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CONTENTS
Volume 2, Number 1, March 2013
 

Abstract
There is a significant demand to make various dissolved gases in water. However, the conventional aeration method shows low gas mass transfer rate and gas utilization efficiency. In this study, a novel rotating wheel entraining gas method was developed for making high dissolved O2 and O3 in water. It produced higher concentration and higher transfer rate of dissolved O2 and O3 than conventional bubble aeration method, especially almost 100% of gas transfer efficiency was achieved for O3 in enclosed reactor. For application of rotating wheel entraining gas method, aerobic bio-reactor and membrane bio-reactor (MBR) were successfully used for treatment of domestic and pharmaceutical wastewater, respectively; and vacuum ultraviolet (VUV)/UV+O3/O2 reactors were well used for sterilization in air/water, removal of dust particles and toxic gases in air, and degradation of pesticide residue and sterilization on fruits and vegetables.

Key Words
rotating whee; entraining gas; dissolved ozone; dissolved oxygen; air purification; water treatment

Address
Haitao Li, Bo Xie and Mizhou Hui: National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China

Abstract
Urine is a widely used matrix in biomonitoring studies on the assessment of human exposure to environmental chemicals such as phthalate esters and bisphenol A (BPA). In addition to the need to apply valid analytical techniques, assurance of specimen integrity during collection and storage is an important prerequisite for the presentation of accurate and precise analytical data. One of the common issues encountered in the analysis of non-persistent contaminants is whether shipping and storage temperature and time since collection have an effect on sample integrity. In this study, we investigated the stability of phthalate metabolites and BPA in spiked and unspiked urine samples stored at room temperature (20

Key Words
storage; urine; biomonitoring; phthalate; BPA; half-life

Address
1Ying Guo, Lei Wang and Kurunthachalam Kannan: Wadsworth Center, New York State Department of Health and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, P.O. Box 509, Albany, New York 12201-0509, USA;
2Lei Wang: Ministry of Education Key Laboratory of Pollution Process and Environmental Criteria and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin, 300071, China

Abstract
Microalgae are receiving an increasing attention because of their potential use as CO2 capture method and/or as feedstock for biofuels production. On the other hand the current microalgae-based technology is still not widespread since it is characterized by technical and economic constraints that hinder its full scale-up. In such contest the growth kinetics of Nannochloris eucaryotum (a relatively unknown marine strain) in batch and semi-batch photobioreactors is quantitatively investigated with the aim of obtaining the corresponding kinetic parameters suitable for process engineering and its optimization. In particular the maximum growth rate was evaluated to be 1.99 10-3 h-1. Half saturation concentrations for nitrates (KN) and phosphates uptake (KP) were evaluated as 5.4 10-4 gN L-1 and 2.5 10-5 gP L-1, respectively. Yield factors for nitrogen (YN) and phosphorus (YP) resulted to be 5.9 10-2 gN g-1biomass and 6.0 10-3 gP g-1biomass, respectively. The possibility of using 100% (v/v) CO2 gas as carbon source is also evaluated for the first time in the literature as far as N. eucaryotum is concerned. The strain showed a good adaptability to high concentrations of dissolved CO2 as well as to low pH. The lipid content under 100% CO2 is about 16.16 %wt wt-1 and the fatty acid methyl esters composition of the extracted oil is in compliance with the European regulation for quality biodiesel.

Key Words
microalgae; kinetics; Nannochloris eucaryotum; lipid content; biofuels; CO2 capture

Address
Alessandro Concas and Giacomo Cao: Centro di Ricerca Sviluppo e Studi Superiori in Sardegna (CRS4), Loc. Piscina Manna, Edificio 1, 09010 Pula (CA), Italy;
Giovanni Antonio Lutzu and Giacomo Cao: Centro Interdipartimentale di Ingegneria e Scienze Ambientali (CINSA), Universita di Cagliari e Laboratorio, di Cagliari del Consorzio \"La Chimica per l\'Ambiente\", via San Giorgio 12, 09124 Cagliari, Italy;
Antonio Mario Locci and Giacomo Cao: Dipartimento di Ingegneria Meccanica, Chimica e Materiali, Universita di Cagliari, Piazza d\'Armi, 09123 Cagliari, Italy

Abstract
Research work on removal of fluoride from water, referred to as water defluoridation, has resulted into the development of a number of technologies over the years but they suffer from either cost or efficiency drawbacks. In this work, enhancement effects of phosphate and silicate on defluoridation of water by low-cost Plaster of Paris (calcined gypsum) were studied. To our knowledge, the influence of silicate on defluoridation was not reported. It was claimed, that the presence of some ions in the treated water samples, was decreasing the fluoride removal since these ions compete the fluoride ions on occupying the available adsorption sites, however, phosphate and silicate ions, from its sodium slats, have enhanced the fluoride % removal, hence, precipitation of calcium-fluoro compounds of these ions can be suggested. Percentage removal of F- by neat Plaster is 48%, the electrical conductance (EC) curve shows the typical curve of Plaster setting which begins at 20 min and finished at 30 min. The addition of phosphate and silicate ions enhances the removal of fluoride to high extent > 90%. Thermodynamics parameters showed spontaneous fluoride removal by neat Plaster and Plaster-silicate system. The percentage removal with time showed second-order reaction kinetics.

Key Words
water treatment; plaster of Paris; calcined gypsum; adsorption; co-precipitation

Address
1Aiman Eid Al-Rawajfeh,Shorouq Hassan and Ruba Qarqouda: Tafila Technical University (TTU), Department of Chemical Engineering, P.O. Box 179, 66110 Tafila, Jordan;
2Aiman Eid Al-Rawajfeh: Jordan Atomic Energy Commission (JAEC), Shafa Badran, Amman, Jordan;
3Asma Aldawdeyah: Tafila Technical University (TTU), Department of Chemistry, P.O. Box 179, 66110 Tafila, Jordan

Abstract
The paper aims to characterise the waste generated in municipality of Varanasi, the most populated city in the state of Uttar Pradesh, India. MSW is a heterogeneous waste and composition of the waste varied from season to season. The generation, collection and management of waste have become a major environmental problem in most of the developing cities. MSW was collected from open dumping grounds for 2 consecutive years. Each year was classified into 3 seasons of 4 months. On analysis it was found that the biodegradable fraction is always more than other fractions with a minimum of 48.25% in rainy season. With such a high fraction of biodegradable wastes, options such as composting and biomethanation could be tried to convert waste into energy. The average weight of waste generation at present is 0.460 kg per capita per day. The study showed that waste generation and collection were increasing every year, which may be attributed to increase in population.

Key Words
characterization; seasons; MSW generation; collection; Varanasi

Address
Betty Dasgupta, Vijay Laxmi Yadav and Monoj Kumar Mondal: Department of Chemical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi-221005, Uttar Pradesh, India

Abstract
Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/m3. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/m3. Outdoor level of TVMCs was varied from 736-5855 cfu/m3. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/m3 in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.

Key Words
colony forming units (CFUs); indoor air quality (IAQ); indoor-outdoor (IO) ratio; relative humidity (Rh); temperature; viable counts of bacteria and fungi (VBCs and VFCs)

Address
Vinita Katiyar: Department of Respiratory Allergy & Applied Immunology, VP Chest Institute, University of Delhi-110017, India


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