进料负荷调控培养好氧颗粒污泥的试验研究

Investigation of Aerobic Granular Sludge Cultivation by Feed Loading as a Control Strategy

采用厌好氧交替的SBR反应器,以进料负荷(即进水浓度)作为主要控制参数,研究了好氧颗粒污泥的关键培养技术.结果表明,在30 min的较长污泥沉降时间下,通过进料COD 0-900 mg.L-1的负荷调控,可以有效控制反应器内污泥生长.初始接种污泥的沉降性能对颗粒污泥产生很重要,SVI值保持在20-50 mg.L-1才能有助于颗粒污泥形成和培养.应用“空曝”这种强力负荷调控方式可大大改善污泥沉降性能,并促进颗粒污泥的形成.通过进料减负荷运行可很好实现污泥的“完全颗粒化”培养.颗粒化转变出现在进料浓度COD 400-500 mg.L-1,污泥浓度约8-10 g.L-1.“完全颗粒化”污泥的性能优异,粒径约1.0mm,SVI值25-35 mg.L-1,最大沉降速率60 m.h-1.污泥颗粒过程的发生可能决定于SBR的独特间歇式运行,即基质浓度的贫富交替,减负荷运行可强化基质贫富交替并增大颗粒化过程的驱动力.

The key cultivation strategy for aerobic granular sludge cultivation was investigated using feed loading control as a main operational parameter in an aerobic/anaerobic SBR system. The results showed that the feed loading by influent COD 0 - 900 mg·L^-1 could effectively control the growth of sludge. The settling characteristic of inoculated sludge was important for aerobic granules formation, and its SVI 20 - 50 mg·L^-1 was favourable to granulation development process. Pure aeration without substrate feeding can greatly improve the settleability of sludge, and stimulate the granulation process. The activated sludge with good settleability could be converted to completely aerobic granular sludge through reducing operational loading in a certain condition. The granulation process occurred in COD feeding 400 - 500 mg·L^-1, and sludge concentration 8 - 10 g·L^-1 . The developed granules were approximately 1.0 mm in diameter, SVI 25 - 35 mg·L^-1 , settling velocity 60 m＂ h ^-1 . The authors proposed that granulation formation process was attributed to a unique operational mode in SBR system, i.e. the famine- feast alternation of substrate in reactor. The control strategy of organic loading by reducing substrate could enhance the variation of famine-feast in substrate, and made the driving force for granulation development.