Application of a multiple criteria analysis for the selection of appropriate radical based processes in treatment of car wash wastewater

In this study, the treatment of car wash wastewater was investigated by radical based hybrid/combined processes. Proposed processes, (Microwave (MW) + persulfate (PS) + Electrocoagulation (EC)), (ozone (O3) + PS + EC) and (MW + PS + O3), were optimized with Taguchi orthogonal array technique for maximum COD removal. The COD removal under optimum conditions was obtained to be 84%, 64.9% and 61.4%, for (MW + PS+ EC), (O3 + PS+ EC) and (MW + PS+ O3) processes, respectively. Operating costs for (MW + PS + EC), (O3 + PS + EC) and (MW + PS + O3) processes have been calculated as 0.2614, 0.1335 and 0.2653 €/L wastewater under optimum operating conditions. Pareto analysis showed that MW time and PS dose are very effective parameters but especially ozone related parameters have no significant effect on COD removal. Processes were evaluated with the PROMETHEE approach in terms of treatment efficiency, operating cost, sludge formation, and preferability criteria to determine the most suitable among the three alternative processes. As a result, the preference order of the processes for the treatment of car wash wastewater with radical based treatment processes was found as (MW + EC + PS) > (MW + O3 + PS) > (O3 + EC + PS).

Monitoring of Wastewater Quality from Laundry and Car Wash Industries at Batu Pahat, Johor

The complexity of environmental chemical exposure become a major concern because an essential objective of the global research effort is to improve life quality feature. Currently, environmental monitoring has become even more critical as human population increase, with the increasing strains on the environment. The unwanted synthetic compounds that presence from grey water in natural water was lead a toxic effect on ecosystems thus may lead to changes in biodiversity. This paper aims to discuss the studies of characterization in the environmental water sample from greywater which were laundry wastewater and car wash wastewater in the area surrounding Batu Pahat, Johor, Malaysia. The samples were directly brought to the laboratory for analysis and the content of grey water quality was characterized by using physicochemical analyses including pH, conductivity, suspended solids, chemical oxygen demand (COD), anionic surfactants (AS), oil and grease, sulfate, chloride, nitrate, and nitrite. All parameters were tested according to the standard method (APHA 2012). The result of this studies showed that the concentrations of AS by using methylene blue active substances (MBAS) were higher in laundry wastewater compared to car wash wastewater which was maximum at 105.0 mg/L. While the COD for car wash wastewater was maximum at 531.1 mg/L which was higher than laundry wastewater. Some of the characterizations indicated high values for many parameters and there is the need for specific treatment prior to discharge to before it has been directly discharged to the drainage.

Car Wash Wastewater Treatment Using an Advanced Oxidation Process: A Rapid Technique for the COD Reduction of Water Pollutant Sources

In this paper, a car wash wastewater (CW) was treated by an economic and eco-friendly method called electro-Fenton (EF) technique. The experiments were conducted to investigate the effect of five important variables including reaction time, current density, pH, H2O2/Fe2+ molar ratio and H2O2/Car wash wastewater (mL/L) on the quality characteristics of wastewater such as COD, BOD5, TOC, TSS, heavy metals, EC, surfactants and hardness. By applying Box-Behnken design (BBD) and response surface methodology (RSM), the optimum operating conditions were obtained. The optimum conditions for COD [as a main factor in a wastewater (according to the environmental protocols)] removal of 68.72% were experimentally found at reaction time of 75.80 min, current density of 58.81 mA/cm2, pH of 3.02, volume ratio of H2O2/CW of 1.62 mL/L, H2O2/Fe2+ molar ratio of 3.66.

Purification of real car wash wastewater with complex coagulation/flocculation methods using polyaluminum chloride, polyelectrolyte, clay mineral and cationic surfactant

In the present study, real car wash wastewater was purified by different coagulation/flocculation methods. As coagulant, polyaluminum chloride (‘BOPAC’), conventional iron(III) chloride, iron(III) sulfate, and aluminum(III) chloride were used, while as flocculant non-ionic and anionic polyelectrolytes were investigated. The effects of added clay mineral (Na-bentonite) and cationic surfactant (hexadecyltrimethyl ammonium bromide – ‘HTABr’) were also investigated. The use of BOPAC was significantly more effective than conventional coagulants. Extra addition of clay mineral was also beneficial in relation to both the sediment volume and sedimentation speed, while polyelectrolyte addition enhanced further the sedimentation. Moreover, the simultaneous addition of HTABr significantly enhanced the color removal efficiency due to the successful in-situ generation of organophilic bentonite. In summary, the application of 100 mg L−1 Na-bentonite with 20 mg L−1 Al3+ (from BOPAC) and 0.5 mg L−1 anionic polyelectrolyte resulted in the efficient reduction of the turbidity (4–6 NTU), the COD (158 mg L−1) and the extractable oil content (4 mg L−1) with efficiencies of 98%, 59%, and 85%, respectively. By applying organophilic bentonite in high concentration (500 mg L−1) with identical concentrations of BOPAC and anionic polyelectrolyte, significant color removal (5 times lower absorbance at λ = 400 nm) and 27% lower sediment volume were achieved.

Characterization of Car Wash Wastewater from Manually dispersed, Snow and Auto Car Wash Stations

Although commonly perceived lightly in the eye of public, car wash wastewater should be taken more seriously as they have the tendency to be harmful and toxic not only towards the environment, but also humans. In this study, car wash wastewater samples were taken from three stations in Johor with different cleaning methods; manually-dispersed car wash (MCW), snow car wash (SCW) and auto car wash (ACW). At each station, samples were taken during the initial rinsing (IR), and final rinsing (FR) of the vehicles. The samples taken were analyzed for its pH, chemical oxygen demand (COD), biological oxygen demand (BOD), oil and grease (O&G), total suspended solids (TSS), anions (anionic surfactant, nitrate, sulphate, chloride, fluoride, orthophosphate) and heavy metals (iron, zinc, magnesium, chromium, manganese, copper, lead, silver). The results obtained shows that there appears to be no specific pattern to differentiate between the IR and FR samples due to the different washing methods, chemicals and equipment used. The level of contamination of the car wash wastewater was SCW>MCW>ACW. Overall, the result shows that some of the samples did not pass the standard discharge limit; pH, COD, BOD, O&G, TSS, AS and Fe. This shows that car wash wastewater produced in the cleaning activities should be given more concern and need to be treated before being released to the water body.