Sludge Dewatering Tanks, why are they used?
Sludge Dewatering Tanks are used for various mainly in the water treatment industry. In the main sludge, tanks are used for the following applications.
- Sludge Thickening
- Sludge Treatment
- Sludge Dewatering
What is Sludge?
Sludge is generally a thick, soft, wet mud or a similar viscous mixture of liquid and solid components which is a product produced during the refining process of wastewater treatment. Sludge covers a multitude of materials, many very different from each other with the common denominator, despite appearances, is that they generally have a very high-water content. Increasing costs involved in its disposal, sludge treatment is becoming one of the greatest costs in running an effective wastewater treatment plant.
Sludge is generally classed as.
- Primary Sludge
- Biological Sludge
- Mixed Sludge
- Digested Sludge
- Mineral Sludge
What is Sludge Treatment?
Sludge treatment is necessary to reduce and to ameliorate the sludges produced within the biological wastewater treatment. Sludge from a treatment process there will generally have less solids in it than it looks like, as a typical DAF plant sludge will be approximately 5% solid-or 95% water equating to 19 tonnes of water and 1 tonne of solids from a 20-tonne load of sludge. By increasing the solids content of the water gives a lot of costs savings on the plant.
What is Sludge Thickening
Sludge thickening is the treatment the sludge undergoes and is possible to reach a volume reduction of up to 80 % by thickening before further treatment is required. This is where wastewater treatment plants drive the sludge off regularly and usually takes place directly in the sludge storage tank.
What is Dewatering?
Dewatering is the reduction of the sludge liquid amount after the thickening process as the liquid still must be dewatered to a dry and porous form generally by machine processes such as a filter press and centrifuge. Sludge Dewatering Tanks are fitted with outlets up the side of the tank to draw water off.
How Is Sludge Dewatered?
Sludge is generally conditioned before thickening and dewatering through either mineral or organic conditioning. Flocculation Tanks will be used to carry out the process of creating the flocs. These work in the following steps
Step 1 – Adding flocculent
Chemical coagulants, also known as flocculants, are added to the water in the 3-stage flash mixer to destabilise the smaller individual particles and cause them to begin aggregating.
Step 2 – Flash Mixing
After the flocculent is introduced, the water is mixed vigorously by the flash mixer so that the chemicals are evenly dispersed throughout the water. Coagulation begins during the flash mixing process as the coagulants neutralise the electrical charge of the fine particles.
Step 3 – Flocculation
After the initial more aggressive mixing, flocculation begins after slowing down the mixing so that the smaller particles produced during the coagulation start adhering together. After the flocculation process, most of the particles should have bonded together, which is called the Floc. Floc consists of larger masses of particulates bonded together in clusters of about 0.1 to 3 mm in size. It is critical that the floc is not too small otherwise, it does not settle well enough or too big otherwise, it will likely break apart in the flocculation tank.
Step 4. Clarification
Clarification is the last of the steps in the flocculation process are in conical tanks which hold the water long enough to allow the floc and other particulates to move to the bottom of the tank. This process can remove particles, sediments, oil, natural organic matter, and colour.
Mineral & Organic Conditioning
- Mineral chemicals such as iron salts and lime are used frequently found in filter press applications. Ferric Chloride and Iron Sulphate are mainly used in conjunction with lime to condition the sludge before a filter press allowing better filtration by the coagulating the colloids and by micro-flocculation of the precipitates. Lime is often used as a conditioning agent with iron salts bringing a mineral nature to the sludge
- Organic chemicals such as coagulants and flocculants, generally cationic in nature, allow the formation of flocs creating a release of the water. This water will thus be easily eliminated during the dewatering step.
Enduramaxx Sludge Dewatering & Decant Tanks
In addition to providing bespoke sludge holding tanks and wastewater storage solutions for a diverse cross-section of clients, equipment mounting, and customisation of these sludge tank include welded fittings, sockets, and flanges. Racking ports allow draining of the water off the sludge while leaving the sediment in the bottom of the cone tank. Other options include industrial mixers liquid level sensor assemblies, fill pipes are available. PN16 and ANSI welded flanges, welded sockets and as well as airtight lids and vents are available to suit your project.
