Research Journal of Chemistry and Environment

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Vol. 16(2) June 2012

Synthesis and X-ray structures of two acidic cobalt (III) complex salts based on oxamide dioxime ligand system

Gouet Bebga1, Mbiangué Y. A.,2 Nenwa J.3* and Fokwa B. P. T.4

The new cobalt(III) complex salts, tris (oxamidedioxime-κ2N,N’)cobalt(III) triperchlorate,[Co(H2oxado)3](ClO4)3 (1) and oxamide dioximato(1-)-κ2N,N’ bis(oxamide dioxime-κ2N,N’)cobalt(III) sulphate hydrate, [Co(Hoxado)(H2oxado)2]SO4.H2O(2), have been synthesized in aqueous medium and characterized. Single crystal X-ray analysis reveals that both compounds belong to the monoclinic system.1 crystallizes in the space group P21/c, with a = 13.4207(9), b = 17.9378(12), c = 10.0136(7) Å, β = 106.738(1)°, V = 2308.5(3) Å3, Z = 4; 2 crystallizes in the same space group but with a different setting P21/n, with a = 11.9371(9), b = 11.7161(9), c = 13.5154(11) Å, β = 100.7700(10)°, V = 1856.9(3) Å3, Z = 4. In the complex cations of both salts, the central cobalt(III) ion is in a strongly distorted octahedral coordination of six imino N atoms of the oxamide dioxime ligand system. The doubly charged cation of 2 ought to be regarded as the product of a single deprotonation of the triply charged cation of 1 – a process reminiscent of catalytic or biological reactions involving transfer of protons. O–H•••O and N–H•••O bridgings reinforce the three-dimensional crystal packing of the two systems.

Characterization and In Vitro degradation studies of Synthesized Polylactide (PLA)

Srivastava Gaurava 1*, Mondal Ankita 1 and Srivastava Pradeep1

Biodegradable polymers represent a useful class of biomaterials. In this study, a biodegradable polymer, poly (L-Lactide) (PLA), synthesized by the optimized process1 was characterized for its suitability for biomedical applications. A pre-polymer was synthesized by carrying out a controlled condensation reaction, then post-polymerized by ring opening the pre-polymer at 1650C. In this paper, the synthesized polymer was characterized by FT-IR, 1H NMR, 13C NMR, Viscometry, GPC and DSC. Measurements on the mechanical properties of PLA testified that the synthesized polymers are polymers with low hardness and big elongation and hydrolytic degradation of the polymer beads in a buffer of pH 7.4 at 37 0C showed that PLA had excellent degradability (all the beads show the weight losses more than 60% after 2 weeks incubation). Degradation study shows that hydrolytic breakdown of PLA polymers is strongly influenced by the presence of BSA in the degradation media. The material is expected to be useful for controlled drug delivery and other biomedical applications.

Fly ash-Sewage Sludge Mixture as a barrier of heavy metal leaching

Kharuba Monika, Rajora Anita and Mittal Susheel K.*

Three different mixtures of fly ash and sewage sludge (FA/SS) in the ratio of 1:1, 4:1 and 1:4 were taken to study the leaching of heavy metal ions in the aqueous medium. Samples were shaken on rotator shaker with controlled conditions of temperature (26±1ºC) and contact time. It was found that for 5g of the sample mixture, 2.5mL dose of the acid, 2 hours shaking time and pH >3 were the conditions to achieve best results of arresting leaching of heavy metal ions. The analysis of five different heavy metals: Pd, Cd, Ni, Cu and Co was carried out with the help of atomic absorption spectrophotometer. It was observed that maximum percentage removal for different metals showed the following trend: Pb - 1:4 (95%) in fourth wash, Cd - 4:1(36.3%) in second wash, Ni – 4:1 (78%) in third wash, Cu – 4:1 (35.2%) in third wash. Co was absent in all the samples and was removed completely.

Complete recycle bioreactor for anaerobic digestion of organic substrates: Food waste

Bodkhe S.Y.* and Vaidya A.N.

