کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9451553 | 1307828 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Microbial activity in a combined UASB-activated sludge reactor system
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم محیط زیست
شیمی زیست محیطی
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چکیده انگلیسی
A combined upflow anaerobic sludge bed-activated sludge (UASB-AS) reactor system with consistently wasting of excess biomass was used to treat suspended-solids pre-settled piggery wastewater (COD = 2000 mg lâ1, total Kjeldahl nitrogen TKN = 400 mg lâ1, suspended solids = 250-400 mg lâ1). Thus, the activity of nitrogen-related microbial groups in each individual bioreactor was investigated. When the granules retention time (GRT) of 20-50 d in the UASB reactor, the solids retention time (SRT) of 10-25 d in the AS reactor and the recycle-to-influent ratio (Re) of 1 were maintained, the combined system removed 95-97% of chemical oxygen demand (COD), 100% of TKN and 54-55% of total nitrogen (TN). Denitrification and methanogenesis occurred in the UASB reactor so that both biochemical processes contributed to most of the COD removal and, complete nitrification (most of the TKN removal) occurred in the AS reactor. Compact granules with good settling abilities developed in the UASB reactor, and rapid rates of granulation of break-up granules in the UASB reactor were confirmed by experiments. The activity of nitrifiers and denitrifiers (an = 0.68-0.87; adn = 0.55-0.70) and the calculated specific nitrification and denitrification rates (qn = 0.26-0.47 mg NH4+-N mg VSSâ1 dâ1; qdn = 0.046-0.076 mg NOx--N mg VSSâ1 dâ1) significantly increased with decreasing SRT and GRT, respectively. Accordingly, the combined UASB-AS reactor system should be regarded a promising alternative for the removal of organic carbon and nitrogen from piggery wastewater.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 61, Issue 7, November 2005, Pages 1032-1041
Journal: Chemosphere - Volume 61, Issue 7, November 2005, Pages 1032-1041
نویسندگان
J.S. Huang, C.S. Wu, C.M. Chen,