Research On Hydrolysis Acidification Sludge Reduction Method With Ozonation As Pretreatment

Nowadays,the technologies of wastewater treatment are becoming more and more perfect,but the excess sludge production and treatment remains the common problem.Specific statistics show that half of the consumption of human and energy resources is in sludge disposal problem.In today's world,the four principles about the treatment of the excess sludge is: stabilization,harmless,reduction,recycling.Stabilization means reducing the risk of harm to the environment;harmless means reducing the damage after the sludge discharge;reduction means reducing the biosolids in the sludge;recycling means the treated sludge can be used in different fields.At present stage,the excess sludge treatment methods which are used mostly always accompany with the problems of wasting resources and large energy consumption.Traditional excess sludge treatment processes,such as,burning may cause the secondary damage to the air,the ground and the water because of the organic and in organic pollutants existing in the sludge;landfill has a long period which may cause the secondary pollution;ozone,the sludge reduction effect of ozone reduction methods has been proved.But the huge cost of the production of ozone limited the development of the ozone reduction method;Adding the uncoupler has receive good effect about the sludge reduction,it acts on the decomposition and composition period,but because of the poisonousness of the uncoupler,the dispose to the uncoupler should be concerned.According to the principle as well as the low investment,the less land occupation and the single ending production,hydrolysis acidification can be used as a sludge reduction method.The investigation is to study about the hydrolysis acidification under the different conditions like different ozone dosage and the different sludge inoculation concentration in different ozone dosage.The result shows that at the moment ozone dosage is over 90 mg/g SS,the concentration of CODcr achieves the peak value 4⁵ days earlier than the control group.Meanwhile the peak concentration of the COD_cr is 2092.27 mg/L which is increased by 68% compared to the control group.Compared the sludge reduction effect between the ozone dosage of 90 mg/g SS and the ozone dosage more than 90 mg/g SS,the law is almost the same,thus concerned about the cost 90mg/g SS is much more economically feasible and more efficiently.Meanwhile the sludge inoculated quantity can influence the hydrolysis acidification directly.Respectively the sludge inoculated quantities are 15%,30% and 50%,the CODcr concentrations raised for 23.6%,35.3% and 38.3% under the same six ozone dosage.Investigating together with the VFAs concentration which is produced from the hydrolysis acidfication systems that are in 30% and 50% sludge inoculated quantity.And the result shows that the VFAs production is difference within 10% per day.The rule is more obvious as well as the raising of the ozone dosage.However the rule is decreased after the ozone dosage reach 90 mg/g SS or more.