δ13C Values of C3 herbaceous plants and their relationships with humidity indexes in arid and humid climatic regions in northern China

Liu X.Z. and Wang C.Z.

By measuring the stable carbon isotopes of C3 herbaceous plants and collecting the carbon isotope data of vegetation in northern China, such data as the geographic locations and climate factors of 47 sampling sites (33 of which were measured in this study) and carbon isotope of 325 plant samples (217 of which were measured in this study) were obtained. In addition, the humidity indexes in different climatic zones in northern China were calculated and moreover the spatial features of δ13C values of C3 herbaceous plants and their relationships with environmental factors such as humidity indexes were analyzed. Within the research scope, the δ13C values of C3 herbaceous plants in northern China ranged from –29.9 ‰ to –25.4 ‰, with the average value of –27.3‰. The average δ13C value of C3 herbaceous plants increased notably from the semi-humid zone to the semi-arid zone to the arid zone; the variation ranges of δ13C values of C3 plants in the above three climatic zones were –29.9‰ to –26.7‰ (semi-humid area), –28.4 ‰ to –25.6‰ (semiarid area) and –28.0 ‰ to –25.4 ‰ (arid area), respectively. Simple regression analysis showed that differences existed in the relationship between δ13C values of C3 herbaceous plants and humidity indexes. In the semi-arid zone, semi-humid zone and overall northern area, δ13C values of C3 herbaceous plants showed obvious linear negative correlation to humidity indexes (P < 0.05). With the increase of humidity indexes, the average δ13C value of C3 herbaceous plants tended to decrease to different extents. In the arid zone, however, linear positive correlation existed between the δ13C values of C3 herbaceous plants and the humidity indexes (P < 0.05). With every 0.1 increase in the humidity index, the average δ13C value increased significantly by 1.3 ‰. Annual average temperature may be the main reason for the differences in humidity indexes of the sampling sites and for the 13C fractionation abilities of C3 herbaceous plants in arid area.

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Kinetics and mechanism of reactions of aromatic acetals with N-Chloronicotinamide

Shenbagam K.1 and Mathiyalagan N.2*

Kinetics of N-Chloronicotinamide (NCN) oxidation of aromatic acetals is studied in acetonitrile medium. The oxidation follows first order kinetics with respect to NCN. The order with respect to acetal is zero. The reaction is accelerated by decreasing the polarity of the medi. The plot of log k vs. 1/D gives a straight line with a positive slope. The rate constant slightly decre-ases with increasing nicotinamide. Increase in ionic strength and added salt has marginal effect on the rate. Arrhenius parameters and activation parameters are calculated.

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Online spectrophtometric determination of Cr(III) and Cr(VI) in tannery wastewater using flow injection combined with low pressure ion chromatography

Shujuan Chen1, Ning Liu3, Xinshen Zhang1,2*, Dongjing Yang1 and Hemei Jiang1

Highly selective, low-cost and easily operating method has been developed for online separation and simultaneous determination of Cr (III) and Cr (VI) by using low pressure ion chromatography combined with flow injection spectrophtometric analysis(LPIC-FIA). Based on the selective adsorption of low pressure ion chromatographic column (LPICC) on Cr(III), a new online separation system of Cr(III) and Cr(VI) was proposed. Thus, the separated Cr(VI) and Cr(III) successively reacted with salicylfluorone(SAF) to form amaranthine complex in the presence of cetyltrimethylmmonium bromide (CTMAB), respectively. The complex gave maximum absorbance at 570 nm. All the variables were studied in order to optimize the reaction conditions. The calibration graphs were linear in the range of 10−1000 μg L−1 (Cr(Ⅲ)) and 5−1000μg L−1 (Cr(Ⅵ)) with correlation coefficients of 0.9996 and 0.9993 respectively. The R.S.D. obtained for 200 μg L−1 of Cr(Ⅲ) and 100 g L−1 of Cr(Ⅵ) was 2.36 % (n=12) and 2.17 %, respectively. The method was applied for the simultaneous determination of Cr(Ⅲ) and Cr(Ⅵ) in tannery wastewater with satisfactory results and recoveries in the range of 95.8%−104.6% and 96.5 %−104.6 % respectively.

