Multimedia Fate Of Nonylphenol And Octylphenol In Environment

Nonylphenol (NP) and Octylphenol (OP) are typical materials of organic chemistry industry. NP and OP are mainly used for manufacturing the Nonylphenols polyethoxylates (NPnEOs) and Alkylphenols polyethoxylates (OPnEOs) which are widely used in detergent and industrial processing aids as the second largest non-ionic surfactants. As the main degradation products of NPnEOs and OPnEOs, a lot of NP and OP have been discharged into the environment through various channels. NP and OP are belonging to endocrine disrupters which can affect reproductive development and immune system of organisms. Studying the fate of NP and OP in environment is very important. In this paper, a multimedia fugacity model (Level IV) was applied to simulate the concentration distribution and transfer fluxes of NP and OP in four environmental compartments including water, up-sediment, middle-sediment and fish in Dianchi Lake from 1991 to 2013. The reliability of this model was analyzed by comparing modeling results with measured data and the key parameters were selected by means of sensitivity analysis.The study results showed that the sediment was the main reservoirs of NP and OP in Dianchi Lake. The highest concentration of NP was observed in the fish and OP was in up-sediment. NP and OP that discharged into Dianchi Lake was removed greatly by its degradation in water, accounting for about 77.11% and 75.50% of the total amounts while the rest was transferred into sediments and advection output. The migration flux from water to sediment, advection output and the migration flux from up-sediment to mi-sediment were the main process of migration among different media. The study results also indicated that the degradation rate of NP and OP in water, degradation rate of NP and OP in fish, organic carbon partition coefficient of NP and OP, organic carbon content of sediment and solid phase volume ratio had significant influences on the model sensitivity. The reliability of the model was verified by the agreement between calculated and measured concentrations. The study showed that the developed model was suitable for simulating the multimedia transfer and fate of NP and OP in the Dianchi Lake.Through the concentration prediction of NP and OP, concentration of NP in environment compartments is: water 1.72E-07 mol·m-3, up-sediment 4.11E-05 mol·m-3, mid-sediment 3.39E-05 mol·m-3, fish 5.52E-05 mol·m-3 and concentration of OP are:water 5.26E-08 mol·m-3, up-sediment 3.13E-05 mol·m-3, mid-sediment2.19E-05 mol·m-3, fish 1.93E-05 mol·m-3. Through the environment ecological Risk Assessment of NP and OP in Dianchi Lake, the concentrations of NP and OP are in the safe range. However, due to NP and OP have a low-dose effects, their potential ecological risk cannot be ignored.