Wastewater treatment necessitates the use of an appropriate method to achieve satisfactory results. The conventional method of Alum addition has been widely used for years, but it is prohibitively expensive. This study uses Moringa oleifera, an inexpensive and readily available plant, as a natural coagulant to treat wastewater collected from university dormitories. Physicochemical parameters such as pH, Turbidity, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Dissolved Oxygen (DO) were examined based on appropriate standards. Wastewater treatment with varied coagulant dosages of 50, 100, and 150 mg.L-1) was monitored using a standard jar test device with an initial wastewater perturbation at 100 rpm for 5 min was reduced to 50 rpm in 10 minutes with a rest time of 30 min. The results showed that the quality of the physicochemical properties of the water improved. The percentage increase in the water quality is; BOD (92%), COD (92%), and TDS (52-64%), with an increase in Moringa coagulant achieving a reduction of 96% of Turbidity. While the DO improved (79%), the pH remained below acceptable limits (6.73-7.56) for effluent disposal. The treated water showed clarity (colorless) and no odor compared to the wastewater. Hence, Moringa oleifera seeds cake residue can be an effective coagulant for wastewater treatment.

The purpose of the paper is to estimate the environmental efficiency of the Vietnamese textile and garment industry and evaluate the impact of the factors on environmental efficiency. The study uses firm-level panel data from the Vietnam annual enterprise survey data for the 2012–2018 period in the Vietnam textile and garment industry to evaluate the environmental efficiency by using the Super-SBM DEA model with undesirable output and applies the Tobit regression model to measure the impact of the factors on the environmental efficiency. This study evaluates environmental efficiency and assesses the impact of some core factors, including the origin of imported machinery and equipment, the origin of imported materials, the management of industrial zones, and the presence of FDI firms, on environmental efficiency at the firm level. The results indicate that the average score for environmental efficiency is 0.233. Some factors, such as income per employee, machined goods imported from developed countries, industrial zones, firm improvement processes, and the presence of FDI, have a positive impact on a firm’s environmental efficiency, whereas materials made in Vietnam have a negative impact.

Urbanization is intrinsically connected to economic progress. India’s rapid economic and population growth has increased its carbon footprint and traffic congestion. A long-term strategy is essential to preserve the balance and alleviate the issues arising from the expansion. Integrating land use and transportation planning has been acknowledged as a means to achieve sustainable urban development worldwide. Transit Oriented Development (TOD) is one such strategy. TOD is a planning and design strategy for promoting urban development by clustering jobs, housing, services, and amenities around public transport stations. This strategy can help achieve sustainable communities and improve the quality of life. This research paper assessed the land use characteristics of an urban fringe area in Trivandrum city and completed a land suitability analysis using GIS software tools. A potential node for re-development was identified by looking at various traffic, demographic, and land use parameters. Detailed TOD recommendations for the area surrounding the transit node were proposed based on its development potential.

Anaerobic digestion produces biogas which usually contains 60-70% of methane (CH4), 30-40% of carbon-di-oxide (CO2), and 10-2,000 ppm hydrogen sulfide (H2S). The concentration of H2S depends upon the type of substrate. H2S tends to corrode pipes and machines carrying them. The high concentrations of H2S present in biogas may adversely affect electricity generation. Hence, the removal of H2S and enrichment of biogas with CH4 is an essential step towards higher energy production. In the present study, the biological method of removing H2S using Thiobacillus sp. was demonstrated for a one cu.m anaerobic co-digestion (ACD) unit running on an organic fraction of municipal solid waste (OFMSW) and septage sludge. Initial lab scale studies were conducted by collecting the biogas generated from 1 cu.m digesters, and continuous experiments were optimized for the process parameters such as flow rate, the volume of medium with culture, time, the height of the column, column composition, etc. The raw biogas was purged in a liquid medium (LM) with a culture containing Thiobacillus sp. The studies with the LM containing Thiobacillus sp. culture showed a 68% removal of H2S in the first 8 min, and the saturation occurred at 75 min when the time-dependent experiment was studied. The smaller flow rate (0.48 L.min-1) and highest volume of culture (500 mL) showed better results than other parameters. The highest and average oxidation rates of sulfate were recorded as 39 and 40.3 ppm.sec-1, respectively, for 0.48 L.min-1 flow rate and 500 mL of the culture volume. In the column studies, a column containing cocopeat (CP) was studied for its efficiency in removing H2S. At a flow rate of 0.9 L.min-1, 25% adsorption was encountered and reached saturation at 90 min. The bed height of 9 inches with CP and plastic support (PS) showed a 20% H2S removal. The filling ratio of CP and PS (1:1) was the best ratio for proper gas passage with optimal time for adsorption/absorption. The kinetic, isotherm, and continuous models helped to understand the capacity of the adsorbent. Freundlich, Yoon-Nelson, and BDST model were best fit for the present study. A pilot scale setup for one cu.m biogas reactor showed an average of 50% removal of H2S for LM with culture, and an additional 20% removal was possible by the introduction of a column along with the liquid bed in series. An overall efficiency of 70-75% of H2S removal was achieved. No significant CH4 loss was encountered during the study.

