Developing nations, such as Bangladesh, face an enormous crisis in maintaining natural sustainability due to heavy metal contamination by the peripheral rivers. Frequent heavy metals discharged from tanneries, dyeing, and potential anthropogenic activities in Savar city pollute the Dhaleshwari river, which is an important river of the capital city, Dhaka. The present study aimed to assess the heavy metals contamination in the Dhaleshwari river sediment and evaluate the subsequent ecological risk indices emerging from the deposits. The contamination levels of heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), and nickel (Ni) were analyzed in the Dhaleshwari River sediment. Various environmental indices, such as Potential Enrichment Risk (PER), Geo-accumulation Index (Igeo), Enrichment factor (EF), Toxic unit analysis (TUs), etc., were observed in various compartments. The concentration of heavy metals ranged as follows: Lead (Pb), 297.3-414.6 mg/L; Cadmium (Cd), 1.5-4.4 mg/L; chromium (Cr), 97.9 -282.4 mg/L; Nickle (Ni), 85.1-264.5 mg/L; Iron (Fe), 11800-14375 mg/L. The metal concentrations were higher than the threshold effect level (TEL) and probable effect level (PEL) standards. Based on the TUs, the probability of toxicity is about 76% (TU > 2.3) at the Dhaleshwari river. Comparative evaluation of different environmental indices between present and past studies indicated progressive deterioration of sediments by heavy metals. Linear correlations of heavy metals in sediment samples demonstrated toxic accumulation of heavy metals in the surrounding ecosystem. The study outcomes emphasize the necessity of systematic investigation in the Dhaleshwari river and warranting effective prioritization to ensure river health over industrial wastewater discharge.

In order to find an effective decolorization method for dye wastewaters, the present work aims at studying the treatment efficiency of an azo dye Acid Red 14 (AR14) by Electro-Fenton process using an undivided electrochemical cell containing different electrode materials. The optimal removal efficiency was obtained using carbon felt or glassy carbon (cathode) and platinum (anode) electrodes. The method is based on the reaction of electrochemically produced hydroxyl radicals leading to oxidative degradation of the AR14. To find the best conditions for treatment of AR14 dye, the effects of Fe2+ concentration, current density, the effect of pH initial, and the nature of support electrolyte were studied. The results showed 94 % removal efficiency in 30 minutes with 120 mA/cm2 of electrolysis current, 0.2 mM of Fe2+, and pH = 3. However, the decolorization efficiency measurements confirmed that the Electro-Fenton process with the platinum anode and the carbon felt cathode was more efficient.

Lake Donuzlav, located in the western part of the Crimean Peninsula is a water body undergoing anthropogenic load, which cannot but affect the state of its bottom sediments.  The content and composition of polycyclic aromatic hydrocarbons (PAH) are representative indicators of the degree and character of an anthropogenic impact in natural habitats. The aim of the work was to assess the level of PAH content in the bottom sediments, to identify potential sources and to assess the toxicity of bottom sediments. It was established that the average content of ∑PAH in the sediments amounted to 806±380 ng/g, with the values of this parameter ranging over 34–4036 ng/g. At five out of ten stations in Lake Donuzlav, PAH values, average for the Black Sea, were exceeded. These stations were grouped along both banks in the inner part of the reservoir. Fourteen PAHs were identified: Nap, 2mNap, Flu, Phe, Ant, Fla, Py, TrPhe, Chr, BbF, BkF, BaP, DBA, BghiP. The main share falls on the binuclear Nap and 2mNap, which indicate the presence of fresh oil pollution. The average share of these compounds over the water area was 60±5%, and at stations with elevated levels of ∑PAH it was 74±4%. There was a close correlation between the content of all polyarenes, which coefficient averaged 0,88. The presence of geochemical relationships between polyarenes entering from different sources was probably due to the functioning of natural mechanisms aimed at the transformation of pollutants, which served to restore the dynamic balance of the system.

