Polychlorinated biphenyls (PCBs) are known amongst the most dangerous toxicants entering the coastal marine waters from various polluting sources. Even the smallest PCBs doses are capable to change physiological and biochemical processes exerting toxic, mutagenic and carcinogenic effects. So, the aim of this study was to analyze the impact of PCBs at 1, 100, 1000 µg/L on oxidative stress parameters (level of oxidized proteins (neutral aldehydes and ketones, basic aldehydes and ketones) and lipid peroxidation), antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT)) and cholinesterase (ChE) activity in the hepatopancreas of mussel Mytilus galloprovincialis during 5 days’ of the toxicological experiment. Level of all forms of the oxidized proteins was found significantly increased at 100 µg/L and 1000 µg/L (+50-78% and +150-282%, respectively) compared to the control (p<0.05). Level of lipid peroxidation was considerably higher at 1, 100, 1000 µg/L (+59%, +134%, +269%, respectively) compared to the control (p<0.05). SOD activity significantly raised at 1, 100, 1000 µg/L (+63%, +200%, +118%, respectively) compared to the control (p<0.05), while CAT activity reduced at 1000 µg/L compared to the control, 1 µg/L and 100 µg/L (-29%, -66%, -40%, respectively) (p<0.05). ChE activity was found lower at 1, 100, 1000 µg/L (-60%, -93%, -30%, respectively) compared to the control (p<0.05). Possible mechanisms of M. galloprovincialis biochemical response to PCBs are discussed. Studied biochemical parameters can be suitable biomarkers for evaluating the toxicity of PCBs and M. galloprovincialis can be used as a bioindicator in the monitoring of marine ecosystems contaminated with these pollutants.

Heavy metal contamination poses grave risks to all kinds of life. The fastest growing automotive, electroplating, and battery industries release the most common heavy metal, Nickel, into the environment, which has lethal impacts on human health. Our research aims to find Ni-resistant bacteria in the metal-contaminated soil that have a great potential for removing Ni from the environment. Attempts have been made to extract and characterize Ni-resistant bacteria from automobile and electroplating industry waste-contaminated soil using serial dilution, streak plating, and various morphological, biochemical, and genetic techniques. The maximum tolerable concentration of Ni and other heavy elements, such as cadmium, lead, and aluminium for the selected isolate, was investigated using the UV-Vis spectrophotometric method. Additionally, the bacterial strain's ability to remove Ni was assessed using an atomic absorption spectrophotometer.  The current research reveals a novel strain of Kluyvera cryocrescens that could withstand Ni, Cd, Pb, Al, and combinations of these heavy metals. The maximum tolerance concentration of K. cryocrescens M7 for Ni, Cd, Pb, and Al was found to be 150 ppm, 200 ppm, 1000 ppm, and 150 ppm, respectively. Additionally, it was also observed that the bacterial strain could remove Ni by 29.57%, 35.36%, 48.41%, 46.91%, and 44.88% after 12, 24, 48, 72, and 96 hours, respectively. The strain has also exhibited resistance to vancomycin, ampicillin, carbenicillin, and streptomycin. This research discovered a novel bacterial strain, K. cryocrescens M7 that may be beneficial for removing heavy metals, particularly Ni, from metal-contaminated soil.

An important practice in environmental risk management is assessing the consequences of heavy metal concentrations resulting from a mine dam tailing failure on soil, water, and trees. To appraise the extent of pollution, an effective classification is essential. In this study, trace element contamination is handled as a two-group classification problem and examined the performance of supervised regularization algorithms as spatial classifiers using imbalanced uncertain data. In addition to conventional shrinkage algorithms such as Ridge, the Lasso and Elastic-Net, the generalized t-statistic-based U-Lasso classifiers have been introduced and tested for mitigating such imbalances and adjusting weights for class distributions. The feature interpretation studies underlined that the most important indicator of the models is Zinc (Zn). The experimental studies revealed that the Ridge classifier (l2 penalty) outperforms the other models. Statistically, the U-Lasso models exhibited notable explanation capacity and their performances recorded close to the conventional shrinkage algorithms. The use of statistical learning-based classification approach to appraise geo-environmental contamination under the conditions of natural variability and spatial uncertainty provides useful meta-data and reliable classification models.

