著者

Li Shuhong Sang Yaxin Zhu Dan Yang Yingnan Lei Zhongfang Zhang Zhenya

出版者

Elsevier

雑誌

Industrial crops and products (ISSN:09266690)

巻号頁・発行日

vol.50, pp.666-672, 2013-10

被引用文献数

28

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In this study, orthogonal experimental design and response surface methodology were employed to optimize the fermentation conditions for crude polysaccharides (MPS) production from the strain Morchella esculenta (M. esculenta) by soybean curd residue (SCR). The MPS yield varied depending on the nutrition contents added in SCR and fermentation time, fermentation temperature and inoculum size by M. esculenta during solid-state fermentation. The optimal fermentation conditions achieved for MPS production 95.82 ± 1.37 mg/g were glucose 4%, (NH4)2SO4 1.5%, water 75% and MgSO4·7H2O 0.2%, fermentation temperature 22.6 °C, fermentation time 21 days and inoculum size 2.67%, respectively. Furthermore, purified polysaccharides (PMPS) exhibited a positive antioxidant activity. The results provide a reference for large-scale production of polysaccharides by M. esculenta using SCR in the medical and food industries.

著者

Liu Chunguang Shi Wansheng Kim Mijung Yang Yingnan Lei Zhongfang Zhang Zhenya

出版者

Elsevier Ltd.

雑誌

International journal of hydrogen energy (ISSN:03603199)

巻号頁・発行日

vol.38, no.18, pp.7246-7252, 2013-06

被引用文献数

22

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Photocatalytic pretreatment of waste activated sludge (WAS) using a flat photocatalytic reactor was undertaken. Photocatalytic pretreatment enhanced the release of soluble substances from WAS, in which the soluble protein and soluble carbohydrate concentration increased by about 50% and 80%, respectively. Significant removal of heavy metal ions from the liquid phase of WAS was also achieved after photocatalytic pretreatment. In addition, the highest hydrogen yield and the highest concentration of volatile fatty acids (VFAs) were achieved from the photocatalysis pretreated WAS by batch anaerobic digestion (55 °C). The cumulative hydrogen yield from photocatalysis pretreated WAS was 211.0 ml/l-sludge, much higher than those from UV pretreated WAS (111.0 ml/l-sludge) and from raw WAS (93.0 ml/l-sludge). The results indicate that photocatalysis is a promising WAS pretreatment method for the enhancement of biohydrogen production, probably due to the photo-oxidation of organics and simultaneous photo-reduction of heavy metal ions in WAS.

著者

Lin Lin Wan Chunli Liu Xiang Lee Duu-Jong Lei Zhongfang Zhang Yi Hwa Tay Joo

出版者

Elsevier Ltd.

雑誌

Bioresource technology (ISSN:09608524)

巻号頁・発行日

vol.136, pp.302-308, 2013-05

被引用文献数

51

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Effects of initial pH (3–12) on mesophilic hydrolysis and acidification reactions of swine manure was studied. The initial pH changed the microbial community in the suspension so as to affect hydrolysis and acidification reactions on swine manure. At pH 10–12 the Clostridium alkalicellum and/or Corynebacterium humireducens were enriched and the soluble chemical oxygen demand (SCOD), total volatile fatty acids (VFAs), proteins and carbohydrates from manure were increased in quantities. In particular, at pH 10 the VFA concentration peaked at 13,600 mg-COD/L, with acetate and propionate accounting for 71.8% of the total VFAs. Acidic environment facilitates release of ammonium from manure. The Butyricimonas sp. was found existing at initial pH 5 which led to accumulated quantities of butyrate. Initial pH adjustment was revealed to be an effective way to manipulate rates and end products of hydrolysis and acidification of swine manure.

著者

Shi Wansheng Liu Chunguang Ding Dahu Lei Zhongfang Yang Yingnan Feng Chuanping Zhang Zhenya

出版者

Elsevier Ltd.

雑誌

Bioresource technology (ISSN:09608524)

巻号頁・発行日

vol.137, pp.18-24, 2013-06

被引用文献数

183 7

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Heavy metals (HMs) immobilization in sewage sludge was investigated by using subcritical water technology (SCWT) in this study. The characteristics of sludge and toxicity of HMs were analyzed after SCWT process. The results showed that besides large reduction in sludge volume, SCWT had some positive effect on HMs dissolution into liquid phase, while the majority of HMs was still accumulated in solid phase. The direct toxicity and bioavailability of HMs in sludge was greatly decreased with no toxicity fractions of HMs highly increased. Pb was always at low risk level and the risk of other HMs was greatly reduced from low risk to no risk after SCWT treatment. Moreover, the leaching toxicity of HMs declined after SCWT and the best result was obtained at 280 °C with the metal concentrations in leachate decreased by 97.46%, 93.91%, 86.14%, 73.67%, 71.93% and 10.71% for Cu, Cd, Zn, Cr, Ni and Pb, respectively.

著者

Lei Zhongfang Wu Ting Zhang Yi Liu Xiang Wan Chunli Lee Duu-Jong Tay Joo-Hwa

出版者

Elsevier Ltd.

雑誌

Bioresource technology (ISSN:09608524)

巻号頁・発行日

vol.128, pp.774-778, 2013-01

被引用文献数

15 1

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Soil infiltration treatment (SIT) is ineffective to treat ammonium wastewaters of total nitrogen (TN) > 100 mg l−1. This study applied a novel two-stage SIT process for effective TN removal from wastewaters of TN > 100 mg l−1 and of chemical oxygen demand (COD)/TN ratio of 3.2–8.6. The wastewater was first fed into the soil column (stage 1) at hydraulic loading rate (HLR) of 0.06 m3 m−2 d−1 for COD removal and total phosphorus (TP) immobilization. Then the effluent from stage 1 was fed individually into four soil columns (stage 2) at 0.02 m3 m−2 d−1 of HLR with different proportions of raw wastewater as additional carbon source. Over the one-year field test, balanced nitrification and denitrification in the two-stage SIT revealed excellent TN removal (>90%) from the tested wastewaters.

著者

Lin Lin Lei Zhongfang Wang Li Liu Xiang Zhang Yi Wan Chunli Lee Duu-Jong Tay Joo Hwa

出版者

Elsevier B.V.

雑誌

Separation and purification technology (ISSN:13835866)

巻号頁・発行日

vol.103, pp.15-20, 2013-01

被引用文献数

236 19

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Zeolites, microporous aluminosilicate minerals, have high affinity to ammonium in water. This study explored the mechanisms of ammonium adsorption onto natural zeolite and NaCl-modified counterpart under different ammonium levels (10–4000 mg-N/L) and initial pH 3.4–11.1. Ion exchange dominated the ammonium adsorption process near neutral pH, with the order of exchange selectivity following Na+ > Ca2+ > K+ > Mg2+. At high ammonium levels, Ca2+ exceeded Na+ as the dominant ions for ammonium adsorption. Conversely, in strong alkaline solutions, molecular adsorption suppressed ion exchange in ammonium adsorption. NaCl modification effectively increased ammonium adsorption capacity by increasing the Na contents in zeolite and by modifying the surface morphology to enhance film mass transfer rate. The modified zeolite presents a potential adsorbent to reduce ammonium concentration in landfill leachates, livestock wastewaters or effluents from anaerobic digestion tanks of livestock manure.