Purification of domestic laundry wastewater in an integrated treatment system consists of coagulation and ultrafiltration membrane process

An integrated unit to purify and reuse domestic laundry wastewater consisting of coagulation, sand filtration, carbon adsorption, and ultrafiltration process is developed. Chitosan and Ameztreat 102 polyamine were used as coagulants and their treatability was measured by color, turbidity and concentration of Linear Alkylbenzene Sulphonates (LAS) at various operation conditions. As a result of the trial studies, the maximum removal efficiency was attained as (i) for Chitosan- 98.2% color, 99.3% turbidity, 100% LAS removal efficiency; (ii) for Polyamine-88% color, 99% turbidity, 100% LAS. The transport mechanism of the pollutant towards the coagulant was described using kinetic models. The thickener area calculated is 0.2436 m2 for the flow rate of 100 L/h by Kynch theory. The results were recommended that the laundry wastewater be efficiently treated in the proposed treatment train and could be reused effectively. [Display omitted] •New configurations were demonstrated to treat domestic laundry wastewater.•Treated wastewater presented meets the drinking water standards completely.•Focus was given to the transport of pollutants through kinetic model study.•Size of thickener needed, distribution of flocs formed were also examined.•The system emerges as an interesting alternative of low-cost sanitation.