Open Access Original Research Article

A Study of the Alkaline Solvolysis of Postconsumer Polyethylene Terephthalate in Primary C1 – C3 Aliphatic Alcohols

O. Sanda, E. A. Taiwo, M. G. Akinrinsola, G. A. Osinkolu

Chemical Science International Journal, Page 1-14
DOI: 10.9734/ACSJ/2016/27697

This study was carried out to examine the thermo-chemical decomposition of postconsumer polyethylene terephthalate (PET) in alkaline solutions of C1 – C3 primary alcohols with a view to developing a simple, yet effective method for the chemical recycling of post-consumer PET. The effect of various process parameters such as temperature, time and sodium hydroxide concentration on the degree of PET degradation and products yield were studied for each alcohol. Response surface methodology (RSM) was used for predicting the optimal conditions for the alkaline solvolysis of PET scrap, with Box-Benkhen design for the three variables chosen as the experimental design. The data obtained from measurement of properties were fitted as second-order equations.

The optimum sodium hydroxide concentration, reaction temperature and time were 32.5 g/l, 100°C and 46.8 min, respectively for methanol; 32.6 g/l, 94.3°C and 40.9 min, respectively for ethanol and 31.4 g/l, 120°C and 40.0 min, respectively for propan-1-ol. Under these optimum conditions, the percentage decomposition of PET was 92.22 for methanol, 91.65 for ethanol and 44.50 for propan-1-ol.

The findings of this study showed that chemical reprocessing of postconsumer PET could be achieved under the relatively simple conditions of alkaline solvolysis, with terephthalic acid being one of the end products.

Open Access Original Research Article

Synthesis, Characterization, DNA Binding, Antibacterial Activity and DFT Calculation of Ru(II) Complexes of Hydroxamic Acids and 1,10-Phenanthroline

Rakesh K. Sahu, Fahmida Khan

Chemical Science International Journal, Page 1-11
DOI: 10.9734/ACSJ/2016/27299

New Ruthenium (II) complexes of mixed ligands, hydroxamic acid (L1 = AHA (acetohydroxamic acid) and L2 = BHA (benzohydroxamic acid)) and 1, 10-phenanthroline (phen) were synthesized, characterized by FT-infra red spectrophotometer, UV-visible spectrometer, ESI-mass spectrometer and elemental analysis. In the complexes, [Ru(phen)2L] (L = AHA, BHA), the metal ion is bind with 6 atoms, 2 O-atoms from hydroxamic acids (AHA & BHA) and 4 N-atoms from 1, 10-phenanthroline to form octahedral Ruthenium (II) complexes. The binding of these complexes with CT-DNA has been studied by UV-visible spectrophotometer. The DNA-binding coefficients for complexes [Ru(phen)2AHA]  and [Ru(phen)2BHA] are 2.29 x 106 M-1 and 3.30 x 106 M-1 respectively. Detailed study indicates that these complexes bind with DNA by intercalation binding. Also studied microbial activity of these complexes against Gram positive and Gram negative bacteria. The structure of metal complexes were optimized and calculated by the Gaussian 09 (G09) software.

Open Access Original Research Article

Removal of Resorcinol from Aqueous Solution by Activated Carbon: Isotherms, Thermodynamics and Kinetics

Omer El-Amin Ahmed Adam

Chemical Science International Journal, Page 1-13
DOI: 10.9734/ACSJ/2016/27637

The adsorption of resorcinol from aqueous solutions onto activated carbon was studied. The specific surface area and point of zero charge of activated carbon were determined. Adsorption experiments were carried out in a batch process and various experimental parameters such as agitation time, initial resorcinol concentration, adsorbent dose, pH and temperature were studied.

The equilibrium sorption data were fitted into Langmuir, Freundlich, Tempkin and Dubinin–Radushkevich (DR) isotherms. The Langmuir isotherm model appears to have better regression coefficients, with a maximum adsorption capacity range (208.33 - 223.21 mg/g). The resorcinol adsorption was strongly dependent on solution pH, and the solute removal become significant at pH @ pHpzc.

Thermodynamic parameters: ∆H°, ∆S° and ∆G° were computed from the experimental data. These values show that the adsorption is endothermic and spontaneous process. Moreover, the relative value of ∆Hads (34.506 kJ/mol) confirms a physical adsorption.

Kinetics of adsorption was investigated and the data were treated according to pseudo-first-order, pseudo-second-order and intra-particle diffusion models. It was found that the adsorption process of resorcinol onto activated carbon follows pseudo-second-order model.

