Before using Zn-rich sewage sludge in agricultural soil, it is very important to study the behavior of this pollutant and its mobility in semiarid climate to prevent the risk that may pose on the human health. Batch technique was used to study sorption and desorption experiments of zinc onto hydromorphic soil with a loamy texture. Results showed that the effect of pH ranged between 6 and 7.8 on zinc sorption amount was negligible. Whereas the coefficient of distribution K (d) at pH = 6 was 1-3 times greater than at pH = 7.8. The increase in temperature from 25 +/- A 2 to 40 +/- A 2 A degrees C increased zinc uptake by 4.37-63.2 % and 3.75-27.09 % at pH 7.8 and 6, respectively. The removal of organic matter slightly enhanced zinc sorption at alkaline pH; while it remarkably reduced it at acidic pH suggesting that organic matter effect depended significantly on pH. All sorption data of zinc fitted only the Freundlich equation. Also, the sorption energies (E) calculated from the Dubinin-Radushkevich equation were high implicating that the main process of zinc uptake was chemisorption. Zinc speciation after sorption experiments showed that the added zinc amount was mostly bonded to oxides fraction at alkaline pH and to organic matter at acidic pH. Zinc mobility in the two investigated soil pH values was similar, while its mobility was not very affected by the organic matter removal. The percentage of desorbed zinc (bioavailable) was higher into 0.05 M of ethylenediaminetetraacetic acid (about 20 %) than into distilled water (a parts per thousand currency sign4 %). From the principal component analysis, we deduced that pH was the main factor controlling zinc sorption and the coefficient of distribution K (d) was the best parameter that describes the mechanism of zinc retention onto hydromorphic soil.