Dissolved air flotation (DAF)

Dissolved air flotation (DAF) is a water treatment process that clarifies wastewaters (or other waters) by the removal of suspended matter such as oil or solids. The removal is achieved by dissolving air in the water or wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank or basin. The released air forms tiny bubbles which adhere to the suspended matter causing the suspended matter to float to the surface of the water where it may then be removed by a skimming device.

There is a wide range of industrial and municipal applications for DAF including:

• Product recovery and reuse
• Pretreatment to meet sewer discharge limits
• Pretreatment to reduce loading on downstream biological treatment systems
• Polishing of biological treatment effluent
• Thickening of biosolids

Polishing Plant

For the removal of additional suspended solids and BOD from secondary effluent, effluent polishing is an effective treatment. It is most often accomplished using granular media filters, much like the filters used to purify drinking water.

Polishing filters are usually built as prefabricated units, with tanks placed directly above the filters for storing backwash water.

Effluent polishing of wastewater may also be achieved using microstrainers of the type used in treating municipal water supplies.

Oil Water Separator

Dema&C Oil-Water separator is a device designed to separate gross amounts of oil and suspended solids from the wastewater effluents of oil refiniers, petrochemical plants, chemical plants, natural gas processing plants and other industrial sources.

Benefits of the System:

• Economical and reliable operations.
• Low operating and maintenance costs.
• Gravity operated, so no utilities required.
• Recyclable oil recovered.
• Can take little above ground space.
• High efficiency and ability to meet environmental regulations.
• Predictable performance.
• Ability to handle surges of oil or water.

Car Wash Recycling Plant

Car Wash Recycling Plant features Include:

• Powerful Separation: Removal of all wax, oils and solids for clean wash water.
• Quality Water Cleaning & Treatment: Strong Oxygenation controls the bacteria level in the treated water with no smell or odors.
• Leading Edge Technology
• Lower Establishment Costs: The system requires considerably smaller pits than other systems resulting in lower installation & pit pumping costs
• Lower Operating Costs: The absence of chemicals and the reduction in operator interaction will reduce operating costs
• Low Maintenance: No filters or elements to clean or replace, no back flushing required and virtually no maintenance.

Odor Control System

Dema&C has already for many years a range of sewage gas filters for odor emission control constructed in double wall, black UV resistant high density Poly Ethylene material. These filters are with integrated equipment such as fan and heater. Now Dema&C has designed a new range of sewer gas filters constructed in Glass Reinforced Plastic (GRP). Additional to the filters Dema&C can supply demisters, fans, heaters, etc. to fulfill client’s requirements.

Typical odor emission control applications are the removal of odor from sewage treatment plants. In these plants several emission sources need odor control equipment e.g. such as pump stations, wet wells, sludge dewatering and sludge trans-shipment operations from silo into trucks.

Sewage odor consists of mainly hydrogen sulphide. Next to hydrogensulphide the gas also contains organic sulphur components (mercaptans, hydrocarbons) and ammonia. In general activated carbon will adsorb all these components.