The quality of surface water has a significant impact on human health and the entire ecological system. Sewer spillages from the surrounding informal settlements discharging into the river, carrying high concentrations of fecal coliforms, are one of the major causes of extreme pollution in the rivers of South Africa. These informal settlements are common in many developing countries, and they are usually located near waterways to compensate for basic demands for water, sanitation, and recreational space, where municipal infrastructure lags behind urban growth. One major problem has been poor sanitation and poor waste disposal practices in the informal settlements, which has led to the contamination of water resources. This study aims to assess the extent to which poor sanitation in informal settlements impacts the water quality of South African rivers, given the rapid rise in population and unemployment rate. The study also highlights health and environmental issues in the local regions caused by poor sanitation. Contamination of water bodies is associated with serious health problems and fatalities. Therefore, there is a need for frequent monitoring and management of waste products discharged into the neighboring aquatic environments.

This study aimed to assess the efficacy of a bimetallic system consisting of Mg0-Pd0 and the bacterium Acinetobacter sp. for the complete detoxification of lindane. Our results demonstrate that palladium immobilized on activated charcoal achieved a removal rate of >99% for 100 mg.L-1 of Lindane within 10 minutes, with the accumulation of trace amounts of intermediates. The reductive transformation of lindane followed 1st-order kinetics, with a calculated rate constant (kobs) of 0.77 min-1. The bimetallic system resulted in the formation of a non-toxic hydrocarbon as the end-product, indicating complete dehalogenation of lindane. Furthermore, Acinetobacter sp. effectively mineralized >98% of 100 mg.L-1 of Lindane after 26 h of cultivation without any accumulation of toxic metabolite(s) in the reaction medium, demonstrating the efficiency of the biological system. Integrating both chemical and biological systems could provide significant advantages for the treatment of lindane, reducing the treatment time and overall cost. This synergistic approach can significantly enhance the overall removal efficiency of lindane from contaminated soil and water.

This study correlates computational predictions with in vivo and in vitro experimental results of inhaled fine and ultrafine particulate matter (PM) transport, dissemination, and deposition in the human respiratory airways. Epidemiological studies suggest that workplace exposure to anthropogenic pollutant PMs is a risk factor for increased susceptibility to acute broncho-pulmonary illnesses. However, investigations on detailed human inhalation and PM transport processes are restrictive from time, cost, and ethical perspectives. Computational simulation based on the Multiple Path Particle Dosimetry (MPPD) model was employed to quantify the risks associated with workplace exposure of these PMs. Here, the physical, mechanical, and electrical properties of PMs of carbon black (CB) and ultrafine particles (UFPs) from wire-cut electrical discharge machining (WEDM), with mass median aerodynamic diameter (CMAD) in the range of 1 nm to 1000 nm, were used as input parameters of MPPD. Additionally, it mimicked occupational workers’ age, body mass index, and oronasal-combinational nose and mouth breathing exposure time. The deposition results were compared with several vivo and in vitro experimental data reported in the literature, and satisfactory agreements were found. For example, a total lung dose of CB-PMs of 100 nm is the highest (28%), while a 380 nm dose is the lowest (15%). Afterward, deposition increases with particle size, reaching 26% for 1000 nm. In the case of WEDM-UFPs, about 98% of all 1.0 nm inhaled particles remain in the lung. Subsequently, the deposition dose decreases with the particle size and reaches up to 28% for 100 nm particles. Approximately 51% of deposited WEDM-UFPs are of CMAD ≤ 5 nm. The images of lung geometry also observed the maximum deposited mass and mass flux rate in the head, tracheobronchial, and pulmonary airways.

Current research explains the comparison of linear and nonlinear regression methods for finding the optimal isotherm study using experimental data for the adsorption of BG on multi-walled carbon nanotubes MWCNTs. BG dye maximum adsorption onto MWCNTs occurred at pH 2 and 35°C, with the apparent equilibrium reached after 15 min. In this study, five error functions were used: ERRS, Hybrid, Chi-square (χ2), ARE, and EABS. The values of error functions suggest that the Langmuir Linear type 3 is a suitable isotherm to describe the adsorption of BG on MWCNTs. The results showed that the Langmuir isotherm is a fit good isotherm to describe the adsorption process. The coefficient of non-determination (K2) showed Hybrid, and ERRS were the preferable error functions used to predict the fit of linear and nonlinear isotherm models. Compared with other studies, MWCNTs can be used as a low-cost adsorbent with low contact time for the removal of BG dye from an aqueous solution.

ABS was the first surfactant used in detergent formulations, but because its molecular structure is branched, it is difficult to decompose biologically, making ABS a toxic compound for the environment. This study aims to remove MBAS surfactant, using a combination of phytoremediation and filtration methods to remove surfactant (MBAS) Chemical Oxygen Demand (COD) from detergent wastewater by optimizing operating factors such as pH, contact time, plant type, and filter media. Water lettuce (Pistia stratiotes) and water hyacinth (Eichhornia crassipes) were selected as plant species and silica-activated carbon was used as filter media. Water lettuce and hyacinth were grown in a 10-liter reactor with detergent wastewater samples for 6 and 12 days. Filter media are placed in the reactor in use, and aeration is done. The efficiency for reducing COD was 81.73%, and the efficiency for surfactant was 99.42% for each experiment, which was thought to be because of plant adsorption and filtering processes. The water lettuce (Pistia stratiotes) plant had the maximum adsorption capability for all the qualities evaluated, with a surfactant content in the roots of 27543.24 (mg/kg MBAS), compared to the water hyacinth plant, which only absorbed 2597.95 (mg/kg MBAS).

