Peyman Mahmoodi - Department of Chemical Engineering, University of Isfahan, Isfahan, Iran
Mehrdad Farhadian - Department of Chemical Engineering, University of Isfahan, Isfahan, Iran.
Ali Reza Solaimany Nazar - Department of Chemical Engineering, University of Isfahan, Isfahan, Iran.
Amin Noroozi - Department of Chemical Engineering, University of Isfahan, Isfahan, Iran.

The efficiency of diazinon (as insecticides) and nitrate (related to nitrogen fertilizer) removal from contaminated water is investigated through NF membrane technique. The effects of nitrate concentration (40-160 mg/l), diazinon concentration (10-1000 µg/l) and pH (5-9) on the efficiency of a commercial polyamide nanofilter membrane at a constant pressure of (800 KPa) are investigated. The response surface method (Box-Behenken design) is applied in design of experiment. As the diazinon concentration and pH are enhanced, the contaminant removal efficiency increases from 85% to 90%; while nitrate concentration has an opposite effect (removal efficiency reduces about 10%). The regression models obtained for nitrate and diazinon rejection show good fitting to the experimental results (r-squared equal to 94% and 98%, respectively). The models are able to predict the evolution of diazinon and nitrate as a function of concentration and pH at a constant pressure.

Contaminated water, Diazinon, Nitrate, Agricultural wastewater, Environment, Nanofiltration