Research Journal of Chemistry and Environment

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Catalytic Co-Gasification of Black Liquor mixed with Pulp Sludge using a Drop Tube Reactor

Sricharoenchaikul V. and Atong D.

Fuel products generated from co-gasification of pulp sludge mixed with black liquor have been suggested as a new energy harvesting option that can be used in addition to recovery boiler in the chemical recovery process. This research was carried out in a drop tube reactor at the temperature of 700, 800 and 900°C, equivalence ratio (ER) of 0.2, 0.4 and 0.6 and ratio of pulp sludge to black liquor of 50:50 and 40:60 with materials feeding rate of 5 g/min. In addition, Ni-La-Mg/Al2O3 catalyst was prepared by co-impregnation method and mixed with raw material before feeding into system to study its effect on thermochemical conversion reaction. Major gaseous products such as CO, CO2, H2 and CH4 were analyzed by TCD-NDIR analyzer. Char and tar residue were collected and calculated by measured weight. The results of non-catalytic cases indicated that the optimal condition was temperature of 900°C, ER of 0.2 and raw material ratio of 40:60 with gas yield of 69.18%, H2 to CO ratio of 0.96, lower heating value of 5.91 MJ/m3 and cold gas efficiency of 79.55%. For catalytic cases, it was found that the catalyst improved the percentages of gas yield around 10 wt%. Lower heating value and cold gas efficiency of catalytic cases were 3.78-6.73 MJ/m3 and 46.02-90.13% while those obtained from non catalytic trials were 3.37-5.91 MJ/m3 and 34.63-79. 55%. From these results, co-gasification process can be considered as alternative for conversion of black liquor mixed with pulp sludge to useful fuel products.

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Biodegradation of cyanide and starch by individual bacterial strains and mixed bacterial consortium isolated from cassava sago wastewater

Sujatha Kandasamy, Balachandar Dananjeyan and Kumar Krishnamurthy

Cassava sago processing industries discharge wastewater containing high organic and cyanide content which poses serious threat to the environment and aquatic life in the receiving waters. The present study was aimed at developing a cost-effective and eco-friendly treatment plant based on microbial system to treat sago wastewater effectively in order to reuse the water for industrial purposes. Autochthonous bacterial isolates that have cyanide and starch degrading ability were isolated from sago wastewater. Among the cyanide degraders, B. pumilus recorded a maximum reduction of 45% in untreated sago wastewater. Whereas among starch degraders, B. anthracis achieved 43 and 56% degradation with untreated and biomethanated wastewater. Based on their individual efficiency, three cyanide and starch degrading isolates were selected to create different microbial consortium. Among the consortia, B. pumilus + B. anthracis + B. cereus showed maximum cyanide and starch degradation of 65% and 75% and a maximum BOD and COD reduction of 42 and 51% in untreated wastewater and 82%starch degradation with 53 and 56% BOD and COD reduction in biomethanated wastewater respectively.

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Study of energy involved in the thermally stimulated desorption of oxygen on ZnO and CdSe layers

Ganfoudi R., Ain-Souya A., Haddad A., Chahmat N. and Ghers M.

We present a study of oxygen’s adsorptions and desorptions carried out on ZnO and CdSe layers. The objective is to determine the magnitude's orders of interaction energies between oxygen and these materials' surface states. We relied on two models, T. Wolkenstein and Polayni-Wigner which allow calculation of the thermal desorption energy Wdes at a temperature Tm whose values are determined from the electrical resistance's variation's curve during the temperature programmed desorption (TPD) whose signature presents peaks at temperatures Tm where some adsorbed states desorb. The obtained Wdes values with both models are very close for the same temperatures and are of the 0.2eV to 1.7eV order. The experimental results show that for adsorptions carried out at temperatures below 100°C for ZnO and less than 150°C for CdSe, the desorption are multienergetics and monoenergetics for higher adsorption temperatures what have deduced the values of radiation wavelengths providing the same desorption energies.

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Production and Optimization of Xylan degrading Enzyme from Microbial Source

Ranjitha J. and Vijayalakshmi S.

Xylanase is one of the important industrial enzymes which find application in pulping and bleaching, degradation of lignocellulose materials, treatment of waste and textile processing. The present study had isolated a strain which degraded xylan, optimized its culture conditions for maximal xylanase secretion and production of enzyme in solid state fermentation. Soil sample was collected near a forest area in Vellore. Totally 35 isolates were isolated and screened for xylan degradation. One of the strains was found to be potential and was characterized for growth conditions and by nucleotide sequencing. Optimizations with respect to physical, chemical and agricultural wastes were also studied. The isolate was identified as Bacillus megaterium SV1, maximum enzyme production was observed in 56 hr (32IU/ml) in basal medium. Optimal conditions were found to as pH 8.0 (35IU/ml), temperature 40◦C (30IU/ml), 200rpm (32IU/ml), 4% salinity (35IU/ml), birchwood xylan (40IU/ml) as best carbon source, yeast extract (36IU/ml) as suitable nitrogen sources and addition of proline (46IU/ml) as better inducer. Metal salts addition to the medium were found to decrease the production. Tween 20 (38IU/ml) and 80 (35IU/ml) improved the enzyme production to greater extent. Agricultural wastes were tested for enzyme production and wheat bran was identified as optimal source. Thus the isolate SV1 could be able to grow and produce enzyme in a wide range of operating conditions and 40% of the enzyme production was increased in solid state fermentation condition.

