Senior Research Sulfate Radical Oxidation Of Crack And The Remaining Sludge Dewatering Performance-Based

With the development of the economy of our country and the increased emphasis on environmental issues, urban sewage treatment plant is gradually increasing, the discharge of sewage increased sharply.The main processing method of ordinary urban sewage activated sludge process and its derivative technology,But the biggest drawback is the process will Can produce a large number of surplus sludge, the amount of sludge generated about 0.3%-0.5% of the quantity of sewage according to statistics.After mechanical dewatering sludge moisture content after the rate is still as high as 80% or more, so the storage, transportation and disposal is difficult, it including organic and inorganic matter, colloid, bacteria and other complex components, and sludge also contains certain pathogens and heavy metals, it is necessary to properly handle and prevent it to cause two pollution.This paper studies the ferrous ion (Fe2+) activated persulfate (S2O82-) to produce sulfate radical (S04- ·) were oxidized to crack the residual sludge, the sludge relative hydrophobicity study (RH), sludge specific resistance (SRF) and soluble COD (SCOD) to characterize the sludge hydrophobicity, dewatering performance and the crack degree. Control mechanism and the key parameters for the Fe2+/S2O82- system of sludge by orthogonal experiments, and provide a new reliable process for the application of sludge reduction technology. In order to improve the dewatering performance of the industry,we try to enhance filtration performance and oxidation cracking performance of sludge by adding fly ash.The experimental results show that:when C (S2O82-),=15mmol/L,C (Fe2+)/C (S2O82-)=0.3, T=35℃ and pH=3 reaction for 8 hours, SRF decreased from 1.65E+11 to 4.6E+10, SCOD increased from 85 mg/L to 550 mg/L, RH increased from 13% to 69%. With the increase of pH, SRF after reaction increased gradually,especially when the pH value is more than 4,there is a sharp rise in resistance. The increase of C(Fe2+)/C(S2O82-) ratio and C (S2O82-) will cause the crack degree of reaction becomes better and then worse, mainly because of an excess of Fe2+ consume the sulfate radical which have already been made and slow down oxidation process. The process of quenching excessive S2O82- will become Quenching agent of SO4- · and inhibite oxidation process.Increasing temperature and increasing the reaction time can be beneficial to the sludge cracking.Microscopic examination found that sludge was oxidized to crack dispersed into granular fragments;FT-IR results showed that the characteristics of the various functional groups present in the surface of the sludge of the absorption peak intensity has weakened after oxidation cracking treatment to some extent; thermogravimetric analysis showed that oxidation treatment of sludge has no obvious physical adsorption of water loss in the area, sulfate the free radical (SO4- ·) under the effect of sludge clump structure because of oxidation was broken loose, lytic release of organic matter, the apparent enhancement of hydrophobicity of sludge, reduce the water binding capacity, which makes the sludge dewatering performance improved significantly and is conducive to sludge reduction.The optimization conditions of adding industrial fly ash to improve the sulfate radical sludge dewatering performance is as follows:when pH=5, dosing quantity of fly ash is 12.5 g/L and C (Fe2+)/C (S2O82-) =0.4,the minimum value of SRF is 6.6E+9, Compared with the minimum value 4.5 E+10 getted in the experiment of sludge in the sulfate, it is improved by 85%, so this paper get the conlusion that the industrial fly ash not only makes the sludge voidage increase and reduce sludge viscosity, but also can be used as filtering framework to improve the performance of sludge water.Another reason is that after the addition of fly ash, a filter frame constructing and releasing metal oxides Fe2O3, CuO, and other active elements by the catalytic activity of The fly ash, can strengthen the sulfate free radicals,significantly reduce the SRF and improve the sludge dewatering performance.