Biological Pollutants Research Articles

Indoor microbial exposure increases complement component C3a and C-reactive protein concentrations in serum

Indoor exposure to microbial growth, caused by moisture damage, has been an established health risk for several decades. It is likely that a damp indoor environment contains biological pollutants that trigger both the innate and adaptive branches of the immune system.In this study, we investigated the association between moisture damage related microbial exposure and serum C3a, C5a and CRP concentrations in Finnish adults.Serum C3a and CRP concentrations were elevated in individuals exposed to moisture damage and microbial growth in an indoor air environment. The elevated concentrations may be due to environmental factors present in moisture-damaged buildings. Complement activation and the resulting proinflammatory cleavage products may be a driving factor in inflammatory responses following exposure to indoor moisture damage and related microbial growth.

Liquid air filtration and continuous monitoring: Customized indoor air quality

Air treatment in environmental air conditioning systems exposes the system to gases, contaminants, and often biological pollutants that cannot be solved by traditional mechanical filtration, motivating decision-makers to diagnose challenges and develop innovative strategies to mitigate the problem. More and more, in environments with high turnover of people (e.g., hospitals, hotels and shopping centers), fresh air ventilations are avoided and replaced by closed windows air purifier solutions to account for undesirable saturation of the atmosphere and the presence of pollutants such as PM10, PM2.5, PM1.0, nitrogen, and carbon oxides. The consensus is that polluting gases render the most efficient traditional filters ineffective. The ANSI/ASHRAE 62.1 and EN13779 standards reveal the absence of air treatment technologies that use the wet route in air conditioning systems. This work discusses the liquid air multi-venturi centrifugation technology of hydrodynamic precipitator purifiers in association with the synchronized and continuous monitoring of parameters (PM10, PM2.5, PM1.0, CO2) in the external urban environment and internal environments of a shopping center. It evaluates the performance of the wet route for the physical-chemical and biological treatment of air. Efficiency for retaining particulate matter in a single step without disposable filter reached levels above F9 (85-95% PM2.5), with a reduction of 82.4% for CO2. Wet route technology extends the air conditioner’s life, reducing external air flows and energy consumption by up to 13%, making IAQ a manageable and customizable variable. Among the conclusion of the investigation, the authors believe that the migration of industrial pollutant control technologies, such as liquid filtration promoted by gas scrubbers and hydrodynamic precipitators, should be considered as a first choice option due to the high efficiency achieved in the three types of pollutants to be controlled. That is micrometric particulate matter such as anthropogenic PM1.0 capable of reaching the lung alveoli, chemicals such as carbon dioxide and nitrogen, and biological assets such as viruses and bacteria that showed the vulnerability of HVAC-R systems during the COVID pandemic that rendered windowless corporate buildings unusable.

Carbohydrate polymer-supported metal and metal oxide nanoparticles for constructing electrochemical sensors

Metal- and metal oxide-carbohydrate polymers are considered a promising tool for electrochemical detection of biological analytes and water pollutants.

Optimum content of incorporated nanomaterials: Characterizations and performance of mixed matrix membranes a review

Environmental concerns about chemical and biological pollution of water are of alarming proportions. Therefore, various polymeric membranes with improved mechanical and physico-chemical qualities for water treatment were developed using mixed matrix membranes (MMMs) or nanoparticles (NPs) embedded with the membranes. However, the problem of fouling and consequent higher operating and membrane replacement costs are barriers to the use of membrane technology. Therefore, a deeper comprehension of membrane fouling is not only essential for finding solutions but also a crucial factor in the development of membrane technology. The conventional blending modification would result in a large number of nanoparticles in the polymer matrix. In reality, the aggregation of nanoparticles in composite membranes is a considerable issue and would result in unfavorable changes to the features of the membrane (e.g. decreased water flux, weakened mechanical strength). In this review, it was looked into the effect of an optimal concentration of the hydrophilic nanoparticle additions to avoid the aggregation of nanoparticles in composite membranes and the reduced of using high amounts of valuable and costly nanoparticles in the membranes production and to obtain better results. The influence of the additives, such as (carbon nanotubes (CNTs), silica (SiO2), titanium dioxide (TiO2), zinc oxide (ZnO), aluminum oxide (Al2O3), and graphene oxide (GO), etc.) was investigated.

