Study On Sludge Dewatering Reagents And Process

China’s economy has been in a state of rapid development. The future we will set a huge investment in sewage treatment. With the construction of a large number of sewage treatment plant, sludge in China increased year by year, sludge problem has gradually become a prominent environmental problem. At present, the disposal of sludge has not been paid sufficient attention to. The sedimentation tank sludge of general sewage treatment plant through Simple concentration treatment. The water content of the sludge up to 95%-99%. No matter which way the follow-up by the sludge dewatering is the first problem to solve in the disposal of sludge. And now Sludge dewatering section of sewage treatment plant still have many problems, such as excessive dosage of medicament, sludge with high moisture content, high energy consumption, the filtrate is difficult to deal with and so on. So it is necessary to launch the research on dewatering performance of sludge and the agent and process of the sludge dewatering, looking for the suitable sludge dewatering agent solution、the best dosage and process. In this paper, the main research contents and the main results are as follows:1.Taking the sludge of Fo Shan Zheng An sewage as research object, sludge settling performance, specific resistance to filtration(specific resistance to filtration, for short SRF); capillary suction time(capillary suction time, for short CST); water content of mud cake and dehydration rate as index to investigated the difference influence between adding single flocculant and organic-inorganic compound flocculant, to discussed the influence of coagulant-aid, such as quicklime and fly ash. The consequence shows(1) Under single flocculant condition, the cationic polyacrylamide(PAM)’ dewatering effect is the best, the best additive quantity is 30 ~ 60 mg/L. Under organic-inorganic compound flocculant condition, sludge dewatering performance shows obvious improved compared with single flocculant condition.(2) Under flocculant plus coagulant-aid condition, sludge dewatering performance shows obvious improved and less flocculant additive amount compared with organic-inorganic compound flocculant condition. Within the scope of experiment, the best sludge conditioner group is 9mg/L cationic polyacrylamide(PAM), 30g/L quicklime, 30g/L fly ash.2. Taking the dyeing sludge of Foshan Jin Fang group as the research object, study on effects of combined with the flocculant and coagulant aid.On the performance of the dyeing sludge dewatering. The results show that the 90mg/L cationic PAM, 25g/L fly ash is the best sludge conditioning agent formula.3. Carried out Foshan Zhenan sewage treatment plant sludge deep dehydration test, the process is, concentrated sludge though the chemical conditioning, and then used the box filter press to dehydrate. Experiments show that, using organic flocculant-inorganic flocculant- lime co-conditioning can reach the best effect. The lowest moisture content of mud cake is 33%, the unconfined compressive strength up to 62.5k Pa, the shear strength up to 46.5 k N/m2. The dewatered sludge can meet the mixed landfill and landfill cover soil material geotechnical requirements.