Scully Colm, Collins Gavin, O'Flaherty Vincent
Microbial Ecology Laboratory, Department of Microbiology and Environmental Change Institute, National University of Ireland, Galway, University Road, Galway, Ireland.
Water Res. 2006 Dec;40(20):3737-44. doi: 10.1016/j.watres.2006.08.023. Epub 2006 Oct 24.
The aims of this study were to demonstrate the (1) feasibility of psychrophilic, or low-temperature, anaerobic digestion (PAD) of phenolic wastewaters at 10-15 degrees C; (2) economic attractiveness of PAD for the treatment of phenol as measured by daily biogas yields and (3) impact on bioreactor performance of phenol loading rates (PLRs) in excess of those previously documented (1.2 kg phenol m(-3)d(-1)). Two expanded granular sludge bed (EGSB)-based bioreactors, R1 and R2, were employed to mineralise a volatile fatty acid-based wastewater. R2 influent wastewater was supplemented with phenol at an initial concentration of 500 mgl(-1) (PLR, 1 kgm(-3)d(-1)). Reactor performance was measured by chemical oxygen demand (COD) removal efficiency, CH(4) composition of biogas and phenol removal (R2 only). Specific methanogenic activity, biodegradability and toxicity assays were employed to monitor the physiological capacity of reactor biomass samples. The applied PLR was increased to 2 kgm(-3)d(-1) on day 147 and phenol removal by day 415 was 99% efficient, with 4 mgl(-1) present in R2 effluent. The operational temperature of R1 (control) and R2 was reduced by stepwise decrements from 15 degrees C through to a final operating temperature of 9.5 degrees C. COD removal efficiencies of c. 90% were recorded in both bioreactors at the conclusion of the trial (day 673), when the phenol concentration in R2 effluent was below 30 mgl(-1). Daily biogas yields were determined during the final (9.5 degrees C) operating period, when typical daily R2 CH4 yields of c. 3.3lCH4g(-1) COD(removed) d(-1) were recorded. The rate of phenol depletion and methanation by R2 biomass by day 673 were 68 mg phenol gVSS(-1)d(-1) and 12-20 ml CH(4) gVSS(-1)d(-1), respectively.
（1）在10-15摄氏度下对含酚废水进行嗜冷或低温厌氧消化（PAD）的可行性；（2）通过每日沼气产量衡量PAD处理苯酚的经济吸引力；以及（3）超过先前记录值（1.2 kg苯酚m⁻³d⁻¹）的苯酚负荷率（PLR）对生物反应器性能的影响。使用两个基于膨胀颗粒污泥床（EGSB）的生物反应器R1和R2对基于挥发性脂肪酸的废水进行矿化处理。R2进水废水补充了初始浓度为500 mg l⁻¹的苯酚（PLR为1 kg m⁻³d⁻¹）。通过化学需氧量（COD）去除效率、沼气中的CH₄组成和苯酚去除率（仅针对R2）来衡量反应器性能。采用特定产甲烷活性、生物降解性和毒性测定来监测反应器生物质样品的生理能力。在第147天将应用的PLR提高到2 kg m⁻³d⁻¹，到第415天时苯酚去除率达到99%，R2流出物中苯酚含量为4 mg l⁻¹。R1（对照）和R2的运行温度从15摄氏度逐步降低至最终运行温度9.5摄氏度。在试验结束时（第673天），两个生物反应器的COD去除效率均约为90%，此时R2流出物中的苯酚浓度低于30 mg l⁻¹。在最终（9.5摄氏度）运行期间测定每日沼气产量，此时记录到R2典型的每日CH₄产量约为3.3 l CH₄g⁻¹COD（去除）d⁻¹。到第673天时，R2生物质对苯酚的消耗速率和甲烷化速率分别为68 mg苯酚gVSS⁻¹d⁻¹和12 - 20 ml CH₄gVSS⁻¹d⁻¹。
