Coagulant Recycling From Water Purification Plant Sludge

This is the systematic study of the efficacy and mechanism of aluminum recycling from the water supply plant sludge by ultrasound synergic with acid. Firstly, we analyzed the main composition of water sludge after dehydration; then we discussed the influence of many factors on the Aluminum coagulant recovery rate, such as the ultrasonic power, acid category, concentration of acid, reaction time and so on. On the other hand, in the process of recycling aluminum, the Ferric coagulant -another important component in water sludge is also be recycled from the water supply plant sludge, and it's also part of this study. At last, the paper made a study on the coagulation efficiency of the recovered coagulant used in dyeing wastewater treatment.The results show that there is a strong synergy founction between acid and ultrasonic in the reaction system. Compared with the traditional acidic way, this method reduced the amount of acid needed in the experiment, saved the reaction time and increased the aluminum coagulant recovery rate. The elimination factors of turbidity, color and CODCr are all high while the recovered coagulant was being used in dyeing wastewater treatment. Compared with FeSO4, the recovered aluminum coagulant showed greater advantages on coagulation efficiency and economic benefits.Based on these findings, recycle aluminum from the water supply plant sludge by ultrasound synergic with acid not only increased the aluminum coagulant recovery rate, reduced the amount of impurities in recovery coagulant, avoided the secondary pollution of excess sludge, but also achieved the efficient use of non-renewable aluminum resource.This study will novelly provide an effective way for the utilization of the water supply plant sludge.