Abstract
We investigated that removal of aqueous U(VI) by nano-sized Zero Valent Iron (nZVI) and Fe(II) bearing minerals (controls) in this study. Iron particles showed different U(VI) removal efficiencies (Mackinawite: 99%, green rust: 95%, nZVI: 91%, magnetite: 87%, pyrite: 59%) due to their different PZC (Point of Zero Charge) values and surface areas. In addition, noticeable amount of surface Fe(II) (181
Key Words
uranium; nZVI; ion- exchange; Fe(II) colloids; LIBD
Address
Youngho Shin, Sungjun Bae and Woojin Lee: Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
Abstract
Bisphenol A and other alkylphenols are widely used in plastic and other industrial consumer products. Release of these compounds into the aquatic environment during their manufacture, use and disposal has been a great scientific and public concern due to their toxicity at high concentrations and endocrine disrupting effects at low concentration on aquatic wildlife and human beings. This paper reviews the published data and researches on the environmental occurrence, distribution, health effects and analytical techniques of bisphenol A and alkylphenols. The aim is to provide an overview of the current understanding about bisphenol A and alkylphenols in the environment and the difficulties faced today in order to establish standard and systematic environmental analysis and assessment process for these endocrine disruptor compounds.
Key Words
bisphenol A; alkylphenols; environmental fates; environmental endocrine disruptors; gas chromatography-mass spectrometry; high-performance liquid chromatography; liquid-liquid extraction
Address
Zhuo Zhu and Yuegang Zuo: Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, University of Massachusetts Graduate School of Marine Sciences and Technology, 285 Old Westport Road, North Dartmouth, MA 02747, USA.
Abstract
Global demand for dwelling energy and implications of changing climatic conditions on buildings confront the built environment to build sustainable dwellings. This study investigates the variability of future climatic conditions on newly built detached dwellings in the UK. Series of energy modelling and simulations are performed on ten detached houses to evaluate and predict the impact of varying future climatic patterns on five building performance indicators. The study identifies and quantifies a consistent declining trend of building performance which is in consonance with current scientific knowledge of annual temperature change prediction in relations to long term climatic variation. The average percentage decrease for the annual energy consumption was predicted to be 2.80, 6.60 and 10.56 for 2020s, 2050s and 2080s time lines respectively. A similar declining trend in the case of annual natural gas consumption was 4.24, 9.98 and 16.1, and that for building emission rate and heating demand were 2.27, 5.49 and 8.72 and 7.82, 18.43 and 29.46 respectively. The study further analyse future heating and cooling demands of the three warmest months of the year and ascertain future variance in relative humidity and indoor temperature which might necessitate the use of room cooling systems to provide thermal comfort.
Key Words
buildings; energy; performance; future weather; sustainability
Address
Joseph Amoako-Attah and Ali B-Jahromi: University of West London, School of Computing and Technology, Dept. of the Built Environment St Mary\'s Road, Ealing, London W5 5RF, United Kingdom.
Abstract
Coagulation-flocculation (CF) was tested coupled with an aerobic biofilter to reduce total petroleum hydrocarbon (TPHs) concentration and toxicity from petrochemical wastewater. The efficiency of the process was followed using turbidity and chemical oxygen demand (COD). The biofilter was packed with a basaltic waste (tezontle) and inoculated with a bacterial consortium. Toxicity test were carried out using Lactuca sativa var. capitata seeds. Best results for turbidity removal were obtained using alum. Considerable turbidity removal was obtained when using Opuntia spp. COD removal with alum was 25%, for Opuntia powder it was 36%. The application of the biofilter allowed the removal of 70% of the remaining TPHs after 30 days with a biodegradation rate (BDR) value 47 mgL-1d-1. COD removal was slightly higher with BDR value 63 mgL-1d-1. TPH kinetics allowed a degradation rate constant equal to 4.05
Address
(1) Erick R. Bandala, Juan Bernardo Tiro, Mariana Lujan, Francisco J. Camargo, Jose Luis Sanchez-Salas and Silvia Reyna: Grupo de Investigacion en Energia y Ambiente, Universidad de las Americas, Puebla, Puebla, Ex-Hacienda de Sta. Catarina Martir, San Andres Cholula 72810 Puebla, Mexico;
(2) Gabriela Moeller: Instituto Mexicano de Tecnologia del Agua, Mexico;
(3) Luis G. Torres: Unidad Profesional Interdisciplinaria de Biotecnologia, Instituto Politecnico Nacional, Mexico.
Abstract
Biosorption represents a technological innovation as well as a cost effective
excellent remediation technology for cleaning up radionuclides from aqueous environment. In the present study, abacteria strain FB12 with high adsorption rate of uranium ion was isolated from the vicinity of the nuclear power plant. It was tentatively identified as Bacillus sp.FB12 according to the 16S rDNA sequencing. Efforts were made to further improve the adsorption rate and genetic stability by UV irradiation and UV-LiCl cooperative mutagenesis. The improved strain named Bacillus sp.UV32 obtains excellent genetic stability and a high adsorption rate of 95.9%. The adsorption of uranium U (VI) by Bacillus sp.UV32 from aqueous solution was examined as a function of metal ion concentration, cell concentration, adsorption time, pH, temperature, and the presence of some foreign ions. The adsorption process of U (VI) was found to follow the pseudo-second-order kinetic equation. The adsorption isotherm study indicated that it preferably followed the Langmuir adsorption isotherm. The thermodynamic parameters values calculated clearly indicated that the adsorption process was feasible, spontaneous and endothermic in nature. These properties show that Bacillus sp.UV32 has potential application in the removal of uranium (VI) from the radioactive wastewater.
Key Words
uranium contamination; Bacillus sp.; mutagenesis; Biosorption; kinetic
Address
Xiaoping Xu, Shengbin He, Zhenshou Wang, Yang Zhou and Jing Lan: College of
Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350108, China.
