Removing environmental pollutants and preserving the environment is an important issue and many efforts have been made in this regard in recent years. In the present work, chromate ions were removed from aqueous solutions by ZnO/CuO acting as both adsorbent and catalyst. Metal oxide fabrication from metal organic framework is one of the most important and interesting scientific issues for the synthesis of high surface area materials. Here, we demonstrate ZnO/CuO synthesis from bimetallic Zn-Cu metal-organic framework (Zn(50)-Cu(50)-BTC) using temperature-programmed oxidation method. The adsorptive and catalytic removal procedure were optimized in terms of its batch efficiency using experimental designs. The effect of hole scavenger type was investigated, and the relationships between the effective important removal procedure parameters and chromate removal efficiency were analyzed through the response surface methodology (RSM) based on central composite design (CCD). The correlation coefficient (R2) and F values were 0.9883 and 74.81, respectively. Finally, simplex non-linear optimization was carried out and the optimal pH, ZnO/CuO amount and contact time were determined to be 2, 20 mg, and 17.5 min. Under these conditions, the predicted removal efficiency of 50 ppm chromate at a 95% confidence level was 98.1 ± 2.4%, which was very close to the recorded response (i.e. 99.4 ± 1.9%). The kinetic and isothermal profiles of the proposed ZnO/CuO, were thoroughly investigated under optimal conditions. The adsorption isotherm follow the Langmuir model and kinetics were found to be pseudo-second-order.

Numerous coagulants, including natural and chemical coagulants, have been examined in the context of water purification. The use of natural coagulants constitutes an affordable and eco-friendly method of purifying water. The main aim of the current study was represented by investigated the feasibility of coagulant extracted from Castanea Sativa Tree Leaves using three different salts and distilled water. The active coagulant component was extracted using 0.25, 0.5, and 1 M of NaCl and KCl, 0.025, 0.05, and 0.1 M of NaOH, and distilled water. Powdered Castanea Sativa Tree Leaves was also used as a coagulant. Jar tests were performed using synthetic turbid water, a turbidity level of 35 NTU to investigate the coagulants’ activity. The pH was measured to study the influence of a range of different pHs, coagulant doses and initial turbidity were also investigated to optimize the coagulation process. The highest level of activity was achieved using 0.5 ml/l of coagulant extracted with 0.5 M NaCl at pH level 8. Coagulant extracted using 0.05 M NaOH demonstrated the second highest level of activity. Poor coagulant activity was observed for the powdered Castanea Sativa Tree Leaves and distilled water extract. The protein content of the extracted coagulant was 0.322, 0.283, and 0.274 mg/ml using 0.05 M NaCl, 0.5 M NaOH, and 0.5 M KCl, respectively. The use of this natural coagulant was also found to moderately increase organic matter content in the treated water, which was proportional to protein contents of the extracts. Coagulation results were statistically examined using SigmaPlot 12.5 software.

Cong-red dye is a precursor of various products of cotton industry and its toxicity in the aquatic environment is a great concern. Present study was highlighted on the efficacy of the fish scale char (FSC) towards removal of congo red from aqueous solution. The prepared FSC was characterized by zero point charge (pHZPC), scanning electron micrograph with elemental analysis (SEM-EDX) and fourier transform infrared (FTIR). Based in the equilibrium and kinetic study, the Langmuir (R2 = 0.967) and Pseudo-second-order (R2 = 1.00) models are appropriate to describe the dye adsorption process. The randomness and exothermic nature of the system were confirmed by the negative values of both entropy and enthalpy, respectively. Finally, optimization by Response Surface Methodology (RSM) study revealed that the experimental data were nicely fitted with central composite design with very high F value (F = 1596.24, p < 0.0001). Perturbation plot suggested that congo-red dye removal is more sensitive with respect to biosorbent dose, pH and initial concentration. The exhausted adsorbent was regenerated with 0.5(M) NaOH solution. Therefore, it can be concluded that fish scale char could be a valuable materials towards purification of industrial effluent.

