Due to rapid industrial growth and the increased economic status of people, water sources across the globe are being significantly polluted with a wide array of effluents. Industrial, agronomic, and customary activities have led to the repeated infestation of water by discarded materials. Consequently, there is an urgent need for advanced technologies to effectively eradicate these impurities from wastewater. Among the various methods established for wastewater remediation, the adsorption process has gained remarkable significance due to its efficiency and effectiveness. The use of nano adsorbents (NADs) represents an emerging solution to these environmental issues. NADs possess exceptional physical and chemical characteristics, which enhance their applicability compared to traditional adsorbents. Their advanced grade, prominence, and excellence in various arenas make them a superior choice for wastewater treatment. Recent explorations have shown that NADs, such as carbon nanotubes, graphene, and metal and metal oxide nano adsorbents, have a pronounced and favorable impact on wastewater treatment. The focus of this review article is to provide current data and insights into the use of NADs for wastewater remediation. It aims to highlight the benefits of these novel materials and to discuss the potential areas for further improvement in this field. By exploring the latest advancements and applications of NADs, this review seeks to contribute to the ongoing efforts to address the critical issue of water pollution and to promote sustainable water management practices.

Nanotechnology has become one of the most active fields in the research area and is getting more attention toward nanoparticle synthesis. Green synthesis methods using various plants, fungi, bacteria, and algae were used to synthesize nanoparticles with proper requirements and maintain sterile conditions to get the desired products. Aloe vera, a bio-medicinal plant, contains a wide range of phytochemicals such as phenolic, hydroxyl groups, alkaloids, polyols, polysaccharides, etc, which act as reducing and capping agents with high efficiency. This review revealed that aloe vera-derived nanoparticles are safe, stable, cost-effective, and eco-friendly, and they also possess significant applications for drug targeting, disease resistance, tissue engineering, wound healing, anticancer, antibacterial, and cosmetic industries. Synthesized metal nanoparticles are characterized through UV-visible spectroscopy, X-ray diffraction, scanning electron and transmission electron microscopy, photoluminescence, and the Well-diffusion method. It is highly interesting to note that aloe vera-mediated silver and zinc nanoparticles possess high potency against multi-drug resistant pathogens. Here, anticancer, antioxidant, anti-inflammatory, and photocatalytic activity separately showed by aloe vera peel, gel, and leaf, along with possible challenging situations faced during plant extract-based nanoparticle synthesis, are highlighted. Additionally, the introduction of GMOs is subjected to play an important role in advancing green methods. However, more research is required to estimate the dose’s safety, degradation, and synergistic mechanism inside the human body for better use of the green method for the treatment of microbial infections.

The monsoon system in India plays a pivotal role in shaping the country’s climate. Recent studies have indicated that the increasing variability of monsoons is attributable to climate change, resulting in prolonged periods of drought and excessive rainfall. Understanding, analyzing, and forecasting monsoons is crucial for socioeconomic sustainability and communities’ overall well-being. Climate forecasts, which project future Earth climates typically up to 2100, rely on models such as the Couple Model Intercomparison Project (CMIP). However, confidence in these forecasts remains low due to the limitations of global climate models, particularly in terms of capturing the intricacies of monsoon dynamics, notably from June to September. To address this issue, researchers have examined precipitation simulations under various future scenarios using both CMIP5 and the latest CMIP6 models. Evaluating the performance of these models from 1979 to 2014, particularly in simulating mean precipitation and temperature, has revealed improvements in multi-model ensembles (MME), highlighting advancements in monsoon characteristics. By comparing the CMIP5 and CMIP6 models, researchers have identified the most reliable models for climate downscaling research, which can provide more accurate predictions of regional climate changes, thereby offering valuable insights for enhancing climate modeling in the Indian subcontinent.

