NISCAIR Online Periodicals Repository Collection: JSIR Vol.71(11) [November 2012]

Pretreatment of textile effluent by ultrasound based hybrid methods for the enhancement of biodegradability

Mon, 29 Oct 2012 22:58:59 GMT

Title: Pretreatment of textile effluent by ultrasound based hybrid methods for the enhancement of biodegradability

Authors: Nachiappan, Senthilnathan; Muthukumar, Karuppan

Abstract: This study presents the biodegradation of real textile effluent pretreated with different hybrid methods. The experiments were carried out with and without pretreatment of effluent to analyze the influence of different pretreatment methods. The advanced oxidation processes such as sonolysis, sono-sorption and sono-Fenton-sorption were employed for the pretreatment of the effluent. In sono-sorption and sono-Fenton-sorption, eco-friendly, cost effective and easily available tea waste was used as an adsorbent. The sorbent was activated using formaldehyde followed by sonolysis. The biodegradation was carried out using mixed culture and the optimal initial pH and incubation temperature were found to be 7 and 32 ^oC, respectively. The UV-vis and FTIR analyses of untreated and treated effluents confirmed the degradation of organic pollutants. The microbial growth data obtained were tested with Monod, Powell, Haldane, Luong and Edward equations and the obtained data were found to fit well with Haldane model.

Page(s): 757-765

Vapour breakthrough behaviour of carbon tetrachloride - a simulant for chemical warfare agent on ASZMT carbon

Mon, 29 Oct 2012 22:58:59 GMT

Title: Vapour breakthrough behaviour of carbon tetrachloride - a simulant for chemical warfare agent on ASZMT carbon

Authors: Srivastava, Avanish Kumar; Shah, Dilip; Saxena, Amit; Mahato, T H; Singh, Beer; Verma, A K; Shrivastava, Smriti; Anuradha

Abstract: ASZMT (Cu, Ag, Zn, Mo, TEDA impregnated) carbon was prepared by impregnation of active carbon with ammonical salts of Cu (II), Ag (I), Zn (II), Mo (VI) and TEDA using incipient wetness technique. Thereafter, ASZMT carbon was characterized using scanning electron microscopy, atomic absorption spectroscopy, thermogravimetry and surface characterization techniques. The ASZMT carbon was evaluated under dynamic conditions against carbon tetrachloride vapour that was used as a simulant for the persistent chemical warfare agents for testing breakthrough times of filter cartridges and canisters of gas masks in the National Approval Test of Respirators. The effect of carbon tetrachloride concentration, test flow rate, temperature and relative humidity on the breakthrough behaviour of the ASZMT carbon for CCl₄ vapour has also been studied. The study clearly indicated that the ASZMT carbon provided adequate protection against carbon tetrachloride vapours. The breakthrough time decreased with the increase of the carbon tetrachloride concentration and flow rate. The variation in temperature and relative humidity did not significantly affect the breakthrough behaviour of ASZMT carbon at high vapour concentration of carbon tetrachloride whereas breakthrough time of ASZMT carbon reduced by an increase of relative humidity at low carbon tetrachloride vapour concentration.

Page(s): 748-756

Macroscopic spray characteristics of palm oil-diesel blends in a constant volume combustion chamber

Mon, 29 Oct 2012 22:58:59 GMT

Title: Macroscopic spray characteristics of palm oil-diesel blends in a constant volume combustion chamber

Authors: Soid, S.N.; Zainal, Z.A.; Iqbal, M. A.; Miskam, M.A.

Abstract: Concern with fossil fuel depletion and environmental degradation promotes the use of renewable energy sources in particular bio-fuel for automotive and power generation. Palm oil in its refined form as cooking oil can be used as fuel in diesel engines. Present study evaluates macroscopic spray characteristics, such as tip penetration, cone angle and spray area using direct injection diesel injector in a constant volume combustion chamber. Palm oil blend with diesel at 20, 40, 60, and 80 % as well as pure palm oil (100 %) and diesel were tested separately using direct visualization technique. Spray developments were investigated at elevated injection pressure starting from 20 MPa (original setting) to 30 and 34 MPa (maximum pressure). Experimental results for palm oil blends show that, spray development process is highly affected with increasing palm oil in the blend. Spray tip penetration and cone angle of blends were found to decrease by about 50 and 30 % respectively compared to diesel fuel. At elevated injection pressures, spray characteristics of the blends show significant improvement. Tip penetration and spray area for P20 at 34 MPa were comparable to diesel at its original injection pressure setting. Moreover, blends average cone angles were found larger at 30 MPa, by about 14.93, 11.47, 7.34 and 1.84 % for P20, P40, P60 and P80 respectively. For P20, 34 MPa injection pressure is sufficient to display spray characteristics similar to diesel, but require higher than 34 MPa injection pressure for other blends.

Page(s): 740-747

Comparison of Chemical constituents and antibacterial activities and antioxidant activities of the essential oil from leaves and fruits of Bridelia retusa (L.) A. Juss.

Mon, 29 Oct 2012 22:58:59 GMT

Title: Comparison of Chemical constituents and antibacterial activities and antioxidant activities of the essential oil from leaves and fruits of Bridelia retusa (L.) A. Juss.

Authors: Sanseera, Duangsuree; Niwatananun, Wirat; Liawruangrath, Saisunee; Baramee, Aphiwat; Khantawa, Banyong; Pyne, Stephen G.; Liawruangrath, Boonsom

Abstract: The essential oils from the leaves and fruits of Bridelia retusa (L.) A.Juss. were isolated by hydrodistillation. The essential oils were obtained in 0.0013% yield as a pale yellow liquid and 0.0026% yield as a violet-light brown liquid for the leaf oil and fruit oil respectively. The composition of each essential oil was analysed by means of GC-(FID) and GC-MS. Eleven constituents accounting for 48.77% of total leaves oil were identified. The most abundant compound was phytol (33.4%), followed by phthalic acid (5.2%), 6, 13-dimethoxy-2, 3, 9, 10-tetramethylpentacene-1, 4, 8, 11-tetrone (3.4%), heptacosane (2.3%) and nonacosane (1.2%). Sixteen constituents accounting for 51.8% of total fruits oil were identified. The major components were dibutyl sebacate (25.6%), phytol isomer (4.8%), diacetin (4.3%), tricosane (3.9%), isophytol (2.7%), erucylamide (2.5%), phthalic acid (1.9%), hexadecanoic acid (1.5%) and eicosane (1.2%). The essential oils exhibited strong antioxidant activities with the IC50 values of 1.12±0.0010 mg/mL and 1.79±0.0005 mg/mL for the leaf and fruit essential oils respectively, by using the ABTS radical cation scavenging assay. The antibacterial activity of the essential oils was performed by using the standard disc diffusion method. The results revealed that the leaf and fruit essential oils of B. retusa were active against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa with the minimum inhibitory concentrations (MICs) between 20-50 mg/mL.

Page(s): 733-739