Ho Jaeho, Sung Shihwu
South Carolina Department of Health and Environmental Control, Columbia, South Carolina, USA.
Water Environ Res. 2009 Sep-Oct;81(9):922-8. doi: 10.2175/106143009x407339.
The performance of a crossflow anaerobic membrane bioreactor (AnMBR) to treat synthetic municipal wastewater was investigated at different hydraulic retention times (HRTs). The AnMBR was operated at chemical oxygen demand (COD) loading rates of 1 to 2 kg COD/m3 x d for 280 days. The permeate COD concentration was always lower than 40 mg/L, and no noticeable volatile fatty acids were detected, regardless of HRT variations, while soluble COD (SCOD) was accumulated in the reactor with decreases in HRT. The particle size reduction was relatively lower than other studies reported, even after a long operation time resulting from the low operation crossflow velocity. Approximately 30% of COD was not available for methane recovery, irrespective of applied HRTs, as a result of the COD loss by dissolved methane, sulfate reduction, and untreated COD in the permeate. The fraction of methane recovered from the synthetic municipal wastewater decreased from 48 to 35%, with the decrease of HRT from 12 to 6 hours, as a result of the increase of mixed-liquor SCOD, which was rejected and accumulated in the AnMBR. Therefore, AnMBR operation with relatively long HRTs and SRTs may be favorable, to enhance methane recovery and reduce or eliminate sludge production.
研究了错流厌氧膜生物反应器（AnMBR）在不同水力停留时间（HRT）下处理模拟城市污水的性能。AnMBR在化学需氧量（COD）负荷率为1至2 kg COD/m³·d的条件下运行280天。无论HRT如何变化，渗透液的COD浓度始终低于40 mg/L，且未检测到明显的挥发性脂肪酸，而随着HRT的降低，可溶性COD（SCOD）在反应器中积累。由于操作错流速度较低，即使经过长时间运行，颗粒尺寸的减小也相对低于其他研究报道的水平。由于溶解甲烷导致的COD损失、硫酸盐还原以及渗透液中未处理的COD，无论应用何种HRT，约30%的COD无法用于甲烷回收。随着HRT从12小时降至6小时，从模拟城市污水中回收的甲烷比例从48%降至35%，这是由于混合液SCOD增加，其被截留并在AnMBR中积累。因此，采用相对较长的HRT和污泥停留时间（SRT）进行AnMBR操作可能有利于提高甲烷回收率并减少或消除污泥产生。
