Industrial waste waters commonly comprise organic and inorganic matter in fluctuating degrees of concentration. They may comprise of toxic and other harmful supplies as well as elements that are non-biodegradable or that can decrease the effectiveness of many waste water treatment procedures. Thus, treatment of industrial wastewaters usually is a very challenging task - far more complex than municipal wastewater treatment. DAF is used extensively in the following industries-Meat, poultry, fish processing, Pulp and paper, Dairy industry, Food and beverage and Petrochemicals.
Eliminating large, suspended and floating solids along with oil and grease is the main focus of the first stage of wastewater treatment. Elimination of oily contaminations through the help of DAF system installed in chemical industry wastewater treatment is an effective flotation technique for water clarification. The word states to the technique of creating flotation by dissolving air in the water under pressure and then discharging the pressure. When the pressure is discharged the solution converts super-saturated with air as loads of tiny bubbles form. These bubbles fasten to the particles in the waste water affecting the density of the particle to become lighter than that of water. The particles then quickly float to the surface for accumulation and elimination; setting behind the clarified water. A common design uses a discrete pressure vessel for compressed air supply.
Emulsified oil in the DAF influent is eliminated by de-emulsification with thermal energy, chemicals or both. DAF units usually make use of chemicals to endorse coagulation and raise flock size to enable separation. Emulsified oil in wastewater is generally pre-treated with chemicals to de-stabilize the emulsion tailed by gravity separation. The wastewater is heated to decrease viscosity, emphasize on density differences and fade the interfacial films alleviating the oil phase.DAF clarifiers function efficiently over a wide variety of hydraulic and contamination loading.
DAF has widespread applications for chemical industry wastewater treatment. DAF is a recognized and effective physical chemical technology usually used for many industrialized and municipal uses including:
Product retrieval and recycle
Pre-treatment to meet sewer discharge limits
Pre-treatment to decrease loading on downstream biological systems
Improving of biological treatment effluent
Eliminating silt and grease from industrial water