Sludge dewatering pretreatment
Source：Jiangsu Envset Time:22 October 2020
Before the sludge is dewatered by a sludge dewatering machine, it should generally be pretreated. This is called sludge conditioning (conditioning). The main purpose is to improve the dewatering performance through pretreatment of the sludge. The pretreatment of sludge dewatering is divided into physical conditioning and chemical conditioning.
The conditioning treatment of sludge is the key link and core technology of deep sludge dewatering. It can be said that the sludge conditioning technology determines the success or failure of the deep dewatering project. There are many methods for sludge conditioning. The method of adding dehydrating agent, flocculant or coagulant to the sludge is generally used to change the existence mode and structure of water molecules (mainly interstitial water and capillary water) in the sludge, which is beneficial to water Separated from mud under certain conditions.
Before dewatering the sludge, it is necessary to judge the dewatering performance of the sludge. Generally speaking, the dehydration performance of primary sludge is better, and the dehydration performance of activated sludge is poor. The mixed sludge of the two depends on the proportion of the two. To determine the dewatering performance of sludge, the specific resistance (R) and capillary water absorption time (CST) of the sludge should be considered. The larger the R and CST, the worse the dewatering performance of the sludge. It is generally believed that only when the specific resistance R of the sludge is less than 4.0*1013m/kg or the capillary water absorption time CST is less than 20s, it is suitable for mechanical dewatering. Therefore, the primary sludge, activated sludge, or mixed sludge of both, after being concentrated or digested, should be quenched and tempered first to reduce the specific resistance R or capillary water absorption time, and then perform mechanical dehydration. When performing chemical conditioning, PAM currently has the best effect. Of course, in the selection of conditioning agents, in addition to considering the overall cost, there is a certain relationship with the type of sludge dewatering machine.
The Multi-Disk Screw Press (MDS) provided by Jiangsu Envset adopts PLC automatic control technology, which can replace the traditional filter press and is an advanced sludge dewatering machine. We are familiar with the various stages of sludge dewatering treatment. If you have any questions about sludge dewatering pretreatment, please contact us.
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