Scope of the Research The scope of this research covers the following: • Analyse the water quality parameters after coagulation-flocculation, sand filtration, and membrane systems • To
Car is a convenient and accessible way of transport for our daily life and its demand is increasing every day According to the Motor Vehicle Census (MVC) in 2016, there are 18.4 million registered motor vehicles in Australia (Australian Bureau of Statistics, 2016) Demand for car washing centers is increasing for better maintenance of these cars An average of 50 to
A single professional car wash consumes approximately 100 gallons (189 to 378.5 liters) of fresh water, contributing to significant wastewater generation daily Annually, over 35 billion liters of contaminated wastewater are disposed of rather than recycled from 10,000 car wash centers across Australia, posing a substantial environmental threat Car wash wastewater contains pollutants such as petroleum hydrocarbons, heavy metals like copper, lead, and zinc, nutrients (phosphorus and nitrogen), surfactants, suspended solids, microorganisms, sand, and dust, all of which can harm soil and water ecosystems if left untreated Notably, one liter of car oil has the potential to contaminate one million liters of water, highlighting its toxicity The use of soaps and solvents further introduces toxic surfactants, hydrocarbons, and heavy metals into the wastewater, exceeding safe health standards and damaging the environment Untreated car wash wastewater has been linked to detrimental effects on rivers, lakes, and coastlines Implementing proper treatment processes is crucial for reducing water waste, preventing environmental contamination, and enabling the reuse of treated water in car wash facilities.
Description of the Proposed Research
Different technologies have been used to evaluate the treatment of car wash wastewater from last few years, and those treatment technologies can be divided as conventional treatment
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane Bioreactor for the Reuse of Car Wash Wastewater technologies and membrane based technologies After critically evaluating the literature review it is found that membrane based technologies can produce high quality treated water compared to conventional treatment Numerous researchers have used different membranes to treat the car wash wastewater in combination with coagulation, flocculation, and sedimentation The waste generated from those treatment processes is an issue This research aimed to develop a treatment method using membrane based technology which will be able to produce higher quality effluent, generating minimal waste with a small footprint for recycling wastewater from the car wash
Two different membrane based technologies were selected in this research
A Treatment system 1-This treatment system was a combination of coagulation- flocculation, sand filtration, ceramic ultrafiltration membrane and reverse osmosis
B Treatment system 2 -An enhanced membrane bioreactor (eMBR)
An enhanced membrane bioreactor (eMBR) comprised of an anaerobic bioreactor (AR1), an anoxic bioreactor (AR2), an aerobic membrane bioreactor (AMBR) and a UV disinfection unit
The main aim of this research is to develop a viable solution to treat and reuse car wash wastewater To do so, two treatment systems were evaluated The first treatment system comprised of coagulation-flocculation and ceramic ultrafiltration membrane and reverse osmosis and the second treatment system is enhanced membrane bioreactor (eMBR) The following objectives were achieved by using these two systems:
• Evaluating the performance of coagulation-flocculation, sand filtration with membrane systems;
• Monitoring and assessing the treated water quality
• Evaluating the performance of eMBR;
• Optimising residence time of eMBR;
• Monitoring the critical flux of membrane;
• Monitoring and assessing the treated water quality
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane Bioreactor for the Reuse of Car Wash Wastewater
The following research questions were answered to fulfil the aims of this research:
• How effective is it to use coagulation-flocculation, sand filtration, and membrane systems to recycle the car wash wastewater?
• Is it feasible (in terms of quality) to use eMBR process to recycle the car wash wastewater?
Understanding the relationships among operating parameters is essential for optimizing Aerobic Membrane Bioreactor (AMBR) performance Transmembrane pressure (TMP) typically increases over time during different hydraulic retention times (HRT), reflecting the accumulation of fouling and solids on the membrane surface Adjusting HRT influences TMP, with shorter HRTs often accelerating fouling development, leading to higher TMP levels Identifying the critical flux—the maximum permeate flux before significant fouling occurs—is crucial for efficient AMBR operation, as operating below this flux helps maintain membrane stability and prolongs operational lifespan Optimizing the balance between HRT, permeate flux, and TMP ensures effective wastewater treatment while minimizing membrane fouling and downtime.