To become the fastest-growing large economy in the world, India has set a target growth rate of 9%, reaching an economy of $5 trillion by 2024-25. It is an immense challenge to meet the growth target and keep the CO2 emissions under control. The present paper aims to discover the determinants for explaining CO2 emissions in India by conducting a complete decomposition analysis, where the residuals are fully distributed to the determinants for the country from 1990-2018. The analysis reveals that the biggest contributor to the rise in CO2 emissions in India is the expansion of the economy (scale effect). The intensity of CO2 and the change in the composition of the economy, which nearly move in tandem, also contribute to the rise in CO2 emissions, although more slowly. A declining energy intensity of the Indian economy is responsible for a considerable reduction in CO2 emissions. As a typical result for an upcoming economy, this paper did not find evidence for an environmental Kuznets curve. This implies that continued economic growth will lead to increased CO2 emissions.

Leather manufacturing processes raw hides and skins into various finished leather products, generating huge amounts of untanned and untanned leather solid wastes (LSWs). The present study investigates the LSWs generation, characterization, and management practices of the Sheba leather industry in Ethiopia. Results revealed that LSWs are categorized as non-chrome solid waste, including de-dusted salt, raw trimming, hairs, fleshing waste, pickle trimming, and splitting wastes. Chrome-based wastes include chrome shaving waste, crust leather trimming waste, buffing dust waste, finished leather trimming waste, etc. Further, solid wastes were characterized for the physico-chemical parameters viz. moisture (31.5%), ash content (7.3%), pH (5.7), carbon content (14.7%), nitrogen content (0.3%), chromium content (2%), calorific value (20,107 kJ.kg-1), VOCs (75.1%) and carbon to nitrogen ratio (52:1). Results obtained suggested various sustainable technological options for the effective LSWs management to preserve environment.

This paper aims to emphasize heavy metals’ impact on water and its removal mechanism with a focus on adsorption. Furthermore, factors affecting bio adsorption, such as temperature, pH, RPM, and initial heavy metal concentration, have been studied for different heavy metals and bioadsorbents. A comparison of their adsorption capacities and efficiencies has been made. This review reviewed different bioadsorbents for their suitability in removing cadmium, lead, and copper ions from water and wastewater, typically by using adsorption as a methodology. A suitable summary compares various heavy metal removal techniques and their advantages and limitations. For adsorption, the characteristics of bioadsorbents and their activation steps have been consolidated. Furthermore, the effects of operational parameters and adsorption mechanisms have been discussed in the review. Apart from assessing the suitability of bioadsorbent, a novel bioadsorbent has been suggested for copper ions removal. The findings shall be significantly useful in applying bioadsorbent in water/wastewater treatment fields to reduce heavy metal pollution. Thorough and well-planned research in this field can facilitate the creation of sustainable and durable technology for wastewater treatment, addressing the increasing demand for safe and dependable water resources, focusing on making it cost-effective and recyclable.

This study assessed the hazard indicators of common chemical and organic fertilizers widely available in the markets of Najaf Governorate, Iraq. The concentrations of natural radionuclides were measured in thirteen types of fertilizers by Gamma spectrum using NaI(Tl) (3*3) detector. The average radioactivity of the nuclides 226Ra, 232Th, and 40K was (48.91, 37.04, and 702.4675) Bq.kg-1, respectively, for (Di-Aluminum Phosphate) the chemical fertilizers of the type (DAP) and the (nitrogen, phosphorus, and potassium) chemical fertilizers of the type (NPK) the average radioactivity of the nuclides 226Ra, 232Th, and 40K were (35.78, 42.356 and 1519.653) Bq.kg-1, respectively, while the average radioactivity of the organic fertilizers (Orga.) were 55.153, 23.148 and 1451.258 for the three studied nuclei. As for the average values for radium equivalent were 155.967, 213.363, and 200.0023 (Bq.kg-1) for (DAP), (NPK) and organic fertilizers, respectively. The values of the external severity index (Hex), gamma radiation hazard index (Iγ), and representative alpha index (Iα) were within the permissible limits determined by the UNCEAR 2000. The highest value of total annual effective dose equivalent(TAED) was 1.468 mSv.y-1, the lowest value was 0.302 mSv.y-1, and the mean values were 0.722 mSv.y-1. In contrast, the highest value for annual gonadal dose equivalent(AGED) was 1392.527 μSv.y-1, the lowest value was 275.361 μSv.y-1, and the average values for all models were 672.135 μSv.y-1. The Excess Lifetime Cancer Risk (ELCR), the highest value was 4.039 × 10-3, the lowest value was 0.833× 10-3, and the average value was 1.988× 10-3 for all fertilizers. The Pearson correlation between radioactive variables and cluster analysis was recognized for the three types of fertilizer samples despite it not being widely accepted. The study can be considered preliminary data for subsequent studies.

Human beings experience adversative effects due to the large fluoride concentrations present in potable water. Because of the low cost and simple operation, the extensively acknowledged process is adsorption. The objective of this study is to investigate the performance of some of the prepared carbons from bio-waste materials viz., Citrus limon, Citrus nobilis, Pithecellobium dulce, and Bombax malabaricum sheaths in defluoridation. Initial concentration, particle size, agitation time, adsorbent dose, and pH were the different parameters chosen to study their effect on adsorption. Studied the adsorption kinetics. Further suitability to adsorption isotherms was reviewed.