A conditioning treatment is performed on alum sludge for the object of enhancing its filterability, thus enhancing water removal from sludge. The sludge used in the experiments is obtained from Kedwan plant, Minia city, Egypt. Conditioners of different types are used, e.g., ferric chloride and lime (as an example of inorganic chemicals), Fenton reagent (adopted as one of the advanced oxidation processes) and Chitosan (adopted as a type of bio-polymers). The parameters studied are: effect of: conditioner dose, rate of mixing, time of reaction and pH value. The results of experiments showed that the minimum values for SRF (target of experiment) are 4.3*1012, 1.5*1012, 1.1*1012, 1.9*1011 and 3.2*1011 for conditioning with lime, FeCl3, Lime+FeCl3, Fenton reagent and Chitosan, respectively. These values represent a percentage reduction in SRF, compared to that of raw sludge, of 79.81, 92.96, 94.83, 99.11 and 98.49% for conditioning with lime, FeCl3, lime+FeCl3, Fenton reagent and Chitosan, respectively. Thus, Fenton reagent proved to be the best conditioner, among the conditioners examined, for conditioning alum sludge, followed by Chitosan, then comes (lime+FeCl3), FeCl3 and lastly lime.