Magnetic properties are used throughout the world to measure the concentration of (ferri) magnetic minerals in soil, sediment and dust. These minerals in soil come from a variety of sources, including air-borne particulate pollution, parent rock and paedogenesis. Changes in the content of magnetic minerals, as well as their spatial and vertical distribution in soil profiles are caused by human activity. Magnetic minerals are distinguished by their affinity for other elements found in soil, such as heavy metal. As a result, magnetic susceptibility has been widely used as an approximation of heavy metal contamination in soil. The current study was conducted in a tropical deciduous forest in Central Uttar Pradesh, namely the kukrail reserve forest in Lucknow to assess heavy metal contamination levels caused by various anthropogenic activities and to confirm the utility of using MS surveying in these types of studies. The current study was conducted at two sites viz. agricultural area and forest area because these sites are the most contaminated ones. Significant correlation between heavy metal concentration and magnetic susceptibility with p<0.005 is noticed for Co, Cr, Pb, Zn, Cu and Fe of agricultural area. Similarly in forest area significant correlation exists between Cr, Ni, Pb and Zn.  The χLF values show a significant correlation with the concentration of heavy metals except for Cu and Cr in forest area and Pb and Zn in agricultural area. In comparison to the methodologies of chemical analysis, the χLF measurement techniques provide us with lower cost and less time consuming method for identification of possible soil pollution.

This work presents an index to evaluate the environmental performance of brick and tile manufacturing. The steps used were: 1) process study; 2) waste analysis; 3) determination of the potential impact of waste; 4) normalization of the potential impact; 5) comparative weighting among the potentials; 6) creation of the index. The index considers three parameters: the amount of waste produced, the disposal of waste, and the spatial dispersion of waste. The index was called CIRI (Ceramic Industry Rating Index) and was tested in a ceramic company. The field application showed that the waste that offered the highest environmental impact were gases generated from the burning of chips (30.850%), ashes generated from the burning of chips (30.483%), and steel drums (28.937%), which total of 90.27%. The CIRI index was 28.732%, which shows bad waste management. In view of the findings, two points must be considered: 1) the impacts generated by gaseous could be mitigated by companies by using technologies for drying tiles and bricks with a lower level of environmental impact; 2) entrepreneurs should be concerned about the fate given to the ashes because the dispose practiced is not environmentally correct. The index is useful for assessing the environmental impact of the brick and tile industry. It is useful for managers insofar as a proposal for process improvements. The novelty of this study lies in the index developed, which was designed to consider: the potential for environmental impact, the amount of waste, the spatial coverage, and the adequacy of waste disposal.

The first future challenge facing human beings is to supply the world's energy needs. However, energy consumption and resource depletion in industrial processes are significantly increasing. Therefore, life cycle assessment can be an excellent tool to quantify resources and energy consumption in different parts of industrial processes. The combination of process simulation and assessment of process life cycle can be resources &amp; energy consumption in different parts is quantified and can be significantly reduced by optimizing the process, energy wastage. The process stimulation is done by HYSIS software, then by collecting output data, energy and materials flow, life cycle assessment is conducted using SIMAPRO software. According to output of the release list, 1709 items are released into the environment, of which 396, 407, 340 items are released into the air, water, soil, respectively and 556 items are extracted from sources. The most appropriate procedure to assess the life cycle of crude oil processing is Cumulative Energy Demand and Cumulative Exergy Demand energy approach. Based on the first-order analysis, the highest consumption of resources and energy is in the crude oil transmission sector; (Road construction with 44.95 petajoules and transmission pipelines with 19.85 petajoules). Also, regarding the second-order analysis, the highest consumption of resources and energy is related to crude oil production processes with 1.65 petajoules per operation and desalination unit, medium voltage electricity consumption with 0.002194 petajoules and exergy of power lines with 0.00087 petajoules.

In most developing nations, municipal wastewater treatment is limited to aerobic secondary treatments, expensive and ineffective in removing nutrients from treated effluents before discharge, resulting in eutrophication and imbalance in receiving bodies. As a result, the effectiveness of Chlorella vulgaris for primarily treated wastewater collected from a sewage treatment plant during an 8-hour detention time was investigated in this study. Microalgae have been found to efficiently remove organics and nutrients to levels far below the desired limit in the present research. After algal treatment concentration of COD, phosphate and ammonia reduced to 12.43 mg/L (93.75%), 0.04 mg/L (98.40%) and below detectable limit (100%) respectively. In addition, remarkable reduction was found in solids (TSS, TS and TDS) and EC concentration. The use of microalgae resulted in an increase in DO concentration. As a result, introducing Chlorella vulgaris into a wastewater treatment system can lower nutrient and organics contents without any additional treatment.

