超高效螺旋式厌氧生物反应器流态研究

Flow patterns of a super-high-rate spiral anaerobic bioreactor

在冷态模拟条件下,采用脉冲刺激响应技术,运用轴向扩散模型和多釜全混流反应器串联模型研究了超高效螺旋式厌氧反应器的流态.结果表明:低负荷下超高效螺旋式厌氧反应器的流态趋于平推流(分散数D/uL<0.2,串联级数N→∞);超高负荷下流态趋于全混流(D/uL≥0.2,N→1).反应器内总死区平均值为27.99%,其中,生物死区平均值为6.98%,水力死区平均值为21.01%.水力死区(Vh)与容积水力负荷(L)和容积产气速率(G)之间满足关系式:Vh=0.7603L+0.1627G-4.0620,容积产气速率对水力死区的影响大于容积水力负荷.超高效螺旋式厌氧反应器流态的适宜范围相当于等容多釜串联级数N≤3.01.最后提出了兼顾反应器传质效果和容积效能的控制措施.

The super-high-rate spiral anaerobic bioreactor has shown great potential for treating high concentration wastewater. To make clear the reactor flow pattern,tracer tests were performed using a pulse stimulus-response technique under the conditions of cold-model tests. Based on the experimental data,the flow patterns were analyzed by the axial dispersion model and the tank-in-series model. The results showed that flow patterns approached a plug flow reactor （PFR） （dispersion number D/uL0.2,series number N→∞） under low loading rate and a continuous flow stirred tank reactor （CSTR） （D/uL≥0.2,N→1） under super high loading rate. The mean dead space in the reactor was 27.99%,divided into mean dead space caused by biomass （6.98%） and hydraulics （21.01%）. The relationship among the hydraulic dead space （Vh）,the volumetric hydraulic loading rate （L） and the volumetric biogas production rate （G） was found to be：Vh = 0.7603L＋0.1627G-4.0620,and the hydraulic dead space was influenced by the volumetric biogas production rate more than the volumetric hydraulic rate. The suitable flow pattern of the super-high-rate spiral anaerobic bioreactor was equivalent to the number of same volume tanks-in-series N ≤ 3.01,and some control measures are suggested to optimize the mass transfer and volumetric efficiency of the reactor.