Bioactives from citrus food waste: types, extraction technologies and application.

The Citrus fruits belong to the category where the groups of fruits are recognized to be an admirable repository of bioactive elements and phytochemical constituents, with strong biological potentials. The prominent use of Citrus fruits for nutrition as well as food processing has led to the release of a large amount of waste into the environment and surrounding, and it simultaneously burdens the nature and existence of many organisms including the human population. In order to rectify such consequences, the reuse of food waste from citrus for various advantageous effects. In this regard, the first part of the article primarily focussed on the various strategies available for the extraction of chemical elements from citrus waste and the remaining strand of the article focussed on the various bioactive compounds with special reference to their pharmacological as well as the medicinal benefits and future prospects.

General aspects and novel PEMss in microbial fuel cell technology: A review.

The current scenario of energy production is mostly shifted towards sustainable renewable energy sources. Other than the energy production from natural resources such as sun, wind and water, microbial fuel cell system (MFC) has earned attraction in recent times. These microbial fuel cell systems are bioelectrochemical cell that possesses a unique ability to generate power as well as treats wastewater simultaneously. In this paper, an overview of the microbial fuel cell system and the effect of significant components on the performance of microbial fuel cell systems are reviewed. Firstly, the importance of the MFC system in power generation, its components, the working principle and various configurations of the MFC were briefly introduced. Biofilm plays a major role in the MFC system. Thus the importance of bio film, bio film formation and characterization techniques are summarised. Further, the review mainly addresses the mechanism of conventional and novel membrane materials on the performance of the MFC system. In addition, special emphasis on ceramic-based materials in the MFC system is presented. Finally, recent applications of the MFC systems are discussed.

Integrated biorefinery development for pomegranate peel: Prospects for the production of fuel, chemicals and bioactive molecules.

Current experimental evidence has revealed that pomegranate peel is a significant source of essential bio compounds, and many of them can be transformed into valorized products. Pomegranate peel can also be used as feedstock to produce fuels and biochemicals. We herein review this pomegranate peel conversion technology and the prospective valorized product that can be synthesized from this frequently disposed fruit waste. The review also discusses its usage as a carbon substrate to synthesize bioactive compounds like phenolics, flavonoids and its use in enzyme biosynthesis. Based on reported experimental evidence, it is apparent that pomegranate peel has a large number of applications, and therefore, the development of an integrated biorefinery concept to use pomegranate peel will aid in effectively utilizing its significant advantages. The biorefinery method displays a promising approach for efficiently using pomegranate peel; nevertheless, further studies should be needed in this area.

Enhanced performance of novel carbon nanotubes - sulfonated poly ether ether ketone (speek) composite proton exchange membrane in mfc application.

Sulfonated poly ether ether ketone (SPEEK) nanocomposite proton exchange membrane (PEM) was prepared by incorporating multi-walled carbon nanotubes (CNT) at different weight percentages for microbial fuel cell (MFC) applications. Physico-chemical, thermal, mechanical and morphological characteristics of the prepared CNT-SPEEK composite membranes were analyzed using various techniques. Further, the water uptake capacity, Ion exchange capacity (IEC) and MFC performance of the CNT-SPEEK composite membranes were evaluated and compared with the pristine SPEEK membrane. Results show that incorporation of CNTs in SPEEK membranes exhibited a better water uptake capacity (34.18%-36.02%) and IEC (1.94-2.15 meq/g) compared to the SPEEK membrane. Improvement in membrane properties resulted in 2-fold higher power density compared to SPEEK membrane. Composite membrane with 0.75% CNT-SPEEK produced the higher power density (1.77 W/m2) in comparison with all the membranes evaluated. Chemical oxygen demand (COD) removal efficiency values of the MFC with SPEEK composite membranes were also found to be around 90%. Overall, the results reveal that CNT-SPEEK composite membrane as a potential PEM for MFC applications.

Evaluation of power generation and treatment efficiency of dairy wastewater in microbial fuel cell using TiO2 - SPEEK as proton exchange membrane.

The aim of this study is to synthesise SPEEK composite proton exchange membrane with the addition of TiO2 nanofillers for microbial fuel cell application. SPEEK composite membrane with varying weight percentage of TiO2 (2.5, 5, 7.5 and 10%) was prepared to study the effect of TiO2 concentration on membrane performance. Synthesized composite membranes were subjected to various characterization studies such as FT-IR, XRD, Raman spectroscopy, TGA, UTM and SEM. Physico-chemical properties of membrane such as water uptake capacity, ion exchange capacity and thickness were also analyzed. 5% TiO2 - SPEEK composite membrane exhibited the higher water uptake capacity value and Ion exchange capacity value of 31% and 1.71 meq/g respectively. Performance of the MFC system with TiO2 - SPEEK membranes were evaluated and compared with the pristine SPEEK and Nafion membrane. 5% TiO2 - SPEEK membrane produced the higher power density (1.22 W/m2) and voltage (0.635 V) than the other membranes investigated. Efficacy of MFC in wastewater treatment was evaluated based on the chemical oxygen demand (COD), total organic carbon content and turbidity. Biofilm growth over the surface of the electrodes was also analyzed using scanning electron microscopy.