Study Of Guangzhou Development District Water Treatment Plant Sludge Drying Experiments

With the flourishing construction of urban water treatment plant, the output of sludgebecomes increasingly fruitful. Because sludge contains pathogens, heavy metals and otherpollutants, there is growing concern about proper treatment, disposal and effective use of thesludge.The thesis is based on the sewage treatment system in Guangzhou Development District.According to the properties of sludge in Guangzhou Development District, it analyzesappropriate technique method for the treatment and disposal of sludge. Sludge dryingexperiments are carried out simultaneously to explore the suitable methods of pre-treatingsludge.Main contents and conclusions of the study are listed as follows:1. According to the monitoring reports of sludge from the6water treatment plants, thenature of the sludge is analyzed. The results show that due to the water shuffling fromindustrial wastewater and domestic sewage, organic matter takes up a small share in thesludge, while parasitic ovum and pathogenic microorganisms excessively grow. The sameproblem also comes to the sludge from some of the water treatment plants in the samedistrict, the content of Cu, Zn and Ni are found to exceed the standard.2. According to the location, the scope and the sludge nature of the water treatment plant, thethesis analyzes the technique method for the treatment and disposal of sludge. In view ofthe low proportion of organic matter and the exceeded content of heavy metal, buildingmaterials recycling and incineration is more appropriate than the anaerobic digestiontreatment and the aerobic composts for the long-term disposal of sludge. In accordancewith Guangzhou City Solid Waste Pollution Prevention Plan, it is recommended toconsider incineration as the final disposal of the sludge from the water treatment plant inGuangzhou Development District.3. To facilitate the transportation, subsequent treatment and disposal of sludge, the sludgedrying experiments are carried out to research the approach to reduce the moisture contentof sludge to about40%, and ensure sludge guarantee stability and security. Sludge dryingexperiments are carried out by Bio-drying method as well as Chemical conditioning and heating drying method. The results show that the both methods can reduce the moisturecontent of sludge to achieve the requirement for an initial reduction, and improve thesmell and color of the sludge. By analyzing the technology, the demand in economy andland for the two methods, it is suggested that bio-drying method is suitable for centralizedtreatment and chemical conditioning and heating drying method for decentralizedtreatment.