The innovation is based on treatment of laundry wastewater, which mainly constitutes of recalcitrant organic compounds, by advanced oxidation process. the reactor system consists of three uv cartridges or reactors, similar to those used in ro/uv filters used at houses, offices and institutions for providing drinking water. the cartridges are sequentially arranged in vertical position, with the outlet of one reactor being connected to the inlet of the next. each cartridge is provided with an 11 watt uv lamp, of which two are kept operational by connecting to a power source by means of a dc choke. upflow condition is maintained and wastewater is allowed to flow into the system at a fixed rate by means of a peristaltic pump. suitable amount of hydrogen peroxide is dosed into the wastewater before its treatment. the uv light helps in formation of hydroxyl radicals, which break down the recalcitrant organic compounds and leads to treatment of the wastewater. treated wastewater is collected at the outlet for analysis. several trials can be performed to achieve optimum conditions corresponding to maximum treatment efficiency.