Potassium Persulfate- Azo Compound Initiated Synthesis, Characterization And Application Of PACS – PAM Hybrid Polymer Flocculant

Currently, flocculation technology is a widely used water treatment method in water plants. The core technology of coagulation process is the development of flocculants, which determined not only the flocculation effect but also the entire water treatment effect. So it is great significant to search a new and efficient flocculant.A new kind of hybrid polymer flocculant poly sulfate aluminum chloride-polyacrylamide(hybrid PACS-PAM) was synthesized using complex initiation system composed of potassium persulfate(K2S2O8) and azo diisobutyl imidazoline hydrochloride(VA-044). The influnces of the preparation factors such as initiator ratio, total dosage of initiator, monomer concentration, total aluminum(AlT) concentration, reaction temperature and reaction time were evaluated in term of the intrinsic viscosity. The optimum synthetization conditions were determined through the experimental. And the intrinsic viscosity of hybrid PASC–PAM was 14.70 d L/g under the optimum synthetization conditions. The characterization of hybrid PASC–PAM using FTIR, conductivity test and DTA-TGA indicated that there was ionic bond forming between the organic component and inorganic component through the bridging role of sulfate-ion(-SO42-) existed in the chain end of PAM. The characterization of SEM showed that the hybrid PACS-PAM had different morphological structure with the composite flocculant PASC-PAM.The flocculability of the hybrid PACS-PAM was studied and the experimental results showed:The study about the turbidity removal of yellow mud suspension indicated that when using hybrid PACS-PAM as coagulant the optimum total aluminum(AlT) concentration, the most suitable p H range of raw water and the optimum temperature range of raw water were 0.20 mol/L, 6~10 and 15℃~45℃, respectively. Coagulation experiment for the high turbidity yellow mud suspension(1000NTU) showed the hybrid PACS-PAM had lower optimum addition than the composite flocculant PASC-PAM and under the optimum addition the hybrid PASC–PAM had better flocculation performance than the composite flocculant PASC-PAM. And the coagulation-aid experiment for the low turbidity yellow mud suspension(20NTU) indicated that the hybrid PACS-PAM had lower optimum coagulation-aid addition than the composite flocculant PASC-PAM and under the optimum coagulation-aid addition the hybrid PASC–PAM had better flocculation performance than the composite flocculant PASC-PAM.The study about the sludge dewatering indicated that when using hybrid PACS-PAM as sludge dehydrating agents the optimum total aluminum(AlT) concentration and the most suitable p H range of raw sludge were 0.15mol/L and 6~8, respectively. The experimental results also showed that hybrid PACS-PAM and CPAM both had superior sludge dewatering performance and CPAM had a little better sludge dewatering performance than hybrid PACS-PAM. But from an economic point of view, hybrid PACS-PAM had an advantage over CPAM.