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CONTENTS
Volume 4, Number 1, March 2015
 

Abstract
A pot experiment was conducted to assess the effects of red pepper (Capsicum annuum) and coriander (Coriandrum sativum) on seedling growth of wheat (Triticum aestivum). The aqueous extracts treatment of red pepper and coriander showed a significant (p < 0.05) reduction in root, shoot and seedling length, number of leaves and seedling dry weight of wheat (T. aestivum) as compared to control. The inhibitory different effect on growth of wheat (T. aestivum) was directly proportional to the increasing concentration (1, 2, 3, 4 and 5%) of aqueous extracts of red pepper and coriander as compared to control treatment (0%). The root, shoot, seedling length and number of leaves of T. aestivum significantly p < 0.05 decreased at 5% concentration of red pepper as compared to control. The root, shoot and seedling growth of T. aestivum was also significantly reduced at 1, 2, 3, 4 and 5% concentration of coriander as compared to control. The root, shoot and leaves dry weight of T. aestivum at 5% coriander extract treatment concentration decreased as compared to control. The tolerance in seedlings of T. aestivum to red pepper and coriander extract treatment was dose dependent as compared to control. The seedlings of T. aestivum showed low percentage of tolerance to pepper extract treatment than coriander extract treatment.

Key Words
red pepper; coriander; plant extracts; allelopathy; phytotoxicity; seedling growth; wheat

Address
(1) Muhammad Zafar Iqbal, Lubna Ahmed, Muhammad Shafiq:
Department of Botany, University of Karachi, Karachi-75270, Pakistan;
(2) Mohammad Athar:
Department of Food Science and Technology, University of Karachi, Karachi-75270, Pakistan;
(3) Mohammad Athar:
California Department of Food and Agriculture, 3288 Meadowview Road, Sacramento, CA 95832, USA.

Abstract
In this study, we numerically investigated the effect of pressure (100-250 bar), temperature (274-288 K), and salinity (3.5% w/w electrolytes) on CO2 hydrate dissolution rates in the ocean. Mass transfer equations and CO2 solubility data were used to estimate the CO2 hydrate dissolution rates. The higher pressure and lower temperature significantly reduced the CO2 hydrate dissolution rates due to the increase of CO2 particle density. In the high salinity condition, the rates of CO2 hydrate dissolution were decreased compared to pure water control. This is due to decrease of CO2 solubility in surrounding water, thus reducing the mass transfer of CO2 from the hydrate particle to CO2 under-saturated water. The results obtained from this study could provide fundamental knowledge to slow down or prevent the CO2 hydrate dissolution for long-term stable CO2 storage in the ocean as a form of CO2 hydrate.

Key Words
CO2 hydrate dissolution; mass transfer; ocean conditions; CO2 storage

Address
Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea.

Abstract
Wastewaters of textile industry cause high volume colour and harmful substance pollutions. Photocatalytic degradation is a method which gives opportunity of reduction of organic pollutants such as dye containing wastewaters. In this study, photocatalytic degradation of C.I. Basic Yellow 28 (BY28) as a model dye contaminant was carried out using Degussa P25 in a photocatalytic reactor. The experiments were followed out at three different azo dye concentrations in a reactor equipped UV-A lamp (365 nm) as a light source. Azo dye removal efficiencies were examined with total organic carbon and UV-vis measurements. As a result of experiments, maximum degradation efficiency was obtained as 100% at BY28 concentration of 50 mgL-1 for the reaction time of 2.5 h. The photodegradation of BY28 was described by a pseudo-first-order kinetic model modified with the langmuir-Hinshelwood mechanism. The adsorption equilibrium constant and the rate constant of the surface reaction were calculated as Kdye = 6.689ù10-2 L mg-1 and kc = 0.599 mg L-1min-1, respectively.

Key Words
photocatalytic degradation; Degussa P25; textile dye wastewaters; Basic Yellow 28; Langmuir-Hinshelwood mechanism

Address
Yildiz Technical University, Chemical Engineering Department, Davutpasa Campus, No: 127, 34210 Esenler, Istanbul, Turkey.

