The rapid depletion of the world’s fossil fuel reserves and global warming issues have promoted the search for sustainable alternative energy resources. In the present investigation, large-scale cultivation of naturally isolated freshwater microalgae Asterarcys quadricellulare strain was carried out using tertiary treated municipal wastewater as a growth medium in an open HRP pond for bioethanol production. A total of 12.091 kg of dry biomass was obtained at the end of the study. The lipid extracted carbohydrate rich spent microalgae biomass was converted to bioethanol by ethanolic fermentation. The biomass was first pre-treated with different concentrations of H2SO4 and HCL hydrolysis with different temperatures and reaction times. The biomass treated with a 2.0% concentration of H2SO4, showed maximum yields of glucose 308.38 mg.g-1 at 100°C with 180 min reaction time. The hydrolysates derived from the hydrolysis of microalgae biomass were used as a substrate for fermentation by using S. cerevisiae. The obtained bioethanol was analyzed using HPLC and the purity of ethanol was 90%.

Households, restaurants, canteens, and hotel wastes constitute kitchen waste. Every day our growing cities generate more and more waste, which is overloading our municipal systems. The main aim of the present work was to prepare a microbial consortium that can effectively and rapidly bring about the degradation of kitchen wastes that can be used in agricultural soils. More than 100 different bacterial isolates were obtained from various kitchen waste dumping areas. The bacterial isolates were studied to produce enzymes like amylase, gelatinase, lipase, and protease on respective media plates. The best 20 isolates were subjected to enzyme quantification. The isolates showing maximum production for all four enzymes were selected for consortia preparation. The consortia of isolates were prepared by permutation combinations. Amongst all consortia prepared consortium No. 7 showed maximum enzymatic potential. The bacterial isolates in the best consortium (No. 7) were further characterized and identified as KW104 Serratia marcescens, KW37 Micrococcus luteus, KW128 Brevindimonas mediterranea, KW91 Bacillus tequilensis, and KW97 Exiguobacterium mexicanum. This consortium showed rapid degradation of waste as compared to others in 15 days duration of time showing good potential for compost formation when applied to plant growth.

Supersaturation of total dissolved gas (TDG) is mainly produced by high dam discharge, excess oxygen production by plant photosynthesis, and a sharp increase in water temperature, which may directly lead to fish and aquatic organisms suffering from “gas bubble disease” (GBD) or death. Aeration was one of the methods used to solve the dissipation of supersaturated TDG. In this paper, aeration had an obvious promotion effect on the dissipation of supersaturated TDG. For the calculation and analysis of supersaturated TDG dissipation coefficient, the aeration rate was proportional to TDG dissipation coefficient and had a promoting effect on it, while the aeration depth and aeration aperture were inversely proportional to TDG dissipation coefficient and played an inhibitory effect on it. The supersaturated TDG dissipation coefficient was affected by a factor of KTDG,Q> KTDG,D> KTDG,H. A quantitative relationship between the supersaturated TDG dissipation coefficient and aeration rate, aeration depth, and aeration aperture was obtained, respectively, as well as important expressions with comprehensive effect factors; their margins of error average within 10%. This research method has an important guiding significance for improving the living environment of fish and other aquatic organisms, alleviating the adverse effects of supersaturated TDG.

The present study selects cities such as Zhengzhou, Kaifeng, Anyang, Hebi, Xinxiang, Jiaozuo, and Puyang along the Yellow River Basin in Henan Province. The data of six pollutants, such as PM2.5, PM10, SO2, CO, NO2, and O3, in various cities from 2019 to 2021, and the monthly primary pollutant data of seven cities in the past five years were collected through various channels. The air quality of the above seven cities was analyzed with the spatial-temporal distribution of pollutants as the research objective and geographic information system as the research tool. The results show that affected by the distribution of key pollution sources and meteorological conditions in the urban area, the PM2.5 concentration generally shows a zonal feature of decreasing from northwest to Southeast. The high-value area is located in the north and west of the integrated area of the seven cities, and the low-value area is located in the Southeast of the seven cities.

Black carbon (BC) is a pollutant aerosol affecting climate and human health. Light absorption coefficients of black carbon (Babs) were measured using an aethalometer model AE33 at wavelengths 370, 470,520,660,880, and 950 nm. Babs for the seven wavelengths at seven sites in Jordan fluctuated with time and peaked at rush hours. The daily average values for all sites were inversely proportional to the wavelength. The average daily visibility values in the seven Jordan sites varied between 72 km and 211km. In the Irbid site, the daily average visibility values for 7-13 Nov. 2021 varied between 43 km and 107 km. BC varied from hour to hour and from day to day. The daily average values of BC in Irbid for the period of 7 -13 Nov. 2021 varied between 2.24 μg.m-3 and 4.66 μg.m-3. BC peaked at the rush hour and had the lowest values on Friday. About 90% of the measured BC was from fossil fuel sources and 10% from biomass-burning sources.

