Aqueous phase reforming coupled to catalytic wet air oxidation for the removal and valorisation of phenolic compounds in wastewater.

Aqueous phase reforming (APR) coupled to catalytic wet air oxidation (CWAO) has been investigated as an approach to remove phenolic compounds from wastewater, converting them into valuable gases. Partial oxidation of phenol was achieved in the first CWAO stage trying to minimize mineralization so to allow a high yield to valuable gases in the second APR stage. APR runs were carried out with different mixtures of compounds corresponding to phenol oxidation pathway (phenol, quinones, long and short chain acids) and representing different degrees of oxidation in CWAO stage. A range of TOC and COD removal (74-90%) was observed in APR stage for the single compounds, with higher removal for long chain acids. Likewise, long chain acids provided with the highest conversion to gases. APR of mixtures rich in acids gave the highest yield to CH4 (11.0 mmol CH4/g TOCinitial). H2 production was low in all cases, due to competing direct conversion of long and short chain acids into CH4. TOC and COD removal from wastewater was similar in APR-CWAO and APR, however the conversion to gases and the yield to CH4 were markedly higher for APR-CWAO, thus overcoming the difficulties previously observed in the direct APR of phenol.

The impact of taxation on tobacco consumption in Mexico.

BACKGROUND: The price of cigarettes to consumers in Mexico, and Latin America in general, remains low in comparison with other regions of the world. In Mexico, taxes represented 59% of the total price of cigarettes in 2006, compared to 75% or more in many high-income countries. The feasibility of raising taxes on cigarettes in Mexico--to both discourage consumption and increase revenues--is an important policy question. METHODS: Using household survey data, we undertake a pooled cross-sectional analysis of the demand for cigarettes in Mexico. We use a two-part model to estimate the price elasticity of cigarettes. This model controls for the selection effect that arises from the fact that the impact of price on the decision to smoke or not is estimated using all households in the dataset. RESULTS: The results indicate that price is a significant factor in household decisions concerning smoking and the number of cigarettes smoked. Holding other factors constant, our simulations show that a 10% increase in the cigarette tax in Mexico--calculated as a percentage of the price--yields a 12.4% increase in the price to the consumer, a 6.4% decrease in consumption of cigarettes and a 15.7% increase in the revenue yielded by the tax. CONCLUSION: In Mexico, there are strong arguments for increasing cigarette taxes. Revenue raised could be used to further prevent tobacco consumption and to finance current funding shortages for the treatment of diseases related to smoking.