Kunming Sewage Treatment Plant Sludge Settling Dewatering Performance

The sludge is leavings of the deposit and the foam in the process of disposing the sewage.It is the second production.With the development of the economic in our country and the increase of the population the pollution becomes more and more severity.The output of the sludge also increases with large rang which needs to be disposed.So it is very important that using the physics or chemical method to change the character of the sludge and made it dehydration easily.In our experiment we research the sludge sedimentation and the dehydration carefully and we get the most compatible flocculating agent and the best conditions which provide the parameter for the engineering design and the administrant during the pretreatment of the sludge.First we research four kinds of flocculating agents and they are FeCl₃. Al₂(SO₄)3,PAM and PAC.We find that the most compatible flocculating agent for the sludge in Kunming sewage plant is PAM and the proper concentration is between 0.09%.the adding quantity is 80 mg/L,the whisk intension is 200 r/min and time is 5min.We also research the influence factor to the sludge sedimentation and find that the order that from important to subaltern is flocculating agent kind＞the whisk intension＞time＞adding quantity＞concentration.This result will provide the gist for the next experiment.Then we do the experiment that research using two kinds of flocculating agents at the same time.We get that the method of using the PAM and PAC is best.The adding quantity of PAM is 60mg/L and adding PAC is150mg/L.At that time the specific resistance of the sludge can be cut down to 1.9×10¹⁰m/kg.The value is 26.9% descendant compared to adding PAM 80mg/L only.And the cost is also 9.4% descendant at the same time.The last we think over adding other materials which is good to the sludge just like the fly ash and diatomite.We find that the method that using PAM and the fly ash is better than the other two and the best adding quantity is that adding fly ash 10g/L and PAM 60mg/L at the same time.the specific resistance of the sludge can be cut down to 2.12×10¹⁰m/kg.This kind of method declines the cost.But at the same time the cubage of the disposal:sludge also can be increased which will be a new problem to the disposal of the sludge.The last we grow the cabbage which grows quickly in the admixture.The admixture is composed by sludge and soil.We find that the cabbage begins to grow in two days but if without sludge it need about three or four days.And the weight of the cabbage is increased with the rate of adding sludge.It shows that the adding of sludge is good for the growing of the cabbage.