Treatment of bentazon herbicide solutions by vacuum membrane distillation

Experimental investigations were carried out to treat bentazon solutions by the vacuum membrane distillation process (VMD). The effects of several parameters, including feed temperature, feed flow rate, vacuum pressure and initial bentazon feed concentration on flux quality and quantity were studied. The VMD process was found to be effective in the treatment of the bentazon solutions as the permeate was absolutely pure water. Results showed that increasing temperature and flow rate and decreasing vacuum pressure and bentazon concentration enhance permeate flux. Temperature and vacuum pressure were found to be the most important factors for permeate flux. Under the best conditions (a feed temperature of 60 °C and a vacuum pressure of 30 mbar), a maximum permeate flux of 92.94 kg/m2 h was obtained. Also, a mathematical model describing the variation of bentazon concentration with time was developed and validated with the experimental results.