The authors propose a methodology for assessing the sources of microplastic pollution (particles 0.5-5 mm in size), which makes it possible to differentiate coastal recreational areas according to the degree of vulnerability to microplastic accumulation. The methodology takes into account the sources of microplastics coming to the beach directly from vacationers - factors of recreational activities, as well as the influence of factors of the adjacent territory: the type of adjacent territory, saturation with transport infrastructure, etc. An analysis of the results of monitoring the microplastic concentration in beach and bottom sediments of seven beaches of the Sevastopol region with varying degrees of anthropogenic load during 2018–2020, as well as an assessment of the sources of microplastic pollution on these beaches using the proposed methodology, made it possible to differentiate these coastal recreational areas according to the degree of vulnerability to accumulation of microplastic pollution. The most vulnerable are the beaches that are actively visited by tourists and located in close proximity to large blocks of apartment buildings and extensive transport infrastructure (Pesochniy and Omega). The beaches Konstantinovsky and Goryachka (placed close tothe thermal power station), located in the zone of active navigation of ships of various tonnage, are confined to areas of low and moderate pollution. The main stream of vacationers on them are local residents with a high turnover rate. The least vulnerable are the beaches with park areas: Uchkuevka, Solnechny and Zolotoy. The source of microplastic pollution on these beaches is mainly vacationers.

Fungi are successful microorganisms in the bioremediation of environmental pollution. So, this study aimed to determine the potential of Trichoderma tomentosum to remediate cadmium, lead, and nickel contaminations from potato dextrose agar (PDA) and potato dextrose broth (PDB) media. Growth rates, toxicity tolerance sporulation, bio-sorption capacity, and bio-sorption efficiency of the fungus were evaluated under different concentrations of CdCl2, Pb(NO3)2, and NiCl2. The findings demonstrated that the growth rate of the fungus differed depending on concentration, metal type, and medium. More metals in PDA medium induced more inhibition on fungus growth rates; however, the rate was independent from the heavy metals concentrations in PDB medium. Cadmium was the most toxic metal tested against T. tomentosum, with a 72h LC50 of 37 ppm. It was about 3.16 and 4.24 times as toxic as nickel and lead, respectively. In the control condition, sporulation of the fungus began at 72 hours, but under the heavy metals, it began at 168, 168, and 192 hours, respectively, for Pb, Ni, and Cd. Both the bio-sorption capacity and efficacy of the fungus were significantly enhanced by an increase in metal content and the highest values were obtained at 200 ppm of the salts. The heavy metals total bio-sorption capacity order was Ni < Cd < Pb in the aqueous medium. The conclusion was that T. tomentosum has a greater potential for the biosorption of heavy metals; hence, the fungus may be employed for the bioremediation of heavy metals from polluted sites, particularly wastewater and industrial influents.

Domestic and industrial wastewater contributed to some urban wastewater, which requires specific processing before being disposed into surface waters or reused for irrigation. This paper aimed to employ kaolin as an adsorbent to remove heavy metals from wastewater, as well as aeration and alum to remove nutrients. Experiment were conducted in three parts: first, involved using the aeration method to determine the ideal amount of time to remove or minimize the nutrients. Second, involves treating the solution with potassium alum using various alum doses at the obvious times to eliminate or minimize the nutrients, while third step involves treating the solution with kaolin ore with a size of < 63 µm at various doses, pH, and contact times to remove heavy metals. The findings showed that the aeration method completely removed CO3, OH, PO4, NO3, Ca, and Mn ions after contact time equal 120, 24, 192, 24, 120, and 48 hrs, respectively. Applaying alum treatment method can remove completely CO3, OH, PO4, NO3, and Mn, after contact time 120, 24, 120, 24, and 24 hrs, respectively. When Kaolin ore used as adsorbent, the removal efficiency of  Fe, Cd, Cr, Cu, Sr, Mn, and Zn were; 92, 100, 100, 100, 94, 100, and 88 % ,respectively in 24 hours contact time. The experiment succeeds in treatment of industrial wastewater that was within the range of specified limitations for disposing into surface water or reuse in irrigation field as stated by Egyptian standard code using the three successive treatment techniques.