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Chemical Water Quality in Upper River Nile

Aluoch June and Sillanpää Mika

Nile riparian countries have developed an interest over the years to use the river Nile resources for economic development. This research seeks to provide information on water quality. 12 samples in total were collected along the White Nile in Uganda during January 2011 sampling period and cation concentrations were determined using ICP-OES. Average concentrations for Na, K, Mg, Ca, S, P, Mn, Li, Cu Fe and Al were measured at 9.49, 4.33, 3.08, 5.76, 0.22, 0.06, 0.014, 0.04, 0.016, 0.028 and 0.037mg/L respectively. Temperature, pH and EC were recorded in-situ with averages of 27.6 ºC, 7.9 and 122.2 mS/m respectively. It was observed that metal constituents seem to be increasing downstream of the river. Comparisons have been made between historical data along the Nile and world average values. The overall risk paused by metal/cation content in River Nile is low in comparison to World Health Organisation drinking water quality guidelines and Ugandan standards for effluent discharge.

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Synthesis, Spectral and Anti-Microbial Investigations of Mixed Ligands of 2- Subsituted Quinoxaline Carboxylic Acid

Kumar Navneet and Sharma Pratima

We used ethoxy, methoxy, hydroxy and amino derivatives of 2-subsituted quinoxaline carboxylic acid. These derivatives react with nicotinic acid and guanine and form mixed ligands named hydroxy quinician, amino quinician, ethoxy quinician, methoxy quinician, hydroxy quinoguanine, methoxy quinoguanine, ethoxy quinoguanine and amino quinoguanine with good yield. These synthesized mixed ligands show antimicrobial activities. The structure of the mixed ligands had been established on the basis of IR, 1H NMR and Mass spectral data.

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Comparative Study of the removal of Cadmium(II) by batch study using normal tea factory waste and activated tea factory waste as adsorbent

Datta Jibesh, Mishra Umesh and Chakraborty Sukanta

Adsorption is a surface phenomenon in which one substance is accumulated on the surface of the other. In the recent years adsorption has become a very effective method for the treatment of waste water. For the removal of heavy metals from the water the adsorption technique has proved to be a useful method. In the present study the comparison of adsorption characteristics of removing Cd(II) from wastewater by normal tea factory waste and activated tea factory waste is studied. The experiments were carried out by the batch process and the effect of the agitation rate, adsorbent dose and initial metal ion concentration is studied. The maximum efficiency of cadmium(II) removal attained was 86.2% for normal tea factory waste and 88.4% for activated tea factory waste. The study showed that the both Langmuir and Freundlich isotherm model can be fitted with the experimental results. The results are also described by pseudo first order, pseudo second order and Elovich model. The study showed the possibility of using normal tea factory waste as a low cost adsorbent for heavy metal removal comparing with activated tea waste.

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Automatic image registration of multi-temporal KOMPSAT-2 images in agricultural areas

Youkyung Han, Junho Yeom, Yeji Kim and Yongil Kim

The objective of this study is to extract well-distributed matching points in agricultural areas having many similar patterns of farming intensity and homogeneous paddies. Mutual information (MI) which is one of the representative intensity-based similarity measures was used to estimate the initial translation difference between multi-temporal high-resolution images. Regular grids were then constructed over the entire images based on the initial translation and the center points of each grid were evaluated as the candidate points for precise matching. Based on these points, corresponding points were determined as the final matching points using the MI method. Multi-temporal high-resolution satellite images from Korea Multi-purpose Satellite-2 (KOMPSAT-2), which was launched in 2006 and has 1 m spatial resolution, were used for the experiments. Using the proposed method, we were able to extract evenly distributed matching points over the entire image and we obtained acceptable registration accuracies for all sites.

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Effect of pH, ionic strength, temperature and humic acid on the sorption of Eu (III) to iron oxides removed red earth

Yu T. and Xia T.

Sorption of Eu (III) on iron oxides removed red earth (IORRE) was investigated under ambient conditions effect of contact time, pH, ionic strength, humic acid (HA) and temperature. Compared with the sorption characteristics of Eu(III) on natural red earth(NRE), the results suggested that IORRE have higher sorption capacity of Eu(III) than NRE. Sorption of Eu(III) on IORRE was strongly dependent on ionic strength at pH<7 and independent of ionic strength at pH>7. The sorption of Eu(III) was dominated by outer-sphere surface complexes and ion exchange on IORRE surfaces at pH<7 whereas inner-sphere surface complexes were the main sorption speciation at pH>7. The presence of HA enhanced the sorption reaction. Sorption of Eu (III) on IORRE increased with increasing temperature and Freundlich model could describe the sorption isotherms of Eu (III) on IORRE well. The thermodynamic parameters (ΔH0, ΔS0 and ΔG0) of Eu(III) sorption on IORRE at different temperatures were calculated from the temperature-dependent sorption isotherms and it suggested that sorption process of Eu(III) was spontaneous and endothermic.

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Approaches towards the synthesis of flavonoids

Gupta Girish Kumar and Kumar Vinod

The biological and medicinal properties of flavonoids have prompted enormous research aimed at developing synthetic routes to these heterocyles. This review focuses on the general structures and classification, food sources, medicinal properties associated with this system. Various synthetic methods developed till now for these compounds are reviewed, particularly those related to the synthesis of flavanones, flavones, aurones, isoflavones and flavonols.

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Fouling and Mitigation Strategies in Membrane Bioreactors for Wastewater Treatment

Keerthi and Balasubramanian N.

Increase in the complexity of waste water generated by industries and its detrimental effect on the environment has brought about stringent water policies. The treatment of waste water by membrane bioreactor (MBR) has gained importance in the recent decade due to its ability to produce high quality water. But fouling of membranes still remains a challenge to the researchers which made the hybrid membrane bioreactors (HMBR) to evolve. This paper reviews on the membrane characteristics, its causes of fouling and its application in different waste water treatment. It also takes a glance on different hybrid systems where MBR has been incorporated with some other pre treatment technologies.

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