Efficacy of exopolysaccharide in dye-laden wastewater treatment: A comprehensive review.

The discharge of dye-laden wastewater into the water streams causes severe water and soil pollution, which poses a global threat to aquatic ecosystems and humans. A diverse array of microorganisms such as bacteria, fungi, and algae produce exopolysaccharides (EPS) of different compositions and exhibit great bioflocculation potency to sustainably eradicate dyes from water bodies. Nanomodified chemical composites of EPS enable their recyclability during dye-laden wastewater treatment. Nevertheless, the selection of potent EPS-producing strains and physiological parameters of microbial growth and the remediation process could influence the removal efficiency of EPS. This review will intrinsically discuss the fundamental importance of EPS from diverse microbial origins and their nanomodified chemical composites, the mechanisms in EPS-mediated bioremediation of dyes, and the parametric influences on EPS-mediated dye removal through sorption/bioflocculation. This review will pave the way for designing and adopting futuristic green and sustainable EPS-based bioremediation strategies for dye-laden wastewater in situ and ex situ.

Overview of the advances in plant microbial fuel cell technology for sustainable energy recovery from rhizodeposition.

In plant microbial fuel cells (p-MFCs) electrochemically active microbes present around the plant root convert rhizodeposits or the organic matter into electrons, protons, and CO2 . This work covers the increasing trend in research with p-MFCs with their mechanism of operation. Different plant species and their selection criteria are also covered. Furthermore, the long-term evaluation of such systems with its cost effectiveness and commercial and environmental perspectives are also presented. A critical aspect for bioelectricity production is the photosynthetic pathway of the plant. Additionally, the microbial communities and reactor configurations employed across different capacities are also reviewed. The challenges with bioelectricity production and the opportunity for developing p-MFCs in conjunction with traditional MFCs are also covered. These electrogenic reactor systems harness bioelectricity without harvesting the plant and has the capacity to utilize this energy for remote power applications.

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

The COVID-19 pandemic presented a chance to investigate the effects of system-wide emergencies on major global commodities such as water and energy. In terms of environmental policies and attaining supply security, these developmental goals are interrelated. Despite pandemic disruptions, there is a compelling need for a systematization in these areas for the transition to clean water access and sustainable energy. This article presents a comprehensive assessment of the effects of COVID-19 on these two sustainable development goals. Further, an integrated aspect of water and energy access for sustainable development is evaluated with insights on the effects of COVID-19 on the water-energy nexus. Additionally, technological evolution for building better water and energy supply systems is presented. An insight into developing robust healthcare systems and how the water and energy SDGs affect population dynamics is also speculated, which indicates varied short-term adaption experiences, and highlights the need for a re-evaluation of the water-energy nexus. The integrated solutions contributing to stability of the water supply chain, energy storage, and policy making during and after an outbreak are critical to achieving developmental goals.

Potential applications of algae in biochemical and bioenergy sector.

Algae have gained substantial importance as the most promising potential green fuel source across the globe and is on growing demand due to their antioxidant, anticancer, antiviral, antihypertensive, cholesterol reducing and thickening properties. Therefore, it has vast range of application in medicines, pharmaceutical, cosmetics, paper and nutraceutical industries. In this work, the remarkable ability of algae to convert CO2 and other toxic compounds in atmosphere to potential biofuels, foods, feeds and high-value bioactive compounds is reviewed. Algae produce approximately 50% of the earth's oxygen using its photosynthetic activity, thus acting as a potent tool to mitigate the effects of air pollution. Further, the applicability of algae as a desirable energy source has also been discussed, as they have the potential to serve as an effective alternative to intermittent renewable energy; and also, to combustion-based fossil fuel energy, making them effective for advanced biofuel conversions. This work also evaluates the current applications of algae and the implications of it as a potential substrate for bioplastic, natural alternative to inks and for making paper besides high-value products. In addition, the scope for integrated biorefinery approach is also briefly explored in terms of economic aspects at the industrial scale, as such energy conversion mechanisms are directly linked with sustainability, thus providing a positive overall energy outlook.

Role of probiotics in prevention and treatment of enteric infections: a comprehensive review.

Microorganisms that inhabits human digestive tract affect global health and enteric disorders. Previous studies have documented the effectiveness and mode of action of probiotics and classified as human-friendly biota and a competitor to enteric pathogens. Statistical studies reported more than 1.5 billion cases of gastrointestinal infections caused by enteric pathogens and their long-term exposure can lead to mental retardation, temporary or permanent physical weakness, and leaving the patient susceptible for opportunistic pathogens, which can cause fatality. We reviewed previous literature providing evidence about therapeutic approaches regarding probiotics to cure enteric infections efficiently by producing inhibitory substances, immune system modulation, improved barrier function. The therapeutic effects of probiotics have shown success against many foodborne pathogens and their therapeutic effectiveness has been exponentially increased using genetically engineered probiotics. The bioengineered probiotic strains are expected to provide a better and alternative approach than traditional antibiotic therapy against enteric pathogens, but the novelty of these strains also raise doubts about the possible untapped side effects, for which there is a need for further studies to eliminate the concerns relating to the use and safety of probiotics. Many such developments and optimization of the classical techniques will revolutionize the treatments for enteric infections.

