We use results of a 3-D photochemistry/transport model for ozone formation in Mexico City during events in 1997 to investigate ambient concentrations of reactive nitrogen in relation to ozone-precursor sensitivity. Previous results from other locations suggest that ratios such as O3/NOy and H2O2/HNO3 might provide measurement-based indicators for NOx-sensitive or VOC-sensitive conditions. Mexic...

Three global Chemistry Transport Models – MOZART, MOCAGE, and TM5 – as well as MOZART coupled to the IFS meteorological model including assimilation of ozone (O3) and carbon monoxide (CO) satellite column retrievals, have been compared to surface measurements and MOZAIC vertical profiles in the troposphere over Western/Central Europe for summer 2003. The models reproduce the meteorological feat...

We present the first simultaneous measurements of HOx, NOx, and Clx radicals in the middle stratosphere obtained during a balloon flight at 34 N in September 1989, along with calculations from a photochemical model, to show that NOx catalytic cycles dominate loss of ozone (O3) for altitudes between 24 and 38 km; the observed abundance of ClO is lower than that expected for altitudes above 30 km...

This work evaluates the efficiency of different advanced oxidation processes (Fenton method, O3, H2O2 and O3/H2O2) for removing total COD (TCOD) and colour from biologically pre-treated swine manure. The Fenton process with a dosage of 100 mg L(-1) of Fe(2+) and 800 mg L(-1) of H2O2 resulted in about 78% TCOD and 96% colour reductions at an initial pH=3 after a reaction time of 30 min. Coagulat...

After sunset, a stable boundary layer (SBL) develops close to the ground, while the upper region of the daytime mixed layer becomes the residual layer (RL). Mixing between the SBL and RL is often quite limited and the RL is thought to be a reservoir for daytime mixed-layer pollutants under such conditions. However, ozone (O3) profiles observed in Maryland, U.S. suggest that the RL is not always...

[1] On 8–11 July 2007 the eastern United States experienced a severe heat wave and smog event with maximum temperatures approaching 38°C and maximum 8 h average ozone mixing ratios of 125 ppbv. We examine this episode with observations and numerical simulations using the Weather Research and Forecasting model with online chemistry (WRF/Chem with RADM2). The general features of this severe smog ...

Wastewater from a pharmaceutical formulation facility (TevaKS, Israel) was treated with a biological activated-sludge system followed by ozonation. The goal was to reduce the concentrations of the drugs carbamazepine (CBZ) and venlafaxine (VLX) before discharging the wastewater to the municipal wastewater treatment plant (WWTP). Both drugs were detected at extremely high concentrations in TevaK...

Background: Of the pharmacological modalities for knee osteoarthritis (OA), intra-articular injections including ozone(O3) and hyaluronic acid (HA) are commonly used for reducing pain and improving function. In this systematic reviewand meta-analysis, we aimed to compare the effect of O3 versus HA in reducing pain and increasing function in patientswith knee OA.Methods: ...

BACKGROUND Elevated tropospheric ozone severely affects not only yield but also the morphology, structure and physiological functions of plants. Because of concerns regarding the potential environmental risk of transgenic crops, it is important to monitor changes in transgenic insect-resistant rice under the projected high tropospheric ozone before its commercial release. METHODOLOGY/PRINCIPA...