Quantitative microbial assessment for Escherichia coli after treatment by high voltage gas phase plasma

Advances of non-thermal plasma discharge technology in degrading recalcitrant wastewater pollutants. A comprehensive review

With development and urbanization, the amount of wastewater generated due to human activities drastically increases yearly, causing water pollution and intensifying the already worsened water crisis. Although convenient, conventional wastewater treatment methods such as activated sludge, stabilization ponds, and adsorption techniques cannot fully eradicate the complex and recalcitrant contaminants leading to toxic byproducts generation. Recent advancements in wastewater treatment techniques, specifically non-thermal plasma technology, have been extensively investigated for the degradation of complex pollutants in wastewater. Non-thermal plasma is an effective alternative for degrading and augmenting the biodegradability of recalcitrant pollutants due to its ability to generate reactive species in situ. This article critically reviews the non-thermal plasma technology, considering the plasma discharge configuration and reactor types. Furthermore, the influence of operational parameters on the efficiency of the plasma systems and the reactive species generated by the system during discharge has gained significant interest and hence been discussed. Also, the application of non-thermal plasma technology for the degradation of pharmaceuticals, pesticides, and dyes and the inactivation of microbial activities are outlined in this review article. Additionally, optimistic applications involving the combination of non-thermal plasma and catalysts and pilot and industrial-scale projects utilizing non-thermal plasma technology have been addressed. Concluding perceptions on the challenges and future perspectives of the non-thermal technology on wastewater treatment are accentuated. Overall, this review outlines a comprehensive understanding of the non-thermal plasma technology for recalcitrant pollutant degradation from a scientific perspective providing detailed instances for reference.

Physical Properties of Chocolates Enriched with Untreated Cocoa Bean Shells and Cocoa Bean Shells Treated with High-Voltage Electrical Discharge

Recently, the enrichment of chocolate has become a very interesting topic, along with the management of food industry by-products, such as cocoa shells. Cocoa shells could be a great raw material for the cocoa industry, both for economical reasons (maximized utilization of cocoa beans) and for their functional properties (increased fiber content). In this research, we used untreated and high-voltage electrical discharge (HVED)-treated cocoa shells in the production of chocolate. Different proportions of cocoa mass were replaced with cocoa shells to produce dark and milk chocolates in a ball mill. Additionally, dark chocolate with 15% and milk chocolate with 5% of shells were chosen for further research and to study the alteration of the composition. The rheology, particle size distribution, hardness, and color were determined for all the prepared samples. Treated cocoa shells provided chocolates with inferior physical properties compared to chocolates with untreated shells. Therefore, untreated cocoa shells were selected for further analysis. The addition of both treated and untreated cocoa shells resulted in softening and darkening of samples, which could have a positive effect for consumers. On the other hand, the particle size distribution and rheology were negatively affected. Further research is needed to find a solution for these problems.

Difficulties with Use of Cocoa Bean Shell in Food Production and High Voltage Electrical Discharge as a Possible Solution

The cocoa and chocolate industries have huge problems with the utilization of waste generated during the production process. Waste material generated during production include cocoa pod husk, pulp, and cocoa bean shell. Cocoa shell is a by-product that has great potential because of its composition. It consists of dietary fibers, proteins, polyphenols, methylxanthines, etc. However, despite its favorable composition, cocoa shell often cannot be used directly in food production because it may contain components that are harmful for human health. Cocoa shell can carry mycotoxins, different microorganisms, polycyclic aromatic hydrocarbons, and heavy metals. High voltage electrical discharge presents a novel non-thermal method that has great potential for the decontamination of waste materials and can also be used for extraction of valuable compounds from cocoa shell.