A study of anaerobic digestion of food waste (FW) was carried out in complete recycle anaerobic bioreactor under ambient temperature conditions. The reduction in chemical oxygen demand (COD) obtained at three different hydraulic retention times (HRT), 5days (d), 7d and 10d were 62%, 78% and 84% respectively. The appropriate HRT for the reactor was found to be 7d with 73% TS and 79% VS removal. The feed stock had well balanced nutrients as detected by nutrient analysis. The C/N ratio of digestate varied between 20 to 27. Seed germination of 100% and incre-ase of 49% in plant growth were observed in plants supplied with digestate as compared to control samples. The study indicated feasibility of semicontinuously operated complete recycle anaerobic bio-reactor for FW slurry treatment.

Synthesis of 2,6-Di-(3,4-Dimethyl Phenyl) Pyrylium Fluoroborate and Perchlorate in single step salts using 3,4-Dimethyl Acetophenone

Byun Jeong-Gyu 1, Wie Jinhyeong 2, Seo Youngmi 1, Kim Hyunook 2 and Cho Sung-Il 1*

Due to its high conductivity, pyrylium has been frequently used in an electron transfer reaction or in synthesis of various sensor materials. Traditionally, the compounds have been synthesized using various methods; mostly in multiple steps. In this study, two pyrylium salts, i.e., 2,6-di-(3,4-dimethylphenyl) pyrylium fluoroborate and perchlorate have been synthesized in a single step. The synthesis of the products was confirmed by LC/TOFMS and FT-IR analyses. Their photo-properties were analyzed using UV/VIS spectrophotometry while their electron transfer capacities were analyzed with a conductivity meter and found their electron conductivities high. When the synthesized compounds were dissolved in acetone, the formation of green fluorescent material could be observed. The fluorescent material can be used as a sensitizer in the environmental sensor manufacturing industry.

Remediation of TCE-contaminated groundwater usingintegrated biosparging and enhanced bioremediation system

Kuo Y.C., 1 Liu J.K., 2 Chien H.Y.,1 Chen C.C.3 and Kao C.M. 1*

A biosparging well (BSW) was installed at the upgradient area of the test site for air injection. Brown sugar, which was used as the primary substrate, was pressure-injected into the TCE plume through the BSW to enhance the rate of TCE co-metabolism. To evaluate the effectiveness of TCE bioremediation, monitor wells were installed in series down gradient of the BSW along the groundwater flow path. Polymerase chain reaction (PCR) and nucleotide sequence analyses indicate that TCE-degrading enzymes (e.g. toluene monooxygenase, toluene dioxygenase, phenol monooxygenase and particulate methane monooxygenase) were identified in field groundwater samples after the air and substrate supplement. Results from the pilot-scale study indicate that the aerobic co-metabolism was the major cause of the decrease in TCE concentrations. Without primary substrate supplement, intrinsic bioremediation and injection of air and nutrients alone could not enhance the aerobic co-metabolic mechanism and cause the decrease in TCE concentrations within the plume. The occurrence of aerobic TCE co-metabolism could be confirmed by the following investigations within the plume: (1) significant decrease in TCE concentrations; (2) increase in chemical oxygen demand (COD) concentrations and microbial populations; (3) increase in dissolved oxygen (DO) and oxidation-reduction potential (ORP) in the BSW; (4) significant depletion of DO and decrease in ORP after the supplement of substrate; (5) production of CO2 and decrease in pH value and (6) detected specific TCE-degrading genes. Approximately 97 and 92% of TCE was removed in BSW and monitor well located 5 m down gradient of the BSW. The operation of biosparging caused the shifting of low oxygen conditions inside the plume to aerobic conditions. Results indicate that the integrated in situ biosparging and enhanced aerobic bioremediation is a feasible and promising technology to remediate TCE-contaminated groundwater.

Synthesis and Antimicrobial Activities of Mn (II) and Fe (III) Complexes with N- S donor Ligand

Gupta Y.K.,1* Agarwal S.C.,2 Madnawat S.P.3 and Ram Narain2

The complexes of ML2 were prepared where M=Mn (II) and Fe (III) and L = 2,5-diamino-1,3,4- thiadiazole. The ligand (L) has been prepared by cyclisation of bithiourea in a 3% hydrogen peroxide medium. The complexes are non-electrolyte in DMF. The elemental analysis, magnetic measurements,conductivity measurements and spectral studies of the complexes were carried out. 2,5-diamino-1,3,4-thiadiazole acts as neutral tridentate ligand and coordinates through the sulphur atom and nitrogen of the amines. The complexes exhibited octahedral geometry. The antimicrobial activities of ligand and its complexes were screened using sensitivity test, minimum inhibition concentration and minimum bacterial concentration method. Metal chelates showed greater antimicrobial activities as compared to the control and the ligand. The metal chelates and the ligand did not exhibit activity against Aspergillus niger and Penicillin species.

