Heating events drive the seasonal patterns of volatile organic compounds in a typical semi-arid city.

The emission characteristics, source apportionment and chemical behavior of volatile organic compounds (VOCs) are important for strategy-making on ozone (O) and fine particulate matter (PM) control. Based on the continuous observation during four seasons, the seasonal characteristics, chemical reactivity and source apportionment of 116 VOCs species were studied in a typical semi-arid city with no relevant research. The results showed that the annual average concentrations of total volatile organic compounds (TVOCs) in Hohhot was 44.

[Adsorption characteristic and form distribution of silicate in lakes sediments].

Taking surface sediments from the Wuliangsuhai Lake and Daihai Lake as adsorbent, the isothermal adsorption experiments of silicate on sediments were carried out and the adsorption behavior was explained by Langmuir, Freundlich and Temkin crossover-type equations, then the form distribution characters of silicate were studied after adsorption in this work. The results showed that the adsorption behavior of silicate on the two lakes sediments can be linear fitting in the lower concentration dose (< or = 3.00 mg x L(-1)); the sediments from the Wuliangsuhai Lake behaved adsorbing silicate while the sediments from the Daihai Lake behaved releasing silicate under the experimental dose; all of the Langmuir, Freundlich and Temkin crossover-type equations can be used to explain the adsorption behavior of silicate on the two lakes sediments, and the native adsorption silicate (NAS) and equilibrium silicate concentration (ESC(0)) calculated by the three equations could be used to explain the sink and source effects of the sediments from the two lakes; the silicate form distribution in the sediments after adsorption indicated that silicate adsorbed on particles were mainly added on the form of IEF-Si, CF-Si, IMOF-Si and OSF-Si, and the IMOF-Si and OSF-Si had important potential bioavailability.