In advanced oxidation processes, the application of ozonation has been immensely used in recent years for the treatment of effluent water from pharmaceutical, textile and chemical industries. In this study, procian blue, a major and vastly used reactive dye in the textile industry was chosen for ozonation. This work investigated the effect of ozonation for the treatment of synthetic textile effluent water. The change of pH values of dye solutions from 2-12 had moderate effect on dye removal. The degradation rate was faster during the initial period of ozonation and reached highest dye removal around 90 minutes. The highest 87% removal of dye was observed for the case of 60 mg/L dye solution at pH 12. At higher pH, the dye degradation increased as the rate of formation of hydroxyl radical increased with pH. Factors influencing on dye degradation like concentration of dye, time of ozonation, and addition of H2O2 with ozone (combined treatment) were also evaluated. The combined treatment (5 g/L of hydrogen peroxide) increased the degradation of dye to 92% as compared to 85% for pure ozonation process of 60 mg/L dye solution of initial pH 10. The procian blue dye degradation followed pseudo-first order kinetics with a value of rate constant 2.48×10-2 /min.

Increasing plastic usage pose a significant threat to the marine environment. Many studies have been conducted to examine the amount and environmental impacts of plastic waste across the world. This study was carried out to investigate the density and quality of plastics on the sea surface and seabed of İskenderun Bay. 35 different seabed sampling and 25 different sea surface sampling were conducted by using İskenderun Technical University R/V ISTE-1 vessel. A total of 1 661 581 m2   and 465 511 m2 swept from the seabed and sea surface were scanned, respectively. As a result of these scans, the amount of plastic waste density per unit area of the seabed was found as  0.126 g / m2 ± 0.011 (p: 0.95), and the amount of plastic waste density per unit area of sea surface was calculated as 0.052 gr ± 0.011 (p: 0.95). Scuba dives conducted in river mouths showed plastic deposition pits at the seabed. Major surface current systems and dominant southern winds were found to be effective in the sea surface distribution of plastic materials.

The purpose of this study was to evaluate the concentrations of potentially toxic elements in the Suches river using standardized geochemical indices and to identify the main sources of contamination in the section from the Suches lagoon up to 33.8 km downstream of the effluent river, in the district of Cojata, Puno, Peru. The concentration of Al, Ba, Co, Fe, M, Ni, P, V and Zn in sediments of the Suches river was determined by means of mass spectrometry from October 2019 to February 2020. The values of Co, Fe, Mn, Ni, P and Zn exceeded the base values of contamination according to the general geological references while Al, Ba and V, did not surpass them. The contamination factor showed that the elements Co and Ni revealed a very high level of contamination, while the Zn, a considerable level. The area has an average pollution load index value of 2.24, indicating moderate general pollution. The elements Co, Ni, Al and Zn were within the moderate and extreme classification according to the pollution index. The Spearman's correlation analysis allowed determining the association between Al, Fe, Mn, P and V, which share a natural origin and the accumulation of these elements is due to the effects of weathering and soil erosion. The evaluation of the contamination indices and the correlation confirm that Cobalt, Nickel and Zinc are toxic elements associated with gold mining and agricultural activities.

Activated carbon was prepared from corn cob agricultural waste with different impregnation ratios and pyrolysis times. The optimal adsorbent prepared using at 4:1 ZnCl2:corn cob char ratio at a temperature of 800 °C for 180 min provided the maximum Brunauer-Emmett-Teller (BET) surface area, total pore volume and average pore width, with values of 912.47 m2/g, 0.52 cm3/g and 22.61 Å, respectively. ZnCl2 was effective in creating well-developed pores on the surface of the activated carbon. The removal efficiency and adsorption capacity of the colour and the chemical oxygen demand (COD) of the biologically pre-treated leachate were examined utilizing the best corn cob activated carbon (CCAC) with varying CCAC dosages, contact times and initial pH values. The greatest colour and COD removal effectiveness were 88.6±0.2% and 83.7±0.4%, respectively, at the optimum CCAC dosage of 12 g for 40 min with an initial pH value of 10. In addition, maximum adsorption capacities were achieved for colour and COD of 10.3±0.02 mg/g and 12.6±0.05 mg/g, respectively, under the same conditions. The kinetics of colour and COD adsorption fitted very well with pseudo-second-order kinetic model. The CCAC performs well as an adsorbent for removing colour and COD in biologically pre-treated leachate.

The induction of oxidative stress in plants grown on crude oil-contaminated soils was investigated using a diesel contaminated soils model. Twelve cassava stems were grown in four garden pots containing different amounts of diesel oil as contaminants: 150 ppm, 300 ppm, 600 ppm and control (0 ppm). The growth of the plants was monitored for 12 weeks, after which chlorophyll contents, total proteins, lipid peroxidation and activities of catalase, glutathione, and superoxide dismutase (antioxidant enzymes) were determined from the leaves. Significant decreases (p<0.05) were observed in the antioxidant enzymes (67-86%), total proteins (79%) and total chlorophyll content (67%) in the cassava grown on diesel contaminated soil (600 ppm) compared to the control. Consequently, there were significant increase (p<0.05) in the leaf ratio and malondialdehyde (a marker for lipid peroxidation) 0.1909 ± 04 and 1.77 ± 0.34, when compared to the control 0.1530 ± 08 sq.cm/g and 0.10±0.01 µmol/mg protein respectively. It was thus concluded that stunted growth of plants and their death in diesel or crude oil contaminated soil could be traced to oxidative stress.

