کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4407683 1618818 2016 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of temperature downshifts on a bench-scale hybrid A/O system: Process performance and microbial community dynamics
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
Effect of temperature downshifts on a bench-scale hybrid A/O system: Process performance and microbial community dynamics
چکیده انگلیسی


• The hybrid A/O process exhibited excellent removal efficiencies.
• Higher richness and diversity in the biofilm samples appeared at 10 °C.
• The relative abundance of functional microorganisms differed between the sludge and biofilm samples.
• The biofilm contributed to more nitrification at low temperature.

Effect of temperature downshifts on process performance and bacterial community dynamics was investigated in a bench-scale hybrid A/O system treating real domestic wastewater. Results showed that the average COD removal in this system reached 90.5%, 89.1% and 90.3% for Run 1 (25 °C), Run 2 (15 °C) and Run 3 (10 °C), respectively, and variations in temperature barely affected the effluent COD concentration. The average removal efficiencies of NH4+-N were 98.4%, 97.8%, 95.7%, and that of TN were 77.1%, 61.8%, 72% at 25 °C, 15 °C and 10 °C, respectively. Although the hybrid system was subjected to low temperature, this process effectively removed NH4+-N and TN even at 10 °C with the average effluent concentrations of 2.4 mg/L and 14.3 mg/L, respectively. Results from high-throughput sequencing analysis revealed that when the operation temperature decreased from 25 °C to 10 °C, the richness and diversity indexes of the system decreased in the sludge samples, while underwent an increase in the biofilm samples. Furthermore, the major heterotrophic bacteria consisted of Lewinella, Lutimonas, Chitinophaga and Fluviicola at 10 °C, which could be central to effective COD removal at low temperature. Additionally, Azospira, one denitrifying-related genus increased from 0.4% to 4.45% in the biofilm samples, with a stable TN removal in response to temperature downshifts. Nitrosomonas and Nitrospira increased significantly in the biofilm samples, implying that the attached biofilm contributed to more nitrification at low temperature.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 153, June 2016, Pages 500–507
نویسندگان
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