Research trend analysis of composting based on Web of Science database

Biosorption of lead ion by lactic acid bacteria and the application in wastewater

Through the study of biosorption of Pb2+ by lactic acid bacteria, two strains called CN-011 and CN-005 with high tolerance and great adsorption to lead were screened. The minimum bactericidal concentration of lead ions for both CN-011 and CN-005 was 1.45 mmol/L. The optimal culture conditions for the removal of 30 mg/L lead ions were achieved by culturing lactic acid bacteria at an initial pH of 7.0, 37 °C and 120 rpm for 48 h. The adsorption rate of CN-011 and CN-005 for Pb2+ were 85.95% and 86.78%, respectively. In simulated wastewater samples, the average adsorption rate of Pb2+ was 73.38% for CN-011 and 74.15% for CN-005. The mechanism of biosorption was characterized by Fourier Transform infrared spectroscopy, Scanning Electron Microscope-Energy Dispersive Spectrometer, X-ray Photoelectron Spectroscopy, which revealed that Pb2+ mainly reacted with hydroxyl ions in peptidoglycan or polysaccharide, and carboxylate radical in teichoic acid or protein on the surface of lactic acid bacteria cell wall. The deposits produced on the bacterial surface were identified as lead oxide and lead nitrate.

Bioconversion of biowaste into renewable energy and resources: A sustainable strategy

Due to its high amount of organic and biodegradable components that can be recycled, biowaste is not only a major cause of environmental contamination, but also a vast store of useful materials. The transformation of biowaste into energy and resources via biorefinery is an unavoidable trend, which could aid in reducing carbon emissions and alleviating the energy crisis in light of dwindling energy supplies and mounting environmental difficulties related with solid waste. In addition, the current pandemic and the difficult worldwide situation, with their effects on the economic, social, and environmental aspects of human life, have offered an opportunity to promote the transition to greener energy and sources. In this context, the current advancements and possible trends of utilizing widely available biowaste to produce key biofuels (such as biogas and biodiesel) and resources (such as organic acid, biodegradable plastic, protein product, biopesticide, bioflocculant, and compost) are studied in this review. To achieve the goal of circular bioeconomy, it is necessary to turn biowaste into high-value energy and resources utilizing biological processes. In addition, the usage of recycling technologies and the incorporation of bioconversion to enhance process performance are analyzed critically. Lastly, this work seeks to reduce a number of enduring obstacles to the recycling of biowaste for future use in the circular economy. Although it could alleviate the global energy issue, additional study, market analysis, and finance are necessary to commercialize alternative products and promote their future use. Utilization of biowaste should incorporate a comprehensive approach and a methodical style of thinking, which can facilitate product enhancement and decision optimization through multidisciplinary integration and data-driven techniques.

Recent trends and advances in composting and vermicomposting technologies: A review

Composting technologies have come a long way, developing from static heaps and windrow composting to smart, artificial intelligence-assisted reactor composting. While in previous years, much attention has been paid to identifying ideal organic waste streams and suitable co-composting candidates, more recent efforts tried to determine novel process-enhancing supplements. These include various single and mixed microbial cultures, additives, bulking agents, or combinations thereof. However, there is still ample need to fine-tune the composting process in order to reduce its impact on the environment and streamline it with circular economy goals. In this review, we highlight recent advances in integrating mathematical modelling, novel supplements, and reactor designs with (vermi-) composting practices and provide an outlook for future developments. These results should serve as reference point to target adjusting screws for process improvement and provide a guideline for waste management officials and stakeholders.