Study On The Integration Of Vertical Enhanced Filtration And Natural Drying And Digestion On Sewage Sludge

This paper described the development of the general situation of sludge reduction and stabilization. In light of the existing problems of domestic sludge treatment and disposal, such as sludge dewatering difficulties, higher energy consumption and so on, we explored from the perspective of the production and practicality, and developed a new type of reactor of integration of vertical enhanced filtration and natural drying and digestion on sewage sludge treatment. By the experiment, we vertified the feasibility of the reactor and analyzed its effect. Main conclusions are as follows:①We developed a new type reactor of integration of vertical enhanced filtration and natural drying and digestion (IVEFNDD) on sewage sludge treatment. Furthermore, we vertified the feasibility of the reactor and analyzed its effect.②The IVEFNDD reactor has a better effect on the sludge concentration. The rate of the moisture content in the sludge is 99.2%. But in the condition of 120 d, the rate of moisture content in the sludge is 79% .The effect on the sludge concentration is better and there is no plugging in the filter material.③The IVEFNDD reactor has been adopted the membrane insulation system, so under the normal temperature, the temperature of digestion in the IVEFNDD reactor has basically reached the medium temperature of sludge digestion.④Under the normal temperature, the IVEFNDD reactor has a better effect on digestion. The organic matter content in sludge which entered in the IVEFNDD reactor is from 52 percent to 30 percent, and the decomposition of organic matter level has reached 44.4%. Better operating parameters: The organic loading is 0.8 kgVSS / (m3 ? d), the sludge staying time is 120 d, the hydraulic retention time is 8.3 d, the sludge concentration is 209.423 g / L, the moisture content of the sludge is 79.06%, the decomposition of organic matter rate has reached 44.4%.⑤Most of the COD value of the sludge leachate is from 200 to 600 mg / L; TN max is 489.5 mg / L, TP max is 117.5 mg / L; Most of the average NH3-N is from 150 to 250 mg / L . So the leachate must be returned to the wastewater treatment plant to deal with.⑥Through the heavy metal examining, we discovered that the copper in the sludge which is treated in the IVEFNDD reactor had exceeded the standard (urban sewage treatment plant pollutant discharge standards GB18918-2002). Therefore, it is not appropriate to use the sludge on the farm, but it can be used as garden soil and soil transformation.⑦Based on the sludge settlement test, we find the prediction model of the IVEFNDD reactor: R = [ 99 - 79.3959t^-0.5529]×100%. Use the prediction model; we can prognosticate the reducing efficiency of sludge.By the experiment, we proved that the IVEFNDD reactor improved the efficiency of slurry separation and enhanced the effect of sludge natural drying, and achieved the reductions, the stability and the resource through digestion. Furthermore, sludge thickening, stability and dehydration process are completed in a device of the IVEFNDD reactor. The management is simple, and the investment is saving.