Phenols have attracted global interest in the sphere of environmental management due to their potential toxicity on human health. This study determined concentrations of three priority phenolic compounds in effluent and water of a local textile industry in Abeokuta, Nigeria.  During tie-dye production, triplicates of effluent, well water, stream and control water were collected three times from five points to give a total of forty-five samples. Physicochemical parameters of samples including temperature, pH, electrical conductivity (EC), total suspended solids (TSS) and total dissolved solids (TDS) were determined according to standard methods while the concentrations of the priority phenolic compounds (4-nitrophenol, 4-chloro-3-methylphenol and 2, 4-dinitrophenol) were determined using High Performance Liquid Chromatography equipped with Ultra-Violet detector (HPLC/UV). Data obtained were subjected to descriptive (mean and standard deviation) and inferential (ANOVA) statistics. pH, EC and TSS of effluent and water samples were higher than the permissible limits of World Health Organization (WHO) and Federal Environmental Protection Agency (FEPA) while temperature of the effluent samples and TDS of the well water samples were within standard values. Higher concentrations of the priority phenolic compounds occurred in effluent than water samples but 4-nitrophenol was below detection limit (DL) in water samples. Concentrations of 4-nitrophenol, 4-chloro-3-methylphenol and 2,4-dinitrophenol in effluent exceeded stipulated standard of WHO (0.01 mg/L) and water samples. High concentrations of phenols in water bodies at the local textile industry suggest uncontrolled discharge of effluent from the industry which could eventually reach surface and ground water with potential significant health implications to the populace.

Environmental threats from the accumulation of plastic trash are getting worse.  It is robust, lightweight, corrosion-resistant, affordable, and durable. Microorganisms play a significant role in protecting our environment by degrading plastic wastes that are harmful either naturally or by chemical modification.  The current study aims to investigate the biodegradation of synthetic polyethylene through the utilization of a laboratory bioreactor. Various types of additives were introduced to the soil samples before subjecting them to a 30-day UV treatment. The degradation of polyethylene was shown through a reduction in weight following a 24-week incubation period with certain bacterial strains. Experimental findings have revealed that models subjected to UV radiation exhibit the highest degree of vulnerability and degradation. Approximately 52% of polyethylene (PE) films underwent degradation when exposed to soil enhanced with peat moss. In contrast, only 40% and 45% of PE films were destroyed when subjected to garden soil that was untreated and treated with UV radiation, respectively. In contrast, the addition of husk resulted in a 48% to 53% reduction in weight for PE films that were buried for the same duration of the experiment.  The highest level of effectiveness was achieved by the disintegration of the plastic material that was introduced into the soil along with organic fertilizers, resulting in a value of 56.60%. The weight loss outcomes have been substantiated by the utilization of the Atomic Force Electron Microscope (AFM) images, which exhibited the highest magnitude in the experimental model using soil supplemented with fertilizers.

Microplastics can contaminate water owing to their small size. If aquatic biota consume microplastics, they disrupt their reproductive processes, digestive tracts, and development. This study aimed to identify microplastic waste from silkworms (Tubifex spp.) in the Brantas River. The study was conducted in a descriptive manner by collecting samples of microplastic waste from silkworms and examining the shape, type, amount, and percentage of microplastic abundance in the river. An FTIR test was used to determine the microplastic content. Using a Zeiss Axio Zoom.V16 at 50x magnification, microplastic particles from individual worms and worm samples were visually identified. Then, the 50% hot needle test was used to determine the composition of the plastic. A total of 263 microplastic particles were found in the worm samples. Silkworms (Tubifex spp.) in the Brantas River, Kediri City, were shown to contain four types of microplastics, namely fibers, filaments, fragments, and granules, which were dominated by filament particles with 49% filament content, 45% fiber, 5% fragments, and 1% granules. The microplastic polymers identified via FTIR were polyethylene and ethylene-polypropylene-diene copolymers. These microplastics can originate from plastic bags, used drinking bottles, rope fibers, and pieces of water hose, which are often found around the Brantas River. Silkworms found in the Brantas River contain microplastic waste from various pollution sources.

This study was undertaken to evaluate concentration of Uranium (U) in the drinking water of the Tonk district of Rajasthan (India). The main objective of the study is to determine the distribution of Uranium concentration and the geochemical behavior of Uranium in pre-monsoon (PRM) and post-monsoon (POM) drinking water samples. Uranium was measured by LED fluorimeter. Total 318 drinking water samples were collected for both seasons. It is observed that the water quality of all the samples is within the limits prescribed by WHO (30 µg/L) except a few, and can be used for domestic purposes. The Uranium concentration was found to be in the range 0.21 to 173.72 µg/L with a mean value of 8.58 µg/L in pre-monsoon and 0.21 to 162.34 µg/L with a mean value of 11.22 µg/L in post-monsoon samples. The geochemistry of the study area shows rock-water interaction. The order of average anionic concentration is found to be HCO3 – > Cl – > SO4 2– > NO3 –. Although no definite trend of seasonal variation in the concentration of U was observed, large samples have higher Uranium concentrations in post-monsoon than pre-monsoon.