Abundance of Xanthium spinosum L. along the different land types and its impacts on invaded plant communities in North Shewa Zone, Ethiopia

A biological invasion is a form of biological pollution that is most likely more terrible than chemical pollution. Xanthium spinosum is one of the most invasive alien plant species. However, its abundance and impacts on invaded plant communities have not yet thoroughly studied. This study aimed to investigate the abundance and impacts of X. spinosum on invaded plant communities in the North Shewa Zone, Ethiopia. The study applied the quadrat method, sampling 80 main plots within 1 m2. Differences in mean cover-abundances of X. spinosum across various land types were compared using one-way-ANOVA followed by Tukey’s Honestly Significant Difference (HSD) Test. The results showed that roadsides and flooded areas exhibited the maximum mean cover-abundance of X. spinosum compared to farmland and rangeland. The number of plant species recorded was 106 in the control areas, compared to only 73 in the invaded areas. Hence, the number of plant species decreased by 31.13% in the infested area compared to the control. Thus, X. spinosum was among the factors contributing to the reduction of plant diversity, affecting the sustainability of biodiversity in the study areas. Therefore, implementing management measures against the spread of X. spinosum is to address the ongoing threat to biodiversity.

FORMATION OF THE NUMBER OF PHYTOPATHOGENIC MICROMYCETE POPULATIONS IN AGROCENOSES OF OAT

The formation of the number of the phytopathogenic micromycete populations as a factor in biological pollution of oat agrocenoses is an important research field, the study of which will make it possible to create some sustainable agroecosystems. Therefore, the influence of the environmental factors (abiotic, biotic, anthropogenic, etc.) on the formation of micromycete populations on the vegetative organs of oat plants using different plant cultivation technologies was studied. This article presents the results of the ecological assessment of oat plant varieties based on the indicators of its their influence on the population number, the frequency of its occurrence, and the intensity of micromycete sporulation. Vegetative organs of oat plants of Parliamentsky and Tembre varieties were selected by BBCH scale for cereals in the phases: 5 tillers detectable (25), node 5 at least 2 cm above node 4 (35), еnd of heading: inflorescence fully emerged (39). It was determined that certain climatic conditions like an abiotic factor (namely an increase in air temperature), frequent droughts, or rare but abundant rains, significantly influenced the formation of micromycete populations in the oat leaf microbiome. Plant growing technologies, as an anthropogenic factor, influenced the spectrum of species and their frequency of the occurrence on the vegetative organs of oats of different kinds of the varieties. Using the organic technology of plant cultivation led to diversification of the spectrum of micromycete populations, but with a lower frequency of occurrence of species compared to the traditional technology of plant cultivation. Also, the varieties of oat plants, as a biotic factor, in terms of some physiological substances of plants, are able to restrain the spread of micromycete populations on the vegetative organs of plants or stimulate them. It was found out that using the traditional and organic technologies of plant cultivation on the vegetative organs of Tembre oat variety, the population density, the frequency of micromycete species occurrence, and the intensity of sporulation were significantly lower compared to the indexes of Parliamentsky oat variety plants. This points to the fact that the cultivation of oat varieties capable of resisting the formation of micromycete populations on an ecologically safe level will ensure a decrease in the level of biological pollution of agrocenoses and at the same time increase the biosafety of plant raw materials.