Sludge Dewatering Tanks
Our sludge tanks can be customised to project requirements with fittings, flanges, sludge decanting valves and pipework. Side access to the tank for maintenance of the tank is an option available to the save the tank having to be accessed from the top hatch of the tank.
View our Sludge Tank Range
|Code||Sludge Tank Range||Lid||Dimensions (mm)||Product Link|
|17222211||10000 Litre Sludge Tank||620 mm Vented||2400 dia x 2500 H||Product Link|
|17222411||10000 Litre Sludge Tank||620 mm Vented||1900 dia x 3700 H||Product Link|
|10000 Litre Sludge Tank||620 mm Vented||2600 dia x 2220 H||Product Link|
|17222511||12500 Litre Sludge Tank||620 mm Vented||2600 dia x 2830 H||Product Link|
|17222911||15000 Litre Sludge Tank||620 mm Vented||2400 dia x 3550 H||Product Link /|
|15000 Litre Sludge Tank||620 mm Vented||2600 dia x 3060 H||Product Link|
|17223011||16800 Litre Sludge Tank||620 mm Vented||2600 dia x 3410 H||Product Link|
|17223811||20000 Litre Sludge Tank||620 mm Vented||2850 dia x 3600 H||Product Link|
|17223511||20800 Litre Sludge Tank||620 mm Vented||2600 dia x 4150 H||Product Link|
|17225011||22000 Litre Sludge Tank||620 mm Vented||3450 dia x 2750 H||Product Link|
|17224011||25000 Litre Sludge Tank||620 mm Vented||2700 dia x 4650 H||Product Link|
|17225511||26000 Litre Sludge Tank||620 mm Vented||3450 dia x 3200 H||Product Link|
|17226011||30000 Litre Sludge Tank||620 mm Vented||3450 dia x 3650 H||Product Link|
Dished Base Conical Sludge Tanks
Sludge tanks are vital in wastewater treatment plant for storage of raw effluent, treated effluent, final effluent, raw sewage and sewage sludge. Conical tanks aid decanting/cleaning to a system of multiple tanks as it allows the sludge in the tank to settle out sludge further so more water can be recovered and further digest the sludge before disposing of. Decant valves are fitted to these to draw off the water of the water as it settles. A bottom drawing out the cone allows the thickened sludge to be taken away for treatment or disposal.
View our Conical Sludge Tank Range
|Code||Dish Based Sludge Tanks||Lid||Description||Dimensions|
|1752143001-F||8000 Litre 30 Deg Dished Base Conical Sludge Tank||620||Product Link||2600 Dia x 3928 H|
|17520466001-F||8000 Litre 60 Deg Dished Base Conical Sludge Tank||620||2600 Dia x 3800 H|
|1752166001-F||8000 Litre 60 Deg Dished Base Conical Sludge Tank||620||Product Link||1900 Dia x 4279 H|
|1752183001-F||10000 Litre 30 Deg Dished Base Conical Sludge Tank||620||Product Link||2600 Dia x 3230 H|
|1752146001-F||10000 Litre 60 Deg Dished Base Conical Sludge Tank||620||Product Link||2600 Dia x 4328 H|
|1752186001-F||12000 Litre 60 Deg Dished Base Conical Sludge Tank||620||Product Link||2600 Dia x 4858 H|
|1752251301-F||13000 Litre 13 Deg Dished Base Conical Sludge Tank||620||Product Link||2600 Dia x 3379 H|
|1752253001-F||14000 Litre 30 Deg Dished Base Conical Sludge Tank||620||Product Link||2600 Dia x 4350 H|
|1752283001-F||15000 Litre 30 Deg Dished Base Conical Sludge Tank||620||Product Link||2600 Dia x 4580 H|
|1752500501-F||25000 Litre 5 Deg Dished Base Conical Sludge Tank||620||Product Link||3450 Dia x 3737 H|
|1752550501-F||30000 Litre 5 Deg Dished Base Conical Sludge Tank||620||Product Link||3450 Dia x 4067 H|