In this study, different methods of electron beam (EB) irradiation and potassium ferrocyanide (K4Fe(CN)(6)) activated by simulated sunlight irradiation (lambda >= 290 nm) were adopted to generate hydrated electron (e(aq)(-)), respectively. Steady-state and laser flash photolysis experiments were conducted to evaluate the feasibility of using e(aq)(-) reduction to enhance the dechlorination of TCS in aqueous solution. Under the EB irradiation, e(aq)(-) was proved to be an effective radical, and significant degradation of TCS was observed. Under simulated sunlight irradiation, TCS degradation efficiency within 60 min increased from 70.3% (without K4Fe(CN)(6)) to 100% [TCS](0)/[K4Fe(CN)(6)](0) = 1/5), and the average dechlorination percentage after 2 h increased from 62.7% to 90.7%, respectively. The degradation of TCS in the presence of e(aq)(-) adhered to the apparent first-order kinetics, and the optimal rate constant (k(p)) was (1.54 +/- 0.02) x 10(-3) s(-1). Several enhanced dechlorination products were obtained and a primary reaction mechanism was proposed. (C) 2014 Elsevier B.V. All rights reserved.