--- title: "Dissolved Air Flotation (DAF) Systems" description: "DAF, cavitation air flotation and shallow air flotation units that remove oil, grease, fats and suspended solids from industrial wastewater. Get a quote." url: https://www.waste-water-equipment-factory.com/products/dissolved-air-flotation/ updated: 2026-11-10 --- # Dissolved Air Flotation Remove oil, grease and fine solids with micro-bubble flotation. Dissolved air flotation (DAF) is a clarification process that uses fine air bubbles to float suspended solids, oil, grease and fats to the surface, where they are skimmed off. It is widely used as pretreatment or primary treatment in food processing, slaughterhouses, dairies, paper mills, refineries and textile plants. ## How it works Wastewater is usually dosed with a coagulant and flocculant to form larger flocs. A portion of clarified effluent is recycled, pressurized and saturated with air in a saturation vessel. When this recycle stream is released into the flotation tank at atmospheric pressure, the dissolved air comes out of solution as microscopic bubbles. The bubbles attach to the flocs and oil droplets, lowering their density so they rise to form a float layer. A surface skimmer removes this sludge to a collection hopper, while clarified water exits from below. Cavitation air flotation generates bubbles mechanically, and shallow air flotation uses a shallow, rotating tank design. ## Models - [Dissolved Air Flotation (DAF) Unit, 4–300 m³/h](https://www.waste-water-equipment-factory.com/products/dissolved-air-flotation/dissolved-air-flotation-unit/): This dissolved air flotation (DAF) unit treats poultry slaughterhouse wastewater by floating fats, blood solids and suspended matter to the surface for removal. Capacity ranges from 4 to 300 m3/h in carbon or stainless steel, on 220V or 380V. It suits slaughterhouses and sewage plants preparing effluent for discharge or irrigation reuse treatment. - [Horizontal-Flow DAF for Paper Mill Wastewater](https://www.waste-water-equipment-factory.com/products/dissolved-air-flotation/horizontal-flow-daf-paper-mill/): This large-capacity horizontal flow DAF system rapidly separates suspended solids, oils, fats and colloids from papermaking wastewater. It treats 1 to 100 m3/h with gearbox, pump, motor and PLC, and is built in stainless or carbon steel. It suits paper mills, textile plants and municipal works pretreating high-concentration suspended solids. - [Compact Ionized DAF Unit, 5 m³/h](https://www.waste-water-equipment-factory.com/products/dissolved-air-flotation/compact-ionized-daf-unit/): This ion-dissolved air flotation unit treats wastewater from manufacturing plants and farms at 5000 liters per hour. An ionized dissolved air system generates fine bubbles that separate suspended solids, powered by a 3 kW motor on 220V or 380V. The 1000 kg unit measures 3300 x 1800 x 2200 mm and suits sites needing compact flotation. - [Cavitation Air Flotation (CAF) Unit, 5–500 m³/h](https://www.waste-water-equipment-factory.com/products/dissolved-air-flotation/cavitation-air-flotation-caf-unit/): This cavitation air flotation unit removes suspended particles, grease and colloids from municipal and industrial wastewater, reducing SS and COD. Treatment capacity ranges from 5 to 500 m3/h with power from 2.75 to 15.4 kW, and its simple structure keeps maintenance easy. It suits chemical, paper and municipal plants, including paper mill fiber recovery and water reuse. - [Shallow Air Flotation Unit](https://www.waste-water-equipment-factory.com/products/dissolved-air-flotation/shallow-air-flotation-unit/): This shallow air flotation unit removes suspended solids from industrial wastewater and paper mill effluent using a dissolved air system and the zero velocity principle. Its shallow tank delivers high treatment efficiency in a small footprint. It is built in anti-corrosion carbon steel or 304 stainless steel for plants that need efficient SS removal or fiber recovery with limited space. - [Cavitation Aerator / Micro-Nano Bubble Generator](https://www.waste-water-equipment-factory.com/products/dissolved-air-flotation/cavitation-aerator-micro-bubble-generator/): This cavitation aerator is a micro-nano bubble generator used in CAF and DAF wastewater treatment systems. A high-speed rotating impeller draws in air and breaks it into fine bubbles, with aerator capacity from 1 to 80 m3/h and 1-3 kW motors. It suits equipment builders and plant engineers upgrading or building air flotation units. ## How to choose - **Flow rate and hydraulic loading:** Size the unit on design flow, including any recycle stream, and on accepted surface loading rates for the application. - **Solids and oil loading:** High concentrations of suspended solids, fats or emulsified oil affect tank area, skimmer capacity and chemical demand. - **Chemical conditioning:** Most DAF applications need coagulant and polymer dosing. Jar testing on representative wastewater helps confirm chemical choice and dose. - **Type of flotation unit:** Conventional DAF suits a wide range of duties, cavitation units offer simpler bubble generation, and shallow flotation saves height and footprint for larger flows. - **Materials of construction:** Choose carbon steel with protective coating or stainless steel based on wastewater corrosivity, temperature and site requirements. ## Applications - Food and beverage processing - Slaughterhouses and meat processing - Dairy and edible oil plants - Pulp and paper mills - Petrochemical and refinery wastewater - Textile and dyeing effluent - Pretreatment before biological treatment ## FAQ ### What does a DAF system remove? DAF removes suspended solids, fats, oil and grease, and with chemical conditioning it can also reduce colloidal material and part of the associated COD and phosphorus. ### Do DAF systems need chemicals? Most applications use a coagulant and a polymer flocculant to form flocs that bubbles can lift. Some streams with free oil may float with little or no chemical addition. ### What is the difference between DAF and cavitation air flotation? DAF dissolves air into a pressurized recycle stream and releases it as micro-bubbles. Cavitation air flotation creates bubbles mechanically with an aerator, which avoids a saturation vessel but typically produces larger bubbles. ### Where should DAF be placed in a treatment plant? DAF is usually placed after screening and equalization and before biological treatment. It protects downstream processes from fats, oils and solids shock loads. ## Contact - Email: inquiry@waste-water-equipment-factory.com - WhatsApp / Tel: +86 176 2154 1688 - Quotation form: https://www.waste-water-equipment-factory.com/contact/ - Company: Shanghai Mars Industrial Co., Ltd., Shanghai, China