Dewatering Of Dying Sludge By Coagulation Conditioning

In recent years, with high-speed development of the textile industry, the printing and dyeing wastewater is increasing year by year. At the same time, a large number of surplus sludge is produced. Sewage treatment plants need to spend too much money in sludge, but the result is not pleased. It has become an important factor restricting the development of the textile industry. It is necessary for us to learn about the property and the moisture content of dyeing sludge, and find the stuitable conditioner and the dosage of the stuitable conditioner.The article, which studied the wastewater treatment process and the process of dewatering sludge, and the emphasis, is about the dewatering sludge. The content including sewage treatment process and which step produced the sludge. Analyse the basic information of chemical sludge and the biochemical sludge. And I experimentalized on the physical and chemical properties of sludge, also on the variety and dosage of conditioner. And then put forward a new and reasonable ingredient of conditioner and also the process of the treatment. The result is that the moisture content of plant sludge is decreased, and the cost of the plant is siginificantly reduced. This experiment contents and the results are as follows:1. Theoretical StudyEffects of conditioner on dewaterability of two kinds of sludge we discussed. I determined the moisture content of sludge, as well as the moisture content of filter cake and sludge specific resistance, etc. And I reached a conlusion that the most suitable dosage of the conditioner.1) The experiment, which studied Polyaluminium chloride(PAC) and Cationic polyacrylamide(CPAM) and also The surfactant(TTAB) and combined both of them to improve dewatering ability of the biochemical sludge, and the best optimal dosage of coagulant. The results were as follows:pH=5.5, the reaction time is10min, the dosage of PAC is8g·L-1, the specific resistance was reduced to2.59×1012m·kg-1. After the centrifugal dewatering, the results showed that the moisture contents were92.05%, and decreasing water-content of filter cake to86.17%; When the dosing method is TTAB+PAC, the dosage of TTAB is0.3g·L-1and the dosage of PAC is10g·L-1, the specific resistance was reduced to2.83×1012m·kg-1. After the centrifugal dewatering, the results showed that the moisture contents were91.88%, and decreasing water content of filter cake to83.05%.2) The experiment, which studied Polyaluminium chloride (PAC) and Cationic polyacrylamide (CPAM) and combined both of them to improve dewatering ability of chemical sludge, and the best optimal dosage of coagulant. The results were as follows: pH=6.93, the reaction time is3min, the dosage of CPAM is25mg·L-1, the specific resistance was reduced to0.98×1012m·kg-1. After the centrifugal dewatering, the results showed that the moisture contents were85.67%, and decreasing water content of filter cake to75.59%.2. Application ResearchAccording to the results of the experiment, we can choose the most stuitable conditioner and also improve the dosage and proportion of the conditioner, so that the moisture content of plant sludge is decreased, and it also can reduce pollution. The most optimal project is that the plant coagulates the chemical sludge as well as the biochemical sludge, and then collects both of them, and iltration dehydration. Finally, the sludge was transported to the landfill.