Car wash wastewater treatment package

Kashefan Nilfam Engineering Company is able to take an effective step in preserving the health of the environment by producing and implementing a car wash wastewater treatment package, knowing about the significant pollution of car wash wastewater. Since the wastewater of a car wash unit has a large volume of chemical compounds and can threaten the health of the environment, its treatment is a serious and necessary matter. Electrochemical methods are practical and important methods in the purification process. Electrochemical methods include: electrocoagulation, electro flocculation and electro flotation. The method of electrocoagulation (electrocoagulation) provides the destabilizing agents that cause the necessary neutralization for the separation of pollutants. Electro flocculation also produces agents that promote particle bridging or coagulation. Electro flotation is a method in which pollutants such as fat and oil are attacked by gas bubbles formed on the surface of the electrode (H2O2) and are transferred to the surface of the solution along with these bubbles. In this way, it will be possible to remove pollutants from the system by performing cupping.

Electrochemical coagulation and flocculation has been able to reduce the parameters in car wash wastewater to the extent you can see in the table below.

پارامترهای اندازه گیری شده
(%)COD
(%)BOD
(%)TSS
(%)سرب
(%)دترجنت
(%)آهن
راندمان حذف
87/96
21/94
23/98
43/99
88/99
67/99
The results of Karoush wastewater treatment sample using electrocoagulation method:
مواد آلوده کننده
تخلیه ­آب های سطحmg/l
تخلیه به چاه های جاذب mg/l
مصارف کشاورزی و آبیاری mg/l
BOD
۵۰
۵۰
۱۰۰
COD
۱۰۰
۱۰۰
۲۰۰
TSS
۶۰
۶۰
۱۰۰
روغن و چربی
۱۰
۱۰
۱۰
دترجنت
۱/۵
۰/۵
۰/۵
رنگ
۷۵
۷۵
۷۵
کدورت
۵۰
۵۰
pH
۶/۵ – ۸/۵
۹-۵
۸/۵-۶

In this method, there is no need to use chemicals as coagulants. The metal ions resulting from direct current passing through the electrochemical cell are hydrolyzed and produce hydroxide metal ions.

Al(OH)3 insoluble clots play the main role in the purification process. Charged ionic pollutant particles are neutralized under the influence of the interaction caused by the ions produced from the dissolution of the sacrificial electrode and are removed by being absorbed by each other, i.e. the action of coagulation. Also, the hydrogen gas that is released in the cathode electrode floats and separates some clots in the solution.

After passing this stage, the wastewater is transferred to the next stage, i.e. slow mixing. In this stage, the flocs formed in the previous stage stick together and cause the formation of flocs that settle better in the sedimentation stage. After this step, the wastewater enters the sedimentation unit, which is designed in a static way, and the wastewater enters the tank from the end of a barrier. Effluent, after overflowing from V-notch, is transferred outside. After this stage, the waste water is free of solids.

Advantages of car wash wastewater treatment with electrocoagulation method

 One of the advantages of car wash wastewater treatment using the EC method is the elimination of the cost of chemicals and the easy operation of this system. The electric coagulation package has 99% efficiency in removing heavy metals, high efficiency in removing suspended substances, turbidity and oil in the car wash effluent. This auto mechanical and integrated package prepares purified water from the purification system for washing cars again.

For more information about how to design a car wash waste water treatment package, you can read the article “Design of a car wash waste water treatment process for local car wash stations”.

The most important results of the project implementation:

  •  Not using chemicals in the wastewater treatment process that do not destroy the color of the car if the treated wastewater is reused.
  •  Low cost and easy operation
  •  No need for skilled operator
  •  Low occupation level of the device
  •  The possibility of using single-phase electricity
  •  Wide use range of the package