The scope of this research covers the following:
• Analyse the water quality parameters after coagulation-flocculation, sand filtration, and membrane systems
• To analyse the water quality parameters at different locations of the eMBR system such as feed, effluents from AR1, AR2, and AMBR and the Permeate
• Monitor the changes to the transmembrane pressure and permeate flux with time at different hydraulic retention time for evaluating the performance of the membrane
• Comparative study between coagulation-flocculation, sand filtration with membrane systems and eMBR with respect to treated water quality
The outcomes of this research are to develop a viable solution and provide concrete guideline to:
• Provide a sustainable treatment of car wash wastewater and recycle the water to reduce the large amount of water demand for car washing;
• Evaluating the performance of eMBR for an extended period
The following sub-sections explained the main motivations of this research
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane Bioreactor for the Reuse of Car Wash Wastewater
Importance of undertaking this research
The consumption of water during car wash is a main concern in the world as recycling of water is a major issue around the globe Individual private cleaning of car has the risk of ecological effect on the environment as the water run off to the drainage system Therefore, many countries regulate for using car wash center to wash the cars (Janik and Kupiec, 2007) On the other hand, it is required to find out a treatment method for recycling wastewater from car wash centers which can produce high-quality recycled water with small footprint and the system is easy to maintain From these points of view, membrane based treatment system consists of ceramic ultrafiltration membrane with reverse osmosis and eMBR were selected to treat and recycle the car wash wastewater
Benefit of this research to the Community
To address the wastage of water by car wash, the Australian Car Wash Association introduced five-star rating scheme which depends on the amount of potable water used by equipment in a standard wash and rates the water efficiency of that equipment Table 1.1 shows the amount of potable water required for different types of car washing and their rating
Table 1-1 Different types of Car washing methods and their ratings based on consumption of potable water
Average potable water consumption per car wash
Star Rating (According to the Australian Car Wash Association)
Washing cars by hand with a hose
Car wash installation with water recycling system
The rating criteria for water consumption per car wash are as follows: a "Not Rated" score indicates water usage exceeding 140 liters per wash, while a 3-star rating corresponds to 121-140 liters A 4-star rating is assigned to washes using 101-120 liters, and a 5-star rating signifies water consumption of less than 100 liters per wash, promoting water conservation (Savewater, n.d.) According to data from Lenntech, water consumption per car wash varies depending on the method used, emphasizing the importance of efficient water use practices (Lenntech, n.d.).
Implementing water recycling systems at car wash centers can save at least 100 liters of water per wash, benefiting the community by conserving resources When regulated cleaning processes are followed, contaminants from wastewater do not pose a threat to the environment, promoting eco-friendly car wash practices.
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane Bioreactor for the Reuse of Car Wash Wastewater
A viable system was developed for the treatment of car wash wastewater which can be easily constructed at a car wash facility to recycle the treated wastewater An enhanced membrane bioreactor (eMBR) was selected for this project considering the satisfactory results of MBR used in a project at Deakin University for recycling the car wash wastewater (Boluarte et al.,
2016) But in that project, MBR was run only for three months and the performance of the membrane; critical flux and the effect of hydraulic retention time on water quality were not evaluated Moreover, a further detailed study was necessary for the commercial type application of this system for recycling the car wash wastewater In this research, the performance of the eMBR was evaluated in detail However, first treatment system (coagulation-flocculation, sand filtration, ceramic ultrafiltration membrane and reverse osmosis) was selected to compare the permeate water quality between the two systems
This thesis consists of 5 chapters The details of each chapter are described below
This chapter provides an overall summary of this research with research scope, objective and rational The thesis outline is also described here.
