An annual reduction in processing expenses results in the direct discharge of millions of litters of diverse wastewater into the environment, which causes eutrophication and depletes pure water sources. Traditional physicochemical treatment are widely employed for wastewater treatment (WWT). However, the optimal functioning of these systems necessitates significant operating and maintenance expenditures and the use of unique technologies for sludge treatment and disposal. One of the most crucial processes in a biorefinery is the effective pretreatment of industrial wastewater, which ensures the bioprocess overall quality and commercial feasibility. Industrial WWT is essential for improving biorefinery and valorization processes for producing biofuels, bioenergy, chemicals, and other valuable products. Consequently, industrial effluent must be managed to facilitate further bioprocessing. Bioelectrochemical systems (BESs) are an emerging field utilized for the removal of organic matter from industrial wastewater, desalination of seawater, and production of bioelectricity. In the distant future, the utilization of BESs will be focused on environmental remediation, WWT, bioanalysis, and the reduction of toxic gas emissions. In recent years, there has been a surge in research endeavors pertaining to BESs, specifically microbial fuel cells (MFCs), microbial electrolysis cells (MECs), microbial desalination cells (MDCs), and microbial electrolysis desalination cells (MEDCs), in an effort to produce energy that is both environmentally friendly and sustainable. This review focuses on the applicability of various advanced treatment approaches for industrial wastewater or sludge and the separation of recovered products from wastewater and its residues. It also highlights the basic operational characteristics of the MFCs, MECs, MDCs, and MEDCs using wastewater. The cutting-edge data presented in this review could improve further interdisciplinary and translational research.
Agricultural industry has been the root of all growth in India and all over the globe, with practices that can be dated back thousands of years, hence there is a need to improve technology and improvise advanced methodologies. Currently one of the major sections in the agricultural industry uses chemicals like fertilizers, pesticides, and insecticides, among other agrochemicals to enhance the productivity of crops. These chemicals pose a risk to human health and the environment, by causing land, water, and air pollution. There is an imminent need for better alternatives to these agrochemicals. This review summarizes one such alternative, the Agro-polymers, specifically designed and employed for enhanced crop productivity. Their versatile nature and various applications are based on features like protective and preventive properties of certain antimicrobial, antifungal, molluscicidal, and herbicidal polymers, water absorbance and retention capabilities of superabsorbent polymers and hydrogels, and controlled delivery of agrochemicals and nutrients property of polymeric delivery systems. The paper discusses future research prospects, with a focus on enhancing the efficiency, stability, and safety of agro-polymer applications. It emphasizes the need for continued research to optimize the use of polymeric materials in agriculture and ensure their compatibility with global environmental requirements.
The present energy demand and technological advancements in biofuel generation favor bioethanol, biobutanol, biodiesel, biogas, and biohydrogen production from renewable substrates. Bioethanol is one of the clean biofuels that has gained widespread acceptance as an alternative to fossil fuels and can be easily adapted in the automotive industry to design engines. Up to date, the commercial production of bioethanol obtained from first-generation biomass as substrates have led to a "Food vs. Fuel" issue. The ecosystem is affected by the use of hazardous pesticides and fertilizers in the cultivation of first-generation crops. These issues compel us to focus on a varied group of autotrophic organisms, the seaweeds, in this article as a potential replacement substrate for bioethanol production. Recently, the spent biomass of the seaweed industry and the economically viable seaweeds that drift on shore have been widely focused on generating revenue by many entrepreneurs and also helping farmers generate additional income from seaweed collection and processing. Classification and status of seaweed research were initially discussed in this article, and characteristics, pretreatment, bioethanol production of seaweed biomass, and spent seaweed biomass were articulated extensively. Eventually, a bioethanol economic scenario was developed to decipher the commercial feasibility of bioethanol in India.
Life cycle assessment is widely applied for quantifying the environmental impacts of products and processes. However, it has limitations due to the static data inputs and steady-state assumptions, which hinder predicting future impact changes and overlook the system’s dynamics issues. System dynamics is often applied to simulate the causal relationships of internal and external factors in the complex systems, enabling the exploration of system nonlinearities and feedback mechanisms on system change in the future. Therefore, life cycle assessment and system dynamics can be integrated to augment the current deficiencies of life cycle assessment research, resulting in more accurately assessed outcomes. This paper reviews the combination of system dynamics and life cycle assessment methods and analyzes the different application cases. The findings reveal that incorporating system dynamics can enhance the timescale and system interaction mechanisms of life cycle assessment, while life cycle assessment expands the scope of system dynamics modeling, thus leveraging the complementary advantages of both approaches. There is no unified framework for the system dynamics and life cycle assessment model, which is often influenced by simplification and assumption of models. Moreover, there are still deficiencies in the indicator system selection and assessment model construction. Future research should focus on incorporating dynamic impact factors to assess all environmental, economic, and social sustainability aspects to enrich the research system by considering temporal and spatial changes. These advancements will support the further development of the system dynamics and life cycle assessment model, ensuring more comprehensive and accurate assessments of the system sustainability.
