Comparison of chemical and microbiological changes during the aerobic composting and vermicomposting of green waste.

Linlin Cai,Xiaoqiang Gong,Xiangyang Sun,Xin Yu,Suyan Li,Andrea Franzetti

doi:10.1371/journal.pone.0207494

Abstract

This research was conducted to compare chemical and microbiological properties during aerobic composting (AC) and vermicomposting (VC) of green waste. Relative to AC, VC significantly decreased the pH and lignin and cellulose contents, and significantly increased the electrical conductivity and total N and available P contents. For AC, BIrii41_norank (order Myxococcales) was the major bacterial genus at 30 d and again became dominant genus from 90–150 d, with relative abundances of 2.88% and 4.77–5.19%, respectively; at 45 d and 60 d, the dominant bacterial genus was Nitrosomonadaceae_uncultured (order Nitrosomonadales) with relative abundances of 2.83–7.17%. For VC, the dominant bacterial genus was BIrii41_norank (except at 45 d), which accounted for 2.11–7.96% of the total reads. The dominant fungal class was Sordariomycetes in AC (relative abundances 39.2–80.6%) and VC (relative abundances 42.1–69.5%). The abundances of microbial taxa and therefore the bacterial and fungal community structures differed between VC and AC. The quality of the green waste compost product was higher with VC than with AC. These results will also help to achieve further composting technology breakthroughs in reducing the composting time and improving compost quality.

Highlights

Given the need for environmental sustainability, the increasing cost of urban green waste treatment, and the cost of importing horticultural substrates, increasing attention is being paid to transforming green waste into useful horticultural products via composting in China and other countries
The experiment was carried out in our scientific research greenhouse which is owned by our institute, no specific permissions were required for these locations/activities
Vermicomposting and aerobic composting of green waste resulted in decreases in total organic carbon (TOC), C/N, lignin, and cellulose, and increases in pH, electrical conductivity (EC), TN, and available P in the final products. pH, TOC, C/N ratio, and cellulose and lignin percentages were lower in vermicompost than in aerobic compost

Summary

Introduction

Given the need for environmental sustainability, the increasing cost of urban green waste treatment, and the cost of importing horticultural substrates, increasing attention is being paid to transforming green waste into useful horticultural products via composting in China and other countries. The rapid development of urban green spaces has resulted in the generation of substantial quantities of green waste in China. Beijing City alone produces 6 million tons of green waste annually [1]. Garden waste disposal commonly involves large-scale incineration or deposition in landfills, but both are environmentally harmful and fail to make use of a potentially valuable resource [2]. According to the different ways of recycling organic solid waste, composting can be divided into three types: anaerobic fermentation, aerobic composting, and vermicomposting.

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Results

Conclusion