This investigation aims to study synoptic analysis in the dynamic structure accompanied by air pollution of extreme heat during July 2019 in the Yazd province. The time-series data analysis for the yearly surface air temperatures during the past two decades shows a significant peak surface air temperature in July 2019 in Yazd province. The long-term mean and anomalies of the daily basis (2001 to 2019) for the daily mean sea level pressure show a decrease in pressure with a maximum of about 6 hPa and an increase in geopotential height at 500 hPa with a maximum of about 20-30 gpm (geopotential meter), which has led to an increase in the average daily temperature of about 2 to 4 degrees Celsius. Also, showed high values for Ozone mass mixing ratio over the study area mostly over the west with a maximum of ~92 ppb in Yazd province on 1 July 2019. The AIRS (Atmospheric Infrared Sounder on NASA's Aqua satellite) data shows a positive trend (2003- 2019) for the total daytime Ozone column-averaged over the study area during July. Furthermore, the results of this work obtained from OMI satellite observation show a significant increase in the ultraviolet aerosol index (UVAI) during the study period time. This study shows the recent extreme weather changes in the study area which may be necessary for a better future forecast for heat warnings along with poor air quality and health risk when such events may happen in the future.

In this work, it was attempted to evaluate and demonstrate disinfection effectiveness of an electrochemical process to entirely remove coliform from wastewater effluent following secondary treatment. For the tests, an experimental bench-scale batch electrochemical cell was constructed, and aluminum electrodes were employed in the electro-disinfection reactor. In the electric disinfection phase, wastewater samples were put in the reactor/disinfector and a direct current (DC) was applied to it. According to findings, a significant decrease occurred in the total number of coliforms in the treated wastewater, and a high improvement occurred in the effluent properties. At a contact time of 15 min and a current density of 5.5 mA/cm2, led to a bacterial killing effectiveness of 97.7% or above. As the current density and contact time increased, a general increase occurred in the bacterial killing efficiency, and the effect of the two above-mentioned factors was much greater than the effect of salinity. Moreover, according to the experimental data, the removal efficiency of chemical oxygen demand (COD) and total suspended solids (TSS) by the aluminum electrodes were 78.50% and 99.93%, respectively. The findings indicate the applicability of the proposed electrochemical treatment to wastewater effluent. Nevertheless, to be able to apply this system at an industrial scale in the future, it is necessary to conduct more research into the optimum operation conditions and make an in-depth comparison of energy consumptions between the electrochemical treatment and the conventional approaches.

We determined the levels of nine heavy elements in water, sediment, and the edible tissues of three frequently eaten fish species collected from the five polluted rivers in different divisions of Bangladesh. These samples were randomly taken from five rivers and analyzed by Flame Atomic Absorption Spectroscopy. We found seasonal fluctuations in the hierarchy of mean concentration for different heavy metals in five rivers’ fish, water, and sediments. In the water, the concentrations of Cd, Cr, Cu, Fe, Mn, Pb, Zn, Ni, and Hg ranged from 0.010-0.081, 0.016-5.531, 0.013-2.445, 0.860-22.924, 0.043-1.424, 0.015-0.933, 0.091-1.451, 0.012-2.888, and 0.010-0.032 mg/l where in the sediment the concentrations ranged from 0.1-1.47, 4.21-284.1, 0.12-28.46, 1860-14971.33, 122.1-480.8, 0.84-42.15, 2.14-210.35, 15.3-30.4, and 0.17-10.44 mg/kg. For fishes concentrations ranging from BDL-0.78, 0.04-86.45, 0.01-1.67, 4.19-102, 0.08-0.94, 0.01-0.99, 0.08-9.56, 0.01-4.56, and BDL-0.2 mg/kg were reported for the above metals order respectively. The highest concentration (mean) of Cr and Fe in waters and sediments was 1023 times and 13020.72 % higher than WHO’s standard and Toxicity Reference Values (TRV), respectively. Besides, the bioaccumulation factors (BAF) of the selected elements for the studied fishes were found to be between 0.036-626.25, where the pollution load index (PLI) for the five rivers ranged from 0-0.95 and the concentration factor (CF) found between 0.02-4.03. Estimated daily Intake (EDI) as well as Target hazard quotients (THQs) analyses revealed potential risks for fish consumers, particularly the level of some metals exceeding the WHO/FAO's tolerable limit, which indicates that the rivers' water and fish are dangerous to humankind.