Experimental investigation of energy saving in air conditioning systems using silver nanofluid

Ehsan Firouzfar* and Amin Hosaini Rivandi M.

Application of methanol-silver nanofluid as the working fluid in thermosyphon heat exchanger in an air conditioning system was investigated and compared with the case where pure methanol is used as the working fluid and the rate of energy saving was calculated. First, the influence of two key parameters of the inlet air conditions namely dry bulb temperature and relative humidity, on the effectiveness of a 3-row heat pipe heat exchanger with pure methanol as the working fluid was investigated at pilot scale. Then the experiments were repeated using methanol- silver nanofluid as the working fluid. Experimental results showed that by using methanolsilver nanofluid, we will save around 8.8-31.5% of the energy by the evaporator and 18-100% by the condenser of thermosyphon heat exchanger. The results of this study are expected to lead to guidelines that will allow the improved performance of the air conditioning systems which reduce its energy consumption.

Study of Ground Water Quality of Ulhasnagar city in Thane District, Maharashtra, India using Multivariate and Microbial Analyses

Verandani S.1* and Vardhan D.2

Water samples were collected from 25 sampling sites during the pre-monsoon season in Ulhasnagar city, Thane district in Mumbai. Different physicochemical parameters were measured and the samples were also analyzed for dissolved metal concentrations. The surface water physicochemical parameters included pH, temperature, turbidity, hardness, total alkalinity, dissolved oxygen (DO), total dissolved solids (TDS), electrical conductance (EC) and turbidity while the dissolved metals were Cd, Cu, Pb and Cr. The ranges for the physicochemical parameters were 28-32 degrees C for temperature, 6.8-8.5 for pH, 0.4-12.8 mg/l for DO, 0-100 NTU for turbidity, 22-580 ppm (as CaCO3) for hardness, 44-61 ppm. for total alkalinity, 250-520 mg/l for TDS and 554-1040 mhos/cm while the dissolved metals (mg/l) were 0.001-0.008 for Cd, 0.002-0.012 for Cu, 0.04-1.30 for Pb and 0.000-0.15 for Cr. Based on multivariate analysis and correlation studies, lead was identified as major dissolved metal contaminant in most of the analyzed samples. Microbial analysis was also carried out by testing the samples for E. coli and thermo tolerant bacteria and ranges for these were from 2-18 ppm for E. Coli and 2-19 ppm for the thermo tolerant bacteria.

Spatial prediction and characterization of heavy metal pollution in soils of Coimbatore district using surfer package

Sherene T.

A survey work was undertaken to assess the concentration of heavy metal pollution in soils of Coimbatore district. Totally three hundred and eight surface (0-15 cm) soil samples were collected around the industrial areas by using auger. Among the different industrial areas, electro plating and sewage water irrigated areas fell in excess tolerable category for Pb and Ni. As per SPI scale, the soils collected in the vicinity of electro plating, textile, casting and sewage water irrigated fields seemed to be dangerously polluted with toxic Pb, Ni, Cd, Cr, Cu and Zn. The delineation of Pb and Ni contaminated sites of Coimbatore district was done using SURFER software package. Therefore, there is a possibility of silent epidemic of environmental metal poisoning from the ever-increasing amount of metals wasted into biosphere.

Development of Starch-Gelatin Complex Microspheres as Sustained Release Delivery System

Vedha Hari B. N.,* Praneetha T., Prathyusha T., Mounika K. and Ramya Devi D.

The starch was isolated from jackfruit seeds and evaluated for its preformulation properties like tapped density, bulk density, particle size. The FTIR analysis was done and compared with that of the commercially available starch which confirmed the properties. Using the various concentrations of jackfruit seed starch the microspheres were prepared, combining with gelatin by ionotropic gelation technique. The developed microspheres were subjected to analysis of particle size, drug content, entrapment efficiency and percentage yield. The spectral analysis confirmed the presence of drug and absence of interactions. Scanning electron microscope image showed that the particles were in spherical shape with a rough surface. The in vitro drug release in water for 12 hours proved to be in the range of 89-100 %. The various kinetic models were applied using release data to confirm the mechanism of drug. It was concluded that the jackfruit starch gelatin microspheres gave satisfactory results and met pharmacopieal limits.

