EXPERIENCES IN TREATING WASTEWATER FROM A LARGE OIL REFINERY IN HUNGARY
Steve Kirkwood, Nigel Reeves, Nicola Henderson, Kevin Jones1,Magdalena Basurto, Rosa Fernandez2 and Balasz Csep3
1Earth Tech UK,
2Earth Tech Mexico,
3Earth Tech Hungary
(free)
The project consists of a design, build, finance and operate contract for upgrading of the refinery’s existing wastewater treatment system to meet new EU and Hungarian legislation plus the management of wastewater services at the refinery for the next 15 years.
The existing wastewater treatment plant was upgraded by retaining the existing API (American Petroleum Institute) oil/water separators and installing a new equalisation tank, dissolved air flotation system, proprietary sequencing batch reactor (SBR) biological treatment plant, sludge handling and dewatering equipment. The oily sludge/solid waste rotary kiln incinerator was also upgraded. The SBR plant has the capability to treat 1000m³/h and short term peak flows of up to 1500m³/h. The effluent standard for the fully treated process stream water includes limits of 80mg/l COD, 25mg/l BOD, 20mg/l suspended solids and 5 mg/l oil and grease. The fully treated process water effluent quality as discharged to the River Danube in 2006 was 41mg/l COD, 7mg/l BOD, 8mg/l suspended solids and 0.6mg/l oil and grease. Oily sludge from the API basins and the DAF units is dewatered using a centrifuge to produce a sludge cake prior to incineration. Biological sludge from the SBR plant is thickened in a drum thickener then dewatered using a centrifuge to produce a sludge cake.
KEY WORDS
Biological treatment, CASS™, decanter, Hungary, oil, refinery, SBR, sequencing batch
reactor
