ANALYSIS OF WASTE WATER FROM ECOLOGICAL CAR WASH - A CASE STUDY

Wastewaters resulted from different stages of washing process from ecological car wash were investigated for its physicochemical parameters and several heavy metals contents. For this purpose 75 samples were collected and analyzed by conductometric, potentiometric techniques and by Flame Atomic Absorption Spectrometry during of November 2010. The results showed that the amount of zinc, copper, cadmium and lead elements in wastewater samples were higher than the Maximum Admitted Level (MAL) values for investigated heavy metals, according to the Order 161/2006, after washing different cars in one week (from Monday to Friday at 14,00). The increase of Pb, Cu, Cd, and Zn concentrations is visible (average weekly collections) and these were higher especially on rainy days when cars came with a load more visible than in the days with good weather. In according with the Order 161/2006, regarding pH tolerance limit, the mean pH values for all collected samples were between 6.00 and 9.00. The temperature ranged between 14.10 - 17.10°C with an average value of 14.91±1.61°C. The highest values for conductivity, turbidity and TDS was found for samples Sp2, Sp5, Sp8, Sp11 and Sp14, before entrance in the first separator.