Energy and water: COVID-19 impacts and implications for interconnected sustainable development goals

Recent Advances in Superabsorbent Hydrogels Derived from Agro Waste Materials for Sustainable Agriculture: A Review

Superabsorbent hydrogels made from agro waste materials have the potential to promote sustainable agriculture and environmental sustainability. These hydrogels not only help reduce water consumption and increase crop yields but also contribute to minimizing waste and lowering greenhouse gas emissions. Recent research on superabsorbent hydrogels derived from agro wastes has focused on the preparation of hydrogels based on natural polymers isolated from agro wastes, such as cellulose, hemicellulose, and lignin. This review provides an in-depth examination of hydrogels developed from raw agro waste materials and natural polymers extracted from agro wastes, highlighting that these studies start with raw wastes as the main materials. The utilization strategies for specific types of agro wastes are comprehensively described. This review outlines different methods utilized in the production of these hydrogels, including physical cross-linking techniques such as dissolution-regeneration and freeze-thawing, as well as chemical cross-linking methods involving various cross-linking agents and graft polymerization techniques such as free radical polymerization, microwave-assisted polymerization, and γ radiation graft polymerization. Specifically, this review explores the applications of agro waste-based superabsorbent hydrogels in enhancing soil properties such as water retention and slow-release of fertilizers for sustainable agriculture.

Supporting health systems and environment in the Democratic Republic of Congo: A call for action

Background

Developing nations have to overcome a number of obstacles to fulfill the Sustainable Development Goals. The Democratic Republic of Congo is one of the five poorest nations in the world and faces several challenges in combating problems related to poverty, health, and sanitation while linking the environment to anthropogenic activities.

Methods

This study analyzes anthropogenic activities and their impact on the environment while providing access to the public health of the Congolese population based on the objectives of sustainable development. Thirty-five articles were selected for further analysis as well as relative data.

Results

In 2022, 21 million cases of malaria were recorded by the national malaria control program, with 13,000 cases of death. The Democratic Republic of Congo has the highest typhoid incidence, with 315 cases per 100,000 people. A number of 31,342 cases of cholera were reported in 2023, according to multiple reports, with 230 deaths, mainly affecting children. In the same year, a triple epidemic of typhoid, shigellosis, and cholera was identified, with 2389 cases and 52 deaths. These observations cause a health emergency, which can be alleviated and resolved by the establishment of an adequate sanitation system. Waste can be recycled and returned to usable raw materials.

Conclusion

Finally, it will be necessary to establish a water safety management plan to combat all diseases linked to the consumption of nonpotable water and improve national coverage on the treatment of recent cases to reduce and at best avoid observed cases of death.

Spatio-temporal trends in long-term seasonal groundwater level of South-western Punjab using non-parametric statistical tests

To manage groundwater resources and develop an action plan, it is crucial to understand the long-term behavior of groundwater level (GWL) fluctuations. In this study, Geographic Information System (GIS) and non-parametric statistical tests were applied for detecting long-term (1973 to 2020) spatio-temporal variations and trends in GWL from 137 observation wells evenly distributed across the south-western part of Punjab. This region has experienced significant changes in GWL over the decades. The non-parametric statistical tests included Mann-Kendall (MK), Sens's Slope Estimator (SSE), and Innovative Trend Analysis (ITA). The study observed significant trends in GWL fluctuations before and after monsoon. The MK and SSE tests showed a statistically increasing trend in observation wells with about 65.7% and 67.2% increase before and after monsoon, respectively. The innovative trend analysis (ITA) also revealed a statistically increasing trend in observation wells with an increase of about 63.5% and 65.7% pre and post-monsoon season, respectively. The results indicate lowering of GWL in the northern districts of southwestern Punjab, while the southern districts experience rising GWLs. This discrepancy can be attributed to diverse agricultural activities and reduced over-exploitation of groundwater in the southern district due to soil salinity and the presence of brackish groundwater. These findings provide valuable insights into the dynamics of GWL in the studied region, highlighting notable trends associated with seasonal variations.

A concise review on waste biomass valorization through thermochemical conversion

Due to an increase in industrialization and urbanization, massive amounts of solid waste biomass are speedily accumulating in our environment, which poses several adverse effects on habitat and human health thus becoming a matter of discussion in the environmental community. With reference to the circular economy, continuous efforts have been put forward for setting up an organised management approach in combination with an efficient treatment technique for increasing the profitable utilization of solid waste. This review aims to provide a systematic discussion on the recent thermochemical technologies employed for converting waste biomass generated from different sources into valuable products like biochar, bio-oil, heat, energy and syngas. The article further focuses on a few important aspects of thermochemical conversion of waste biomass to useful products like technical factors affecting thermochemical processes, applications of by-products of thermochemical conversion, and biological pretreatment of waste biomass. The review assists interesting recent and scientific trends for boosting up the systematic management and valorization of solid waste through low-cost, efficient, environment-friendly and sustainable technologies.

A concise review on wastewater treatment through microbial fuel cell: sustainable and holistic approach

Research for alternative sources for producing renewable energy is rising exponentially, and consequently, microbial fuel cells (MFCs) can be seen as a promising approach for sustainable energy production and wastewater purification. In recent years, MFC is widely utilized for wastewater treatment in which the removal efficiency of heavy metal ranges from 75-95%. They are considered as green and sustainable technology that contributes to environmental safety by reducing the demand for fossil fuels, diminishes carbon emissions, and reverses the trend of global warming. Moreover, significant reduction potential can be seen for other parameters such as total carbon oxygen demand (TCOD), soluble carbon oxygen demand (SCOD), total suspended solids (TSS), and total nitrogen (TN). Furthermore, certain problems like economic aspects, model and design of MFCs, type of electrode material, electrode cost, and concept of electro-microbiology limit the commercialization of MFC technology. As a result, MFC has never been accepted as an appreciable competitor in the area of treating wastewater or renewable energy. Therefore, more efforts are still required to develop a useful model for generating safe, clean, and CO2 emission-free renewable energy along with wastewater treatment. The purpose of this review is to provide a deep understanding of the working mechanism and design of MFC technology responsible for the removal of different pollutants from wastewater and generate power density. Existing studies related to the implementation of MFC technology in the wastewater treatment process along with the factors affecting its functioning and power outcomes have also been highlighted.