Theoretical study on the absorption of SO2 on alumina aerosol surface

Kemei Pei1,2*, Mingyang Su1,2 and Lin Chen1

The absorption of SO2 on alumina aerosol surface is explored by quantum chemistry calculations in Gaussion 03 program. The surfaces of two most important anamorphosises α-Al2O3 and γ-Al2O3 are modeled. The results indicate that the nature of SO2 absorbed on α-Al2O3 is chemical process and strong bonds are formed between SO2 and α-Al2O3 but SO2 on γ-Al2O3 is more physical absorption. Vibration frequency analysis indicates that the typical vibrationfrequencies of SO2 will be disappeared when it absorbed on α-Al2O3 and the main modes of SO2 absorbed on γ-Al2O3 show red shift or blue shift character. The absorption energies are also calculated.

An overview of ozonation associated with nano-filtration as an effective procedure in treating dye effluents from textile industries with the help of a bubble column reactor

Palit Sukanchan

Recalcitrant chemicals in wastewater cannot be degraded by primary and secondary treatments. Primary treatment comprises flocculation and coagulation while secondary treatment comprises activated sludge process or filtration through trickling filters. Tertiary treatment process comprises ozonation, membrane filtration, adsorption and other advanced oxidation processes. The importance of ozonation as an advanced oxidation process is due to the fact that ozonation process is environmental friendly and sound. The ozone method is known to be effective for decomposing organic chemicals containing carbon-carbon double bonds, olefenic double bonds, acetylenic triple bonds, aromatic compounds, phenols, polycyclic aromatics, heterocyclics, carbon-nitrogen double bonds, carbonhydrogen bonds, silicon-hydrogen and carbon-metal bonds. Synthetic dyes and pigments released to the environment in the form of effluents by textile, leather and printing industries cause severe ecological damages. Due to the inhibitory nature of many compounds for biological oxidation, the need for pretreatment by advanced oxidation process (AOP) has become essential. Ozonation of water is a well known technology and the strong oxidative properties of O3 and its ability to effectively oxidise many organic compounds in aqueous solution have been well documented. Ozone treatment of several types of wastewater has resulted in considerable COD reduction and has been used for treatment of dyes, phenols, pesticides etc. In recent years, ozonation is emerging as a potential process for colour removal of dyes, since the chromophore groups with conjugated double bonds, which are responsible for colour can be broken down by ozone either directly or indirectly forming smaller molecules, thereby decreasing the colour of effluents. Due to its high electrochemical potential (2.08V), O3 is the strongest oxidant available and applicable as compared to H2O2 (1.78 V) and can react with several classes of compounds through direct or indirect reaction. Unlike other oxidizing agents such as Cl2 oxidation with O3 leaves no toxic residues that have to be removed or disposed. Nanofiltration is very effective and it is the next generation science and technology.

Antioxidant potential in vegetable oil

Rubalya Valantina S.1* and Neelamegam P.2

This paper reviews the properties of natural antioxidant in vegetable oil which is one of the most significant active components that plays an important role in reducing fat oxidation. Frying is widely used in food industry and household cooking which leads to degradation of oil that induces important chemical changes in oils, specifically oxidation, polymerization, isomerism, hydrolysis and cyclization. Effective control over the limitation of the above reaction is technically done by the simplest way of the natural antioxidant in the oil. Antioxidants reduce the oxidative stress in cells damage and health problems including cancers, degenerative diseases, cardiovascular diseases, inflammatory diseases etc. This study reveals the stability and efficiency of natural antioxidants present in sunflower oil, groundnut oil, soya bean oil palm oil, sesame oil, rice bran oil and corn oil and the changes on heating.

Novel nanoparticles for water and waste water treatment

Velhal S. G.,2 Kulkarni S. D.1* and Jaybhaye R. G.3

Water is a vital component of life on earth. The existence of life on earth is made possible largely because of the presence of clean water which is important to metabolic processes within the body. Clean and fresh water are essential for the very existence of life. The different pollutants in aquatic system will interfere with many beneficial uses of water. Contamination of natural water sources by hazardous pollutants affects the human health and ecosystem. Hence photo catalytic processes for water and waste water treatment are new area having vast applications. This review is focused on principle, mechanism and applications of titanium dioxide nanoparticles for water and wastewater treatment.