Kritsunankul Chanyud, Wantawin Chalermraj
The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok, Thailand.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2008 Jul 15;43(9):1085-92. doi: 10.1080/10934520802060092.
The objective of this study was to investigate the possibility of using a biofilm process for partial nutrient removal from digested swine wastewater containing low ratios of chemical oxygen demand (COD) to nitrogen and phosphorus; on average, 1.6 g COD g(-1) N and 7 g COD g(-1) P. We used a laboratory-scale sequencing batch biofilm reactor with alternating conditions of 4 hours anaerobic/ 12 hours aerobic, and a hydraulic retention time of 16 hours. Although the concentration of dissolved oxygen under aerobic conditions was > 2.5 mg L(-1), the efficiency of denitrification was up to 85% of the theoretical maximum at the available influent COD, with an ammonia removal rate of 0.73 g N m(-2) d(-1) and without the accumulation of nitrite or nitrate. Activity tests showed that the biomass from the reactor consisted of denitrifying polyphosphate accumulating organisms (DNPAO) that can use nitrite as an electron acceptor. The organic carbon in the digested swine wastewater was utilized very effectively through the denitrifying phosphorus uptake process, as implied by the low utilization ratios of COD to nitrogen, 4.2 g COD g(-1) N, and phosphorus, 14 g COD g(-1) P. A COD value as low as 50 mg L(-1) and an increased ratio of nitrogen to phosphorus from 4:1 to 6:1 in the effluent, which is more suitable for use as a liquid fertilizer, were achieved through the processes of nitrification and denitrifying phosphorus uptake in the sequencing batch biofilm reactor.
本研究的目的是调查使用生物膜工艺从化学需氧量（COD）与氮和磷比例较低的消化猪废水中部分去除营养物质的可能性；平均而言，COD与氮的比例为1.6 g COD g⁻¹ N，COD与磷的比例为7 g COD g⁻¹ P。我们使用了一个实验室规模的序批式生物膜反应器，采用4小时厌氧/12小时好氧的交替条件，水力停留时间为16小时。尽管好氧条件下溶解氧浓度>2.5 mg L⁻¹，但在现有进水COD的情况下，反硝化效率高达理论最大值的85%，氨去除率为0.73 g N m⁻² d⁻¹，且没有亚硝酸盐或硝酸盐的积累。活性测试表明，反应器中的生物质由可利用亚硝酸盐作为电子受体的反硝化聚磷菌（DNPAO）组成。消化猪废水中的有机碳通过反硝化吸磷过程得到了非常有效的利用，这从COD与氮的低利用比4.2 g COD g⁻¹ N以及COD与磷的低利用比14 g COD g⁻¹ P中可以看出。通过序批式生物膜反应器中的硝化和反硝化吸磷过程，出水的COD值低至50 mg L⁻¹，氮磷比从4:1提高到6:1，更适合用作液体肥料。
