自热式高温好氧消化工艺的氧化还原电位研究

采用自热式高温好氧消化(ATAD)中试工艺系统，通过间歇式运行，改变进泥初始ρ(VSS)和曝气强度，考察了系统中氧化还原电位(ORP)的变化情况.对进泥初始ρ(VSS)为45.4和34.2 g/L的曝气强度恒定在1.0 m3/h，搅拌转速为95r/min，停留时间为25 d；初始ρ(VSS)为40.7 g/L污泥的曝气强度在0.4～1.0 m3/h间由大到小进行调节，搅拌转速为95 r/min，停留时间为44 d.结果表明，初始ρ(VSS)与曝气强度对ORP有影响，当曝气强度充足时，ORP呈先下降再回升趋势，最终ORP能达到0 mV以上.对于pH的变化，初始ρ(VSS)为45.4和34.2 g/L的污泥规律相似，均呈先上升后下降趋势，初始ρ(VSS)为34.2 g/L的污泥pH从开始的6.01上升到8.11，然后下降到5.60～6.03.但初始ρ(VSS)为40.7 g/L的污泥pH的变化规律有所不同，pH一直呈上升趋势，从开始的7.33到最终的9.16.表明由于溶胞作用，系统中ρ(总氮)，ρ(氨氮)，ρ(总磷)较高，pH上升，若曝气强度充足，pH随后下降，ORP回升；若曝气强度较低，pH则一直呈上升趋势，ORP则处于较低值.因此ORP与进泥初始ρ(VSS)，曝气强度，反应温度，ρ(氨氮)和pH等因素有关.从ORP的测试结果看，ATAD系统处于厌氧到微好氧之间的状态. 

Study of Oxidation-Reduction Potential ORP on Autothermal Thermophilic Aerobic Digestion Process

Using an autothermal thermophilic aerobic digestion pilot-scale process,oxidation-reduction potential(ORP) was investigated by way of varying VSS concentration of feed sludge and aeration intensity with intermittent operation.VSS of feed sludge at mass concentrations of 45.4 and 34.2 g/L were operated with aeration intensity of 1.0 m3/h,mixing velocity of 95 r/min,and retention time of 25 days,while VSS at mass concentration of 40.7 g/L were operated with aeration intensity from 1.0 to 0.4 m3/h,mixing veloc...