Rui L, Xia H, Ruopeng L, Yi Q
ESPC State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China.
Huan Jing Ke Xue. 2001 May;22(3):20-4.
A comparison between a submerged membrane bioreactor (MBR) and a conventional activated sludge process (CAS) was carried out under similar operational conditions. MBR demonstrated a more stable and excellent effluent quality than CAS. Its effluent COD concentration was 55.5 mg/L on average, much lower than that of CAS (79.7 mg/L). Soluble microbial products accumulated in the MBR during the first 120 days in operation due to membrane interception of macromolecules, but these accumulated substances were degraded at last with microbial acclimation. No similar phenomenon was observed in the CAS system. Compositions of the CAS effluent, MBR supernatant and membrane permeate were found quite different. In the CAS effluent and MBR supernatant, both macromolecules with MW > 60,000 and small molecules with MW < 3,000 were dominant and macromolecules had a much larger occupation in the MBR supernatant. In the membrane permeate, however, small molecules with MW < 3,000 were the major component. The relatively small floc size in the MBR was proved favorable to improve oxygen transfer rate.
在相似的运行条件下，对浸没式膜生物反应器（MBR）和传统活性污泥法（CAS）进行了比较。MBR的出水水质比CAS更稳定且更优。其出水COD浓度平均为55.5mg/L，远低于CAS的出水COD浓度（79.7mg/L）。在运行的前120天里，由于膜对大分子的截留作用，可溶性微生物产物在MBR中积累，但这些积累物质最终随着微生物的驯化而降解。在CAS系统中未观察到类似现象。发现CAS出水、MBR上清液和膜透过液的成分有很大差异。在CAS出水和MBR上清液中，分子量大于60,000的大分子和分子量小于3,000的小分子均占主导，且大分子在MBR上清液中的占比更大。然而，在膜透过液中，分子量小于3,000的小分子是主要成分。事实证明，MBR中相对较小的絮体尺寸有利于提高氧传递速率。