The ecological balance of an ecosystem has a relation to its biodiversity. Although it has been established that biodiversity and ecological stability are related, generalization about the exact nature of this relation remains elusive and more so in microbial diversity. A growing volume of studies has indicated that anthropogenic activities impact biodiversity, but it is difficult to generalize the impact of anthropogenic activities on microbial diversity. Landfilling by municipal solid waste is one such activity where microbes play a major role, and leachates are released from the landfill, altering the soil’s physical and chemical nature. Change in factors like carbon source, pH, and toxicity of the soil is most likely to affect the indigenous microflora of the soil. The present study was undertaken to compare the microbial diversity of soil receiving landfill leachate with that of the soil not receiving any landfill leachate to assess the impact of the landfilling activity on microbial diversity. The landfill site selected for the study was that of Kamrup Metro District of Assam, located at Boragaon, near the Ramsar wetland called Deeporbeel. By using the Denaturing Gradient Gel Electrophoresis (DGGE) method, it has been found that the microbial diversity of the soil receiving leachate was higher than that of the soil not receiving any leachate from the landfill.

In recent years, there has been a significant increase in the needs of the overgrowing population. Naturally, industrial belts increased worldwide to satisfy the variety and quantity of needs. While producing the products, a huge quantity of waste is generated and added continuously to the environment, causing hazardous effects on the flora and fauna. Spent wash is one of the most important types of industrial waste since it is the liquid waste that is left over after making alcohol and it pollutes the environment. Despite effluent quality standards, untreated or partially treated sewage frequently enters water courses or soils. It is always overloaded with organic and inorganic substances. The stabilization of the effluent by microorganisms is reflected in the form of COD reduction. The present study attempted to isolate the PHB-producing organisms and use them to stabilize the spent wash. The locally isolated, characterized, and identified 11 PHB-producing microorganisms from the Karad region of Maharashtra were used to stabilize spent wash. They include Candida orthopsilosis, Bacillus subtilis, Bacillus cereus, Bacillus megaterium, Klebsiella grimontii, Citrobacter fruendii, and members of Staphylococcus and Rhodococcus. All potential organisms were reported to stabilize the spent wash. The degree of stabilization was measured in terms of the percent reduction of COD and BOD. The % reduction was reported at 95.31% and 81.39% of COD and BOD, respectively, by Klebsiella grimontii, followed by 92.18% and 80.46% reductions of COD and BOD, respectively, by Staphylococcus. These organisms are promising in the treatment of spent wash.

Methyl Violet (MV), a triphenylmethane dye, has been subjected to comparative studies with hydrogen peroxide and dimethyl dioxirane under optimum situations. When employing hydrogen peroxide, the photolysis process becomes slower, but the dye solutions are entirely decolored and mineralized. The decolorization rate exhibits pseudo-first-order kinetics. The effect of pH, oxidant dosage, and methyl violet concentration on the degradation is also examined. Generated o-leucoaniline,1,3-diphenylurea,2-hydroxy benzoic acid, phenol, acetone, water, carbon dioxide, and carbon monoxide are identified and measured by GC-MS analysis. These substances remain in the dye solution along with dimethyl dioxirane, which is released faster during the last stages of degradation. The degradation rates of methyl violet reached 97.9% and 65.8% within 30 mins and 180 min of reaction time using dimethyl dioxirane and hydrogen peroxide.

As climate change continues to cause more frequent weather shocks such as droughts and floods and increasingly erratic rainfall, people in developing regions are threatened by crop failures and hunger. In this study, the researchers describe how climate change influences food security in Central Java, seen from the frequency of floods, rainfall, and rainy days. This study also added another variable, i.e., economic growth, reviewed through GRDP and the amount of rice production. Using the Common effect model, the study results revealed that rainy days and population were the variables significantly influencing food security in cities/regencies in Central Java Province. Meanwhile, two other variables, i.e., rainfall and GRDP, had no significant effect on food security in cities/regencies in Central Java Province.

Globally, vehicular pollution is one of the greatest concerns in urban areas. Several studies on air pollution have been conducted using deterministic, statistical, and soft computing methods. However, there has been little research on how soft-computing methods like Artificial Neural Networks (ANN) can help us comprehend vehicular pollution’s non-linear and highly complex dispersion. This study uses an ANN-based vehicular pollution model to investigate the effect of vehicular traffic on PM2.5 concentrations in built-up and open terrain-surrounding environments. Five distinct pollution models were developed for two locations in Delhi, considering PM2.5 pollutants, meteorological variables, traffic flow, and traffic composition into account. The results concluded that under open terrain conditions, the significance of the traffic variable in its association with PM2.5 is almost half the significance observed under built-up conditions. Also, in terms of PM2.5 reductions, the maximum reduction observed at Location-1 (built-up environment), and Location-2 (open terrain environment) is 1.85 and 2.44 times the percent reduction in traffic during peak hours, respectively. The study’s findings have significant ramifications for the current practices of ignoring the contribution of traffic and the built environment to pollution and adopting measures like an odd-even rule and high fuel and parking prices to combat pollution.