Study of synergistic effect of diatomite and modified attapulgite on reducing asphalt volatile organic compounds emission

Abstract

The irritating flue gas generated during the heating process of asphalt is a serious emission pollution, causing both health risks and environmental hazards. In this work, a hybrid modified asphalt was prepared to reduce the volatile organic compounds (VOCs) emissions by using diatomite as the primary adsorption material and modified attapulgite as the flame retardant. The physical and rheological property tests showed that the compound of diatomite and modified attapulgite can improve the elevated temperature capability of the binder while slightly reducing the fatigue resistance. The results of the gas chromatography-mass spectrometer test (GC–MS) indicated that the total amount of VOCs released by the compound modifier modified asphalt was reduced by 81.5% compared with that of virgin asphalt (VA), the type of aliphatic hydrocarbons (ALHs) and hydrocarbon derivatives (HYDs) was also reduced by 77% and 92%, respectively. Scanning electron microscopy (SEM), simultaneous thermal (TG), and brunaurer emmett teller (BET) analysis showed that the mechanism of VOCs concentration reduction by the compound modifier might be chelation of dilution (water)-adsorption (hole)-blocking (insulating layer). This study provides a clean asphalt production method to reduce VOCs emission.