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Adsorption Kinetics for the Removal of Hexavalent Chromium using Low Cost Materials

Khaldoun Al-Sou'od

This study proposes Jordanian Pottery as a low cost adsorbent for the removal of chromium from aqueous solution. The effect of contact time, initial concen-tration of Cr(VI), temperature and ionic strength on the adsorption of Cr(VI) onto clay's pottery were studied and discussed. Four kinetic models, the pseudo first and second-order equations, the Elovich equation and the Ritchie’s equation were selected to follow the adsorption process. The mechanism of sorption was investigated by using the intraparticle diffusion model. Kinetic parameters rate constants, equilibrium adsorption capacities and correlation coefficients, for each kinetic equation were calculated and discussed. Activation energy values were found to be between 13.85 and 33.10kJ mol-1.

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Synthesis, Characterization and Biological Studies of 9-Aryl Substituted Acridinedione Derivatives

Nalini V. and Girija R.*

Nearly fourteen acridinedione derivatives are prepared by thermal method using P2O5 / ethanol catalyst. The same compounds are prepared by solvent free green approach involving the exposure of neat reactants to microwave irradiation of three component reaction of dimedone, aromatic aldehydes and amines in a stoichiometric ratio 2:1:1 for few minutes and afforded the formation of stable acridinedione derivatives in an excellent yield (80-95%). The structure of all the products has been characterized by IR, 1H, 13C NMR and mass spectral studies. The percentage of yield and purity is compared and found to be excellent in greener method and this method is found to be environmental friendly.

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Chemical composition, antimicrobial and antioxidant activities of the essential oils of Murraya microphylla and Murraya alata

Huang Ya Si, Yuan Ke and Bai Yan*

Essential oils (EOs) of two Rutaceae species, including Murraya microphylla and Murraya alata, harvested in Hainan province, extracted by hydrodistillation, were analyzed by GC and GC/MS. Both oils were rich in sesquiterpenoids. The main components of EOs of M. microphylla were caryophyllene (26.17%), germacrene D (11.08%), 1-ethenyl-1-methyl-2 -(1-methylethenyl)-4- (1-methyl ethylidene)-Cyclohexane (8.62%), 1,2,3,5,6,7,8,8a -octahydro -1,8a-dimethyl-7- (1-methylethenyl)-Nap hthalene (7.85%) and cis, cis, cis- 1,1,4,8-tetramethyl-4,7,10- cycloundecatriene, (6.24%), whe reas those of M. alata were1,2,3,4,4,5,6,7-octahydro- 1,1,4,7-tetramethyl-1H-cycloprop (e) azu lene (40.32%),5,6-diethenyl-1-methyl- Cyclohexene (7.60%),and 1-ethenyl-1-methyl-2-(1-methyl ethenyl)-4-(1-methylet hylidene)-cyclohexane (6.07%). The antibacterial effects of the two EOs were assessed on four species of bacteria and four species of fungi using Kirby-Bauer disk-diffusion method. Most of the bacteria tested were susceptible to the two EOs, while the most fungi tested were not. Meanwhile, both of the EOs were evaluated for antioxidant activity by 2,2-diphenyl-2-picrylhydrazly(DPPH) assay, the antioxi-dant capacity of essential oil that obtained from M. microphylla was greater than that from M. alata.

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The Effects of the Rice Variety and Type of Fertilizer on the Emission of Greenhouse Gases from Rice Paddy Fields