The paper provides data on spatial distribution of petroleum hydrocarbons, heterotrophic and hydrocarbon-oxidizing bacteria in water and bottom sediments as well as on heavy metals in bottom sediments at different sites in the zone of fresh and saline water mixing, with the salinity range 1–18 ‰ during spring low water and high water. Physical and chemical characteristics of the bottom sediments are given. The highest hydrocarbon-oxidizing bacteria percentage of the heterotrophic bacterioplankton count in the indicated areas was found in April, with the maximum of 55 % determined in the transition zone waters. The share of hydrocarbon-oxidizing bacteria in the heterotrophic bacteria abundance in the water was larger than that in the bottom sediments. The highest concentrations of chloroform-extractable substances and petroleum hydrocarbons were detected in the marine zone bottom sediments, and their lowest concentrations were found in the river zone. During the period under study, the petroleum hydrocarbon input (in almost equal volumes) was constant, which is indicated by the hydrocarbon percentage of chloroform-extractable substances, which on average was 31 % for the marine zone, 29 % for the transitional zone, and 32 % for the river zone. In contrast to the river and transition zones, the concentration of chloroform-extractable substances observed in the marine zone bottom sediments was constant.

In this study, the purpose was to investigate the histopathological, genotoxic effect, oxidative stress and cell death due to Metronidazole (MTZ), which is a 5-nitroimidazole compound used widely for the treatment of anaerobic organism infections in fish and humans on gill and liver tissues of Oncorhynchus mykiss.Trout fishes were exposed to 5, 10, and 20 mg/L of MTZ in the aquariums for 2, 4 and 8 days. Staining technics namely H&amp;E, NOS immunohistochemistry, and TUNEL were performed to determine histopathological changes, oxidative damage and apoptosis. Additionally, smear preparations were also prepared from gill blood for genotoxic evaluations. The organ damage started in the 2nd day with 5 mg/L MTZ application and effects increased per duration and dose-dependent manner. It was observed that the gills had the primary and secondary lamellae lengths, with formation of clavate lamellae, fusion in secondary lamellae, separation of epithelium and aneurysm. Regional necrosis, vacuolization of hepatocytes, pycnotic nucleus, enlarged sinusoids were also determined in the liver. NOS immunoreactivity increased with the inducible immunoreactivity (iNOS) that was more prominent when compared to the endothelial immunoreactivity (eNOS). Apoptotic immunoreactivity was higher in the 10 mg 8th day experimental group at liver and gills, and was lower 20 mg 8th day experimental group. When the gills and liver compared with each other, in all doses, immunoreactivity was lower in gills, compared with liver. Genotoxic examinations showed that both number of micronucleated erythrocytes and nuclei abnormalities were higher in MTZ-treated groups.

This study aims to assess the pollution of honey by heavy metals based on the efforts of an urbanization gradient in the city of Annaba (Northeast Algeria) where the dosage of five heavy metals (Fe, Cr, Ni, Cu, Cd) was carried out in four sites.The level of heavy metals was determined by atomic absorption spectrophotometer. The results obtained indicated that even when all the samples were contaminated they were of good quality since the concentrations did not exceed the international standards.According to the results of heavy metal concentrations in the honeys studied, the most abundant element is Fe with an average concentration of 6.956 ± 2.045 (mg/kg), Cr 0.765 ± 0.197 (mg/kg), Ni 0.6005 ± 0.159 (mg/kg), Cu 0.21025 ± 0.065 (mg/kg) and Cd 0.01425 ± 0.005 (mg/kg).The heavy metals studied are present in all samples but trace amounts. Moreover, the comparison of the honey from the four sites indicates to us that the healthiest honey is that of the urban site.

Increasing the pollution rate of water sources is one of the most severe issues that the world faces. This issue has stimulated researchers to investigate different treatment methods such as adsorption, chemical precipitation, membrane filtration, flocculation, ion exchange, flotation, and electrochemical methods. Among them, adsorption has gained broad interest due to its ease of operation, low cost, and high efficiency. The critical factor of the successful adsorption treatment process is finding attractive adsorbents with attractive criteria such as low cost and high adsorption capacity. In the last few decades, nanotechnology has attracted much attention, and numerous nanomaterials have been synthesized for water and wastewater treatment. This work provides a quick overview of nanomaterials, which have been investigated for water remediation as adsorbent and photocatalyst. This work reviewed more than 100 articles to provide a critical review that would determine the limitation of using nanomaterials in water treatment at the commercial scale.

The current research study the comprehensive health and environmental hazard levels of Particulate matters originating from natural radionuclides sources collected from different Qassim region locations, Saudi Arabia. Activity concentration for 226Ra, 232Th, and 40K was assessed using a Sodium Iodide detector. Gamma-ray parameters as the Radium equivalent, Gamma level index, absorbed dose, annual effective dose, and lifetime risk were measured to predict the growth of radiological dangers. The average activity concentration for 226Ra, 232Th, and 40K is 35±0.06, 32.6±0.4, and 294.99±1.31 Bq/kg. Ra(eq) ranges from38.3 to 143.1 with an average of 104.37 Bq/kg, absorbed dose ranges from 18 to 66.49 with an average of 48.18 nGy/h, and annual effective dose ranges from 22.09 to 81.58 with an average of 59.11 μSv/y. The relative contribution was 26%, 33%, and 41% for 40K, 226Ra, and 232Th, respectively. The obtained results do not cause apprehensions from the radiation population compatible with permissible public limits. The obtained database helps the investigators follow the future pollution exchange due to Scientific progress in the use of radioactive materials.