Steam Cleaners

 

Steam Cleaners

Remove oil, water, metal, and dirt to reuse water again and again


Steam cleaners are used in many industrial applications to clean parts and equipment. Some major users of steam cleaning equipment include truck and bus washing, engine cleaning, and all types of repair facilities. Treating the waste streams generated from steam cleaner units operating in California has proven effective in separating the oil and water and removing metals and dirt from the water so the water can be reused.

One example is the waste water from a steam cleaner used to clean oil field service equipment which contains 8 ppm of chrome, lead, and zinc with lesser amounts of the other 17 metals on the states standard test along with a few ppm of oil and grease. At these concentrations the water is considered a hazardous waste with disposal costs ranging from $0.60 to $2.30 per gallon.

After treatment by electrocoagulation, the clear water met all federal secondary drinking water standards with the exception of surfactants. This was not a concern because the water was recycled through the steam cleaner and the recycled surfactants reduced the need to add soap to the steam cleaner system. It should be noted that charcoal could be used in conjunction with the EC process to make the water meet secondary drinking water standards. The sludge from the EC process contained 90 mg/kg oil and grease. The heavy metals were converted into oxides and the sludge passed the states TTLC and STLC as required by CAC title 22. As a result the State Health Board approved the EC processed sludge as a non hazardous waste.

Steam Cleaner / Recycling of steam cleaner wash water (004-263)
Constituent Wastewater (PPM) EC Water (PPM) % Removal
Antimony <0.01 0.014
Arsenic 0.30 <0.01 96.7%+
Barium 8.0 <0.10 98.7%+
Beryllium <0.01 <0.01
Cadmium 0.141 0.031 78%
Chromium 7.98 0.05 99.4%
Cobalt 0.13 <0.05 61.5%+
Copper 6.96 <0.05 99.3%+
Lead 7.4 1.74 76.5%
Mercury 0.003 <0.001 66.7%
Molybdenum 0.18 0.035 80.7%
Nickel 0.4 <0.05 99.3%+
Selenium <0.005 <0.005
Silver <0.01 <0.01
Thalliums <0.10 <0.10
Vanadium 0.23 <0.01 95.7%+
Zinc 19.4 1.20 93.8%

 

 

Dry sludge separated from the steam cleaner wastewater listed above (005-462)

Element TTLC Raw (mg/kg) Max State STLC Raw (mg/l) Max State
Antimony 2.4 500
Arsenic 3.85 500
Barium 307 10,000
Beryllium nd 75
Cadmium nd 100
Chromium 59.2 2,500
Cobalt 10.4 8,000
Copper 498 2,500 3.8 25
Lead 790 1,000
Mercury 0.15 20
Molybdenum 21.3 3,500
Nickel 25.5 2,000
Selenium nd 100
Silver 2.7 500
Thalliums 14.2 700
Vanadium 42.1 2,400
Zinc 1,798 5,000 60 250
Oil & Grease 89,780