Germain E, Nelles F, Drews A, Pearce P, Kraume M, Reid E, Judd S J, Stephenson T
School of Applied Sciences, Cranfield University, Cranfield BEDS, MK43 0AL, UK.
Water Res. 2007 Mar;41(5):1038-44. doi: 10.1016/j.watres.2006.10.020. Epub 2007 Jan 10.
Ten biomass samples from both municipal and industrial pilot and full scale submerged membrane bioreactors (MBRs) with mixed liquor suspended solids concentrations (MLSS) ranging from 7.2 to 30.2g L(-1) were studied at six air-flow rates (0.7, 1.3, 2.3, 3, 4.4 and 6m(3)m(-3)h(-1)). Statistical analyses were applied to identify the relative impacts of the various bulk biomass characteristics on oxygen transfer. Of the biomass characteristics studied, only solids concentration (correlated with viscosity), the carbohydrate fraction of the EPS (EPS(c)) and the chemical oxygen demand (COD) concentration of the SMP (SMP(COD)) were found to affect the oxygen transfer parameters k(L)a(20) (the oxygen transfer coefficient) and alpha-factor. The relative influence on k(L)a(20) was MLSS>aeration>EPS(c)>SMP(COD) and on alpha-factor was MLSS>SMP(COD)>EPS(c)>aeration. Both k(L)a(20) and alpha-factor increased with increasing aeration and EPS(c) and decreased with increasing MLSS and SMP(COD). MLSS was found to be the main parameter controlling the oxygen transfer.
研究了来自市政和工业中试及全尺寸浸没式膜生物反应器(MBR)的10个生物质样品,混合液悬浮固体浓度(MLSS)范围为7.2至30.2 g L⁻¹,考察了六种空气流速(0.7、1.3、2.3、3、4.4和6 m³ m⁻³ h⁻¹)。应用统计分析来确定各种整体生物质特性对氧传递的相对影响。在所研究的生物质特性中,仅发现固体浓度(与粘度相关)、胞外聚合物(EPS)的碳水化合物部分(EPS(c))和溶解性微生物产物(SMP)的化学需氧量(COD)浓度(SMP(COD))会影响氧传递参数k(L)a(20)(氧传递系数)和α因子。对k(L)a(20)的相对影响为MLSS>曝气>EPS(c)>SMP(COD),对α因子的影响为MLSS>SMP(COD)>EPS(c)>曝气。k(L)a(20)和α因子均随曝气和EPS(c)的增加而增加,随MLSS和SMP(COD)的增加而降低。发现MLSS是控制氧传递的主要参数。