Review of Sustainable Grid-Independent Renewable Energy Access in Remote Communities of India.

In the last decade India has seen an increase in the adoption of solar energy-based technologies by consumers, which has been supported by various government efforts and policies. The rural areas and low-income households that lack a proper electricity supply have emerged as a market for solar off-grid technologies, with private developers increasing their market base slowly in this group. This has promulgated the need to restructure the decentralized energy sector. Existing literature points out the suitability of solar off-grid in such markets; the present study investigates the challenges that have hindered its growth. The study reviews the concept of poverty with respect to the energy sector and analyzes methods of determining poor energy access in the present scenario. It emphasizes the need to understand and reconceptualize policy instruments in order to make solar off-grid a powerful tool in tackling energy demand and providing adequate energy access. It further explores the causes of energy disconnects and how grid-independent solar energy is a technological solution of utmost relevance and in consonance with the idea of sustainable development. For a successful venture, both consumer behavior and marketer objectives are important determinants. The work also provides insights into various models, tools, factors, and social constructs that affect consumer perception and subsequently demand. Over the course of the study, it has been revealed how private players and entrepreneurs are tapping the wrong solar market, leading to misappropriation of solar energy technologies. The suggested improvements and recommendations of the present study from the analysis can serve as a guide for policy makers, technological innovators, and financial stakeholders. Integr Environ Assess Manag 2021;17:364-375. © 2020 SETAC.

Sustainable power generation from sewage and energy recovery from wastewater with variable resistance using microbial fuel cell.

Wastewater from sewage sources contribute significantly to water pollution from domestic waste; one way to recover energy from these sources while at the same time, treating the water is possible using Microbial Fuel Cell. In this work, a two chambered microbial fuel cell was designed and fabricated with carbon cloth electrodes and Nafion-117 membrane, having Platinum as the catalyst. Wastewater from an organic load of 820 ± 30 mg/l reduced to around 170 mg/l, with the change in pH from 7.65 ± 0.6 to 7. 31 ± 0.5; over the time of operation the biochemical oxygen demand from an initial 290 ± 30 mg/l reduced to 175 ± 10 mg/l. Open circuit voltage was achieved mostly between 750-850 mV, with inoculated sludge produced a peak open circuit voltage of 1.45 V between fed-batch cycles. For characterization of power generated, polarization curves are evaluated with varying resistance to examine system stability with varying resistance. The current density and power density are reported to peak at 0.54 mA/m2 and 810 ± 10 mW/m2 respectively. The development of stable biofilms on the anode contributes to the power generation and was evaluated using microscopic analysis, this shows bacteria present in wastewater are electroactive microbial species which can donate electron to an electrode using conductive appendages or nanowires, while consuming the organic matter present in the wastewater. Such systems employ microbial metabolism for water treatment and generate electricity.

Ultrasensitive sensor for detection of early stage chronic kidney disease in human.

A facile label free, ultrasensitive platform for a rapid detection of chronic kidney disease has been fabricated. Early intervention in patients with chronic kidney disease has the potential to delay, or even prevent, the development of end stage renal disease and complications, leading to a marked impact on life expectancy and quality of life. Thus, a potable electrochemical diagnostic biosensor has become an attractive option as electrochemical analysis is feasible to use for on-site detection of samples. In human, Cystatin C present in human body fluids is freely filtered by the glomerulus, but reabsorbed and catabolised by the renal tubules. Trace detectable amount is eliminated in urine, giving this molecular marker an edge over serum creatinine's disadvantages. A carboxyl functionalized multiwalled carbon nanotubes screen printed electrode was immobilized with papain (cysteine protease) where amino group of papain covalently bound carboxyl group on electrode surface by EDC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide) and NHS (N-hydroxysuccinimide) chemistry. The modifications on sensor surface were characterized by field emission scanning electron microscopy. Interaction between papain and chronic kidney disease specific biomarker, Cystatin C was detected by cyclic voltammetry and differential pulse voltammetry within 10min. The sensor is highly specific to Cystatin C and showed negligible response to non-specific macromolecules present in urine. The sensitivity of the sensor was 1583.49µAcm-2µg-1 and lower limit of detection of Cystatin C was found 0.58ngL-1 which presents as a promising platform for designing potable kidney disease detector.