Yuexiang Yuan
Chinese Academy of Sciences
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Featured researches published by Yuexiang Yuan.
Bioresource Technology | 2015
Dong Li; Shengchu Liu; Li Mi; Zhidong Li; Yuexiang Yuan; Zhiying Yan; Xiaofeng Liu
In order to investigate the effects of feedstock ratio and organic loading rate (OLR) on the anaerobic mesophilic co-digestion of rice straw (RS) and cow manure (CM), batch tests (2.5L) were carried out at volatile solid (VS) ratios of 0:1, 1:2, 1:1, 2:1, and 1:0 (RS/CM), and continuous bench experiments (40 L) were carried out at OLRs of 3.0, 3.6, 4.2, 4.8, 6.0, 8.0, and 12.0 kg VS/(m(3) d) with optimal VS ratio. The optimal VS ratio was found to be 1:1. Stable and efficient co-digestion with average specific biogas production of 383.5L/kg VS and volumetric biogas production rate of 2.30 m(3)/(m(3) d) was obtained at an OLR of 6 kg VS/(m(3) d). Anaerobic co-digestion was severely inhibited by the accumulation of volatile fatty acids instead of ammonia when the OLR was 12 kg VS/(m(3) d). Further, significant foaming was observed at OLR ⩾ 8 kg VS/(m(3) d).
Bioresource Technology | 2015
Zhiying Yan; Zilin Song; Dong Li; Yuexiang Yuan; Xiaofeng Liu; Tao Zheng
This study investigated the possibilities of improving the biogasification from solid-state anaerobic digestion (SS-AD) of composting rice straw (RS) based on the optimized digestion temperature, initial substrate concentration (ISC) and C/N ratio. RS compounds, such as lignin, cellulose, and hemicellulose, were significantly degraded after composting. A significant interactive effect of temperature, ISC and C/N ratio was found on the biogasification of SS-AD of composting RS, and a maximum biogas production was achieved at 35.6°C, with a 20% ISC and a C/N ratio of 29.6:1. The verification experiment confirmed the optimization results. High-throughput sequencing analysis indicated that microbial communities in the SS-AD mainly consist of Methanobacteria, Bacteroidia, Clostridia, Betaproteobacteria, and Gammaproteobacteria. A dominant Methanobacteria was shifted from Methanobacterium to Methanoculleus during the SS-AD process. This study provides novel information about the interdependent effects and microbial behavior of AD.
PLOS ONE | 2014
Zilin Song; GaiheYang; Xiaofeng Liu; Zhiying Yan; Yuexiang Yuan; Yinzhang Liao
Agriculture straw is considered a renewable resource that has the potential to contribute greatly to bioenergy supplies. Chemical pretreatment prior to anaerobic digestion can increase the anaerobic digestibility of agriculture straw. The present study investigated the effects of seven chemical pretreatments on the composition and methane yield of corn straw to assess their effectiveness of digestibility. Four acid reagents (H2SO4, HCl, H2O2, and CH3COOH) at concentrations of 1%, 2%, 3%, and 4% (w/w) and three alkaline reagents (NaOH, Ca(OH)2, and NH3·H2O) at concentrations of 4%, 6%, 8%, and 10% (w/w) were used for the pretreatments. All pretreatments were effective in the biodegradation of the lignocellulosic straw structure. The straw, pretreated with 3% H2O2 and 8% Ca(OH)2, acquired the highest methane yield of 216.7 and 206.6 mL CH4 g VS −1 in the acid and alkaline pretreatments, which are 115.4% and 105.3% greater than the untreated straw. H2O2 and Ca(OH)2 can be considered as the most favorable pretreatment methods for improving the methane yield of straw because of their effectiveness and low cost.
