Continuous dynamics in anaerobic reactor during bioconversion of rice straw: Rate of substance utilization, biomethane production and changes in microbial community structure

Akiber Chufo Wachemo; Huan Tong; Hairong Yuan; Xiaoyu Zuo; Rashid Mustafa Korai; Xiujin Li

doi:10.1016/j.scitotenv.2019.05.411

Continuous dynamics in anaerobic reactor during bioconversion of rice straw: Rate of substance utilization, biomethane production and changes in microbial community structure

Sci Total Environ. 2019 Oct 15:687:1274-1284. doi: 10.1016/j.scitotenv.2019.05.411. Epub 2019 May 30.

Authors

Akiber Chufo Wachemo¹, Huan Tong², Hairong Yuan², Xiaoyu Zuo², Rashid Mustafa Korai³, Xiujin Li⁴

Affiliations

¹ Department of Environmental Science and Engineering, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing 100029, PR China; Faculty of Water Supply and Environmental Engineering, Arba Minch University, P.O. Box 21, Arba Minch, Ethiopia.
² Department of Environmental Science and Engineering, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing 100029, PR China.
³ Department of Environmental Science and Engineering, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing 100029, PR China; Department of Petroleum & Gas Engineering, Dawood University of Engineering & Technology, New MA Jinnah Road, Karachi 74800, Sindh, IR, Pakistan.
⁴ Department of Environmental Science and Engineering, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing 100029, PR China. Electronic address: xjli@mail.buct.edu.cn.

PMID: 31412461
DOI: 10.1016/j.scitotenv.2019.05.411

Abstract

Anaerobic digestion (AD) technology is one of the best eco-friendly waste-to-energy processes. Hence the trend of biogas production shows considerable ranges of fluctuations in entire digestion period. This study analyzes the daily substance conversion dynamics, biomethane production and changes in microbial community structure. The results show that in the first peak of biogas production during 1st up to 4th days of the digestion period, CO₂ was the dominant component. However, the daily methane production (DMP) reveal accelerated increment starting from day 8 up to the peak point on day 13 (462.11 mL/d). The concentration of acetic acid covered 21.80% up to 62.00% of the total VFAs in the first 10 days of digestion period. On the other hand, the accumulation of propionic acid is in the range of 1735.70 mg/L- 2893.12 mg/L in between day 5-15, which is beyond the inhibition level (1000 mg/L) but the system didn't stop biogas production. The distribution of bacterial family such as Clostridiaceae_1, Prevotellaceae, Enterobacteriaceae and Peptostreptococcaceae are the dominant group at early stage as compared to composition in remaining stages except Enterobacteriaceae which have marginally high abundance in lowest biogas production point. The archaeal genus Methanosaeta is dominant among the samples collected at early stages (65.66%-77.22%). However, the Methanobacterium is predominant (34.88%-59.40%) in samples obtained at late stages of AD period. On the other hand, the distribution of Methanosarcina is comparable in the first three samples (S1(16.60%), S2(22.21%) and S3(20.38%)) than the stable stage (S4 (6.7%)). This study demonstrates the detailed conditions at fluctuating and constant biogas production periods, which would benefit future researchers working in similar area.

Keywords: Anaerobic digestion; Biogas fluctuation; Microbial community; Rice straw; System stability.

MeSH terms

Bioreactors / microbiology*
Microbiota*
Oryza
Waste Disposal, Fluid*