EVALUATION OF POSSIBILITIES FOR USING ELECTROCHEMICALLY ACTIVATED WATER FOR IRRIGATION

In order to check the possibility of using electrochemically activated water (ECHAW) in irrigation, a study was conducted to determine the influence of anolyte on biological pollutants of wastewater and the reduction of water mineralization by electrochemical activation, as well as the influence of catholyte and anolyte on the germination of seeds of cereal crops, the development of seedlings of pepper and tomato, and the yield of tomato. The research was conducted in laboratory conditions on two varieties of pepper and four varieties of tomato. ECHAW was obtained using laboratory water activators of our own production. Wastewater samples were taken at the Bortnychy wastewater aeration station in Kyiv. Experiments were carried out using vegetation containers of various types and one-time bacteriological tests. It was found that by electrochemical activation of mineralized water it is possible to reduce the level of its total mineralization by more than 50% and, with an anolyte, to destroy disease-causing bacteria in wastewater. The use of ЕCHAW accelerates the germination of seeds of cereal crops. On the 3rd day of germination, wheat grain germinated using EHCAW has a 9% longer root length than the grain germinated under the same conditions using non-activated water. Wheat grain germinated using EHCAW also has 33% longer sprouts. The growth rate when irrigated with activated water, depending on the variety of tomato plants, increases by 9,8-25,2%, the increase in stem diameters was equal to 11,3-22,4%. The yield of tomatoes when irrigated with activated water is 12,6-15,8% higher than in the case of irrigation by ordinary water, the size of the fruits is 15,4-25,1% larger. The results of the conducted research indicate the possibility and perspective of using EHCAW to increase the yield of crops under irrigation and improving the quality of drainage and wastewater by reducing their mineralization and providing their disinfection.

Формування фітопатогенного мікобіому на вегетативних органах рослин пшениці озимої

Cultivated plants, which are characterized by high resistance to phytopathogenic microorganisms, create significant selective pressure on their populations and select highly pathogenic and aggressive forms. Highly susceptible plants to such microorganisms ensure a rapid growth in the population of phytopathogenic micromycetes in agrocenoses. Cultivation of such plant groups on production crops leads to an increase in biological pollution of the agrosphere and a significant decrease in the level of biological safety. This requires increased use of chemical means of plant protection against diseases, which causes chemical pollution of agroecosystems and leads to a significant decrease in the quality of plant products through the accumulation of metabolic products of phytopathogenic microorganisms in it and a decrease in biological safety in agrocenoses. Therefore, the assessment and selection of winter wheat varieties as a factor in the regulation of the phytopathogenic mycobiome in agrocenoses is a highly relevant area of research that ensures the selection of ecologically safe varieties of cultivated plants. Cultivation of such varieties leads to a decrease in the level of biological pollution in agrocenoses and increases the quality and safety of plant products. It is known that biotic, abiotic and anthropogenic factors affect the formation of populations of microorganisms. Therefore, the formation of the mycobiome on the vegetative organs of winter wheat during the ontogenesis of plants under traditional and organic technologies was investigated. It has been proven that the meteorological conditions during the years of the study, namely: high air temperature and a significant amount of precipitation during the growing season, which was observed in 2021 and in the long dry years of 2020 and 2022, had a significant impact on the formation of the population of micromycetes in the agrocenosis of winter wheat. According to the results of our own research, the population density of micromycetes and the intensity of sporulation of mushroom species decreased during the phase of emergence into the tube using traditional cultivation technology. At the same time, during the earing phase, mushroom sporulation increases by 2–3 times. This can be explained by the homeostatic reaction of the population of micromycetes in the mycobiome of vegetative organs of winter wheat plants to the chemical pressure of applied pesticides, which can cause contamination of agrocenoses with infectious structures of pathogens and their toxic metabolites. At the same time, the population density of micromycetes, under organic cultivation technology, increased during the growing season from the tillering phase to the earing phase, depending on the soil and climatic conditions. Under the conditions of various winter wheat cultivation technologies, significant changes in the formation of micromycete populations were observed due to the influence of varietal characteristics of plants. A significantly lower frequency of occurrence of species and their intensity of sporulation was observed on the vegetative organs of the Skagen variety, compared to winter wheat plants of the Podolyanka variety. This testifies to the ability of physiological and biochemical substances of plants of various varieties of winter wheat to stimulate or restrain the development of micromycetes in the mycobiome of vegetative organs of the culture. Evaluation of the plant variety based on indicators of influence on the density, frequency of occurrence and intensity of sporulation of micromycetes will ensure a decrease in the level of biological pollution and an increase in the biosafety of plant raw materials.

