Factors Affecting the Dehydration Effect of Organic Sludge

Proportions of organic matter in sludge can affect the moisture content of mud cakes, which is related to the water content of organic matter itself. Under normal circumstances, when the properties of inorganic matter are relatively stable, a high organic matter content will result in a high moisture content of mud cakes. However, many non-organic parts of sludge also contain a large amount of bound water. In this case, it is difficult to control the moisture content of mud cakes. For example, a large amount of inorganic flocculant in sludge can also cause the mud cake to contain a lot of bound water, which cannot be removed by conventional physical or chemical methods. Below, we will discuss the influencing factors of organic matter on the sludge dewatering effect.

Influence of sludge properties on sludge dewatering effect

The moisture content of sludge cakes mainly depends on the properties of sludge, because if the content of bound water is high, it is impossible to continuously reduce it using any chemicals or equipment. Therefore, bound water mainly depends on the comprehensive properties of sludge. The properties of sludge mainly depend on factors such as influent water quality, use of chemicals, treatment processes, and management. Sometimes, the properties of sludge may be affected by these factors but are not easily noticeable. Therefore, the properties of sludge are difficult to stabilize, and sewage treatment undergoes significant changes. This requires long-term observation, analysis, and experimentation to make adjustments and achieve the best treatment effect with the lowest moisture content.

Influence of equipment on sludge dewatering effect

The operation and management of sewage treatment equipment, such as centrifuges, is influenced by factors such as operating speed, sludge loading, dosage of chemicals, concentration, and dosing points. If the properties of sludge change and the equipment operation is not adjusted accordingly, the effect may not be ideal. Low-speed centrifuges are beneficial for the dryness of mud cakes, but within a certain range. The equipment structure of centrifuges directly affects the treatment effect and applicability to different sludge, such as adjusting the length-to-diameter ratio, rotational speed, differential speed, and sensitivity, as well as the height of the effluent weir plate. Therefore, the same sludge treated with different centrifuges will yield different results.

Influence of chemicals on sludge dewatering effect

Due to the different properties of sludge generated by various industries, the dewatering effect with different chemicals is also different. In many cases, it is not necessarily difficult to dewater sludge with a high organic matter content. It requires a comprehensive consideration of various sludge properties, conditions of coagulant equipment operation control, and other factors.

sludge thickening is a method of removing water from liquid, concentrated, or digested sludge and converting it into semi-solid or solid sludge blocks. After dewatering, the moisture content of sludge can be reduced to 55% to 80%, depending on the nature of the sludge and sludge thickening equipment efficiency. Further dewatering of sludge is called sludge drying, and the moisture content of dried sludge is less than 10%. The methods for sludge thickening include natural drying, mechanical dewatering, and granulation. Natural drying and mechanical dewatering are suitable for sewage sludge, while granulation is suitable for coagulation and sedimentation sludge.