Difficult to Meet Standards for Wastewater Suspended Solids? TNW dissolved air flotation (DAF) Complete Sets – Preferred Pretreatment Solution for Industrial Wastewater
Environmental engineers and wastewater operation personnel know well that floating oil, fine suspended solids and colloids in many types of industrial wastewater cannot be easily removed by sedimentation. Conventional sedimentation tanks have limited treatment efficiency. Tiny flocs settle slowly, resulting in turbid effluent, disrupting downstream biochemical systems and bringing risks of exceeding environmental discharge standards.
Dissolved Air Flotation (DAF) is a mature pretreatment equipment for efficient separation of floating oil and suspended solids. However, DAF units on the market vary greatly in quality. Many manufacturers simplify internal structures, leading to easily blocked releasers, poor air dissolution and declining processing capacity after short operation.
TNW Environmental specializes in manufacturing complete water treatment equipment. We independently develop and produce complete DAF systems, widely applied in printing, food slaughtering, machining, chemical and sand washing wastewater projects. Our equipment is highly recognized by general environmental contractors and operation companies for new wastewater projects and retrofits of old sewage stations.
1. Working Principle of DAF: Key to Proper Equipment Selection
In short, the DAF system dissolves air into clean water under high pressure to form saturated dissolved air water. When dissolved air water is released inside the flotation tank, numerous microbubbles are generated. Bubbles adhere to suspended solids, oil flocs and carry impurities upward to the water surface. Slag is scraped off by the slag scraper, while purified water flows out from the bottom to realize rapid solid-liquid and oil-water separation.
Stable operation relies on three core components: dissolved air system, releasers and slag scraping mechanism. Many low-cost products cut corners. Improper aperture design causes frequent blockage of releasers; poor mixing inside the air dissolving tank generates large bubbles with weak adsorption capacity, failing to achieve expected effluent quality.
2. Outstanding Advantages of TNW Complete DAF Equipment
2.1 High-efficiency Dissolved Air System with Fine Microbubbles for Stable Purification
Equipped with vertical pressure air dissolving tank, reflux pump and air compressor, the system realizes sufficient air-water mixing to produce abundant micron-sized microbubbles. Tiny and uniform bubbles effectively capture colloids, emulsified oil and suspended flocs, delivering remarkable oil-water separation performance for printing chromatic wastewater, oily slaughter wastewater and machining cutting fluid wastewater.
Optimized anti-clogging dissolved air releasers differ from ordinary products. They resist impact from impurities; fibers and fine contaminants in wastewater hardly cause blockages, lowering downtime for cleaning and suiting complex industrial water conditions.
2.2 Integrated Skid-mounted Design for Easy Installation, Ideal for Retrofits
Standard models adopt skid-mounted integrated assembly. Flotation tank, air dissolving tank, water pumps, slag scrapers, pipelines and valves are pre-installed. Clients only need to connect inlet, outlet, slag discharge pipelines and power supply for commissioning.
For aging sewage stations with limited space and restricted civil reconstruction, skid-mounted DAF avoids large-scale infrastructure work and shortens construction cycles. Non-standard customization is available; equipment dimensions can be adjusted according to treatment capacity and site layout.
2.3 Customizable Materials for Wastewater with Different Corrosivity
Wastewater corrosivity varies across industries, and single material cannot fit all scenarios. TNW offers flexible material options:
✅ Carbon steel with anti-corrosion coating: Cost-effective for sand washing wastewater and general neutral industrial sewage.
✅ Full 304 stainless steel: Widely adopted for food slaughter, printing and machining wastewater, featuring corrosion resistance and easy maintenance.
✅ Full 316L stainless steel: Designed for coastal high-salinity wastewater, chemical pickling wastewater and electroplating wastewater. It resists acid, alkali and chloride corrosion to extend service life.
2.4 Automatic Control System Supports Interconnection with Other Water Treatment Equipment
Standard electric control system enables timing operation of slag scrapers. Upgraded PLC control cabinets can link with dry powder dosing units, fine screens and screw presses. The whole pretreatment line works coordinately to realize minimally manned or unattended operation.
Sound-light alarms will be triggered under pump overload, abnormal liquid level and other faults to facilitate timely troubleshooting.
3. Wide Application Scenarios for DAF Equipment
Printing & papermaking wastewater: Remove dyestuff suspended solids, fibers and ink, reduce chroma and relieve load on biochemical tanks.
Food, slaughter and prefabricated food factories: Separate animal grease and protein suspended solids to prevent biochemical bacteria from being wrapped by oil.
Machining & hardware cleaning wastewater: Treat cutting fluid, emulsified oil and tiny metal debris.
Sand washing and mud wastewater: Separate suspended sediment for rapid water reuse.
Chemical park wastewater & surface treatment sewage: Remove colloidal pollutants and floating oil.
Pretreatment of catering wastewater and composite community sewage, achieving better oil removal than traditional oil separators.
4. One-stop Supply of Complete Sets for Full Wastewater Treatment Lines
Many contractors source equipment from multiple suppliers separately. Mismatched parameters between screens, dosing systems, DAF and screw presses lead to difficult linkage debugging.
TNW Environmental provides one-stop supply of full pretreatment equipment: internally fed screens, automatic dry powder dosing systems, DAF units and screw sludge dewatering machines. All equipment is pre-debugged at the factory with high process compatibility, simplifying on-site pipeline connection and accelerating project acceptance.
Practical Tips for DAF Procurement
Do not judge merely by unit price. Focus on releaser structure and air dissolving tank design. Blockage will trigger frequent shutdowns and raise operation costs.
Communicate working conditions in advance for wastewater rich in oil and fibers. Optimize tank flow guide structure to avoid scum accumulation.
Confirm tank material for corrosive wastewater. Carbon steel tanks suffer rust and leakage quickly under high-salinity conditions.
Backup reflux pumps are recommended for continuous operation to avoid production halt caused by single pump failure.
Prioritize integrated complete sets if possible to reduce on-site pipeline welding and installation workload.
Conclusion
As core pretreatment equipment for industrial wastewater, stable operation of DAF directly affects the entire subsequent wastewater treatment process. Blindly purchasing simplified low-cost units often leads to substandard effluent and frequent malfunctions, whose rectification costs far exceed the initial price difference.
As an original manufacturer, TNW Environmental supplies standardized and customized complete DAF systems, supported by pre-sales process design, factory inspection and nationwide after-sales service. We provide tailored solutions for new wastewater treatment projects and replacement of outdated DAF equipment.