Multifunctional nanofiber membrane for high removal efficiency of biological/organic contaminations and oil-in-water emulsion under gravity-driven separation

Treating oily wastewater is a significant challenge, and developing cost-effective, durable, and efficient membranes is crucial for this purpose. This study introduces a novel and simple approach to transform a superhydrophobic/superoleophilic polystyrene Fe3O410%@ PS membrane, with a contact angle of 162°, into a multifunctional superhydrophilic-underwater superoleophobic (SUS) SiO2@Fe3O4@ PS membrane, with a 0°contact angle. Fabrication entails electrospinning highly porous Fe3O410%@ PS nanofibrous membranes coated with silica nanoparticles to achieve a unique surface structure with multiscale roughness and surface energy. The resulting membrane demonstrates excellent performance in gravity-driven separation, effectively removing oils, oil-in-water emulsion, dyes, and biological pollutants while maintaining high permeability (up to 1530 L.m−2.h−1). The SiO2@Fe3O4@ PS nanocomposite membrane exhibits outstanding separation efficiency for oil/water mixtures, emulsions, algae, parasites, and organic dyes like Methylene blue (MB) with a removal effectiveness of 99.9 %. Furthermore, this multifunctional membrane nanocomposite is durable and is utilized in various challenging environments, including alkaline, acidic, salty, and hot water. It can withstand at least 50 separation cycles without retraining, which is cost-effective.

Current Trends and Future Perspectives in the Remediation of Polluted Water, Soil and Air—A Review

The protection of all environmental compartments (water, soil, air) is of great interest for the normal functioning of life on Earth. The environment is systematically polluted with different concentrations of physical, biological and chemical pollutants. For the purpose of environmental protection, numerous in situ and ex situ biological, chemical and physical remediation techniques have been developed. Most techniques have limitations, such as high cost, processing time or environmental feasibility. In general, biological techniques have proven to be the most environmentally friendly compared to chemical and physical techniques. Furthermore, remediation is an extremely complex procedure due to the complexity of the pollutant composition. Therefore, the implementation of individual physical, biological or chemical remediation techniques is often not sufficient for adequate remediation of the polluted environment. Accordingly, for more economical and efficient environmental remediation, it is recommended to use a combination of techniques that should meet the requirements of efficiency and treatment duration. Ultimately, this review provides a concise overview of the recent application of physical, biological and chemical remediation techniques to all compartments of the polluted environment. A critical review of existing knowledge on environmental remediation through a search of the relevant literature has helped to assess the basic challenges and limitations that arise in the issue of environmental remediation, as well as providing recommendations and guidelines for future research.

Micro/nanorobots for remediation of water resources and aquatic life.

Nowadays, global water scarcity is becoming a pressing issue, and the discharge of various pollutants leads to the biological pollution of water bodies, which further leads to the poisoning of living organisms. Consequently, traditional water treatment methods are proving inadequate in addressing the growing demands of various industries. As an effective and eco-friendly water treatment method, micro/nanorobots is making significant advancements. Based on researches conducted between 2019 and 2023 in the field of water pollution using micro/nanorobots, this paper comprehensively reviews the development of micro/nanorobots in water pollution control from multiple perspectives, including propulsion methods, decontamination mechanisms, experimental techniques, and water monitoring. Furthermore, this paper highlights current challenges and provides insights into the future development of the industry, providing guidance on biological water pollution control.

Buoys are non-indigenous fouling hotspots in marinas regardless of their environmental status and pressure

Marinas contribute to the degradation of coastal ecosystems, constitute non-indigenous species (NIS) hotspots and function as steppingstones in invasion processes. These often enclose highly modified water bodies that promote the concentration of pollutants and propagules, favoring NIS abundance. In these habitats, floating structures are often the most invaded by fouling NIS. This study aims to address the effect of floating substrate (buoys vs pontoons) on fouling assemblages, with special focus on NIS, in 6 marinas of Cadiz Bay during summer and winter seasons. Since the effect substrate type can depend on the water physicochemical conditions and environmental state and pressures of marinas, an environmental assessment was carried out for each marina using literature, physicochemical water measurements and environmental risk assessments. Despite the registered seasonal variation in fouling assemblages and the environmental variability among the studied marinas, the type of substrate played a key role in fouling assemblages' structure and abundance. The higher abundance of fouling assemblages in buoys than pontoons favor NIS prevalence in marinas and increase the risk of NIS dispersal, particularly considering that buoys are more likely to detach and drift at sea than pontoons. The results indicate that high-risk consideration should be given to this substrate type and that the potential environmental effects of biological pollution must be considered in risk assessments.