Pantawat Sampanpanish1,2

This study evaluated the Suphanburi 1 and Pathumthani 80 rice varieties and the effects of using organic fertilizer (cow manure), organic fertilizer pellets and chemical fertilizer on the emission of greenhouse gases, namely carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The rice varieties were planted in a double-crop organic rice field at Pathumthani Rice Research Centre, Pathum-thani Province, Thailand. Chambers were used to cover each set of the designed experiments categ-orized by the stage of rice growth, as follows: before planting stage (0 day), initial stage (30 days), vegetative stage (60 days), panicle-formation stage (90 days) and maturation stage (120 days). The gas emitted from each set was collected into sampling bags and analyzed to determine the amount of carbon dioxide and methane using gas chromatography and the amount of nitrous oxide using infrared spectrophotometry. The Suphanburi 1 rice variety with chemical fertilizer emitted the highest quantity of carbon dioxide, 534.10 ± 109.05 mg/m2/day, as averaged over all of the stages of rice growth. In contrast, Suphanburi 1 rice without addition of fertilizer showed the lowest carbon dioxide emission at all stages, averaging 269.72 ± 39.59 mg/m2/day. The emission of methane was also the highest for Suphanburi 1 rice with chemical fertilizer, emitting an average rate of 1.79 ± 0.98 mg/m2/day, whereas methane emission was the lowest for the Pathumthani 80 rice variety with chemical fertilizer, emitting an average rate of 0.53 ± 0.62 mg/m2/day. The nitrous oxide emission was the highest in the set of experiments using the Pathumthani 80 rice variety with organic fertilizer (cow manure) at an average rate of 1.76 ± 0.20 mg/m2/day and was the lowest for Suphanburi 80 rice without added fertilizer at an average rate of 0.27 ± 0.10 mg/m2/day. Therefore, it is concluded that both varieties of rice and all 4 types of fertilizers used in this study have effects on the greenhouse gas emissions during each growth stage with the differences in the results being statistically significant (P>0.05).

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Limnological Studies on Indian Brackish Water Lonar Lake with Special Reference to Trophic Status and Potential Public Utility

Verma Sanyogita R.* and Chaudhari P.R.

Lonar Lake is one of the largest Crater Lakes in the world and situated in Buldhana District of Maharashtra State in India. Limnological survey of lake was carried out to understand the unique ecosystem. The sources of eutrophication of the lake were observed to be natural run-off water and a small patch of agriculture in the catchment area of the lake. The lake water was observed to be highly saline and alkaline in nature with nutrient enrichment and marginal level of organic pollution. It was interesting to note that ground water table around Lonar Lake was not observed to be deteriorated due to seepage of Lonar Lake water. Lonar Lake was observed to support dense bloom of phytoplankton dominated by Spirulinaplantensis, a protein rich blue-green alga of commercial importance. Fish and zooplankton species were not recorded in the lake due to high salinity and low dissolved oxygen content. Physico-chemical characteristics of Lake Water responsible for the formation of blue-green algal bloom are discussed in this paper. Potential uses of Lonar Lake viz. tourism, exploitation of lake water for commercial production of single cell protein, algal biomass for production of pharmaceuticals, cosmetics and bio-chemicals, irrigation of salt tolerant crops, grasses, fruit trees and production of potable water through reverse osmosis of lake water, have been delineated and discussed with the view of socio-economic development of the area.

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Effects of soil temperature on degradation of oxytetracycline in soils

Li Zhao-jun1*, Fan Fei-fei1 and Long Jian2

Antibiotics, especially tetracyclines (TCs) are widely used in agriculture in world. The adverse effects of TCs contaminants on non-targets organisms have generated an interest in the fate of TCs in soil environment. In order to illustrate the effects of soil temperature on degradation of TCs such as oxytetracycline (OTC) in soils, the degradation of OTC in three soils including fluvo-aquic soil, black soil and red soil were investigated at the temperature of 5 oC, 15 oC, 25oC respectively. The contents of OTC in three soils decreased gradually with time. The degradation rate of OTC was higher at 25 ºC than at 5ºC and 15ºC. The degradation curve of OTC in three soils could be described by the first-order kinetic model and the correlation coefficients ranged from 0.8895 to 0.9922. Under the same conditions, OTC degradation rate was higher at the initial added level of 20 mg kg-1 than that at the initial added level of 200 mg kg-1. The differences in degradation of OTC in three soils were also observed. OTC degradation in fluvo-aquic soil is faster than that in the other two soils.

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Adsorption of TNT and RDX Contaminants by Ambrosia trifida L. var. trifida Derived Biochar

