Biomorphic nano-hydroxyapatite (HAP) was fabricated by a co-precipitation method using cotton as bio-templates and employed in adsorptive removal of ofloxacin (OFL) and triclosan (TCS) that are two representative pharmaceuticals and personal care products (PPCPs). The surface area and porosity, crystal phase, functional group, morphology and micro-structure of the synthesized HAP were characterized by Brunauer–Emmett–Teller isotherm, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron macroscopic and transmission electron microscopy. The effects of initial pH, ionic strength, initial concentration, contact time and temperature on the removal of PPCPs were studied in a batch experiment. The adsorption of OFL and TCS was rapid and almost accomplished within 50 min. Kinetic studies indicated that the adsorption process of OFL and TCS followed the pseudo-first-order and pseudo-second-order models, respectively. The Freundlich isotherm described the OFL adsorption process well but the adsorption of TCS fitted the Langmuir isotherm better. Thermodynamics and isotherm parameters suggested that both OFL and TCS adsorption were feasible and spontaneous. Hydrogen bond and Lewis acid–base reaction may be the dominating adsorption mechanism of OFL and TCS, respectively. Compared to other adsorbents, biomorphic HAP is environmentally friendly and has the advantages of high adsorption capacity, exhibiting potential application for PPCPs removal.
Modeling Tip: Importing & Exporting Traffic Data in CALRoads View
The CALINE series of models was developed to estimate pollutant concentrations from motor vehicles at roadway intersections. It includes three primary models: CALINE, CAL3QHC, and CAL3QHCR. The latter allows processing of real meteorological data (up to one year) and input of vehicular emissions, traffic volume, and signalization (ETS) data. Data reflecting traffic conditions for individual hours of a week can be input into CAL3QHCR. Lakes Environmental recently released CALRoads View Version 6.5 which includes...
Study shows online consumers want environmentally friendly options
Reducing the carbon footprint of what we buy isn’t easy, but the opportunity for impact is substantial: In the United States, producing and delivering consumer purchases releases twice as much carbon into the atmosphere as home energy use and personal travel. By gathering and sharing information on carbon emissions associated with their products, companies can make environmentally friendly choices easier for consumers and boost their own reputations as planet-friendly businesses. Advances in online technolog...
Studies on competitive adsorption of dyes onto carbon (XC-72) and regeneration of adsorbent
Carbon as an adsorbent has been widely studied for wastewater treatment, but the regeneration of adsorbent has been scarcely reported. In this paper, an economical and environmental method was applied to regenerate carbon (XC-72). Results showed that both anhydrous ethanol and deionized water did not obtain optimal effect for the desorption of Acid Orange 7, Ponceau 2R and Rhodamine B, but the desorption effect was dramatically improved when anhydrous ethanol and deionized water were mixed in a certain volume...
Beliefs, Politics, and Environmental Policy
IntroductionMany of us who work on environmental issues have faced the challenge of conveying their importance to nonspecialists. Perhaps we have found ourselves defending the robustness of climate science to a contrarian uncle, or extolling the importance of biodiversity to a dubious aunt. Our relations and friends are often educated people, skilled in their own professions, who have formed strong opinions about the science underlying environmental problems, their potential consequences for their own lives, and...
Intrinsic kinetics for fixed bed bioreactor in hospital wastewater treatment
Variation in hospital wastewater (HWW) pollutants and differences with municipal wastewater (MWW), make the use of biokinetic coefficients obtained from activated sludge in the MWW treatment unprofitable for designing, modeling and evaluation of biological processes for HWW treatment. Since this study was conducted to evaluate the performance and biokinetic coefficients of a fixed bed bioreactor (FBBR) using rice husks as fixed media in HWW treatment, a new modified method was also proposed for biokinetic estimatio...