Humic substance/metal-oxide multifunctional nanoparticles as advanced antibacterial-antimycotic agents and photocatalysts for the degradation of PLA microplastics under UVA/solar radiation

As a result of the accumulation of plastic in the environment, microplastics have become part of the food chain, boosting the resistance of fungi and bacteria which can frequently encounter human beings. Employing photocatalytic degradation is a possible route towards the removal of chemical and biological pollutants, such as plastics and microplastic wastes as well as microorganisms. Using biowaste materials to design hybrid nanoparticles with enhanced photocatalytic and antimicrobial features would uphold the principles of the circular bioeconomy. Here, two unexpensive semiconductors-namely titanium dioxide (TiO2) and zinc oxide (ZnO) - were synthetized through solvothermal synthesis and combined with humic substances deriving from agrifood biomass. The preparation led to hybrid nanoparticles exhibiting enhanced ROS-generating properties for simultaneous applications as antimicrobial agents against different bacterial and fungal strains and as photoactive catalysts to degrade polylactic acid (PLA) microplastics under UVA and solar irradiation. In comparison to bare nanoparticles, hybrid nanoparticles demonstrated higher antibacterial and antimycotic capabilities toward various pathogenic microorganisms as well as advanced photocatalytic activity in the degradation of PLA with a carbonyl index reduction in the range of 15–23%, thus confirming a noteworthy ability in microplastics photodegradation under UVA and solar irradiation.

Bioaerosols in swine confinement buildings: A metaproteomic view.

Swine confinement buildings represent workplaces with high biological air pollution. It is suspected that individual components of inhalable air are causatives of chronic respiratory disease that are regularly detected among workers. In order to understand the relationship between exposure and stress, it is necessary to study the components of bioaerosols in more detail. For this purpose, bioaerosols from pig barns were collected on quartz filters and analysed via a combinatorial approach of 16S rRNA amplicon sequencing and metaproteomics. The study reveals the presence of peptides from pigs, their feed and microorganisms. The proportion of fungal peptides detected is considered to be underrepresented compared to bacterial peptides. In addition, the metaproteomic workflow enabled functional predictions about the discovered peptides. Housekeeping proteins were found in particular, but also evidence for the presence of bacterial virulence factors (e.g., serralysin-like metalloprotease) as well as plant (e.g., chitinase) and fungal allergens (e.g., alt a10). Metaproteomic analyses can thus be used to identify factors that may be relevant to the health of pig farmers. Accordingly, such studies could be used in the future to assess the adverse health potential of an occupationally relevant bioaerosol and help consider defined protective strategies for workers.

Comparing The Ability to Treat Artificial Cow Wastewater by Constructed Wetland Model Using Sorghastrum nutans and Brachiaria humidicola

In addition to meat production, the cattle industry generates significant waste, including bedding materials, wastewater, animal manure, and losses related to feed. If not managed correctly, these byproducts can have adverse environmental impacts. Constructed wetlands (CWs) offer a cost-effective and eco-friendly solution for sustainable wastewater treatment. By virtue of their extensive root systems and filtration matrices, CWs effectively reduce pollution by eliminating suspended particles, organic matter, heavy metals, and pathogens from wastewater. This research aims to assess pollutants present in cattle wastewater and evaluate the efficacy of Sorghastrum nutans and Brachiaria humidicola in purifying contaminants within constructed wetlands (CWs). CWs planted with B. humidicola exhibited higher removal rates for nutrient pollutants compared to CWs utilizing S. nutans. After a week of treatment, B. humidicola-based CWs demonstrated removal percentages of 94.07% for total nitrogen and 91.58% for phosphate (PO₄³⁻). Constructed wetlands also prove effective in eliminating biological contaminants like Escherichia coli and Shigella sp. This study highlights that the CW model incorporating B. humidicola outperforms the S. nutans model, achieving 100% removal of E. coli and 97.37% removal of Shigella sp. In conclusion, cow wastewater contains nutrient and biological pollutants, both effectively mitigated by CWs using selected plant species. Notably, B. humidicola surpasses S. nutans in its capacity for pollutant removal.

