Study on melt-blown processing,web structure of polypropylene nonwovens and its BTX adsorption

Petroleum hydrocarbons can have adverse impacts on the environment and human health especially when they exist in the form of emulsion and aqueous solution. Nonwovens prepared by melt-blown method are a potential candidate for the removal of petroleum hydrocarbons. In this study, the processing-structure-oil sorption relationships of the PP (polypropylene) melt-blown nonwovens were investigated. Besides, the kinetics and mechanism of toluene sorption in simulated fire-fighting wastewater on the optimized prepared PP melt-blown nonwovens were studied at the static and dynamic conditions. The results showed that the web structure can be effectively controlled by adjusting the hot air temperature, metering pump speed and distance of collector to die to obtain an average fiber diameter of 3.0-10.5 μm, surface area of 0.5-1.5 m²/g and porosity of 71.0-99.0 %. The sorption capacity for pure BTX medium increased with the decreasing fiber diameter and increasing porosity. The pseudo-second-order kinetic model better fitted the experimental data to describe the sorption of emulsified and dissolved form of toluene at static and dynamic conditions. The toluene sorption can be a combination of adsorption and capillarity, the contribution of which was about 1:14.