Shelf areas of the seas and oceans characterizing high productivity are the spawning sites of many aquatic organisms. However, they are strong impacted for anthropogenic pollution, including oil contamination, which negatively influence on marine organisms. The effects of mazut and diesel fuel in the concentrations of 0.05, 0.1 and 0.2 ml/l on the activity of antioxidant enzymes which are recognized as biomarkers of the oxidative stress namely superoxide dismutase (SOD), catalase (CAT), peroxidase (PER) and glutathione reductase (GR) in the developing embryos of two marine blennies Parablennius sanguinolentus and Salaria pavo (Perciformes: Blenniidae) on the V - VI developmental stages were studied. The results demonstrated higher mazut toxicity as compared with diesel fuel. In P. sanguinolentus embryos exposed to mazut the activity of key anti-oxidant  enzymes SOD and CAT were significantly higher (+413% and +100% as  compared with the control, p<0.05), while in the case of diesel fuel the enzymes level varied insignificantly. In the embryos of S. pavo SOD and CAT activities were also increased at mazut incubation (256% and 103% respectively, p<0.05), while the differences between enzymes level in embryos exposed to diesel fuel were lower. In contaminated S. pavo embryos enzyme activities varied less as compared with the embryos of P. sanguinolentus, therefore they are more resistant and adaptive to oil contamination. The possible mechanisms of fish embryos antioxidant system response to oil pollution are discussed.

Naphthenic acids are a group of polar organic carboxylic acids that are present in crude oil naturally. They are cycloaliphatic carboxylic acids which have 10 to 16 carbons, which gained importance since the early twentieth century because of corrosion in oil refineries. Moreover, they are the most important environmental pollutants caused by oil extraction from oil sand reserves. Heavy crude oils which have high concentration of naphthenic acids are usually considered as poor-quality oil and sold at a lower price. Often, the high concentration of naphthenic acids in crude oil reduces the life of the equipment which are used in the exploration and refining process because of corrosion. Hence, researchers are increasingly interested in the chemical properties of naphthenic acids and the acidic components of the crude oils. The most popular methods for the identification and analysis of naphthenic acids are liquid and gas chromatography (GC), liquid-liquid extraction, Fourier transform infrared spectroscopy (FTIR), and solid-phase extraction (SPE). Naphthenic acids are the most important environmental pollutants caused by oil extraction from oil sand reserves. Previous studies have revealed that naphthenic acids can be absorbed by fish, but their distribution in different tissues of fish has not been specified. Experimental samples showed the highest toxicity to fish, while there was less toxicity to invertebrates and algae. Moreover, naphthenates have various industrial utilizations; they are used in synthetic detergents, corrosion inhibitors, lubricants, fuel and oil additives, wood preservatives, insecticides, fungicides, pesticides, wetting agents, napalm thickening agents, and oil desiccants that are utilized in painting and treating wood surfaces.

Metals contamination in water is becoming a threat to human health. The studies ecological and health risk assessment of trace metals was conducted in seven water bodies in Akwa Ibom State, between May 2021 and April 2022 (twelve months), to evaluate the levels of trace metals contaminant and suitability of the waters for human consumption. Six trace metals were assessed in the water samples; using atomic absorption spectrophotometer after digestion. Pollution indices such as heavy metal pollution index, comprehensive pollution index, contamination index and health risk assessment for non-carcinogenic were employed. The findings were compared with Nigerian Standard for Drinking Water Quality. The mean concentration of some metals (Pb, Cd, Cr, and Cu) in some stations were exceeded the standard limits, while Fe and Ni exceeded the acceptable limits in all the stations, due to anthropogenic activities. The values for HPI in stations I, II, IV and VII were exceeded the threshold of 100, ranging between 61.4 and 743.5; CPI ranged from 1.05 to 3.72, while Cd ranged from 0.94 to 16.3, indicated that the water bodies are highly contaminated. The CDI and HQ values for Fe, Cd, Cr and Cu exceeded the oral toxicity reference dosage of contaminant and stipulated threshold (1) for HI in some stations both in children and adult, indicated that the water bodies are not suitable for human consumption. The findings call for concern regarding their effects on human health, which could be detrimental to the people drinking from these water.