Study On Enhancement Of Sludge Dewaterability Based With Aerobic Digestion And Hydrogen Peroxide Oxidation

With the popularity of biological wastewater treatment technology, The needs for treatment and disposal of sludge volume also increased dramatically. If untreated sludge mechanical dewatering directly, the dewatering level was still as high as about 80%, This is far lower than the solid waste landfill standards in our country, which should be lower than 60%. so how to enhance sludge dewaterability and achieve more efficient dehydration is a very practical significance of the research subject.Based with the combined process of sludge aerobic digestion technology and hydrogen peroxide oxidation lysis technique, this study investigated the effect on sludge dewaterability by the two kinds of combination process. By the comparison of factor test and the orthogonal test, when it was sludge aerobic digestion for 48 h, the dewatering level and velocity could be to a minimum by hydrogen peroxide oxidation; The priority order for two kinds of combination process was sludge aerobic digestion first to improved the floc structure of loose, and then goes to the oxidation of hydrogen peroxide under acidic conditions. it was found that temperature and concentration of aerobic digestion for sludge had a greater influence on dewaterability, and the impact of conditioning time and the sludge aerobic dissolved oxygen concentration and initial p H was much smaller when using the two kinds of combination process to condition sludge. The optimal condition parameters for sludge conditioning were determined as follows: conditioning temperature range were nearly 30?, initial p H and concentration of sludge were 3 and 12000mg/L respectively, Aerobic digestion of dissolved oxygen concentration was 2.5mg/L, conditioning time was 60 minutes, hydrogen peroxide dosing was 75?l/g. Under the optimal conditions, dewatering level and velocity increased by 10.66% and 62.58% respectively compared to the control sample.It was found that micro-bubbles by hydrogen peroxide oxidation can have an effect of air flotation concentrate on sludge, which also can cause further spate separation effect. Its dewatering level when dewatering the extraction upper concentrated sludge increased by 4.15% respectively compared to the even mixing of Aerobic sludge digestion, and also increased by 10.90% respectively compared to the control sample, dehydrating effect have been further enhanced, and it also get rid of the compressed air of mechanical and power cost compared to the general flotation concentration method.To further analyze the mechanism of a combination of two processes enhancing the sludge dewaterability, this study investigated the effect of polysaccharides, proteins, SCOD and the composition of the EPS on sludge dewateability, which were from the combination of the two processes sludge dewatering supernatant. After sludge was conditioned by hydrogen peroxide, the contents of LB-EPS and the ratio of LB-EPS/TB-EPS significantly reduced compared to the control sample, which showed that reducing the contents of LB-EPS and the ratio of LB-EPS/TB-EPS was beneficial to enhance sludge dewaterability.