Study On Residual Sludge Reducing From Dyeing And Printing Wastewater Biological Treatment

How to deal with excess sludge effectively in biological disposal of organic waste water, which is a cosmopolitan problem that not solved yet. To solve the problem, according to theory of hydrolysis-acidification and characteristic of the excess sludge, the excess sludge are regarded as a resource at the first time in this paper. In terms of cleaner production, it is regarded as a whole that minimize excess sludge production in biological disposal of printing and dyeing waste water and system oneself. Some results are achieved that adopt hydrolysis-acidification process in biological disposal of printing and dyeing waste water so as to realize minimization excess sludge production. The summary is as follows:At first it is studied that used periodic hydrolysis-acidification process (?) acidic-dyes waste water so as to realize minimization excess sludge production. Through different process conditions have influence on the result of hydrolysis-acidification , it is proved that: 1) Accumulation or consumption of the organic acid and that of Ammonia -Nitrogen are the main reason that the pH changes in the system. With the different concentration of sludge, the lowest pH and the time of reaching the lowest pH are different. 2) Under the function of hydrolysis-acidification bacterial The decrement of three kinds concentration of sludge that the experiment selects can be achieved effectively. 3) The temperatures of among 25-40centigrade are suitable for the function of hydrolysis and producing acid fungus. 4) The different speeds of mixing in the system have very great influence on the concentration of NH3-H in liquor supernatant. It is unable to give full play to the efficiency of hydrolysis-acidification fungus if having not mix or mix excessively. It can promote largely the function of hydrolysis-acidification fungus when the speed of mixing are 10r/min and 30r/min.It is studied that used continuous hydrolysis-acidification process in active and disperse dyestuffs waste water. When all excess sludge flow back to the process system of the waste water, sludge can keep a balance in every reactor during the time of experiment, and needn't to be discharged. It is proved that this process can realizeeffectively "zero discharging". The process conditions have certain influence on of decrement of excess sludge. In order to ensure excess sludge "zero discharging" in the system, and the water drawing accords with National grade-one standard, it must be controlled that temperatures are above 25 centigrade, hydraulic residence time of every reactor above lOh, and the COD volume loadings of inflow are under 2.31kg CODcr/m3 ? d. The recirculation of excess sludge can improve effectively the efficiency of decolorization printing and dyeing waste water and can supply the nutriment in the course of treatment.The degradation of pollutants in the continuous type hydrolysis-acidification system are analysed by adopting different instruments. The analytic result of three instruments can prove each other that the organic pollutant in water ruptures and resolves gradually, the kind decreased, the concentrations are reduced with the proceeding of hydrolysis-acidification. And the aerobic process is more effectively. It is proved theoretically that hydrolysis-acidification process is valid to deal with excess sludge.It's the first time to set up dynamics equation of continuous type hydrolysis-acidification system. From the dynamics parameter it can be found that the concentration of non-biodegradability organic in aerobic system is lower than the concentration of that in the facultative system. It prove that the degradation performance in the aerobic process are better than that in the facultative system in active and disperse dyestuffs waste water are concerned.In this paper a large amount of experiments and theoretical researches are carried on. The systematic studies are made that process conditions and recirculation of excess sludge and so on influence on the effect of excess sludge decrement in the system of hydrolysis-acidification process treatment different dyes waste water. Under ensuring the waste water quality up to standard, minimization excess sludge production are accomplished. This research results offer a new thinking for minimization excess sludge production, also have greater theoretical meaning and practical value.