This chapter mainly includes the literature review that was carried out during this research In the first stage, different types of car wash centers and pollutants generated with current disposal systems are explained briefly Different wastewater treatment technologies used by different researchers to recycle the car wash wastewater are discussed in the second stage The third stage explained the basis on the selection of membrane based technology with two different membrane based treatment systems.
This chapter describes the details of the experimental plan of first treatment system which consists of coagulation-flocculation, sand filtration, ceramic ultrafiltration membrane and
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane Bioreactor for the Reuse of Car Wash Wastewater reverse osmosis The details of methodology with analysis of water quality changes after each step are also included here.
This article details the experimental setup of integrated Membrane Bioreactor (eMBR) systems, including materials, methods, and data analysis, to evaluate treatment efficiency It examines short-term critical flux under both intermittent and continuous operation modes, highlighting the role of microorganisms in wastewater biodegradation Additionally, the study investigates the relationship between hydraulic retention time (HRT) and permeate quality, illustrating how process parameters influence treatment outcomes A comparative analysis of two different treatment systems assesses effluent quality, demonstrating their effectiveness in recycling car wash wastewater.
The overall conclusions and future scope of this research are described in this chapter
Evaluating the performance of first treatment system and eMBR for recycling the car wash wastewater is the main concern of this research To fulfil this objective eMBR was run for an extended time The permeate quality and the performance of eMBR for recycling the car wash wastewater were investigated A comparison study between two treatment systems were carried out, and the findings are described in detail in this thesis
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane Bioreactor for the Reuse of Car Wash Wastewater
The rapid increase in vehicle numbers in Australia over the past decade, with a 27.8% growth since 2006, highlights the rising demand for car maintenance and wash services As the number of vehicles grows, so does the need for proper car wash facilities, which are essential to prevent ecological issues associated with home washes that release wastewater into stormwater systems, as seen in countries like Switzerland and Germany To address environmental concerns, the number of professional car wash centers is expanding, but this raises challenges related to water consumption and wastewater management Recycling treated car wash wastewater offers a sustainable solution to reduce water usage; various treatment technologies such as coagulation-flocculation, sand filtration, oxidation, and membrane filtration have been explored for this purpose This article discusses the different types of car wash centers, their water requirements, pollutant sources, environmental impacts, and current disposal methods It further reviews innovative treatment methods, focusing on membrane technologies like ceramic ultrafiltration, reverse osmosis, and enhanced membrane bioreactors (eMBR), explaining their advantages and suitability for efficient wastewater treatment in the car wash industry.
Types of car wash centers
Commercial car wash centers can be categorized into various types, including self-serve, in-bay automatic, conveyor, touchless, and hybrid systems, each distinguished by their construction and washing technology These different car wash formats cater to diverse customer needs and operational preferences, making them essential in the automotive cleaning industry Understanding the features of each type helps businesses optimize their services and enhance customer satisfaction.
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane Bioreactor for the Reuse of Car Wash Wastewater technologies In addition, the consumption of water varies in every system For example, self- service, in bay automatic, conveyor (friction) and conveyor (frictionless) require 15, 50-60 and 65.8 and 85.3 gallons of fresh water per vehicle washing respectively (Brown C, 2000) Queensland state in Australia and some other countries in Europe have restricted the use of fresh water for a single car wash to less than 70 L (Zaneti et al., 2011) In Belgium, the water consumption rate is very high (up to 400 L per wash) in the automatic car wash bays (Boussu et al., 2007, Zaneti et al., 2011) Furthermore, some car wash centers use rain water to save potable water for the initial car wash by establishing a rain water system in the car wash centers (Zaneti et al., 2011) Lenntech has published the required amount of water for different car washing services and showed that car wash installation with recycling system requires only 10-
50 L of water in contrast to the conventional car wash installation system which requires 150
Implementing recycling systems in car wash centers significantly reduces water consumption, making it the most effective strategy for conservation According to Lenntech (n.d.), car wash centers with advanced recycling systems can save a substantial amount of water, promoting sustainability and environmental responsibility in the industry.
