Treatment of Municipal Wastewater Contaminated with Heavy Metals and Hydrocarbons by Chlorella vulgaris

The current study was conducted using the green algae Chlorella vulgaris to treat municipal sewage water taken from the central Rumaitha water treatment plant, Muthanna Governorate, Iraq. It aimed to assess the efficiency of algae in improving water quality through algae treatment (Phycoremediation) for some heavy metal pollutants such as lead, cadmium and copper, in addition to the total hydrocarbons present in those waters. The experiment was carried out by adding contaminated water to the algal culture after the algae Chlorella vulgaris reached to the Stationary phase. The treatment process continued for 8 days before the algae reached to the Death phase, in order to obtain the best efficiency period for the algae during the treatment process. The results showed a high efficiency of Chlorella vulgaris in treating municipal wastewater, where the results showed the removal percentage after 4 days of treatment and it was as follows, copper 98.9%, cadmium 94.75%, lead 57.5% and total hydrocarbons 64.5%. While it was noted that the reduction percentage increased after a treatment period of 8 days, the results were as follows: copper 99.2%, cadmium 97.9%, lead 75.3% and total hydrocarbons 72.3%. The results of this study confirmed the efficiency of Chlorella vulgaris in the treatment process and its high ability to remove heavy metal and hydrocarbon pollutants. Thus, algae processing is a promising, highly efficient and environmentally friendly biological treatment technology.