不同温度下高温好氧消化工艺的溶氧特性  

Characteristics of Dissolved Oxygen During Thermophilic Aerobic Digestion Process at Different Digestion Temperatures

作　　者：程洁红[1] 戴雅 孔峰[1] 

机构地区：[1]江苏理工学院化学与环境工程学院,江苏常州213001

出　　处：《环境科学研究》2014年第12期1519-1524,共6页Research of Environmental Sciences

基　　金：第三批高校优秀中青年教师和校长赴境外研修项目;江苏省省级环境保护科研项目(2013029);江苏省太湖水污染治理专项资金(第七期)项目(TH2013303)

摘　　要：为探索ATAD(自热式高温好氧消化)污泥系统中ρ(DO)及其对污泥稳定化的影响,分别考察了在不同消化温度下不同成分污泥(初沉泥、二沉泥和混合泥)的Eh(氧化还原电位)、污泥溶胞效果和污泥稳定化效果.结果表明:在消化的24 d中,尽管曝气充足,但消化前期Eh仍处于0 m V以下,并且随着消化时间的延长,Eh逐渐升至0 m V以上,说明ATAD工艺系统并不是全程好氧状态,消化前期处于兼氧或厌氧状态,后期才呈好氧状态.65℃下容易使细胞破裂发生分解,污泥上清液中ρ(SCOD)(SCOD为可溶性化学需氧量)和ρ(TP)维持较高值,至消化结束时,ρ(SCOD)仍高达13 708 mg/L,ρ(TP)为126.4 mg/L,ρ(PO43+-P)为106 mg/L.尽管消化前期Eh较低,但在15 d时VSS去除率仍超过38%,满足US EPA(美国国家环境保护局)A级污泥VSS去除率的标准.消化初期的兼氧和厌氧状态没有减缓污泥达到稳定化,因此在合适范围内减少曝气量有利于ATAD工艺的工程化应用.In order to understand the influence of dissolved oxygen on sludge stabilization in auto-heated thermophilic aerobic digestion systems, the oxidation reduction potential （Es ）, efficiency of cell lysis and sludge stabilization were studied at different digestion temperatures （45, 55 and 65 ℃ ） with different sludge types （ from a primary sedimentation tank, a secondary sedimentation tank and mixed sludge）. The results showed that Eh remained below 0 mV at the initial stage of digestion, despite sufficient aeration supply. With digestion time prolonged, the ATAD system was not always running in the aerobic regime during the entire digestion process. Instead, it was operating in either anoxic or anaerobic condition at the initial stage, followed by aerobic digestion at the later stage. Compared with the other two digestion temperatures （45 and 55 ℃ ） , cells in sludge digested at 65 ℃ were easily broken and lysed, which resulted in high concentrations of soluble COD （SCOD） and phosphorus in the sludge supernatant. The concentrations of SCOD at 65 ℃ were still high-up to 13,708 with TP of 126.4 and orthophosphate of 106 mg/L at the end of digestion, which showed that cell lysis can take place easily at the thermophilic temperature and oxygen-deprived condition. Although Eh values were generally low at the initial digestion stage, the VSS removal rates still remained greater than 38% in the first 15 days of digestion, which meets the Standard of Class A in Item 503 enacted by US EPA. This suggests that the stabilization efficiency for sludge treated by the ATAD process was not affected during the initial stage of anoxic and anaerobic digestion. Therefore, the aeration level can actually be reduced to a proper range to promote engineering applications of the ATAD process.

关 键 词：自热式高温好氧消化 城市污泥 氧化还原电位 

分 类 号：X703[环境科学与工程—环境工程]