Treatment and recycling potential of laundry wastewater containing surfactant by electrocoagulation method

Surfactants are a large group of chemicals that occupy an important place in many areas. These areas vary in cleaning, textile, dyeing and many more applications. Surfactants that affect (mostly reduce) surface tension when dissolved in water or an aqueous solution consist of hydrophilic and hydrophobic portions. Within the scope of this thesis, the treatment and recovery potential of the gray waste laundry wastewater with high surfactant content was investigated. Laundries are establishments that serve institutions such as hotels, restaurants and hospitals, use high volumes of water and, consequently, cause high levels of wastewater generation. Suspended solids, Chemical Oxygen Demand (COD), Total Organic Carbon (TOC), color, conductivity and pH parameters come to the fore in this wastewater, which is in the gray water class. These waters, which can be used in different stages of the process after being treated, are discharged. Traditional treatment methods such as biological physical and chemical treatment methods are insufficient in the removal of suspended solids, surfactants and color removals in the treatment of laundry wastewater. For this reason, advanced treatment methods were preferred because it is safer, more effective and environmentally friendly in wastewater treatment. Among these methods, electrocoagulation and electroflotation are very effective in the treatment of wastewater containing surfactants. In this study, aluminum electrodes are preferred in the electrocoagulation process for the treatment of laundry wastewater, while iron electrodes are used for electroflotation. As a result of the optimization studies, 4,5 pH, 7,89 mA/cm2 current density and 7 min operating values were determined, and under these conditions, the treatment efficiency was calculated as 93-97 % for surfactant, 98 % for color and 99 % for turbidity. The results obtained showed that the electrocoagulation method has a high potential for the treatment and reuse of laundry wastewater.