Technical Challenges and Process Innovation in Power Plant Wastewater Treatment
Power plant wastewater mainly includes fuel oil tank cleaning water, flushing water from oil pump and pipeline leaks, and water mixed with lubricating grease from coal handling systems. It has the following characteristics:
Complex composition: contains free oil, emulsified oil (0.1~10 μm), suspended solids and heavy metals; oil content in some wastewater reaches 2,000 mg/L.
Strong fluctuations: volume and quality are heavily affected by operating conditions — for example, oil content surges during tank cleaning, easily shocking the treatment system.
High environmental risk: emulsified oil is hard to separate by gravity settling, and direct discharge would damage the biological system of downstream wastewater plants.
Limitations of Conventional Processes
Low efficiency:
API separator + air flotation tank: removes only 60%-80% of free oil, is nearly ineffective on emulsified oil, and effluent oil is ≥50 mg/L.
Composite sedimentation tank: relies on chemical demulsifiers, generating hazardous oily sludge with high disposal costs.
Unstable operation:
Conventional flotation bubbles are large (300~1,000 μm), giving low oil droplet capture efficiency and easily clogging filters.
Poor shock resistance; effluent frequently exceeds limits when water quality fluctuates.
Economic and environmental issues:
Large footprint (conventional flotation needs 15~40 minutes of retention) and high civil construction cost.
Treatment cost ≥CNY 1.5 per ton, and chemical dosing causes secondary pollution.
Direction of Technical Innovation
SINOKLE's CDFU cyclonic dissolved gas flotation plus KFM active filter media process stands out:
It solves the above problems through the following breakthroughs:
Micro/nano bubble technology: generates 5~30 μm bubbles (one-tenth the conventional diameter), achieving single-stage oil removal >90% without chemicals.
Purely physical separation: the recovered oil can be reused directly, sludge is reduced by 90%, and cost drops to CNY 0.2~0.3 per ton.
Skid-mounted design: treating 100 m³/h requires only 14 m × 3 m, cutting construction time by 50%.
Oily wastewater treatment facility at a heavy oil power plant in Sierra Leone (two-stage CDFU cyclonic dissolved gas flotation + KFM filters)