Open Access Original Research Article

Transfer Characteristics of Trace Metals from Soil to the Edible Parts of Some Vegetable Species Grown in Ibeno, South-South Nigeria

E. A. Moses, I. I. Udousoro, A. B. Edem

Chemical Science International Journal, Page 1-9
DOI: 10.9734/ACSJ/2016/27123

The aim of this study was to assess the levels of trace metal in soils and leafy vegetables at Ibeno, as a result of crude oil exploration activities in the area. The study areas were Mkpanak, Iwuoachang and Ukpenekang all in Ibeno Local Government Area of Akwa Ibom State, Nigeria. Soil and vegetable samples (Telfaria occidentalis, Spinacia oleracea and Talinum triangulare) were collected randomly from sampling sites and analyzed for trace metals (Pb, Zn, Cu, Co and Cd) using atomic absorption spectrophotometric technique. Bioaccumulation of trace metals in plant parts were estimated as transfer factors (TF). Metal concentrations in the soil ranged from          85.56 mg/kg to 143.84 mg/kg for Zn, 39.24 mg/kg to 52.55 mg/kg for Co, 2.66 mg/kg to 4.50 mg/kg for Cu and 0.01 mg/kg for Pb and Cd in the soil. Trace metal levels in soils were below Federal Environmental Protection Agency (FEPA), Nigeria limits for agricultural soils except for Co. Higher levels (P< 0.05) of metals were measured in soils at the various locations compared to the control soils. At Levels of trace metals in vegetables varied in the order, Telfaria occidentalis>           Spinacia oleracea>Talinum triangulare and the concentrations were higher than WHO/FAO limits. TF values showed higher accumulation of Pb with a Pb>Cd>Cu>Zn>Co gradient. The results showed that Telfaria occidentalis exhibited the most ability to accumulate trace metals followed by Spinacia oleracea and Talinum triangulare. This showed the potential of using Telfaria occidentalis as an indicator of trace metal pollution in soils. The high TFs observed in this study indicated bioaccumulation of the metals in plants and a possibility of systemic toxicity when these plants are consumed by either humans or animals.

Open Access Original Research Article

Corrosion Inhibition of Mild Steel in 1M H2SO4 Solution by Microdesmis puberula Leaf Extract

Okon U. Abakedi, James E. Asuquo

Chemical Science International Journal, Page 1-8
DOI: 10.9734/ACSJ/2016/28419

The inhibition of mild steel corrosion in 1M H2SO4 solution by Microdesmis puberula leaf extract was studied by weight loss and hydrogen evolution methods. Results obtained show that Microdesmis puberula leaf extract was a good inhibitor of mild steel corrosion in sulphuric acid solution. The inhibition efficiency increased with increase in Microdesmis puberula leaf extract concentration and temperature. The inhibition efficiencies by both weight loss and hydrogen evolution methods were in good agreement. The calculated thermodynamic parameters revealed that the corrosion inhibition process was both endothermic and spontaneous. Microdesmis puberula leaf extract adsorbed chemically onto mild steel surface in conformity with the Langmuir adsorption isotherm.

Open Access Original Research Article

The Effects of Boric Acid on Fiberboard Properties Made from Wood/Secondary Fiber Mixtures: Part 1. Utilization of Recycled Newsprint Paper Fibers

Ali Ihsan Kaya, Halil Turgut Sahin

Chemical Science International Journal, Page 1-8
DOI: 10.9734/ACSJ/2016/27276

It was realized that both boric acid (BA) and secondary fibers (S) from recycled newsprint papers had negative impact on thickness swelling (TS) properties of boards in water. The highest TS value of 48% was observed in both type boards that produced only from 100% secondary fibers. However, the highest Modulus of Elasticity (MOE) values of 1783 MPa was found, A4 experimental boards that produced from 60/40 (W/S) proportion with 5.0% boric acid content (type1) whereas the highest MOE values of 970 MPA was found, A2a experimental boards that produced from 80/20 (W/S) proportion with 10% boric acid content (type2). It is clear that increasing secondary fiber content impact on lowering MOE values in some level. But except of the boards of A10 and A10a which produced only from recycled newsprint papers (secondary fibers) with both type, all other boards have higher MOE values than standard value of 600 MPa. The highest Internal Bond (IB) mean value of 0.18 MPa was obtained with board of A1 following by A3 (type1). However, the highest IB values of 0.16 MPA was found A1a experimental boards that produced from 90/10 (W/S) proportion with 10% boric acid content (type2).

The lowest thermal conductive was realized for both type boards at 10/90 (W/S) fiber proportion with 0.15 W/mK and 0.22 W/mK, respectively. However, the results indicate that heat conductivity values decrease (improved) as secondary fiber content increase in board’s structure. This is very important findings considering improving heat insulation properties of boards. Hence, secondary fibers from recycled newsprint papers had positive impact against heat conductivity properties of boards.