Oily Sludge Dewatering Equipment and Technology (3)

4. Development of Oily Sludge Dewatering Equipment

With the continuous improvement of environmental protection requirements, different treatment processes are used for oily wastewater to produce diversified and complex oily sludge. Therefore, the development of multifunctional, highly efficient and automated mechanical dewatering equipment or systems has become the current development trend of oily sludge treatment.

4.1 Automatic Plate and Frame Filter Press

Automatic plate and frame filter press can greatly improve productivity and reduce labor intensity. According to literature reports, when heavy oil sludge is dewatered by automatic plate and frame filter press without adding any chemical agents, the moisture content of the scum after dewatering will be reduced from about 95.2% to 70%, and its oil content accounts for about 2% of the sludge weight. The filter cake can be transported or landfilled for subsequent treatment.

4.2 Drum Thickening Belt Filter Press

Drum thickening belt filter press integrates sludge thickening and belt pressing, overcomes the disadvantages of low sludge concentration, greatly improves the sludge treatment capacity, and has the advantages of high efficiency, energy saving, and large processing capacity compared with the traditional belt filter press.

4.3 Three-phase Decanter Centrifuge

Three-phase decanter centrifuge achieves the separation of oil-water-mud (solid) three phases, and has a good effect on the treatment of oily sludge. The three-phase decanter centrifuge is the ideal equipment and development direction for the treatment of oily sludge in the future.

5. Some Suggestions on Dewatering of Oily Sludge

5.1 Pay Attention to Chemical Conditioning Technology of Oily Sludge

It is impossible to achieve the expected effect of mechanical dewatering of oily sludge by relying on advanced dewatering equipment alone. It is necessary to develop corresponding chemical conditioning technology through experiments according to the properties of different oily sludge.

5.2 Pay Attention to Mechanical Dewatering Technology of Oily Sludge

Mechanical dewatering is the key to oily sludge treatment technology. Only by achieving three-phase separation of "clear water, dry mud, and pure oil" can the post-treatment cost of oily sludge be significantly reduced. Vigorously developing efficient and multifunctional three-phase equipment that integrates sludge concentration and oil-water separation can reduce secondary pollution caused by filter medium backwash, improve the working environment and reduce labor intensity.

5.3 Pay Attention to Secondary Pollution in Oily Sludge Treatment

When developing mechanical dewatering and chemical conditioning technologies for oily sludge, efforts should be made to avoid secondary pollution. For example, mechanical dewatering equipment has no filter medium; mechanical dewatering equipment is made into a closed type (such as decanter centrifuge), which can avoid polluting the workplace.

5.4 Developing Appropriate Sludge Treatment Technology

Since different types of oily wastewater require different treatment processes, the properties and quantities of the oily sludge produced are also different. Therefore, attention should be paid to developing different sludge treatment technologies according to local conditions.