Activated sludge deep dewatering method

Abstract

The invention belongs to the technical field of water treatment sludge, and particularly relates to an activated sludge deep dewatering method. The method includes the steps: firstly, extracting sludge (with water content about 99%-96%) in a concentration tank; secondly, adding an appropriate number of amidino-containing cationic high molecular reagents into the sludge and then mixing the reagents with the sludge; thirdly, exhausting the flocculated sludge into a plate-and-frame filter press for filter pressing to obtain a filter cake with the water content lower than 60%. Compared with a conventional sludge deep dewatering method, the activated sludge deep dewatering method has the advantages that the sludge can be conditioned only by adding one organic compound without adding dry base materials such as lime, the water content of the filter cake after filter pressing is lower than 60%, the process is simple, the filter-pressed filter cake has no effect on sludge resource utilization in subsequent incineration and the like, and accordingly the filter cake has a fine practical application prospect.

Description

technical field [0001] The invention belongs to the technical field of water treatment sludge, and in particular relates to a method for deep dehydration of activated sludge. Background technique [0002] With the continuous development of my country's economy and the continuous improvement of urbanization level, the number of urban population is increasing, so the amount of urban sewage generated is also increasing day by day, and the amount of sludge generated is also increasing day by day. As of the end of June 2015, there were 3,802 sewage treatment plants in my country, with a sewage treatment capacity of 161 million cubic meters per day. The amount of by-product sludge after sewage treatment has also increased dramatically. According to the mud production rate of 10,000 m 3 Based on the calculation of 7 t of sludge (80% moisture content) from sewage, the national sludge output is expected to have exceeded 110,000 t / d, and the total output of sludge is still increasin...

AI Technical Summary

Problems solved by technology

The combination of coagulant and flocculant can greatly improve the dewatering performance of sludge, but the use of these materials can easily lead to the disadvantages of large dosage, increased capacity of mud cake, and impact on subsequent treatment and disposal.

[0010] It can be seen from the above that the current technology is not yet fully mature: (1) The dosage of traditional inorganic flocculants is large, and the flocculation effect is not good. However, there are still disadvantages such as large dosage and impact on subsequent treatment and disposal.

(2) Although the dosage of organic flocculants is small, the mud cake has high moisture content after dehydration when used alone, and the decomposed monomers have certain biological toxicity and are difficult to biodegrade.

(3) The use of coagulant aids such as fly ash and quicklime can change the degree of combination between sludge particles and water molecules and improve the dehydration performance of sludge, but when used, the dosage is too large, which may easily cause the mud cake to expand , have an impact on the follow-up processing and other issues

(4) Although biological flocculants have a good dehydration effect on concentrated sludge, their practical application range is limited due to some shortcomings.

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