Pollutants in car wash wastewater: Sources and their impact on the environment
Car wash centers generate significant volumes of wastewater annually, contributing substantial pollution to the sewerage system In Australia alone, over 35 billion liters of contaminated wastewater are produced each year by approximately 10,000 car wash facilities (Boluarte et al., 2016) Effective wastewater management in car wash centers is essential to minimize environmental impact and promote sustainable water usage.
According to Boluarte (2014), approximately 15 million liters of polluted water enter the stormwater system annually in New South Wales (NSW) due to car washing activities Car wash wastewaters contain a mixture of impurities, including organic and inorganic substances, microorganisms, and heavy metals, which originate from various sources such as traffic emissions and chemicals used during washing These pollutants pose significant environmental risks and are detailed in Figure 2.1, highlighting the diverse origins of contaminants in car wash runoff (Boluarte, 2014; Janik & Kupiec, 2007).
According to the International Car Wash Association, professional car wash operators prioritize managing pollutants such as total suspended solids (TSS), total dissolved solids (TDS), oil and grease, biochemical oxygen demand (BOD), chemical oxygen demand (COD), detergents, and heavy metals like lead, zinc, and trace amounts of other priority metals to ensure environmental compliance and maintain water quality.
The Australian Car Wash Association (ACWA) has documented the levels of various contaminants present in car wash runoff, highlighting potential environmental impacts (Boluarte, 2014; Australian Car Wash Association, n.d.) These findings, summarized in Table 2.1, underscore the significance of properly managing wastewater to prevent pollution Implementing effective water treatment and recycling practices is essential for reducing the environmental footprint of car washing operations.
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane Bioreactor for the Reuse of Car Wash Wastewater
Figure 2-1 Main origins of pollutants in wastewater emanating from car wash
(Janik and Kupiec, 2007, Boluarte, 2014) Table 2-1 Types of pollutants in car wash wastewater and their sources and environmental impacts
(Australian Car Wash Association, n.d, Boluarte, 2014)
Average concentration of Car wash waste water
Suspended Solids 200 mg/L • Traffic, road surfacing, atmospheric pollutants
• Car wash chemicals such as detergents
• Exceed the accepted health standards
Recent research efforts have focused on treating car wash wastewater using various methods, emphasizing key parameters such as chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), suspended solids, and turbidity (Bhatti, 2011; Mohamed et al., 2014; Li et al., 2007) However, many studies have overlooked the presence of detergents, oil, grease, and organic pollutants, which are also significant contaminants in car wash wastewater Addressing these pollutants is essential for comprehensive treatment and environmental protection.
Application of Ceramic Ultrafiltration/Reverse Osmosis Membranes and Enhanced
Membrane bioreactors (MBRs) offer an effective solution for the reuse of car wash wastewater by addressing various pollutants that significantly impact the environment Key impurities in car wash effluent include detergents, oil, grease, and organic pollutants, which can contaminate water sources and harm aquatic ecosystems Implementing MBR technology helps remove these harmful substances, ensuring cleaner water for reuse and reducing environmental pollution caused by car wash operations SEO keywords such as "membrane bioreactor," "car wash wastewater treatment," "detergent removal," and "environmentally sustainable water reuse" are essential for optimizing search visibility.
Detergents used in car wash centers contain various types of surfactants, including anionic, cationic, and non-ionic compounds (Tu et al., 2009) These surfactants are environmentally persistent and bioaccumulative, posing potential health and environmental risks Effective removal of these surfactants from car wash wastewater is essential, and Table 2.2 outlines the specific surfactants present and the treatment methods employed to eliminate them from water.
Table 2-2 Surfactants found in different car wash wastewater and the treatment methods used to remove the surfactants
Initial concentration (in car wash wastewater)
Removal efficiency Treatment applied References
21 mg/L 12 mg/L 40% Flocculation column flotation, sand filtration, chlorination
3-20 mg/L