Vertical flow-constructed wetlands (VFCW) are well-established, cost-effective, and sustainable options for wastewater treatment. Along with organic matter removal, wetlands are helpful in the removal of microbial pathogens. This study focuses on understanding the bacterial pathogen removal efficacy of three different design types of VFCWs and understands the best designs for the efficient removal of pathogens in a tropical climate. The three wetlands studied for removal efficiency were (a) two-stage vertical flow constructed wetland (TSVFCW), (b) Single-stage vertical flow constructed wetland (SSVFCW), and (c) single-stage saturated vertical flow constructed wetland (SSSVFCW). Results revealed that all three types of wetlands were effective in removing pathogenic bacteria. Still, TSVFCW was found to be more efficient in pathogen removal (Total Coliforms, Shigella spp., Salmonella spp., Pseudomonas spp., Vibrio spp., Enterococcus faecalis) 7.04 ± 0.17, 6.53 ± 0.08, 4.0 ± 0.42, 7.67 ± 0.08, 5.73 ± 0.70 and10 5.23 ± 0.96 Log10 reductions respectively compared to SSVFCW (5.28 ± 0.18, 5.18 ± 0.09, 3.74 ± 0.74, 6.98 ± 0.01, 3.97 ±0.32, 4.74 ± 1.08 Log10 reductions respectively) and SSSVFCW (4.48 ± 0.46, 4.83 ± 0.15, 2.74 ± 0.44, 6.71 ± 0.03, 4.31 ± 0.49, 5.03 ± 1.20 Log10 decreases respectively). For abiotic factors (Chemical oxygen demand, total Kjeldahl nitrogen, and phosphorus) also TSVFW shows better efficiency (45 ± 8.7, 24.7±4.5 and 3.1, ± 0.2 g.m-2, respectively) than SSVFCW (12 ± 1.3, 7.6 ± 0.4 and 1.8 ± 0.2 g.m-2 respectively) and SSVFCW (6.3 ± 1.1, 7.7 ± 0.1 and 1.2 ± 0.1 g.m-2 respectively). However, the removal efficiency of both single-stage wetlands was comparable.

Agro-waste can provide a non-metallic, environmentally friendly bio-precursor for the production of green silica nanoparticles. To manufacture silica nanoparticles from rice husk, biogenic silica nanoparticles were generated using an alkaline precipitation approach. Rice husk as a source of silica nanoparticles is environmentally and economically valuable because it is a plentiful lower price agricultural derivative that can be used to help with waste management. During the synthesis process, the dose of rice husk ash was used at 5 g at pH 7, alkali dose concentration of 0.5 M, reaction period of 3.5 h, and temperature of 90°C that produced maximum silica nanoparticles with a yield of 88.5%. To optimize the silica nanoparticle production from rice husk ash Box Behnken Design (BBD) a subcategory of the response surface methodology (RSM) was accomplished. BBD model was successfully matched, as evidenced by the high correlation values of adjusted R2 0.9989 and predicted R2 0.9977. Silica nanoparticles’ amorphous form generated from rice husk ash is indicated by XRD analysis 2Ө peak at 22.12° and UV-Vis Spectroscopy absorbance peak at 312 nm. The amorphous shape of silica is amorphous and crystalline defined through XRD. nanoparticles generated from rice husk ash is indicated by FESEM analysis and EDX analysis, confirming that the SiO2 elemental configuration comprises the highest concentration of Si and O. The existence of a siloxane group in the produced compound was revealed by FTIR spectra stretching vibrations at 803.69 and 1089.05 cm-1

The disposal of the huge volume of glass waste is one of the significant environmental issues that need to be addressed. One of the efficient ways to solve this problem is to incorporate ground glass waste in concrete mixtures. However, its inherent surface smoothness and microcracks within the glass particle harm the hardened properties of concrete. Minimizing the particle size and controlling the amount of cement in the mixture can reduce the adverse effect of using glass in concrete. This study utilized ground glass waste (850 μm) as aggregate filler in a concrete mix. More specifically, this study investigated the effect of paste volume (Vp) on the properties of fresh and hardened concrete with ground glass waste as aggregate filler. Based on the test results, ground glass waste as aggregate filler negatively affects the workability of fresh concrete, but increasing the amount of paste can mitigate it. Vp values in terms of void volume (Vv) in the aggregates of 1.6Vv and 1.8Vv achieved satisfactory consistency of fresh concrete. In addition, the concrete compressive strength increased when increasing Vp. The test results have shown that ground glass waste has the potential to be utilized as aggregate filler in concrete mixtures.

