Study On Sludge Treatment Efficiency Strengthened By Alkaline Hydrolysis And Chemical Oxidation

As the most widely applied biological treatment Process in the wastewater treatment field, the conventional activated sludge Process has its drawback of high sludge Production.The are many hamful components in sludge, which could pollute the environment without proper treatment. Thus, for the treatment and disposal of sludge,there are many sorts of study and achievement on it. Among them, sludge anaerobic fermentation is one of the most usual and economical biological treatment. However,the disadvantages of the treatment technique are that the waste activated sludge is dificult to degrade, resulting in the slow degradation and long residence time and high costs. It reported that the restrieted step of anaerobic digestion is hydrolyztion, so pretreatment before digestion are taken to promote it by disintegrating the sludge flcos and distrupting bacterial cells’ wall. The aim of this experiment is to study and compare the upgrading of anaerobic digestion of complex formulation of hydrogen peroxide oxidation, hydrogen peroxide oxidation,complex formulation of hydrogen peroxide oxidation in alkaline environment and hydrogen peroxide oxidation in alkaline environment pretreatment. In addition, seeking economic and suitable dehydration method to improved the dewaterability of digestion sludge.The research results indicated that the disintegration performances of different pretreatments followed the order: complex formulation of hydrogen peroxide oxidation in alkaline environment > oxid ant B in alkaline environment >alkaline pretreatment>complex formulation of hydrogen peroxide oxidation > hydrogen peroxide oxidation, determining that the best dosage of complex formulation of hydrogen peroxide oxidation is 20 g / kg SS and the optimum dosage of oxid ant B is200 g / kg SS. To acheive the same crack effect, you need the dosage of oxid ant B is nearly 10 times than the complex formulation of hydrogen peroxide oxidation.Under alkaline environment the optimum conditions that pretreatment sludge is: the p H of sludge is adjusted to 11, and Pretrea--ted by 20 g / kg SS complex formulation of hydrogen peroxide oxidation. Compared with the raw sludge, SCOD dissolving rate increased from 1.0% to 21.75%, SS removal reach 24.2%, VSS removal rate reach36.3%.The supernatant of pretreatment suldge was discarded, followed by anaerobic digestion for 15 d, caused that the removal of organic matter in the sludge improved.Under an alkaline environment,complex formulation of hydrogen peroxide oxidation pretreatment sludge imroved most,and organics removal rate reached 40.1%. Compared with raw sludge, pretreated sludge after anaerobic digestion increased total acid production and total gas production. The acid production is highest when pretreat sludge by complex formulation of hydrogen peroxide oxidation under alkaline,and with the initial raising the p H increasing. : It reaches the highest total gas production at the initial p H of 11 as 200 g / kg SS hydrogen peroxide oxidation under alkaline environmentpratreated sludge, besides incresing gas production rate by 64%; It reaches the highest total gas production at the initial p H of 11 as 20 g / kg SS complex formulation of hydrogen peroxide oxidation under alkaline environment pratreated sludge, besides incresing gas production rate by 73%.Respectively Using CPAM,PAC deal with sludge pretreated and digested.Compared with raw sludge, the pretreated sludge dewatering performance deterioration,but its degree of dehydration was improved. The dose of agent pretreatment sludge demands more than raw sludge When taking same agent. For anaerobic digestion sludge that pretreated by 20 g / kg SS complex formulation of hydrogen peroxide oxidation in initial p H of 11, the optimal dosage of PAC is 3g / L,the optimal dosage of CPAM is120 mg / L, as DS value reachs 20.14%. For anaerobic digestion sludge that pretreated by 200 g / kg SS hydrogen peroxide oxidation at p H =11, the best dosage of PAC is2.4g/L, the best dosage of CPAM is 150mg/L,and DS is 19.34%. By comparison, the optimal condition is 20 g / kg SS complex formulation of hydrogen peroxide oxidation in initial p H of 11.