Arsenic (As) is a renowned threat to the environment and human well-being. Its concentration is increasing year after year in several countries. The utmost pretentious are mining regions of India, as per government surveys and available research findings. Population residing near mining regions are bounded to consume arsenic tainted water in their routine life and evolve various hazardous health problems. Besides many physicochemical techniques at hand for its purification, none are promising. The microbial mediated arsenic detoxification involving oxidation/reduction and extrusion by a membrane-associated efflux pump may perhaps financially acuity and a promising method for bioremediation. The arsenic richness in mining regions triggered the evolution of bacterial cells to come up with a potential mechanism to survive in As rich environment. Microbial extrusion strategy of As in both As3+ and As5+ forms may also be involved in increasing As in abandoned mining regions in underground water. So, to understand the involvement of these bacterial cells in the increment of As in these regions the present study was performed by personally visiting these sites and conversation with local residents. We have witnessed many jaw-dropping truths about As exposure risk to humans and domesticated animals, which has been discussed in this article. This review comprehensively summarizes current studies associated with arsenic exposure, environmental dispersal and its bioremediation through arsenic metabolizing bacteria covering recent developments, pathways, action mechanism and understanding arsenic metabolizers with the depiction of future prospects on arsenic bioremediation from contaminated systems.

The present study was carried out in the forest of Kedarnath valley in Garhwal Himalaya. The aim of the study was to access the diversity status and ecological status. The study was conducted following the stratified sampling techniques by placing quadrates (1m×1m) for herbs, (5m×5m) for shrubs, and (10m×10m) size for trees in the forest area. A total number of 221 plant species were recorded during the floristic survey in the project area. Plant diversity of the project area encompasses 49 species of trees, 28 species of shrubs, and 144 species of herbs. Important value index, the Shannon diversity index, and total basal area species were recorded. The tree density in the present study was highest in the Kedarnath valley which ranged from 0.3 to 8.5 no./ha. Shrub density in the present study varied from 0.4 to 13.5 no./ha, whereas herb density ranged between 0.2 to 22.4 no.ha-1. Total basal cover (TBC) for trees showed a range of 9.542 to 0.075 m2.ha-1, and the Shannon diversity index (H) for tree species was recorded from a minimum of 0.976 to a maximum of 3.048. The horrific disaster in the Kedarnath valley in 2013 caused a lot of damage to the bugyals (High altitude grass) and forests of the valley. About 500 species of vesicular medicinal plants, fodder plants, and other important plant species were washed away (Botanical Survey of India 2015). The current study is a pioneer in the aspect and can be helpful in making district forest plans, protocols, and implementation of forest policy to protect the forest by local people.

Various ecological problems have become increasingly prominent due to the accelerated growth of urbanization. Ecological security and ecological conservation have become an important topics in the current scenario. This study took southern Anhui as an example, constructing comprehensive assessment models to conduct source identification from three perspectives, i.e. ecosystem services, ecological sensitivity and residents’ ecological needs. Landscape resistance surface was built based on the reciprocal of habitat quality and night-time light data. According to the circuit theory, the ecological process in the heterogeneous landscape was simulated to identify ecological corridors, extract pinch points and divide barriers that need improvement, thereby to construct the southern Anhui ecological security pattern (ESP). The pattern comprised 20 ecological sources, 37 ecological corridors, 9 pinch points and 2 levels of improvement areas. Specifically, ecological sources were mainly distributed within the area of Huangshan city and Xuancheng city, mostly covered with trees; ecological corridors were mostly located in the northern part of the research area; pinch points were mainly farmland or beside construction land; the primary improvement area was mainly in Chaohu city and Maanshan city, while the secondary improvement area was distributed around the primary area. The study discussed the diversified improvement strategies of different barriers and introduced the optimization scheme “one centre, two wings, one belt”, providing planning advice for decision-makers. The study expanded the construction of regional ESP, and partly guided the steady development of ESP of southern Anhui.

This study aims to determine the composition and the weight of individual single-use items (SUIs) generated in the selected fast-food restaurants (FFRs) in Ho Chi Minh City (HCMC), Vietnam. A semi-structured questionnaire was used to collect data of SUIs consumed per day from 126 FFRs covering six popular fast food companies (FFCs). At the same time, waste from 30 FFRs was collected, and its composition and weight were determined. Consequently, the amount and composition of the waste varied among the studied FFCs and is dependent on the food menu, the number of franchises for each FFC, customer number, size, and the type of SUIs used at these restaurants. Total waste collected across the six FFCs was 6 t.d-1 and was equivalent to 1560 t.yr-1 in HCMC. Of which, single-use plastic items (SUPIs) waste and single-use paper items (SUPaIs) waste accounted for 39% and 28%, respectively. The total weight of unnecessary SUPIs (condiment containers, straws, and forks) generated was about 44 t.yr-1. The results suggest that the necessity of standardizing the type and size of the SUIs used at the FFRs, phasing out the use of unnecessary SUPIs, improving the local waste management practices through material recovery and recycling.

The fastness properties of the flower of Opuntia ficus-indica dyed cotton fabric have been studied using different combinations (1:3, 1:1 and 3:1) of various mordants, such as myrobolan-nickel sulphate, myrobolan-aluminium sulphate, myrobolan-potassium dichromate, myrobolan-ferrous sulphate and myrobolan-stannous chloride. The wash, rub, light and perspiration fastness of the dyed samples have been evaluated. It is found that the flower of Opuntia ficus-indica dye can be successfully used for the dyeing of cotton to obtain a wide range of colours by using various combinations of mordants.