Biotechnology and Bioprocess Engineering | 2013
Zhiying Yan; Xiaofeng Liu; Yuexiang Yuan; Yinzhang Liao; Xudong Li
With the transition of livestock production from the traditional small household farming to large-scale centralized breeding, the odor pollution caused by livestock manure has become pressing in China. In this study, two yeast strains Y1 and Y2 with high deodorization efficiency were isolated from the sample collected from an outlet in a swine farm in Shuangliu County, Sichuan Province. The scale-up deodorization experiments were carried out for strains Y1, Y2, and their mixture Y1+Y2. The results showed that the reduction rate of treatments on NH3 was in the sequence of Y1+Y2 (35.6 ∼ 68.7%) >Y1 (20.3 ∼ 63.7%) >Y2 (−11.7 ∼ 53.8%). The reduction rate of treatments on H2S was in the sequence of Y1+Y2 (47.2 ∼ 70.1%) > Y2 (36.6 ∼ 60.8%) > Y1 (27.6 ∼ 42.0%). The reduction rate of treatments on total volatile organic compounds (TVOC) was in the sequence of Y1+Y2 (49.1 ∼ 68.3%) > Y1 (36.2 ∼ 54.6%) >Y2 (20.8 ∼ 48.6%). The reduction rate of treatments on odor intensity was in the sequence of Y1+Y2 (27.2–60.3%) > Y1 (16.3 ∼ 38.5%) >Y2 (−0.4 ∼ 35.2%). Furthermore, the concentrations of VFAs, indole, skatole, total nitrogen (TN), organic nitrogen (ON), total sulfur (TS), and ammonium nitrogen (AN) in swine manure during deodorization by yeast strains Y1, Y2, and their mixture Y1+Y2 were assayed. The results showed the concentrations of VFAs, indole, and skatole in the manure with Y1, Y2, and Y1+Y2 treatments were all lower than those of the control group. The concentrations of TN, ON, and TS in treatments were all higher than that of the control group. The concentrations of AN in the treatment groups were all lower than those of the control group.
Bioresource Technology | 2017
Min Wang; Xueying Zhang; Jun Zhou; Yuexiang Yuan; Yumei Dai; Dong Li; Zhidong Li; Xiaofeng Liu; Zhiying Yan
Anaerobic co-digestion is considered to be an efficient way to improve the biogas production. The abundance, dynamic and interactional networks of prokaryotic community were investigated between co-digestion and mono-digestions of corn stalk and pig manure in mesophilic batch test. Co-digestion showed higher methane production, and contributed to suitable microenvironment as well as stable prokaryotic community structure. The highest methane production was achieved with the highest relative abundance of Methanosaeta. Prokaryotic community in mono-digestions might inhibited by FA or FVFA. The functional modules in co-digestion and mono-digestion of pig manure clustered together with bigger size and higher degree, and the connections of metabolic functions were better-organized, which means high-efficient utilization of substrate and prevention of the two digestion systems crash. The partial mantel tests showed the functional modules were significantly affected by environmental factors. These results further explained that why co-digestion was more efficient than mono-digestion owing to suitable microenvironment.
Chinese Journal of Appplied Environmental Biology | 2012
Dandan Qian; Longlong Ma; Yuexiang Yuan; Zhiying Yan; Xiaofeng Liu; Yinzhang Liao; Rongna He
An alkalophilic methanogen T13 was isolated by anaerobic techniques of Hungate from cow muck in Hongyuan county,Sichuan,China enriched in culture for methanogen at 15 ℃.Its optimum pH for producing methane was 8.5,and the temperature for growth was observed at the range of 8~45 ℃.The culture was visible particulate.Cells were aggregated and gram-positive.The colony was pale yellow,mulberry-like and fluoresced.T13 could grow using acetate,methanol or methylamine as sole carbon source,and it was sensitive to chloramphenicol and gentamicin.The optimum temperature and NaCl concentration for its growth were 30 ℃ and 0~0.15 mol L-1,respectively.It grew at the pH range between 6.5 and 9.5.The morphological and physio-biochemical characteristics combined with 16S rDNA sequence analysis of strain T13 demonstrated that it was a strain of Methanosarcina mazei.Since its optimum pH for growth was 8.5,strain T13 therefore was considered preliminarily as a new strain of M.mazei.
