Renewable energy development is growing rapidly due to vast population growth and the limited availability of fossil fuels in Southeast Asia. Located in a tropical climate and within the Ring of Fire, this region has great potential for a transition toward renewable energy utilization. However, numerous studies have found that renewable energy development has a negative impact on the environment and nature conservation. This article presents a systematic literature review of the impact of renewable energy development on the environmental and nature conservation in Southeast Asia. Based on a review of 132 papers and reports, this article finds that the most reported negative impact of renewable energy development comes from hydropower, biofuel production, and geothermal power plants. Solar and wind power might also have a negative impact, albeit one less reported on than that of the other types of renewable energy. The impact was manifested in environmental pollution, biodiversity loss, habitat fragmentation, and wildlife extinction. Thus, renewable energy as a sustainable development priority faces some challenges. Government action in integrated policymaking will help minimize the impact of renewable energy development.

Currently, different nanomaterials are being used in various commercial products in different sectors. Among them, carbon nanomaterials are one of the most promising engineered nanoforms of material. The excellent flexibility and capability to conduct electricity and heat make them suitable for many industrial purposes. It is predicted that nanomaterials production volumes will be increasing constantly during the next decades. However, the question arises what would be the impact of this wide usage of carbon nanomaterials on the environment in upcoming years. As ultimate disposal of these nanomaterials occurs in the aquatic ecosystems, it is very essential to assess its toxicological impact on it. Nevertheless, the risk assessment of carbon nanomaterials is a very intricate task. The reason is that a quantification of carbon nanomaterials in the carbon-rich environment is not at all easy. Hence, it is well evident that there is a necessity of the current research and development to investigate the potential aquatic toxicity of nanomaterials. Algae being an integral part of an aquatic ecosystem could play a role in monitoring tool for assessing the impact of carbon nanomaterial on the aquatic ecosystem. Seeking this correlation, this review focuses on the impact of carbon nanomaterials on algal flora. The mechanism effectually attributing the toxicity on algae is discussed, and future recommendations are made.

Sustainability of environment and food production is among the greatest challenges of the twenty-first century. Green revolution, however, achieved the targets of high food productivity, but at the cost of environmental degradation such as water pollution, soil contamination, climate change and biodiversity loss. Feeding the growing population and sustaining the quality of the environment are the two major challenges of Indian agriculture system. Traditional agricultural practices have been an integral part of food production in India since ages. These practices have the potential to mitigate the adverse effects of climate change with spatial and sequential diversity. This review covers three aspects of traditional farming of India: cultivation, biological method of pest management and locally available sustainable practices of crop protection. Double cropping, mixed cropping, crop rotation, agroforestry, use of local varieties and resources with host–pathogen interaction are some of the prominent traditional agricultural practices in India which have to be strengthened in view of the environment and food security. Such practices have a significant role in achieving the sustainability of agriculture by improving nutrition quality. The overall objective of this article is to highlight the potential of these practices for the sustainability of environment and food production.

CO₂ hydrogenation to methanol is a promising environmental-friendly route for combatting CO₂ emissions. Methanol can be used to produce a variety of chemicals and is also an alternative fuel. The CO₂-to-methanol process is mostly studied over multi-component catalysts in which both metal and oxide phases are present. The difficulty in elucidating the influence of the different phases on the catalytic performance has led to intense debate about the nature of the active site. Consequently, the main stumbling blocks in developing rational design strategies are the complexity of the multi-component catalytic systems and challenges in elucidating the active sites. In this paper, we reviewed the most promising catalyst systems for the industrial CO₂-to-methanol processes. Firstly, the copper-based catalysts are discussed. The focus is on the debate regarding the promotional effect of zinc, as well as other metal oxides typically employed to enhance the performance of copper-based catalysts. Other catalytic systems are then covered, which are mainly based on palladium and indium. Alloying and metal–metal oxide interaction also play a significant role in the hydrogenation of CO₂ to methanol over these catalysts. The purpose of this work is to give insight into these complex catalytic systems that can be utilized for advanced catalyst synthesis for the industrial CO₂-to-methanol process.

Perchlorate is an inorganic chemical reported to be resulting in widespread contamination of water bodies and even drinking water systems. The presence of perchlorate was identified in various drinking water sources (well, tap, borewell and bottled water) using liquid chromatography–mass spectrometry technique. The concentration of perchlorate in these samples is found in the order of bottled water ≫ well water > tap water > bore well water. Since most of the people in the study area depend upon this contaminated water for drinking purpose without any treatment, another important goal of this study was to propose suitable methods to remove or minimize the perchlorate concentration. This has been accomplished by advanced reduction processes (ARPs). Screening experiments including advanced oxidation processes such as UV photolysis, sonolysis, Fenton’s reaction in combination with reducing agents like sulfite, persulfate, ferrous iron at different pH and various concentrations were done. The experiments with ARPs are found to be degrading the perchlorate up to 32% in 5 h in Fenton-type reaction, and further experiments with modifications in the activation methods and reducing agents may give promising results for perchlorate degradation. Therefore, ARP technique offered more prominent results in terms of perchlorate removal, which can be easily extended in large-scale applications.

This study was attempted towards the retrieval of silica from rice husk ash to annihilate the local problems of disposal from the rice milling industries for enhancement of silica purity. Optimization of process factors using the Taguchi technique involved variation in sodium hydroxide concentration (NaOH), alkali impregnation volume per unit weight of the rice husk ash, and reaction time for designing the experimental matrix utilizing L16 orthogonal array at four different levels. The maximum silica extraction was 98.26% obtained with 4 N of NaOH, 20 ml/g of alkali volume, and treatment time 60 min. The identical experimental data set was also applied to an artificial neural network model (ANN) with the LM algorithm for predicting the feasibility of the extraction process. Both Taguchi and neural networks suggested a high coefficient of determination and a satisfactory correlation between experimental and predicted silica recovery values. The detailed characterization of the synthesized silica powder and residual rice husk ash was executed using field emission scanning electron microscopy (energy-dispersive spectroscopy), Fourier transform infrared spectroscopy, thermogravimetric, Brunauer Emmett Tellet surface area, and particle size analysis. The simultaneous reuse of residual ash and silicate was performed to ensure the best possible reclamation of silica and reusability of rice husk ash. The detailed cost estimation of the synthesized silica powder further suggested the effectiveness of the optimized process. Thus, a comprehensive approach for enhancement of the silica yield and purity by adopting Taguchi and ANN optimization proved to be useful in this study.