TARHOKAR Engineering CO 
Contact: (+98 21) 28429513 - 28429831

Car wash Wastewater Treatment

In today's world of our apartment, the need for machine mechanization in carwashes has become noteworthy, as a result of this need of people and the economic cycle, wastewater or cumulative sewage in car washes that pollute such as scrubbing from the washing, detergent, fat and oil, suspended matter.
The effluent or sewage produced in car washes can be carried out in two chemical methods, namely; adding coagulants and coagulants aiding in the market or the method of electrical coagulation, EC or electrocoagulation which is direct current of electricity and sheets of iron electrode and Aluminum is refined and with the help of additional filtration of this wastewater or sewage can be reused in car washes.
Design, construction and installation of various types of wastewater treatment packages by Electrocoagulation, EC (or chemical coagulation) methods performed based on the analysis and nature of effluent in the TARHOKAR engineering company.

Car wash wastewater

Type of Sewage in the car wash treatment

The first thing that happens in carwashes on cars is washing with water which is mud on cars with this action to the water, the output is added to the sewage industry, called TSS or suspended matter which can be deposited. The next level in car wash, car wash is added the foam or what is called detergent which has surfactants. This substance has an organic nature and causes a change in chemical quality in water. Other materials contained in wastewater or sewage car washes is oil and grease that is added to the water and causes severe water pollution and also heavy metals, such as lead should be considered in the treatment of effluent or sewage produced in carwashes.

In car washes, waste water from cars washed evacuated directly into the wells or water channels which causes contamination and poisonous aquifers and groundwater resources that require clean-up of wastewater from carwashes.
 Aytomatic car wash

Sample of Analysis Pollutants in Car washes wastewater

There is a precise analysis of pollutants for the design of sewage treatment package in carwashes. Therefore, before designing the unit of sewage treatment, several important parameters in the carwashes should be measured such as chemical oxidation and total solid suspended materials TSS.  In the following table, some analysis in the carwashes is mentioned
Parameter The results of analysis
PH 6-7
COD 350-500 mg/l
TSS 300 mg/l
Oil & Grease 20-40 mg/l
Surface active substances 35 mg/l

Car wash wastewater Treatment Method

As seen in the analysis, the presence of solid particles (TSS) as well as foaming and decontamination are the most important problems of the sewage output from a carwash. The conventional cleaning methods of sewage are carwashes that can be coagulated by coagulation of the coagulation and electrical clotting or EC Electrocoagulation.

Description of the car wash wastewater Treatment by Coagulation

In the treatment of carwash sewage by chemical coagulation and clotting, the sewage enters the unit after the passage of the physical purification units which mainly consists of scavenging in order to achieve uniformity in terms of the quality and quantity of wastewater and then enter quickly the coagulation or mixing tank (cogolasion). In the rapid mixing of sewage, colloidal particles are unstable due to electrical charge which is referred to as coagulation. In this unit through injecting the chemical that is determined by the jar testing, the minimum consumption of coagulants and the best result of the coagulation is obtained. Carwash sewage after passing through the mixing unit in order to coagulate and dispose of unpolluted colloids and the formation of large coarse particles, the same flocculation in the flocculation unit or the slow mixing of flocculation is mixed with poly-electrolyte materials then into the dock to separate the fluxes formed in the car wash sewage and the sewage treatment process Carwash is completed

Disadvantages of Car wash Sewage Treatment by Chemical Methods

The disadvantages of car wash wastewater treatment are the chemical cost of charging chemicals and the operator and the emergence of significant amounts of sludge. In the treatment of carwash wastewater by chemical means to remove heavy metals, the pH of the face needs to be adjusted. Because each of the heavy metals in the field of PH can be coagulated. Also, when the coagulated colloids are not sufficiently high, they can easily be deposited, they will accelerate with the injection of poly-electrolyte to settle. All of this adds various chemicals to the wastewater during the wastewater treatment process and increases the cost of utilizing the package.
Car wash wastewater chemical treatment

Description of the Process of Car wash Wastewater Treatment by Electrical Coagulation or EC

In the process of wastewater treatment, electrocoagulation is treated using direct current (DC) and metallic plates made of aluminum and iron as chemical electrodes, car wash wastewater which is briefly referred to as EC.
In electrocoagulation or electrical coagulation, electrodes which include iron and aluminum, form metal hydroxide molecules such as Al (OH) 3 or Fe (OH) 2 which due to their high absorption properties which can form a complex, then it will be settled and eventually separated from the wastewater in the EC-sedimentation tanks and the car wash wastewater treatment process will be completed.

Advantages of Car wash Wastewater Treatment with Electrical Coagulation Method

The advantages of car wash wastewater treatment by the EC method are to eliminate the cost of chemicals and the easy operation of this system. The electric coagulation package has a 99% efficiency removal of heavy metals, high efficiency in removing suspended solids, and the quality of the carwash in the wastewater. This package automatically and seamlessly draws refined water from the refining system to recycle cars
car wash wastewater treatment by electrocoagulation

Water Reuse in Car wash Wastewater Treatment

At the end of a carwash unit, the use of a sandy filter and a carbon together with a feed pump and this filtration causes the residual color, turbidity and suspended solid particles (TSS) to be completely removed and thus can be used with this water in carwashes and ensure that there are no stains or deposits on the car's surface.