The removal of organic dyes such as Methylene Blue, Thymol Blue, Malachite Green and Methyl Violet from aqueous solution have been attempted by ZnO doped magnetic activated carbon. The phase compositions and morphology of the composite were characterized by using XRD, SEM, EDAX and FT-IR. The influence of various parameters such as effect of agitation time, dye concentration and pH has been studied. The ZnO-Fe3O4/Activated Carbon composite attained a maximum removal efficiency of almost 95% under natural sunlight irradiation for 90 min as compared with pure ZnO (58%). First and Second order kinetic models were evaluated to study the adsorption kinetics in case of Methylene Blue. The adsorption system follows second order kinetics. Even Langmuir isotherm has also been studied for 1st cycle as well as 2nd cycle of the composite used for removal. As far as the Langmuir Isotherm is concerned, it gives the best data correlation based on homogeneous surface i.e surface consists of identical sites, equally available for adsorption. The theoretical monolayer removal capacity Qo of the composite is found to be 34.84mg/g and 33.55mg/g for 1st cycle and 2nd cycle respectively. The effect of desorption at different pH shows that the adsorption is very less. However, the results shows that the composite is quiet effective as there is a vast reduction in COD of industrial effluent samples which has been collected from Hosur, India. After the careful study of photocatalytic activity and reusability of ZnO loaded magnetic activated carbon, it can be a promising photocatalyst under sunlight for practical use in wastewater treatment to control water pollution.