Abstract
Bisphenol A is widely used in plastic and other industrial consumer products. Release of bisphenol A and its analogues into the aquatic environment during manufacture, use and disposal has been a great scientific and public concern due to their toxicity and endocrine disrupting effects on aquatic wildlife and even human beings. More recent studies have shown that these alkylphenols may affect the molting processes and survival of crustacean species such as American lobster, crab and shrimp. In this study, we have developed gas chromatography with flame ionization detection (GC-FID) and gas chromatographymass spectrometric (GC-MS) methods for the determination of bisphenol A and its analogues in shrimp Macrobrachium rosenbergii, blue crab Callinectes sapidus and American lobster Homarus americanus samples. Bisphenol A, 2,4-bis-(dimethylbenzyl)phenol and 4-cumylphenol were found in shrimp in the concentration ranges of 0.67.5.51, 0.36.1.61, and < LOD (the limit of detection)-1.96 ng/g (wet weight), and in crab of 0.10-0.44, 0.13-0.62, and 0.26-0.58 ng/g (wet weight), respectively. In lobster tissue samples, bisphenol A, 2-t-butyl-4-(dimethylbenzyl)phenol, 2,6-bis-(t-butyl)-4-(dimethylbenzyl)phenol, 2,4-bis-(dimethybenzyl)phenol, 2,4-bis-(dimethylbenzyl)-6-t-butylphenol and 4-cumylphenol were determined at the concentration ranges of 4.48-7.01, 1.23-2.63, 2.71-9.10, 0.35-0.91, 0.64-3.25, and 0.44-1.00 ng/g (wet weight), respectively. At these concentration levels, BPA and its analogs may interfere the reproduction and development of crustaceans, such as larval survival, molting, metamorphosis and shell hardening.

Key Words
bisphenol A; alkylphenol; 4-cumylphenol; 2,4-bis-(dimethylbenzyl)phenol; 2-t-butyl-4-(dimethylbenzyl)phenol; gas chromatography-mass spectrometry; GC-FID; lobster, crab, shrimp

Address
(1) Yuegang Zuo, Zhuo Zhu, Mohammed Alshanqiti, Joseph Michael:
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;
(2) Yiwei Deng:
Department of Natural Sciences, University of Michigan, Dearborn, MI 48128, USA.

Abstract
Chemically activated and carbonized adsorbents were prepared from Moringa oleifera pod husks (MOP), characterized and evaluated for their ability to remove a common antibiotic - ofloxacin (OFX) from aqueous solution. The pulverized precursor was steeped in a saturated ammonium chloride solution for a day to give the chemically activated adsorbent (AMOP). A portion of AMOP was pyrolyzed in a muffle furnace at 623 K for 30 min to furnish its carbonized analogue (CMOP). The adsorbents showed favorable physicochemical attributes. The effects of operational parameters such as initial OFX solution pH and concentration, adsorbent dosage, temperature and contact time on OFX removal were investigated. At equilibrium, optimal removal efficiencies of 90.98% and 99.84% were achieved at solution pH 5 for AMOP and CMOP, respectively. The equilibrium adsorption data fitted into both the Langmuir and Freundlich isotherms. Gibbs free energy change (ΔGo), enthalpy change (ΔHo) and entropy change (ΔSo) indicated that the adsorption of OFX was feasible, spontaneous, exothermic and occurred via the physisorption mode. Adsorption kinetics obeyed the Blanchard pseudo-second-order model. The results may find applications in the adsorptive removal of micro-contaminants of pharmaceutical origin from wastewater.

Key Words
ofloxacin; Moringa oleifera pod husks; adsorption isotherms; adsorption kinetics; wastewater

Address
Department of Chemistry and Centre for Agrochemical Technology,Federal University of Agriculture, Makurdi 970001, Nigeria.


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