Case Studies: Car Wash Water Recycling System

Client: A Famous Car renting company in Dubai, UAE.

Topic: Setting up of a highly economical and compact treatment plant to treat the vehicle wash water which was not suited for disposal.


  1. Our client is a big name in the car renting business
  2. They wanted to reuse the treated effluent for washing their cars
  3. The plant room provided was of very less area and called for a plant of very less footprint.

Action taken to alleviate the troubles:-

Standard vehicle wash water parameters were taken as design parameters. The treatment system including an oil separator, Flocculation tank, coagulation tank, and settling tank were set up. This was followed by a water polishing unit which included a pressure sand filter, activated carbon filter and a system for bringing about effective disinfection of the effluent.

Results Observed:-

  1. Provided area was 30m2. The footprint for setting up the plant was 20% of the provided area.
  2. The post and pretreatment parameters have been shown below.
Sl No Parameters Unit Influent Effluent
1 pH 5.5-9 7.5
2 BOD mg/l 100-150 <10
3 COD mg/l 200-300 <50
4 Suspended solids mg/l 150 <100
5 Oil and Grease mg/l 15 <10

It is crystal clear from the above table that the effluent parameters are suitable for reuse. 70% of the treated water is advised to be mixed with 30% of makeup water prior to its employment for washing the cars.