Abstract:The objective of this work was to determine the effect of pH, temperature and initial Cr (VI) concentration on kinetics of Cr (VI) reduction, and to develop two kinetics models for the rate constants upon pH and temperature, respectively. Results indicated that the redox reaction of gallic acid and hexavalent chromium was the pseudo-first-order kinetics reaction at pH 2.0~5.0; because H+ is insufficient, the reaction was not pseudo-first-order at pH 6.5. The rate constants (103kobs) were 951.6, 103.6, 17.3and 7.5h-1respectively when pH was from 2.0to 5.0. At pH 2.5, increasing temperature could increase the kobs, and the kobs increased by 0.61 and 2.68 times when temperature was adjusted from 10℃ to 20℃ and 30℃. The rate constants of Cr (VI) reduction were gradually decreased with increasing initial concentration ratio of Cr (VI) and gallic acid. The kinetics equation of the rate constants and [H+] was obtained through a weighted least-squares linear regression method, and Arrhenius formula was used to develop the kinetics equation of the rate constants and temperature. These provided a model reference for analysis and forecast the reaction rates and Cr (VI) concentration on reaction of Cr (VI) reduction with gallic acid.