Evaluating the performance of water companies is of great importance for both water utilities and water regulators. This paper explores comparative levels of technical efficiencies and technology gap ratios with the metafrontier concept by estimating an input distance function using stochastic frontier techniques. The metafrontier framework is employed in the water services of water and sewerage companies (WaSCs) and water-only companies (WoCs) in England and Wales. The results show that the English and Welsh water industry is an efficient industry, with WaSCs more efficient than WoCs. On average, a water company can increase its technical efficiency by operating in more densely populated areas and by investing in technology to reduce bursts in water mains. We also link the efficiency results with the regulatory cycle to assess the impact of regulation on the efficiency levels of water companies.

A novel composite material (nZVI/UiO-66) of nanoscale zero-valent iron (nZVI) with a functionalized metal-organic framework was synthesized by this study via a coprecipitation method, which was used for the efficient removal of U(VI) in the aqueous solution. The nZVI/UiO-66 had an excellent removal capacity of 404.86 mg g⁻¹ with an initial U(VI) concentration of 80 mg L⁻¹, 313 K and pH = 6. The transmission electron microscopy (TEM) revealed that nZVI particles were inhomogeneously distributed on the surface of UiO-66. The analysis by the X-ray diffraction (XRD) has further illustrated that the introduction of nZVI did not change the structure of UiO-66. The adsorption process closely followed the pseudo-second-order kinetic and the Freundlich isotherm model. The removal process of U(VI) by nZVI/UiO-66 was spontaneous and endothermic. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses have illustrated that the mechanism was mainly related to adsorption of U(VI) from UiO-66 and reduction of U(VI) by nZVI. The Zr-O bonds were shown to play a vital role in the uranium removal. nZVI/UiO-66 could be recycled. The uptake rate could be maintained at around 80% after 5 cycles of use. Therefore, these results manifested that the nZVI/UiO-66 is a promising sorbent for the efficient and selective removal of U(VI) in radioactive wastewaters.

The original publication of this paper contains a mistake.

The original publication of this paper contains a mistake.

This paper aims to find out relationships among the energy, environment, and the industrial production for a developing country which is in earlier stages of development. It also tests a few contradicting hypotheses to find the possible shape of an environmental Kuznets curve. Using the time series data, the study finds robust long-run relationships between energy, environment, and industrial production for Pakistan. The scale economy is also assumed. It is also found that the capital and labor elasticities of income show increasing returns in the presence of energy and emission variables. It finds evidence of EKC in a quadratic restricted model but not in a cubic function. This analysis implies that the focus of policy authorities should be to persuade environment-friendly energy resources. After an initial stage of economic development, society has to take serious measure to tackle the issues of environmental degradation.

Municipal wastewater treatment facilities produce a lot of sludge which is concentrated with different pollutants. The sustainable design of the sludge disposal alternatives is of crucial importance for touristic cities like Mashhad in Iran. Increasing sludge generation and its accumulation in the city and more stringent legislations highlight the challenge of sludge disposal, recently. This study compares different alternatives to reach maximum possible environmental benefits as well as the most cost-effective technologies. In this study, life cycle analysis (LCA) assesses different scenarios for disposal of sewage sludge which is aerobically treated and dewatered for two real case studies. Alteymore and KhinArab are wastewater treatment units in the city. The scenarios include incineration, composting, and landfilling alternatives. The incineration and landfill scenarios are the least interesting solutions according to different life cycle impact categories. The heavy metals’ emission to the soil worsens their impacts. Also, lifecycle cost analysis reveals that composting scenario is more cost-saving than others. However, main disadvantage of the composting scenario is its contribution in freshwater eutrophication. To move towards sustainability, the composting scenario is here determined as the best scenario for sludge disposal in Mashhad.

The availability of quality water is imperative to human health and ecosystem functioning. This study was aimed at determining the water quality index and examining its suitability to different water uses. Water samples were collected in dry and rainy seasons to capture the influence of seasonal variation. Water quality indicators (pH, electric conductivity (EC), temperature, total dissolved solids (TDS), turbidity, total suspended solids (TSS), nitrate, phosphate, and ammonia) were analyzed in the laboratory, and weighted arithmetic index method was employed to determine the quality index. The water quality index (WQI) showed higher value 870.3 and 1,313 for dry and rainy seasons which indicates that the water is unfit for human use, and the status of the water body is hypereutrophic. With cautions handling, the water appeared to be suitable for irrigation and livestock production but undesirable for aquatic life and resulted in an impairment of the ecosystem. The statistical analysis revealed a significant difference in water quality parameters between dry and rainy seasons (p < 0.05). The overall water quality status demonstrated concerns that could pose a significant risk; hence, measures should be taken to improve the quality and manage water to safeguard human health and environmental safety.

Several methods, such as pretreatment, membrane surface modification, feed water chlorination, and chemical cleaning, have recently been applied to control biofouling on reverse osmosis (RO) membranes—with limited success. As an alternative, compounds that inhibit bacterial quorum sensing can be used to disrupt formation of bacterial colonies. In this study, anti-biofouling using vanillin, which is a natural substance among quorum sensing inhibitor compounds, was trialed, by modifying RO membrane surfaces with vanillin, at various concentrations. We then reviewed consequential changes to membrane surface characteristics and vanillin anti-biofouling properties. A long-term RO membrane simulator was used to analyze permeability, contact angle was measured for hydrophilicity evaluation, and membrane surface morphology was analyzed, through atomic force microscopy and scanning electron microscopy. A quorum quenching effect was confirmed by utilizing Petrifilm to count bacteria on the surface of a modified membrane. As a result, the permeability of the surface modified membranes was slightly decreased compared to the pristine membrane, but the hydrophilicity was increased, and the number of colonies decreased remarkably, the membrane modified with 0.5 M vanillin outperforming that modified with 0.25 M vanillin.

Many studies have highlighted the link between indoor air pollution from the burning of solid fuels for cooking and heating and the occurrence of various health problems particularly in women and children under 5 years. In developing countries, solid fuels remain the main sources of energy. The purpose of this study aims to describe the distribution of household cooking fuel types and to analyze the factors influencing household cooking energy choice in Ouagadougou. A cross-sectional survey was conducted in 2017 in 3 neighborhoods of Ouagadougou. A total of 1734 household were randomly selected. We performed a multivariable logistic regression and a multinomial logistic regression to measure the relationship between selected determinants and households’ primary cooking fuel. 59.53% of the households of Ouagadougou reported using solid fuels as the main cooking fuel. Wood is the most common primary cooking fuel used (43.93%), followed by LPG (40.41%) and then charcoal (15.60%). About 84% combine at least 2 types of energy for cooking. Cooking fuel choice is strongly influenced by the socioeconomic status, the family size, and also by the woman’s educational attainment, her age and the main cooking fuel used in her parents’ house. Actions aimed at reducing the impact of solid fuel use in the environment or health must consider these factors.