高温污泥厌氧消化器的启动

Start-Up of a Thermophilic Anaerobic Sludge Digester

污泥厌氧消化是最常用的污泥减量化和稳定化技术,高温消化污泥稳定快,但我国缺乏启动和运行经验,故进行了高温厌氧消化器处理剩余活性污泥的中试启动试验.所采用的消化器为内循环消化器,它属于升流式反应器,依赖回流沼气控制反应器的水力状况.启动采用了分步适应的策略,促进厌氧细菌适应温度、反应器构型和处理对象的变化.主要措施有:启动初期以容易降解的葡萄糖促进厌氧细菌的稳定和繁殖,有机负荷(以COD计)为2.4 kg/(m3.d);促进内循环形成;控制反应器pH变化;逐渐增加加入的剩余污泥量并及时启动热水解槽促进污泥水解.第63 d启动完成时,有机负荷(以VSS计)为1.60 kg/(m3.d),VSS的平均产气率为0.51 L/g,即每m3污泥(96%含水率)产15.3 m3沼气,VSS和SS去除率分别为60.8%和45.8%,表明启动策略和措施有效.

Anaerobic digestion is one of the most widely-used technologies of the sludge reduction and stabilization,in which thermophilic digestion has advantage of fast stabilization.But it is lack of operation experience in China.Thus start-up of a thermophilic anaerobic sludge digester treating excess activated sludge was investigated.The digester was an internal circulation anaerobic sludge digester.It belongs to upflow reactor and its hydrodynamic conditions can be controlled by backflow biogas.A multistep strategy was applied to the start-up to enhance anaerobic bacteria to adapt the changes of temperature,reactor and treated sludge,including： to feed the digester with easily-degraded glucose to enhance bacteria reproduce at the first beginning with COD organic loading of 2.4 kg/（m^3·d）;to accelerate the internal circulation;to control pH within a optimal range;to gradually increase excess sludge flow rate as well as to initiate pydrohydrolysis to enhance hydrolysis.The start-up took 63 days and when it finished,the VSS organic loading reached 1.60 kg/（m^3·d）,the average VSS biogas rate was 0.51 L/g,i.e.15.3 m^3/m^3 sludge（96% water content）,VSS and SS removals were 60.8% and 45.8%.This shows that the strategy is valid.