Septage comprises the solid and liquid constituents of any primary treatment system, including a Septic Tank. In this study, the wastewater collected from a septic tank is passed through a partially converted anaerobic filter, and a vertical flow constructed wetland (VFCW) before being sent to a soak pit. The main objective of this case study was to check the effectiveness of incorporating a VFCW between a septic tank and a soak pit to bring down the consequences created due to effluent seepage from soak pits to the groundwater. Conventionally, the effluent gets directly passed to soak pits after primary onsite treatment in the septic tank. The soak pit walls made of porous materials allow the gradual seepage of final effluent into the ground, polluting the groundwater reserves. We analyzed the septic tank effluent from 60 households wherein the effluent was let off into the soak pits. The various parameters analyzed with their averages were 393.83 ± 293.41 mg.L-1 for COD, 151.48 ± 94.37 mg.L-1 for BOD, 30.81 ± 13.05 mg.L-1 for NO3-, 23.35 ± 13.54 mg.L-1 for PO43-, 7.35 ± 0.31 for pH, 184.05 ± 163.20 mg.L-1 for TSS, 3.05 x 107± 2.04 x 108 CFU.100mL-1 for TC. Therefore, it is certain that the final effluent being sent into soak pits after primary treatment does not meet the Central Pollution Control Board (CPCB) discharge standards. In this case study, we were able to obtain final effluent values after VFCW treatment as 55.72 mg.L-1 for COD, 12.12 mg.L-1 for BOD, 10.2 mg.L-1 for NO3-, 3.74 mg.L-1 for PO43-, 7.41 for pH, 8.37 mg.L-1 for TSS, 379.27 mg.L-1 for TS and 51.9 CFU.100mL-1 for TC. With this case study, we were able to resolve this impediment by bringing down the values of all the parameters considered while analyzing under the limits of discharge standards set by CPCB. The removal efficiency of COD, BOD, NO3-, PO43-, pH, TSS, and TC after wetland was found to be 89.46%, 88.051, 63.484, 44.37%, 3.41%, 98.47%, 97.71%, 97.19% respectively. The study has proven that with the introduction of another decentralized treatment system between a septic tank and soak pit, it is safe to dispose of the effluent into soak pits, thereby reducing the chances of groundwater pollution considerably.

At present, the resource utilization of solid waste in China is facing prominent problems such as high production intensity, insufficient utilization, and low added value of products. The preparation of biomass composites from biomass solid waste and plastic solid waste reduces not only environmental pollution and energy consumption but also promotes the high-value utilization of solid waste. So, the characterization and preparation experiments of samples with two different biomass are carried out. The wheat straw fiber and corn straw fiber were added into the bio-asphalt mixture with the content of 0.1%, 0.2%, 0.3%, and 0.4%, respectively, with the content of 9% and 12% bio-heavy oil. The physical properties and rheological properties of asphalt were analyzed and evaluated by three indexes and a dynamic shear rheological test. Through the rutting test and immersion Marshall test, high-temperature performance and biological asphalt mixture’s water stability were evaluated. The results show that straw fiber can improve bio-asphalt mixture’s road performance, especially the performance of high-temperature rutting. When the fiber content of bio-asphalt with 9% bio-heavy oil content is 0.3%, the physical properties and rheological properties of bio-asphalt are the best. Corn straw fiber’s influence on bio-asphalt mixture was better than that of wheat straw fiber.

Water is essential for life and it is an inorganic constituent of living matter. Water pipeline systems are sighted as problematic in aquatic habitats in which multiple pathogens are occupied including fungi. They have rigid cell walls containing glucans and chitin. The bodies of fungi comprise filaments called hyphae. These hyphae are split into a mat of interwoven single cells made of mycelium. Fungi can pollute the drinking water system and are responsible for biofilm formation. Biofilms are complex polymers containing many times their dry weight in water. Moisture is essential for biofilm formation. The occurrence of biofilms affects the quality of drinking water. Hence, the present study is aimed at recovering the fungi from drinking water samples and their biofilm formation in the water pipeline system. Drinking water samples such as mineral water, tap water, and RO-purified water are collected from different places. Fungi such as Aspergillus, Penicillium and Mucor were recovered from these samples and most species belong to Aspergillus and Penicillium. Further, the biofilm formation of fungi from cast iron in the pipeline system was detected using fluorescence microscopy and fluorescent in situ hybridization analysis.