Assessing indoor PM2.5 microbial activity in a university campus environments in Beijing

Most people spend 90 % of their time inside, indoor bioaerosols significantly impact human health. This study aimed to investigate the substantial impact of indoor bioaerosols, particularly the harmful small particle-size components within Particulate Matter 2.5 (PM2.5), on human health in a crowded campus setting. Conducted during the summer at a Beijing university, the research assesses microbial activity within PM2.5 in offices (occupied by both teachers and students) and student dormitories, encompassing bedrooms and common areas. The optimized Fluorescein Diacetate (FDA) hydrolysis method was employed for assessment. Indoor microbial activity ranged from 1.18 to 176.56 ng m−3 sodium fluorescein while outdoor activity ranged from 6.14 to 90.15 ng m−3 sodium fluorescein. Meteorological factors, including heavy rain and strong winds, influenced the correlation between indoor and outdoor microbial activity, contrasting with the effect of air pollution levels. Offices with high occupancy and outdoor environments with strong winds or heavy rain often resulted in an I/O ratio >2, and a negative correlation was observed between the I/O ratio and indoor microbial activity. The study underscores the significance of ventilation type (air conditioning vs. natural ventilation), emphasising the importance of maintenance and clean living habits in reducing indoor microbial loads. Furthermore, it identifies population density as a pivotal factor affecting microbial activity in office air. This study contributes to assessing Indoor Air Quality (IAQ) and controlling bioaerosol pollution, and provides an effective measure for rapidly evaluating biological air pollution in crowded indoor environments using the PM-based microbial activity.

Photodegradation of salicylic acid in aqueous phase by TiO2 / UV System

Man uses the background where he lives and transforms it; he becomes the factor controlling the ecosystem conditions and the main reason of degradation of environment especially by industrialization and rejecting wastewaters. Water pollution can be soluble or not. The main categories of the water soluble pollution are represented by: inorganic pollutants, biological pollutants and organic pollutants. There are numerous methods to treat wastewaters; they depend on the characteristics of pollution. This study aims to examine the application of the advanced oxidation process, particularly heterogeneous photocatalysis. This process has been applied for degradation of salicylic acid dissolved in water; its degradation occurs in a photocatalytic reactor made up of a titanium dioxide (TiO2) as a semiconductor supported on a glass plate placed at the middle of the reactor and subjected to the U.V irradiation. The assessment of the parameters influence related to the reactor such as recirculation flow and initial concentration of pollutant has shown that at low recirculation flow, the photodegradation of pollutant was accelerated about 98 % of salicylic acid was degraded after 3 hours of irradiation, in addition the heterogeneous photocatalysis process is applied even at low concentration. Kinetic analyses indicated that the photodegradation of pollutant can be described by a pseudo-first-order reaction. The Langmuir Hinshelwood model was used to assess the kinetics of the heterogeneous photocatalytic process, the rate constant, kapp for the photocatalytic degradation was determined at different concentrations.

Unveiling the photocatalytic property of La2O3–CuO nanocomposites for organic pollutants in wastewater treatment

Photocatalytic degradation was considered the best strategy for removing hazardous dye contaminants in water bodies from wastewater. The photocatalyst of pure La2O3 nanoparticles and La2O3–CuO nanocomposites synthesized by sonochemical method. The nanocomposites were used to investigate the degradation activity of Safranin (SR) and crystal violet (CV) under sunlight irradiation. The physicochemical characterization methods (e.g., Field emission scanning electron microscopy (FESEM), high resolution-transmission electron microscopy (HR-TEM), ultraviolet, visible spectroscopy (UV–Vis), and BET analysis indicate that the composite has been constructed successfully that enhances the widened visible light absorption, induces charge transfer and separation efficiency of electron–hole pairs. X-ray diffraction (XRD) experiment demonstrated that introducing copper into lanthanum resulted in alterations in the size of the crystallites and the average size of the nanoparticles, shifting from 21.93 to 43.19 nm. The photocatalytic activity of all samples was examined through the photodegradation of Safranin and crystal violet in an aqueous medium. The photocatalytic degradation rate of nanocomposite catalysts could eliminate 95.80 % and 97.05 % of Safranin and crystal violet dyes in 135 min, about 1.4 times that of pure La2O3 nanoparticles. The current study will give an efficient nanocomposite photocatalyst for removing biological and textile dye aqueous pollutants.

