A New Approach to Treating Highly Emulsified Coking Acidic Wastewater
Coking wastewater, generated in coking, gas purification, and chemical product recovery and refining (such as high-temperature carbonisation, gas cooling, coal washing and wet quenching), is a highly challenging, toxic and poorly biodegradable organic wastewater.
Its core characteristics are striking:
Complex and refractory composition: many pollutant species at high concentration with extremely poor biodegradability, and excess nitrogen further increases the difficulty of treatment.
High emulsification and suspended solids: high concentrations of fine coke powder and severely emulsified fine oil droplets not only impair stripping efficiency and liquid ammonia quality but readily clog the stripper and even cause unplanned shutdowns, with major economic losses.
Safety and environmental pressure: the wastewater releases irritant gases such as sulphides and ammonia nitrogen, endangering the environment and employee health; refractory carcinogens such as polycyclic aromatic hydrocarbons pose a long-term pollution threat to human health; and the large discharge volume and difficult treatment leave companies facing heavy environmental pressure when effluent is out of compliance.
An innovative solution:
Given these characteristics, the company has innovatively adopted a patented purely physical demulsification and separation technology built around CDFU (cyclonic dissolved air flotation), an SiC filter and the KHC high-efficiency coalescing oil separator as core equipment.
The technical advantages are significant:
1. Efficient demulsification and separation: CDFU pre-treatment uses ultrafine nanobubble technology for initial demulsification and rapid oil-water separation; the KHC coalescing separator achieves efficient, stable separation by purely physical demulsification, and the recovered waste oil is of high quality with low water content and can be re-refined directly.
2. Safe, clean and additive-free: the whole process runs automatically, sealed and under pressure, removing safety and environmental risks; no chemical agent is needed at any stage, eliminating secondary pollution such as scum and oily sludge and reducing operating and downstream treatment costs.
3. Stable, reliable and easy to maintain: the equipment is mainly static with a high degree of automation, simple maintenance, long turnaround intervals and strong shock resistance; treatment performance is stable and reliable and the footprint is small.
Successful practice:
After a petrochemical company in Luoyang adopted this technology, the effluent quality became stable and the oil removal rate reached more than 99%, completely solving its long-standing acidic wastewater treatment problem. This successful case sets an efficient, clean and economical benchmark for the industry in treating highly emulsified coking acidic wastewater.