Accurate prediction of non-point source water pollution is conducive to the prevention and control of rural water pollution. To improve the prediction accuracy of agricultural non-point source water pollution and achieve timely prevention and control, a prediction model of agricultural non-point source water pollution based on the grey correlation method is designed. According to the historical data of agricultural non-point source water pollution, the influencing factors of water pollution degree are determined by using the grey correlation method, and standardized pretreatment is carried out. The pretreatment results are transformed into function expression forms, and the original sequences of different influencing factors are generated, which are brought into the function table to achieve the results, and the whitening differential equation is constructed to measure the concentration of agricultural non-point source water pollution. The structure design of the prediction model of agricultural non-point source water pollution can realize the prediction of agricultural non-point source water pollution. The results show that the prediction model of agricultural non-point source water pollution based on the grey correlation method has high prediction accuracy and small prediction error.

The world needs to increase renewable and alternative fuel sources such as Biomass, Bioethanol, and Biodiesel to compete with fossil fuels. Biodiesel is an important renewable fuel source since it can be used in regular diesel vehicles without requiring engine modifications. Conventional biodiesel production takes around 90 min of reaction time. A longer reaction time is not suitable for commercial production. Furthermore, traditional products such as oil react with biodiesel methoxide to produce a maximum of 90% biodiesel yield. As the catalyst is not involved with the reaction, pure methanol and methoxide (methanol with KOH catalyst) are separately added to the system to enhance the pre-reaction step. By changing the methanol to methoxide ratio, biodiesel is produced, and yield is calculated. The highest yield, which is 95%, is obtained with a 5:15% methanol to methoxide ratio. The total reaction time with the new experimental procedure is only 20 min. That is a significant reduction by saving operating costs such as energy consumption. Produced biodiesel show similar properties to that of standard biodiesel.

With the acceleration of economic development and urbanization in China, sewage sludge generation has sharply increased. To maximize energy regeneration and resource recovery, it is crucial to analyze the environmental impact and sustainability of different sewage sludge recycling systems based on life cycle assessment. This study analyzed four sewage sludge recycling systems in China through life cycle assessment using the ReCipe method, namely aerobic composting, anaerobic digestion and biomass utilization, incineration, and heat utilization and using for building materials. In particular, the key pollution processes and pollutants in sewage sludge recycling systems were analyzed. The results demonstrated that aerobic composting is the most environmentally optimal scenario for reducing emissions and energy consumption. The lowest environmental impact and operating costs were achieved by making bricks and using them as building materials; this was the optimal scenario for sludge treatment and recycling. In contrast, incineration and heat utilization had the highest impact on health and marine toxicity. Anaerobic digestion and biomass utilization had the highest impact on climate change, terrestrial acidification, photochemical oxidant formation, and particulate matter formation. In the future, policy designers should prioritize building material creation for sludge treatment and recycling.

In this study, the applicability of electrocoagulation using iron electrodes in real dyeing wastewater treatment was assessed based on pollutants removal efficiency, sludge generation, energy consumption and operation cost in practice. The effects of current density, pH, conductivity, and reaction time on treatment performance were evaluated. The operation cost of electrocoagulation was calculated including the energy cost, the iron plate cost, generated sludge treatment cost, and added substances cost. The results indicated that the colour, CODcr and TSS removal efficiencies were high and quite stable with short reaction time (reached 92.07 ± 1.21%, 65.7 ± 1.47%, and 89.8 ± 1.2%, respectively, with only 15 min). Average sludge generation, specific energy consumption, and operation cost were determined respectively as 0.645±0.0543 kg/m3, 1.182 kWh/m3 and 0.517 USD/m3. Coagulation-flocculation using FeSO4 was performed as a control experiment as well. Compared to coagulation-flocculation, electrocoagulation has the same removal efficiency but has less generated sludge (only 50%) and little to no added chemicals. Therefore, the operating cost was quite less than the others, with only 0.517 USD/m3 instead of 1.99 USD/m3 (equal to 1/3.5).

The obvious manifestation of urban development is the integrated development of urban architectural design and construction. The environmental protection of green building design and construction has become an important link that cannot be ignored in the process of urban green development. Green building materials, green design, and other environmentally friendly building programs are the subjective manifestations of the implementation of the green development concept. However, the degree of environmental protection is still a black box that needs to be explored urgently. To explore the environmental pollution caused by urban architectural design and construction in the process of urban development, an evaluation model of urban architectural design and construction on environmental pollution was constructed. The first-level evaluation indicators include ecology, natural, and social environments, of which the corresponding secondary indicators mainly include noise, water, and air pollution and other 12 indicators. The weights of the evaluation indicators at all levels were calculated using the expert evaluation method, and the weighting method was then combined to evaluate the pollution. Results show that the main sources of environmental pollution caused by urban building design and construction are solid waste pollution and traffic congestion rather than traditional noise and air pollution. Noise and air pollution are effectively controlled in the construction process. The evaluation system provides further directions for improvement in the prevention and control of environmental pollution in building construction and provides a reference for effective improvement of environmental governance.