Two-stage wastewater treatment technology for high salinity, oily-emulsion water
Wastewater from car washing typically contains oil, oil emulsion contaminants, suspended solids (sand, mud), and the latter appear as dissolved salts in the wastewater. The conventional coagulation-flocculation method was used to treat the oil-emulsion contamination. The dissolved salts were removed by membrane filtration in a second purification step.
Waste water disposal method, characteristics of the waste water
The site is used for cleaning the inside and outside of railway wagons. The internal cleaning is essentially the collection of rubbish, without the generation of waste water.
External washing is generally done without chemicals, with detergents used only in exceptional cases. The high-pressure washer uses around 400-800 litres of water to wash a wagon. The area around the washing tracks (purpose-built) is paved and the washing water is drained in a closed channel, while particulate contamination is removed through a 1.5 mm slotted filter. Rainwater also drains through the same system.
The pollutant load considered in the design is shown in Table no. 1.
Title |
Value |
pH |
5,5-8 |
KOI |
500 – 5000 mg/dm3 |
SZOE |
20-50 mg/dm3 |
Floating material |
300-1000 mg/dm3 |
Total N |
150-200 mg/dm3 |
Total dissolved substances |
000 mg/dm3 |