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Most of the volatile organic compounds (VOCs) are toxic and harmful to human health and environment. In this study, hydrochars activated with CO2 were applied to remove VOCs. Two typical VOCs, acetone and cyclohexane, were used as the ‘model’ adsorbates to evaluate hydrochars’ performance. Specific surface areas of pristine hydrochars were small (<8 m2/g), whereas activated hydrochars showed much higher values (up to 1308 m2/g). As a result, the adsorption of VOCs onto the pristine hydrochars (13.24–24.64 mg/g) was lower than that of the activated ones (39.42–121.74 mg/g). The adsorption of the two VOCs onto the hydrochars was exothermal. In addition, there were significant correlations (R2 > 0.91) between the VOC removal and hydrochars’ specific surface area. These results suggest that the governing mechanism was mainly physical adsorption. Increasing experimental temperature (80–139 °C) desorbed the VOCs from the hydrochars. Due to its higher boiling point, cyclohexane desorption required a higher temperature than acetone desorption. The reusability of the activated hydrochars to the two VOCs was confirmed by five continuous adsorption-desorption cycles. The overall results indicated that hydrochars, particularly after CO2 activation, are sufficient for VOC abatement.

Hickory wood was pyrolyzed at 300 °C, 450 °C, and 600 °C to produce biochars, which were then modified by ball milling. The pristine and ball-milled biochars were used to remove volatile organic compounds (VOCs) including acetone, ethanol, chloroform, cyclohexane, and toluene. Compared with the corresponding pristine one, each ball-milled biochar showed significantly improved structural characteristics. Their specific surface area (SSA) increased by 1.4–29.1 times, average pore size (APS) decreased slightly, and the hydrophilicity and polarity were also enhanced according to the elemental analysis. The adsorption of VOCs by ball-milled biochar increased by 1.3–13.0 folds, and the maximum adsorption capacity of acetone was up to 103.4 mg/g. The adsorption of polar VOCs (acetone, ethanol, and chloroform) onto ball-milled biochars was mainly controlled by surface adsorption process, which was affected by the SSA, APS, and volatile organic matter of the biochars, as well as the properties of the VOCs. The adsorbed VOCs were completely desorbed from the ball-milled biochars at relatively low temperature (≤115.2 °C). Reusability experiments with five adsorption-desorption cycles showed that ball-milled biochar had an excellent reusability for all VOCs. Ball-milled biochars can therefore be used as an effective and regenerable adsorbent for the removal of VOCs.

This study analyzes the effects of OEF/OIF deployment (including deployment location, frequency of deployment, and days deployed) on the probability of being diagnosed with Post-Traumatic Stress Disorder (PTSD), schizophrenia and bipolar disorder. The authors examine active duty personnel in all four services of the U.S. armed services since the start of the Global War on Terrorism. The data are provided by the Defense Manpower Data Center (DMDC) and TRICARE; they include deployment, administrative, and medical information for all active duty service personnel between FY2001 and FY2011 (N=2,800,999). The authors used descriptive statistics, as well as multivariate analysis (probit models), to assess the deployment effects. Results show that a deployment, especially to Iraq, is associated with an increased probability of being diagnosed with PTSD and that the magnitude of the effect is higher for deployments after 2005 for the Army. Serving in combat-arms specialty fields is also associated with a higher probability of being diagnosed with PTSD among Army and Marine Corps service members. Deployment is associated with a lower probability of diagnosis for bipolar disorder. The total cases of schizophrenia among active duty service members are very low; thus, this condition is excluded from the multivariate analysis., http://archive.org/details/atenyearlookback1094527860, Major, Singapore Army, Civilian, Ministry of Defense, Singapore, Approved for public release; distribution is unlimited.