Biogas projects have significant benefits, in particular, considerable reduction of the negative impact on atmospheric air. In order to highlight the benefits of biogas projects, it is necessary to consider the features of the source of heat or electricity generation and to compare it with the fossil fuel being replaced. Currently, the existing methodological tools do not consider the specifics of the use of various types of fuels, including alternative ones, when conducting an environmental assessment of energy projects. The purpose of this study is to develop methodological approach to the evaluation of biogas energy projects using integrated greenhouse gas (GHG) emission metrics. The indicator for the environmental efficiency assessment of an investment project with partial replacement of power consumption from the grid in terms of GHG emissions was proposed and tested on the regional energy facilities. The developed indicator considerably complements existing approaches to the efficiency assessment of biogas projects and allows to evaluate the performance of biogas projects using a single indicator that significantly simplifies the assessment procedure. It could also be paired with economic indicators such as net profit value, total capital costs in order to build a dependency matrix diagram for environmental and economic assessment of the projects. The proposed methodology could be especially useful for biogas projects implemented in countries and territories with large reserves of fossil fuels, when the profitability and economic efficiency of renewable energy projects are low.
Wastewater is characterized by multipollutant, and the presence of competitive adsorption could affect removal efficiency. Hence, the decontamination of water by adsorption in a multicomponent system allows an understanding of the practically and adsorbent efficiency. In this study, we present an analysis of the adsorption phenomena in a binary solution comprising compounds from distinct families, a dye, and an antibiotic, utilizing activated carbon obtained through a sustainable procedure. Locally available agricultural biowaste, specifically macadamia nutshell (MNS), served as a sustainable precursor to produce hierarchical porous activated carbon. The activation conditions were fine-tuned using the Box–Behnken experimental design. The resultant activated carbon was employed to remove a binary solution (BS) comprising the cationic dye, methylene blue (MB) and an ionic molecule amoxicillin (AMX) under specified conditions, including a pH range of 2 to 12, an initial concentration of BS ranging from 50 to 800 mg/L, and an adsorbent dosage within the range of 0.1 g to 0.3 g in a single adsorption system. The results revealed that higher temperatures adversely impacted the carbon yield, with a pronounced interaction effect observed between temperature and time. The activation temperature and K2CO3:precursor molar ratio predominantly influenced the textural and morphological properties of the activated carbon. Under optimal conditions (900 °C, 1 h, and a K2CO3:precursor ratio of 2:1), remarkably high-surface area (1225 m2/g), pore volume (0.801 cm3/g), and a nanopore size of 0.406 nm were achieved. In binary adsorption studies, R2-MNS demonstrated a maximum adsorption capacity of 578.925 mg/g. A pH above 4.5 produced an antagonistic effect on the removal of AMX due to competitive adsorption. Evaluation of three isotherm models demonstrated that the Khan isotherm best describes the affinity of BS to R2-MNS. The pseudo-second-order kinetic model best describes the data, indicating a chemisorption mechanism. The interparticle diffusion test revealed that the adsorbent exhibited very fast adsorption behaviour at the initial stage.
Households play a crucial role in global energy consumption. Based on a dynamic multi-regional input–output model, this study examines household energy consumption patterns worldwide and their driving forces from 2000 to 2014. The results reveal the continuous increase in global household energy consumption over the study period: the total amount of household embodied energy consumption being roughly three times that of their direct energy consumption. Despite the shift toward cleaner household direct energy consumption in some countries, the structure of household embodied energy consumption has not changed significantly. The energy transition still requires more effort. The structural decomposition analysis shows that the demand-level effect contributes most to the growth of household embodied energy consumption, while the energy-intensity effect is the main factor offsetting the growth. The analysis at the regional and sectoral levels provides insights for promoting household energy conservation and transition, especially for embodied energy.