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

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.