Abstract:Sludge reduction can be achieved through the predation by oligochaeta worm-Limnodrilus sp.. To analyze the effect of aeration intensity on the process of sludge predation, changes in worm activity, sludge properties and sludge reduction efficiency under different intensities of aeration were investigated. The results showed that these worms had limited tolerance to aeration intensity. The number of injured worms increased with the increasing aeration intensity and retention time in sludge, and fewer injured individuals (1.7% of the total)was found under the mild intermittent aeration. The lactate dehydrogenate activity of worms was higher under the aeration intensity of 2.8~9.5m3/(m2·h), which may imply the higher level of material metabolism and energetic consumption of the worms at those aeration conditions. Less nitrate accumulation was found in the supernatant of sludge during the predation under the lower aeration intensity, and the increase in sludge volume index (SVI) caused by lack of dissolved oxygen was restrained by the worms, showing their performance for improving sludge settling. The sludge reduction of worms for the intermittent aeration of 2.8m3/(m2·h) was more stable than those for continuous aerations.
张晓琦, 田禹, 王强. 曝气强度对蠕虫捕食污泥过程的影响[J]. 中国环境科学, 2014, 34(2): 345-351.
ZHANG Xiao-Qi, TIAN Yu, WANG Qiang. Effect of aeration intensity on the process of sludge predation by worms. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(2): 345-351.