A Review of On-Site Carwash Wastewater Treatment

Abstract

In recent years, people’s environmental awareness has increased. The high density of the urban population has caused a considerable increase in the demand for car washing services, which has created large quantities of car wash wastewater. The main pollutants in car wash wastewater are detergents, dirt, oil, and grease. Untreated wastewater released into rainwater sewer systems or other water bodies may pollute the water and generate excessive bubble foams, which negatively affects urban appearance. Car washes are divided into mechanical car washes and manual or self-service car washes. In general, car washes have a small operation and scale, occupy limited land, and cannot afford wastewater treatment costs. Therefore, most car washes are not equipped with wastewater treatment facilities. Consequently, the discharge of wastewater from car washes negatively affects the water quality in the surrounding environment and results in wasteful use of water resources. This study reviewed 68 research papers on the quality, treatment techniques, treatment costs, and treatment effectiveness of car wash wastewater to provide a reference for car wash operators to contribute to the preservation of water resources. We found that there is a higher chance of recycling car wash wastewater when combing two different techniques for car wash wastewater treatment.

The Application of Polyethersulfone Ultrafiltration Membranes for Separation of Car Wash Wastewaters: Experiments and Modelling

“…Obviously, water recovered from wastewater must meet the required quality criteria for reuse [ 2 , 11 , 12 , 13 , 14 ]. For instance, suspensions may be effectively removed from wastewater by several methods, such as coagulation, sedimentation, adsorption and sand filtration [ 3 , 7 , 15 , 16 , 17 , 18 , 19 ]. It is necessary to point out that car wash wastewaters also contain significant amounts of pathogenic microorganisms [ 20 , 21 , 22 ]; hence, ensuring biosecurity is another key challenge.…”

Electrocoagulation Process as a Consolidated Technology in the Treatment of Industrial Effluents and as a Promising Process in the Treatment of Effluents Generated by Car Washes: A Brief Review

“…It is worth underlining that these compounds have high toxicity and contain numerous toxic metals such as arsenic, barium, cadmium, chromium, lead, iron, nickel, silver, sulfates, COD, BOD, nitrites, nitrates, E. coli, oils and greases, MBAS, among others, which, when discharged into receiving bodies without proper treatment, cause eutrophication, toxicity to aquatic species, undermine the oxygenation of the environment, and all this, associated with other potential effects, make the disposal of this type of effluent a major contributor to environmental pollution, and the volumes discharged annually are too significant to be ignored by environmental agencies. 28,30,41,43 Currently, in Chapeco, for example, the only treatment process for effluents from car wash stations are boxes (SAO, as per its Portuguese acronym), which are concrete boxes, built at ground level, containing three sections with dividing walls through which the effluent is transported, retaining the coarse solids and OGs before the effluent is disposed of in streams or in the sewage collection system of the city. Still, at the scientific research level, there are studies conducted in the past decade that, as introduced and thoroughly discussed, 256 employed biological systems, chemical coagulation/flocculation systems, membrane separators, advanced oxidative processes, EC processes, and some inter-combinations for the treatment of vehicle wash station effluents (VWSE).…”

“…Therefore, the treatment of these effluents has become an eminent need on a global scale. 28,29 Was reported that 30 by 2020, there were estimated to be 1.5 billion vehicles on the planet; and, if they were washed just once a month, 1.8 billion tons of wastewater would be generated from the water used in these operations, enough to serve 33 million people and costing $1.8 billion annually. The authors highlight that this volume represents the total consumption of the population of Malaysia, Venezuela, the Republic of Ghana, Oceania (including Australia and New Zealand), or the combined population of Denmark, Norway, Switzerland, Finland, and Iceland.…”

“…In the last two decades, the increase in transport facilities and the improvement of the standard of living of people have driven the acquisition of vehicles and, with this, the vehicle wash activities have increased expressively and, consequently, the volume of effluents generated in this activity has increased expressively. Therefore, the treatment of these effluents has become an eminent need on a global scale. , Was reported that by 2020, there were estimated to be 1.5 billion vehicles on the planet; and, if they were washed just once a month, 1.8 billion tons of wastewater would be generated from the water used in these operations, enough to serve 33 million people and costing $1.8 billion annually. The authors highlight that this volume represents the total consumption of the population of Malaysia, Venezuela, the Republic of Ghana, Oceania (including Australia and New Zealand), or the combined population of Denmark, Norway, Switzerland, Finland, and Iceland.…”

“…Vehicle wash wastewater is discharged into water bodies with major contaminants, such as oils, greases, toxic metals, and detergents, and can bioaccumulate or rapidly interfere with the life cycle of the aquatic ecosystem at these sites. ,− Besides these, other contaminants such as lubricants, kerosene, gasoline, and diesel oil can also be found in the waste from car wash processes. − Mineral lubricating oil, for example, has surface chemical stability, besides the fact that its biodegradation process is very slow in natural ecosystems, which can impair biological functions in the environment for many years or decades. Therefore, the removal of oils from the wastewater of car wash processes is currently one of the great challenges. , Another class of contaminants, MBAS, can cause many problems, since there are already reports of toxic effects on aquatic microorganisms at concentrations of 0.02 mg·L –1 , including oxidative stress, uncontrolled growth of cyanobacteria, and cell lysis. , …”