Real-time monitoring of Black Carbon and Particulate Matter was done by Aerosol Black Carbon Detector (ABCD) and GRIMM portable aerosol Spectrometer in Agra at five different locations (R1, R2 traffic and R3, R4, R5 residential road sites). Major portion of PM mass was contributed by PM10 followed by PM2.5 and PM1.0. Major portion of PM in number mode is contributed by PM10=PM0.25 followed by PM5.0 =PM0.5, PM1.0, and PM2.5. All the PMs mass and number concentration was highly associated with the R1 site due to the vehicular and other anthropogenic activities and was least at R5 except for PM10. The highest concentration of BC was found at R2 site followed by R1 while During the sampling events NO2 and O3 was found highest at R2 site followed by R1. The source of BC, PMs, NO2, O3 at R1&amp; R2 may be vehicular activities, population activities, crowded area, and industrial activities. BC contribution in PM1.0 was highest followed by PM2.5. The children category in the traffic site has high PM deposition mass visualization as compared to the residential road site so they are highly affected by lung diseases instead of the residential road site children category. From health risk assessment results, it was found that no population was at non-carcinogenic risk from chronic exposure to PM10 while children may be at possible risk from acute exposure. However, cancerous risk assessment showed that both children and adult were at risk from exposure of PM2.5 and may develop cancerous diseases.

Most tilapias are microphytes, but some prefer higher plants. Ammonia is one of the most important toxic compounds of nitrogen, which is a serious problem in the environment and aquaculture industry. In the present study, juvenile Oreochromis niloticus were exposed to 10, 20, and 30% (96h LC50) of ammonia for two weeks, which are equivalent to 0.9, 1.8, and 2.7 mg / l, respectively. After this period, the fish were anesthetized and blood samples were taken from the caudal stalk with a heparin syringe for evaluating blood indicators. The tissue samples were taken 0.5 cm from the liver, fixed in 10% formalin buffer, and after dehydration with alcohol, clarification with xylol, blocking with paraffin, and cutting 4-6 microns thick with microtome were done. Finally, the stained slides were studied with a light microscope. The results showed phenomena such as hyperemia, nuclear hypertrophy, sinusoidal dilatation, increased melanomacrophage centers, nucleus margination, hepatocyte vacuolation, and cell necrosis in the liver. In the studies of blood serum factors with the increase of ammonia, it has been increased in  AST, ALT, and ALP compared to the control and other groups. Also, as the ammonia concentration increased, the severity of the lesions also increased. Therefore, ammonia causes changes in the structure and activity of metabolic enzymes of the liver, which must be controlled by creating the appropriate ammonia and management conditions in the aquatic environment.

The Huatanay River in Cusco-Peru, is affected by wastewater discharges along its course. In order to evaluate this impact, we evaluate antibiotic residues and their impact on the increase of bacterial resistance in the city of Cusco treatment plant. For this purpose, water samples from the influent and effluent of the treatment plant were analyzed by chromatographic methods; additionally, sensitivity tests were performed with three bacterial strains (Escherichia coli, Salmonella sp., and Klebsiella sp.), which were isolated from the same place. Six antibiotic residues were identified (ceftriaxone, amoxicillin, trimethoprim, sulfamethoxazole, dicloxacillin, and lincomycin). Those found in the highest concentration were: amoxicillin (91495 and 0 µg/L) and lincomycin (33970 and 10800 µg/L) in the influent and effluent, respectively. There is more resistance in the effluent than the influent in the case of E. coli shows resistance in the effluent to cephalexin (30 µg) and azithromycin (15 µg). Salmonella sp. is resistant to amoxicillin (15 µg), dicloxacillin (1 µg), lincomycin (2 µg), ceftriaxone (30 µg), cephalexin (30 µg), and ciprofloxacin (5 µg). Finally, Klebsiella sp. is sensitive to ceftriaxone (30 µg), amoxicillin (15 µg), and cephalexin (30 µg). This confirms that the antibiotic residues contained in the wastewater of Cusco generate resistance in the isolated bacteria.

Elevated level of fluoride (> 1.0 mg/L) in drinking water leads to both dental and skeletal fluorides. Present research is dedicated to check the efficacy of duck shell dust towards removal of fluoride. Various analytical tools (XRF, XRD, SEM-EDAX and zero point charge) were used to characterize the present adsorbent. The entire batch mode study results were further optimized by Response Surface Methodology (RSM). The results revealed that Langmuire isotherm is best fitted (R2 = 0.819) with adsorption capacity 4.894 mg/g. However, kinetic study suggest that the fluoride adsorption followed pseudo-second-order kinetic equation (R2 = 0.956). Similarly, thermodynamic study revealed that the fluoride adsorption by duck shell dust is endothermic and entropy driven process. Finally, optimization study demonstrated the optimized condition such as initial concentration, adsorbent dose, contact time and pH are 89.29 mg/L, 1.112 g/100 mL, 42.5 min and 9.91, respectively. Therefore, it may be concluded that duck shell dust could be a promising adsorbent for decontamination of fluoride from contaminated body.