A systematic review and meta-analysis of pollutants in environmental media.

Environmental pollutants are ubiquitous in our environmental media, resulting in detrimental impacts on both humans and the environment. An evidence-based review, particularly a systematic review and meta-analysis, performs a crucial function in assessing the pollution status of pollutants in environmental media at national and global scales. We selected and thoroughly investigated 76 papers focusing on systematic reviews and meta-analyses of contaminants in environmental media. The need to broaden the scope of studies was observed with an increase in the total number of publications, andthere were greater focuses on food safety, water pollution, biological pollution, and environmental risks. Furthermore, this review outlined the fundamental procedures involved in a systematic review and meta-analysis, including literature searching, screening of articles, study quality analysis, data extraction and synthesis, and meta-analysis. A meta-analysis typically comprises fixed- and/or random-effects meta-analysis, identifying and measuring heterogeneity, sensitivity analysis, publication bias, subgroup analysis, and meta-regression. We specifically explored the application of meta-analysis to assess the presence of contaminants in environmental media based on twodifferent pollutant categories, namely, non-biological and biological pollutants. The mean value is commonly utilized to assessthe pooled concentration of non-biological pollutants, while the prevalence serves as the effect sizeofbiological pollutants. Additionally, we summarized the innovative applications,frequent misuses, and problems encountered in systematic reviews and meta-analyses. Finally, we proposed several suggestions for future research endeavors.

Microbiological and physicochemical quality enhancement of treated wastewater using raw and chemically modified clays from Sidi Bouzid region, Tunisia

Environmental discharge of wastewater represents a source of chemical and biological pollutants. This study firstly evaluates the microbiological and physicochemical quality of treated wastewaters collected from two wastewater treatment plants (WWTPs) located in two different Tunisian cities namely Sidi Bouzid (SB) and Gafsa (G). Then, the capacity of three raw and acid/base-activated local clays to enhance the quality of wastewaters was assessed. The results indicate that the quantities of enteric bacteria (oscillating from 1.381 × 103 to 1.4 × 108 CFU/100 mL), fungi (between 1.331 × 103 and 1.781 × 104 CFU/100 mL), as well as SARS-CoV-2 (between 4.25 × 103 and 5.05 × 105 CFU/100 mL) and Hepatitis A virus RNA (form 4.25 × 103 to 7.4 × 104 CFU/100 mL) detected in effluent wastewaters were not in compliance with the Tunisian standards for both studied WWTPs. Likewise for other indicators such as electrical conductivity (ranging 4.9–5.4 mS/cm), suspended matter (145–160 g l−1), chemical oxygen demand (123–160 mg l−1), biological oxygen demand 5 (172–195 mg l−1), chloride, Total Kjeldahl nitrogen (TKN) and phosphorus contents (710, 58–66 and 9.47–10.83 mg l−1 respectively), the registered values do not agree with the set standards established for wastewater treatment. On the other hand, the pH values fitted (oscillating from 6.86 (at G) to 7.24 (at SB) with the Tunisian standards for both WWTPs. After treatment, wastewaters showed better values for the microbiological parameters, especially for the clays designed as AM and HJ1, which eliminated 100% of viruses. In addition, when acid-activated AM clays were applied, a marked improvement in the quality of physicochemical parameters was obtained, especially for suspended matter (2 and 4 g l−1 for SB and G, respectively), TKN (5.2 (SB) and 6.40 (G) mg/l), phosphorus (1.01 (SB) and 0.81 (G) mg/l). Our results open perspectives for the possibility of efficiently using these specific clays in the enhancement of the quality of treated wastewaters.