Yakkala Kalyan,1 Yu Mok-Ryun,1 Yang Jae-Kyu2 and Chang Yoon-Young1*

Groundwater levels are often contaminated with powerful explosives 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) which were known to be carcinogenic and mutagenic. So far, costly physicochemical processes and time consuming methods have been applied for the removal of TNT and RDX in their binary system from wastewaters. In the present work, the adsorption of TNT and RDX from the aqueous solutions in single and binary system was investigated using the biochars (BC) derived from a waste plant, Ambrosia trifida L. var. trifida (buffalo weed) at pyrolysis temperatures of 300°C, 500°C and 700°C as an effective adsorbent. The effects of various parameters like pH of solution, removal capacity and contact time were studied using the batch method. It was observed that the biochar BC 700 was found to have greater removal capacity for TNT and RDX than the other developed biochars BC 300 and BC 500. The results showed that pseudo-second order kinetics provided the best parameters and the isotherm could be well described by Langmuir and Freundlich adsorption models. The maximum adsorption capacity onto the biochar BC 700, calculated from Langmuir equation was 76.923 mg g-1 and 55.556 mg g-1 for TNT and RDX respectively. The present adsorption process suggests that, ion exchange and chemical interactions were the main mechanisms involved. This work shows that Ambrosia trifida L. var. trifida derived biochar being a low cost material can be effectively used as an alternative adsorbent for the treatment of water and wastewater that are contaminated with explosives TNT and RDX.

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Equilibrium and Kinetic Studies on Biosorption of Cr (VI) using Novel Aspergillus Jegita isolated from Tannery Effluent

Issac Reya*, Lakshmi Prabha M. and Emilin Renitta R.

The present work is concerned to remove Cr (VI) using the biosorption potential of the novel fungal biomass Aspergillus jegita isolated from tannery effluent. The dry fungal biomass was used to optimize various parameters such as contact time, initial metal ion concentration, pH, biomass loading etc. The percentage removal of chromium using various chemical pre-treatments was carried out. Maximum of 90.86% Cr (VI) removal was observed in 25 mg/L initial Cr (VI) metal ion concentration using dry Aspergillus jegita biomass. Maximum of 92.8% Cr (VI) removal was observed in 25 mg/L initial Cr (VI) metal ion concentration using dry alkali treated A. jegita biomass at 37ºC, pH 2.0 and 150 rpm. Further equilibrium modeling was carried out using Langmuir and Freundlich adsorption isotherm and the data were fitted. The kinetics of hexavalent chromium biosorption has been evaluated with respect to first order and second order kinetic equations. The characterization studies were carried out using SEM. The Cr (VI) metal was found to desorb effectively using 0.1M HCl and removal efficiency was found to be 96.3 % and can be recycled.

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Development and Numerical Validation of a Formula for the Escape Time of Heavy Particles from a Vortex

Sánchez Urbano

This paper describes the behaviour of small heavy particles trapped inside a three-dimensional vortex and a formula is obtained that gives the time that elapses until the particle escapes from it. By means of the numerical simulation the validity of that formula has been verified. This formula can be applied to environment in situations such as man-made pollutants, pollen particles dispersion etc. Moreover, it is a widespread assumption to consider the turbulent motion as a superposition of vortices or eddies of various sizes, vorticities and frequencies, making it clear that any advance in the understanding of turbulence undergoes a proper study and understanding of the dynamics of vortices it is composed. It is also a known fact that heavy particles with small inertia may remain trapped inside a vortex for extended periods of time depending on both the properties of the particle as the vortex. One of the most important applications of this formula would be the design and determining the usefulness of the PIV systems (Particle Image Velocimetry) to visualize flows in general and vortex flows in particular because it is required a minimum residence time of the particles inside the vortex. Another application is that the formula developed allows the calculus of a critical value of the particle diameter from which the small particles remain trapped in the cores of the vortices while for the larger particles the settling velocity will increase very quickly, with application to the behaviour of particulate systems such as the growth of water droplets in clouds.

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Review Paper: Bioremediation: An emerging technology for remediation of pesticides

Chawla Niti, Suneja Sunita, Kukreja Kamlesh and Kumar Rakesh*

Environmental contamination is increasing day by day because of increase in population, industriali-zation and urbanization. It is a potential threat to human health. The risk of adverse health or environmental effects caused by contamination has led to international efforts to tackle the contaminants. The ideal solution for pollution abatement is bioremediation. It is the most effective innovative technology that makes use of living microorganisms to degrade environmental pollutants or to prevent pollution. It is a multidisciplinary approach but its central thrust depends upon Microbiology. This technology includes a number of techniques like biostimulation, bioaugmentation, bioaccumulation, biosorption, phytoremediation and rhizoremediation. The aim of the present review is to describe limitations and challenges associated with some generally accepted bioremediation strategies and subsequently to evaluate the potential applications of these remedial strategies to remove pesticides from the environment.

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