Hydrolysis of l-(2-chlorobenzoy|)-3-(4-chlorophenyl) urea in aquatic system

The degradation of the insect growth regulator 1-(2-chlorobenzoyl)-3-(4-chlorophenyl)urea (CCU)was studied both in distilled water and in buffer solution．The experimental results indicated that CCU is not stable in aqueous solution and easily decomposes in alkaline water．At pH 6 and pH 10，the half lives (Tv2)of hydrolysis arc about 9 days and 2 days，respectively．The rate of hydrolysis increases as either the concentration of alkalinity or temperature increases．At NaOH]=0.01865 mol/L，with every lOoC increase in temperature，the reaction rate increases about 3 times．the activation energy for hydrolysis is 7l.56 kJ/mol．Basic catalyzed degradation of CCU at levels greatly above its solubility in water resulted in rapid degradation to as many as four identified products：(4-chlorophenyl)urea，2-chlorobenzoic acid，2-chlorobenzamide，and 4-chloroaniline．The major products were(4-chlorophenyl)urea and 2-chlorobenzoic acid．