Experimental Study Of The Chemically Enhanced The Activity Of Activated Sludge

In the aerobic activated sludge waste water treatment system, the microbial activity is one of the key factor of the efficiency of the waste water treatment. Many factors will influence the microbial activity, the main factors are the concentration and different kinds of inlet substrate, temperature, pH value, DO and so on. Except for these, some mineral nourishment are needed in the phase of microbial's growth and metabolism, when such mineral elements are absent, excess or disproportional, it can affect the normal metabolism of the microbial ,and it can lower the activity of the microbial. Generally recognizing, the component of the waster water is complex, and it contains enough mineral nourishment for the needs of the microbial growth, but it is not true, some industry wastewater or the municipal wastewater with large proportion of industry wastewater are short of one kind or several kinds of mineral nutrition elements sometimes. So it has great significance to find the kind and the range of mineral element which can promote the activity of activated sludge, that it can guarantee and enhance the efficiency of the biological treatment of sewage.In this topic, through a series of contrast experiment we want to find the effect of different chemical methods to the activity of the activated sludge in the biological treatment system of sewage, and it is expected to increase the sewage biological treatment efficiency by enhance the activity of the microbial from the chemical phase. In this experiment, COD removement is used as the macro-index to reflect the change of the activity of microbial indirectly and we expect to find the optimum concentration of the growth of microbial in the biological treatment system of sewage. The metal-salt, such as MnCl₂·4H₂O Mg(NO₃)₂·6 H₂O FeSO₄·7H₂O, are put in the reactor separately to activate the activity. Through the parallel experimentation, it is indicating:(1)It can improve the ratio of COD removement to some extent when the MnCl₂·4H₂O was put in the sewage. When the concentration of Mn²⁺ is 0.5mg/L, compared with parallel reactor the ratio of the COD removement of dosing reactor is improved about 4.3 percent. When the concentration is more or less than 0.5mg/L, the improvement is less than 4.3percent.(2)Putting in properly Mg²⁺ can promote the activity of the activated sludge; improving the water quality of outlet water. When the concentration of Mg²⁺ is 20mg/L, comparing to parallel reactor the ratio of the COD removement of dosing...