Bioresource Technology | 2016
Dong Li; Qingjing Wang; Jiang Li; Zhidong Li; Yuexiang Yuan; Zhiying Yan; Zili Mei; Xiaofeng Liu
Mesophilic-hydrothermal (80-160 °C, 30 min)-thermophilic (M-H-T) digestion and control tests of mesophilic (M), thermophilic (T), hydrothermal-mesophilic (H-M), and mesophilic-thermophilic digestion (M-T) of green corn straw were conducted for a 20-day fermentation period. The results indicate that M-H-T is an efficient method to improve methane production. A maximum methane yield of 371.74 mL/g volatile solid was obtained by the M (3 days)-H (140 °C)-T (17 days) process, which was 20.44%, 16.55%, 31.44%, and 14.31% higher than the yields of the M, T, 140-M, and M-T processes. The enhanced methane production was attributed to (1) the improved hemicellulose degradation and lignin disorganization; (2) prevention of the degradation of soluble sugar, easily hydrolyzed hemicellulose and cellulose into furfural and methylfurfural; and (3) lack of formation of Maillard reaction products during initial hydrothermal treatment.
Journal of The Air & Waste Management Association | 2016
Zhiying Yan; XiuLi Wei; Yuexiang Yuan; Zhidong Li; Dong Li; XiuFeng Liu; LiHong Gao
ABSTRACT Odor pollution is a big environmental problem caused by large-scale livestock production in China, and developing a practical way to reduce these odors is pressing. In this study, a combination of 0.2–1.0 U/mL lignin peroxidase (LiP) and one of three peroxides (H2O2, CaO2, 2Na3CO3·3H2O2) was examined for its efficiency in reducing the release of eight chemicals (propionic acid, isobutyric acid, isocaproic acid, isovaleric acid, phenol, p-cresol, indole, and skatole), NH3, H2S, and odor intensity from pig manure. The results showed an approximately 90% reduction in p-cresol, 40–60% reduction in odor intensity, 16.5–40% reduction in indolic compounds, and 25–40% reduction in volatile fatty acids. Being the electron acceptors of LiP, 2Na3CO3·3H2O2 and CaO2 performed better than H2O2 in reducing the concentration of eight chemicals, NH3, H2S, and odor intensity from pig manure. The effect of deodorization can last for up to 72 hr. Implications: In China, one of the major environmental problems caused by confined feeding is odor pollution, which brings a major threat to the sustainability, profitability, and growth of the livestock industry. To couple the LiP with the electron acceptors, a low–cost, simple, and feasible method for odor removal was established in this study. Based on the study results, a practical treatment method was provided for odor pollution and supply the farm operators a more flexible time to dispose treated manure.
Chinese Journal of Appplied Environmental Biology | 2012
Ming Han; Yuexiang Yuan; Zhiying Yan; Rongna He; Xiaofeng Liu; Yinzhang Liao
Using CMC Congo Red agar plate method,an actinomycetic strain producing cellulase with high temperature tolerance and pH stability was isolated from the sample collected from mushroom plantation.The strain was identified and named as Thermobifida fusca DY3 by morphological,physiological and biochemical characteristics,and 16S rDNA gene sequence analysis.The study on the cellulase showed that the extracellular thermostable cellualse exhibited the maximum activity at 65 ℃ and retained more than 75% of its maximum activity after incubation for 60 minutes at 70 ℃.The enzyme also showed its pH stability between pH 5.5 and 10.0,and retained 80% of its maximum enzymatic activity after treated at pH 10.0.The sodium carboxymethylcellulose was its best zymolyte.All the characteristics of the enzyme provide reference value for its application in biological pretreatment of lignocellulose.
International Biodeterioration & Biodegradation | 2011
Fenghui Sun; Jiang Li; Yuexiang Yuan; Zhiying Yan; Xiaofeng Liu