剩余污泥与营养土联合堆肥的条件优化研究

Study on conditions optimization of residual sludge and nutrient soil co-composting

为研究污水厂剩余污泥和生活垃圾RD湿解筛下物（营养土）联合堆肥的可行性，以钾细菌为接种菌，进行了中温堆肥实验，对钾细菌接种模式、物料初始含水率、初始pH等参数进行了优化。结果表明：（1）钾细菌具有分解不溶矿物钾的能力，培养时间以32h为宜，此时产芽孢较多，菌剂存活率高；（2）无论从提高速效养分含量，还是钾细菌增殖数量来说，发酵前期接种（M1）效果要优于发酵中期接种（M2）；（3）M，模式下，确定了物料最佳初始含水率为50％～60％，最佳初始pH为6．5，此时M1肥效、钾细菌有效提高；（4）接种钾细菌能提高系统微生物数量和活性，但也会造成堆肥体内Cu、Zn、Ni部分重金属活性提高，应进一步开展金属钝化相关研究。

In order to find the feasibility of the co-composting of residual sludge from municipal wastewater treatment plant and siftage （nutrient soil） from garbage RD thermal decomposition, the mid-temperature compost experiment with K-releasing bacteria as bioaugmentation strain was conducted. And the parameters of inoculation mode, initial water ratio and initial pH were optimized. The results show that： （1） K-releasing bacteria have the ability to decompose insoluble mineral potassium, and the appropriate cultural time is 32 h. At the moment, the quantity of spore and the survival rate of K-releasing bacteria reach maximum; （2） The pre-inoculation mode （M1） is superior than the mid-inoculation mode （M2） based on either the available nutrient or K-releasing bacteria＇s quantity increasing; （3） Under the M1 conditions, it is determined that the best initial water ratio is 50%-60% and the best initial pH is 6.5 for co-composting substrate. At this time, the available nutrients and K-releasing bacteria quantity in compost are increased; （4） The measure of inoculating K-releasing bacteria can increase the quantity and activity of microorganisms in system, which may lead to the increasing of activity of heavy metals including Cu, Zn, Ni. Thus the further research on metal passivation should be carried out.