Sludge Management

Veolia Environmental Services applies an innovative suite of harvesting and processing sludge management technologies for the management of waste/sludge/oil heavies at medium, to large-scale industrial facilities including:

• Sewage sludge farms
• Settling ponds
• Tank cleaning
• Large-scale cooling towers

Harvesting

The removal of the waste/sludge/oil heavies has traditionally been done with super suckers, buckets and shovels. This removal process still has its place, particularly on smaller scale projects and confined space areas. Today, Veolia Environmental Services provides robotic applications and larger scale dredging operations for the harvesting of sludges, whilst keeping tanks online.

Sludge Management Equipment

Hydro Dozer

The dozer is a hydraulic driven small dozer which can be easily disassembled and used in a number of applications. This robotic application is ideal for removing slurry and bulk product inside a tank and or pond area, negating the need for manned entry and avoiding human exposure to sludges. With a progressive cavity pump, the Hydrodozer is capable of up to 90m3/hr movement of sludge.

The Hydrodozer in the pump configuration can be used very effectively in a submerged state, in ponds and open top tanks with the use of the remote control station. This remote control station allows the tank to remain on line whilst the sludge removal occurs

Pelican Dredge

The Pelican Dredge specialises in the removal of sludge and silt from lagoons, tailings dams, sewage ponds, lakes and waterways. As a key piece of Veolia’s sludge management equipment, the Pelican Dredge is a self-propelled cutter suction dredge.

Advantages of the Pelican Dredge are as follows:

• Easily Transportable
• Can operate in shallow water (600mm)
• Able to pump product over long distances (500metres)

Sludge Management Processing Solutions

Veolia Environmental Services has three key sludge processing technologies, for a range of applications, these include:

Centrifuge

The state-of-the-art Centrifuge application is generally applied to the recovery of oil from crude oil tanks. The centrifuge works by spinning a stainless steel drum whilst simultaneously introducing the contaminated oil, and within this spinning, gravity is increased 100 times. Aided by the possible heat and flocculants, the oil and water are hence separated.

Belt Press

The use of the mobile belt press is ideally suited to large volumes of sludge that can be “easily” de-watered. Typically the solids content of the sludge may be 8-20% w/w. The belt press operation is not suited to oil sludges.

The unit can process between 8,000 to 15,000 litres per hour, dependant on the sludge and quantity of solids. An important aspect of the belt press is the pre-work that ensures that the correct flocculants and or coagulant, is used to allow ease of de-watering and containment of the sludge on the belt.

Plate Filter Press

Veolia’s mobile Plate Filter Press provides a dewatering capacity for small projects where maximum dewatering capacity is required. The unit can be set up in a variety of configurations to suit the particular project requirements. The unit requires 240V power supply and 175CFM air to drive the process diaphragm pumps and the opening and closing of the press. A unique aspect of the press is its ability to carry out a secondary pressing of the cake, ensuring maximum dryness and hence a reduction in the quantity of waste required for disposal. Typically it could be reasonable to expect the cake dryness to be in the order of 35% solids w/w. The unit weighs 10.3T and has a footprint of 3.2m x 6.4m.

The press is ideally suited to inorganic sludges, but can be adapted some organic sludges with the addition of filter aids such as fullers earth. It could be reasonably be expected that the unit will process in the order of no more than 3000-5000 litres per hour of sludge. This is highly dependant on the sludge and no costing should be done without either a trial and or experience with the specific waste in question.