Sludge thickening dewatering process of various sludge types

STP typically requires sludge dewatering prior to final disposal of sludge/biosolids, or as a prelude to further processing or stabilization. Since the dewatering process has significant differences in reducing the moisture content of the sludge, the final sludge treatment method usually has a significant impact on the dewatering process that is most suitable for a particular STP. The effect is also the characteristics of the sludge that needs to be dewatered; that is, whether the sludge is raw or digested, whether the sludge contains WAS or whether the sludge has previously thickened. For raw sludge, the freshness of the sludge will have a significant impact on dewatering performance (sewage sludge is more difficult to dewater than fresh raw sludge).

filter press and Sludge Thickening Tank

A reasonable design basis for sludge production value should be established. Instead of actual sludge production data, an overall plant mass balance should be provided to account for sludge generation for each process unit process, including the liquid and solid series and the effect of the recycle stream on the main liquid system process.

Table 1 shows the solids capture for various sludge thickening and dewatering process methods, the solids concentrations typically achieved, the energy requirements and the appropriate final disposal schedule. The solids concentration shown in the table assumes that the sludge has been properly regulated. Designers should be aware that dephosphorization chemicals (ie, alum or ferric chloride) reduce the allowable solids loading rate of the dewatering equipment and produce a lower cake solids concentration than without phosphorus removal. This is expected due to the additional sludge load caused by the chemical sludge and its potentially lower initial concentration.

Table 1 – Sludge Thickening Methods and Performance with Various Sludge Types
Thickening Method Sludge Type Expected Performance
Centrifugation Waste Activated with Polymer 8-10% TS and 80-90% Solids
Capture with Basket Centrifuges;
4-6% TS and 80-90% Solids
Capture with Disc-nozzle Centrifuges;
5-8% TS and 70-90% Solids
Capture with Solid Bowl Centrifuges.
Gravity Belt Thickener (GBT) Waste Activated with Polymer 4-8% TS and ³ 95% Solids Capture
Rotary Drum Thickener (RDT) Waste Activated with Polymer 4-8% TS and ³ 95% Solids Capture
Gravity Raw Primary 8-10% TS
Gravity Raw Primary and Waste Activated 5-8% TS
Gravity Waste Activated 2-3% TS (Better results reported for oxygen-rich activated sludge)
Gravity Digested Primary Digested Primary and Waste Activated 8-14% TS
Dissolved Air Flotation (DAF) Waste Activated (Not Generally Used for Other Sludge Types) 4-6% TS and 95% Solids Capture With Flotation Aids

Related Articles

filter press exported to South Afcica

Solutions of filter press break downs

Overview of the automatic filter press The automatic filter press detects the oil pressure of the hydraulic system of the current pull plate through a pressure transmitter. Converts the perceived pressure signal into an analog quantity that can be recognized by the PLC, thereby realizing the advancement and retreat of the control pull plate. The photoelectric switch is set to…

tailings deep cone thickener

Tailings disposal dewatering equipment

Tailings treatment is an important part of mine production and an important part of the construction and operation of the ore dressing plant. In recent years, due to environmental and safety pressures, many problems exist in the traditional tailings surface storage methods, Develop safe and efficient tailings treatment technology. Introduction to high-efficiency gravity sedimentation dewatering equipment High-efficiency gravity sedimentation dewatering…

belt filter press for oil sludge dewatering

Dewatering filter press for oil sludge

Filter press definition A mechanical device that uses a special filter medium to apply a certain pressure to an object to cause the liquid to bleed out. Function: extract the solid in the mixture to achieve solid and liquid separation. Sludge is a solid precipitation material produced by water and sewage treatment processes. As the nature of various types of…

2019 Peru Arequipa International Mining Exhibition

Exhibition Name: Perumin-34 Mining Convention Exhibition time: September 16-20, 2019 Exhibition cycle: two years Venue: Arequipa, Peru LZZG Booth: 717   Exhibition Introduction Organized by the Peruvian Institute of Mining Engineers and held in Arequipa, Peru, the Perumin-34 Mining Convention is the most important multidisciplinary professional conference and technology exhibition in the Latin American mining industry. It also has a…


First Rate Service
Product Knowledge
Service Network
Privacy Policy
Spare Parts