Abstract：With addition of lime, rapid sludge dewatering and sludge stabilization could be achieved. However, high cost and high pH are occurred due to the increase of lime usages (> 5%), and the utilization possibility of the final product is greatly limited due to the high pH values. The effect of co-composting by addition of low ratio lime mixture (￡5%) during the sludge composting process was studied. Four laboratory scale composting trials were set up, in which the lime mass fraction of 1%, 5% and 5% were mixed with sludge as compost raw materials respectively, and in the trial 3some matured compost materials were also added, and the trial CK without lime was used as control. Oxygen-temperature control system was applied to control ventilation with real-time feedback. The results showed that pH values of sludge mixtures significantly decreased from 9.06, 12.17 and 12.34to weak alkaline level (<8.3) and volatile solid of sludge decreased from 57.35%、45.97%、44.59% to 44.20%、39.28%、38.42% respectively after composting processes. The over 50% of weight reduction in three trials could be achieved, while there was no significant difference for reduction rate except trail 2. In addition, heavy metal concentrations in the leachates were strongly influenced by pH. Moreover, Cu, Ni, Zn concentrations in the leachates with 5% lime addition were lowest. For practical application, lime mass fraction of 5% mixing with a certain amount of matured compost materials for sludge composting is recommended in order to improve composting efficiency and product quality.
冯瑞, 银奕, 李子富, 张健, 刘璇, 周晓琴. 添加低比例石灰调质的脱水污泥堆肥试验研究[J]. 中国环境科学, 2015, 35(5): 1442-1448.
FENG Rui, YIN Yi, LI Zi-Fu, ZHANG Jian, LIU Xuan, ZHOU Xiao-Qin. Experimental study on composting of dewatered sewage sludge by addition of low ratio lime mixture. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(5): 1442-1448.
