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LCC Organic Waste Recycling Team publishes their latest research results

November 13, 2020      Author:

Recently, Associate Professor Zhang Jingxin of China-UK Low Carbon College of Shanghai Jiao Tong University, together with his team, published a series of papers on methanation mechanisms and application principles of iron cycle and conductive materials in anaerobic digestion process in several international academic journals, including Water Research, Applied Energy and Chemical Engineering Journal. One article titled "Internal enhancement mechanism of biochar with graphene structure in anaerobic digestion: the bioavailability of trace elements and potential direct interspecies electron transfer" was published in Chemical Engineering Journal, with postgraduate student Qi Qiuxian as the first author and Associate Professor Zhang Jingxin as the corresponding author.

The research group has cooperated with National University of Singapore for a long time, and has established long-term and short-term exchange mechanisms based on the Create-E2S2 center to provide students with exchange opportunities in Singapore. The cooperative research mainly focuses on resource technology of urban organic solid waste and ecological energy system. A Create-E2S2 project of "sustainable development solutions for energy and environment in megacities" is being carried out, which aims to effectively treat organic waste and produce resource-based products such as electric energy, thermal energy and organic fertilizer, and further provide solutions for the key technologies of organic solid waste disposal and the promotion and application of complex decision-making problems in the development of megacities.

 

ABSTRACT:

The main aim of the work is to understand the internal mechanism of biochar improving anaerobic digestion (AD) performance. This study evaluated the impact of biochar produced at 400 °C and 900 °C pyrolysis on the AD performance. The results indicated that the methane content increased from an inhibited value of around 60% in the control group to the theoretical value of 75% in the reactor with biochar produced at 900 °C pyrolysis, and the specific methane production increased to 725 mL/g VS/d. The bioavailability of trace elements (TEs) including Fe, Co and Ni was enhanced with the addition of biochar. Correspondingly, enzymatic activity test and metagenomic analysis signified the abundance of the enzyme gene as well as enzyme activity increased with the enhancement of the bioavailability of TEs by biochar. According to the metagenomic analysis of the microbial community and the metabolism pathway, Pseudomonas could participate in direct interspecies electron transfer (DIET) with Methanosaeta via biochar with graphene structure as an electron contact through carbon dioxide reduction so as to heighten methane metabolism. The obtained findings may provide new insight into the internal enhancement mechanism between enzymes as well as the bioavailability of TEs by biochar.

 

Author: SJTU China-UK Low Carbon College

Affiliation: SJTU China-UK Low Carbon College