High phosphate content in water causes eutrophication, leading to many risks to the aquatic environment and human health. This study used biochar derived from macadamia husks at the pyrolysis temperatures (300, 450, and 600℃) to remove P from water. Adsorption parameters such as initial pH, biochar dosage, initial P concentration, and adsorption time when biochar was exposed to the P solution were determined. The results show that pH 4 is optimal for P removal with biochar pyrolyzed at 300 and 450°C, while pH 6 gives biochar 600°C, biochar dosage 10 g.L−1, concentration Initial P 25-200 mg.L−1 and adsorption time 40 minutes for 3 types of biochar. The maximum P adsorption capacity is 20.07, 20.03, and 20.03 mg.L−1 corresponding to 3 forms of biochar 300, 450, and 600°C. P adsorption data were consistent with the Freundlich isotherm model for all three biochar forms. The pseudo-second-order kinetic model was suitable for all three types of biochar, showing that the main adsorption mechanism is a surface chemical reaction. The study suggested that hydrogen bonding plays an important role in the adsorption of P onto biochar derived from macadamia husks. This study indicates that biochar derived from macadamia husks pyrolyzed at temperatures of 300, 450, and 600°C are all potentially effective and low-cost adsorbents for phosphate removal from water.

Effective treatment of industrial wastewater effluents before discharging them to the soil and water bodies has always been one of the paramount environmental concerns. The pollutants in untreated wastewater effluents have hazardous implications for human health and the ecosystem. Conventional physical and chemical processes of industrial wastewater treatment have many complications and they often fall short in the treatment of new and diverse varieties of pollutants. Several microbial strains in nature have shown their remediation property, but they possess limited efficiency in breaking down pollutants into non-toxic components. Synthetic biology is a perfect amalgam of two fields – biological science and engineering, and it has transformed our ways of understanding the functioning of complex biological systems. Researchers have reported that some engineered microbes can achieve remediation efficiency of up to 100% in specific pollutants such as heavy metals and hydrocarbons. For example, microbes like Pseudomonas veronii have been shown to reduce cadmium concentrations by up to 100%, and Pseudomonas putida has been shown to reduce phenol concentrations by 92%. Synthetic biology-based biosensors are also being developed for pollution monitoring and control of industrial wastewater. In this review, we discuss these advancements of synthetically engineered microorganisms in the treatment of industrial wastewater.

Community Health Centers are small-scale hospitals that serve community medicine in Indonesia. These activities generate wastewater containing various contaminants, such as pathogens, chemicals, and nutrients, which can pollute the environment and endanger human health. So, efforts are needed to reduce their impact through wastewater treatment. This research applies an anaerobic-aerobic biofilter system with Moving Bed Biofilm Reactor (MBBR) technology combined with activated carbon and chlorine in treating wastewater. The treatments in the study were different service capacities and wastewater treatment, with three replicates in each treatment. The residence time of wastewater in the system is 4 h. The results showed that combining MBBR technology, activated carbon, and chlorine could reduce temperature, TSS, pH, BOD5, COD, NH3, and Coliform values in wastewater in three Community Health Center services. Thus, it can be concluded that the different services and wastewater treatment efforts, combined with MBBR, activated charcoal, and chlorine, have been proven to affect and improve the quality of wastewater from the Community Health Center to meet the effluent quality standards.

In the face of the pressing global issue of waste management and the diminishing availability of natural resources, the management of non-biodegradable waste materials, including brick waste, poses significant challenges. Ineffective disposal practices not only create logistical obstacles but also pose health hazards. This study explores the potential of utilizing waste refractory bricks (RB) as a sustainable substitute for natural fine aggregates in concrete production. Various experimental investigations were conducted to evaluate the feasibility and performance of RB sand in concrete mixtures. Tests included assessments of fresh and hardened properties, such as slump values, compressive strength, tensile strength, flexural strength, and resistance to elevated temperatures. The research revealed that RB sand, when used as a partial replacement for fine aggregates, can significantly enhance the compressive strength of concrete, with optimal results observed at a 30% replacement level. Moreover, RB-based concrete exhibited improved split tensile strength compared to traditional concrete, particularly at replacement levels of 10% to 30%. Flexural strength also showed notable improvements, with the 40% replacement level demonstrating optimal performance. Additionally, the study investigated the effects of elevated temperatures on concrete specimens and found that RB-based sustainable concrete showed higher compressive strength retention compared to conventional concrete at a 30% replacement level. Furthermore, weight variation analysis indicated that RB-based concrete had a lower density compared to traditional concrete. Overall, the findings suggest that incorporating RB sand in concrete mixtures could offer a promising solution for sustainable construction practices, contributing to environmental conservation and human health preservation by reducing reliance on natural aggregates and minimizing adverse environmental impacts.

