for pollutant mitigation from various ecological lattices has been addressed. Mechanism of microbial bioremediation in the aspect of factors affecting, the role of microbes and interaction between the microbes and pollutants are the focal topics of this review. In addition, emerging strategies and technologies developed in the field of genetically engineered micro-organism and micro-organism-aided nanotechnology has shown up as powerful bioremediation tool with critical possibilities to eliminate water pollutants.

Phytoremediation of industrial effluents assisted by plant growth promoting bacteria.

Industrialization plays a crucial role in the economic development of a country; however, the effluents produced as a byproduct generally contain toxic substances which are detrimental to living organisms. In this regard, it is essential to treat these toxic effluents before exposing them to the natural environment by selecting the most appropriate method accordingly. Several techniques are used to remediate industrial effluents including physical, chemical, and biological. Although some physical and chemical remediation technologies are of substantially important in remediation of industrial effluents, however, these technologies are either expensive to be applied by developing countries or not suitable for remediation of all kinds of effluents. In contrast, biological remediation is cost effective, nature friendly, and easy to use for almost all kinds of effluents. Among biological remediation strategies, phytoremediation is considered to be the most suitable method for remediation of industrial effluents; however, the phytoremediation process is slow, takes time in application and some effluents even affect plants growth and development. Alternately, plant microbe interactions could be a winning partner to remediate industrial effluents more efficiently. Among the microbes, plant growth promoting bacteria (PGPB) not only improve plant growth but also help in degradation, sequestration, volatilization, solubilization, mobilization, and bioleaching of industrial effluents which subsequently improve the phytoremediation process. The current study discusses the role of PGPB in enhancing the phytoremediation processes of industrial effluents.

Evaluation of the water quality of a highly polluted stream with water quality indices and health risk assessment methods.

The water quality of Çorlu Stream, located in the Thrace region of Türkiye, and exposed to intense industrial pressure, was evaluated by monitoring 10 toxic metals and 13 other water quality variables in the dry and wet seasons of 2021. Seven different water quality indices were applied to determine the pollution level at the sampling stations in the stream. In addition, human health risks from exposure to toxic metals in stream water via ingestion and dermal contact were evaluated. The results showed that the water quality at stations S2 and S3 of Çorlu Stream receiving domestic and industrial discharges are seriously polluted by NH4-N, PO4-P, COD, BOD5 and suspended solids according to surface water quality standards. In addition, these stations were highly polluted and had poor water quality according to the results of the water quality indices. The average Cr level at station S3 exceeded the permissible levels set for the protection of aquatic life due to effluent discharges from the leather factories. Considering the results of the health risk assessment methods, non-carcinogenic risks from ingestion of combined metals in stream water can be expected at station S3 for both children and adults and at station S2 for children. Also, it was estimated that Cr and As at station S3 may cause carcinogenic health risks for residents.

Use of lignocellulosic waste materials in the passive treatment of highly alkaline wastewater contaminated with sulfates and metals - From a laboratory study to pilot scale.

Passive wastewater treatment systems are an alternative to costly and ineffective chemical wastewater treatment methods. Lignocellulosic waste materials (LWM) are often used in passive wastewater treatment systems as a cheap and accessible source of nutrients. LWM, such as spent mushroom compost and woodchips, have been implemented for the successful management of mildly alkaline effluents, which constitute a large fraction of industrial wastewater. The objective of the study was to provide an extensive study of the parameters in four types of commonly used LWM (raw and composted sawdust, spent mushroom compost and woodchips), which can be used in the planning of a passive wastewater treatment plant. LWM were shown to remove up to 90% Zn2+ and Pb2+ from a model solution and neutralize wastewater. Moreover, the LWM were inhabited by a physiologically diverse microbial consortium containing sulfate-reducing and cellulolytic microbes, which can influence the treatment process. Another purpose of this study was to construct a pilot wastewater treatment plant based on the use of LWM and gravel and to present its ability to effectively treat extremely alkaline flotation wastewater (pH = 12) originating from a lead and zinc mine located in Montenegro. The treated wastewater had a unique, but challenging chemical composition for passive treatment, as it was heavily contaminated with sulfates (∼1200 mg/L) and lead (∼1 g/L). The removal within the developed installation reached a rate of 66%, while the treated effluent, after initial neutralization, was maintained at a pH of approximately 7. Lead and zinc concentrations after treatment were also kept at levels required by Montenegrin law for wastewater disposal.