Monitoring water quality changes in any body of water is crucial as it directly relates to climate change. Evaluating the quality and quantity of fresh water for various uses is essential to maintaining safe water sources now and in the future. This study examined the water quality of the Main Outfall Drain River (MOD) in the eastern part of Al-Qadisiya Governorate at three sites over four seasons in 2023, using the Iraqi Water Quality Index (IQ-WQI). In most cases, the concentrations of dissolved oxygen (DO), biochemical oxygen demand (BOD5), and total dissolved solids (TDS) exceeded allowable limits for freshwater and aquatic life protection. The major contributing parameters to the river’s low water quality were TDS, BOD5, turbidity, and DO. The use of the MOD for discharging agricultural effluents led to increased levels of TDS, BOD5, and turbidity. Temporal variation indicated that the summer season had the highest values compared to other seasons due to increased evaporation and low water discharge. Spatial variation showed the IQ-WQI of the sites in descending order from very poor water to unsuitable, with Site 3 having double the TDS concentrations compared to other sites. This increase may be attributed to the impact of the Al-Dalmag Marsh discharge canal, which comes into contact with the MOD at this site. Sensitivity analysis using backward linear regression was applied to predict the IQ-WQI and determine the most influential parameters on the IQ-WQI score. The test was conducted for two sets of water parameters (from the IQ-WQI calculation) and included 7 parameters for each freshwater and aquatic life use, obtaining different models.

Exploration of microbial flora in red mud ponds is a topic of economic importance. In this study, we report two bacterial strains isolated from red mud ponds of Utkal Alumina, Odisha India. These strains were identified to be Brevundimonas sp. and Pseudomonas sp. through 16S rDNA analysis which showed more than 99% similarities with their respective clades. The LD50 values showed metal resistance to As, Cr, Cu, and Pb in a range of 2-8 mM. Both the strains showed a high tolerance towards arsenic and lead but a low tolerance towards chromium and copper salts. The bioaccumulation of copper was found to be the maximum and that of arsenic was the minimum. To find out the underlying genetic mechanism of the metal tolerance, a degenerate PCR approach was made to find out the genes responsible for the metal efflux or transformation. Two putative arsB genes could be identified from these two strains. Phylogenetic analysis of deduced amino acid sequences showed similarities with the amino acid sequences of arsB genes of Pseudomonas strains and formed monophyletic clades with their arsB proteins. These strains thus harbor potential genetic mechanisms for metal tolerance. Determination of whole operons and their cloning is the future aspect of the study. Moreover, these bacterial strains have a high potential to accumulate copper and can be used in studies related to biomining of copper.

Water conservation and management are significant features of ancient Indian Vedic culture. However, India’s rapid industrialization, globalization, and urbanization have posed a serious threat to this practice. Many metropolitan cities and other cities will likely have groundwater depletion in the near future. As per the ‘United Nations University - Institute for Environment and Human Security (UNU-EHS)’ report titled “The 2023 Interconnected Disaster Risks Report”, India is close to reaching its tipping point of groundwater depletion. It also highlighted that 27 of 31 major global aquifers are depleting faster than they can be replenished. A combination of factors, including climate change, private land ownership, mechanical pumping, etc., led to the depletion of groundwater and water scarcity for farming and other purposes. Additionally, NITI Aayog and the Central Water Commission have released several reports that highlighted the plight of the country’s aquifers. India’s groundwater resources are not only a potential source for agricultural, domestic, and industrial needs in the country but also a threat to its sustainable development and equitable distribution. At present, there is no central law on the groundwater regulation. Although the Model Groundwater (Sustainable Management) Bill 2017 is an affirmative step, its effectiveness depends on implementation by state governments, the establishment of robust local institutions, and removing political incentives from groundwater management. Until now, landowners have enjoyed monopolistic access to groundwater due to common laws that recognize uncontrolled rights over the resources. These restrictions have perpetuated gross inequities in accessing groundwater, which makes a remarkable shift from previous laws. This paper evaluates India’s existing groundwater laws to achieve sustainability, equity, and the effective execution of water rights. It also delves into the lacunae in the existing laws and suggestive measures to control the challenges of groundwater in India.