Open Access Original Research Article

Production of Fat and Sterol by Aspergillus nidulans in Submerged Fermentation

Ogbonnaya Nwokoro, Ogechi H. Ekwem, Uchenna Oyeagu

Chemical Science International Journal, Page 1-8
DOI: 10.9734/CSJI/2017/35197

The efficiency of fat and sterol production by Aspergillus nidulans was evaluated. The fungus was grown in media containing various carbon and nitrogen sources. Some agricultural waste materials namely, corn cob, rice husk and potato peels were also used as sole carbon sources for fat and sterol production. Sodium acetate was added into culture media at various concentrations. After a 72 h incubation, mycelia obtained from culture media were assayed for fat and sterol contents. Among the sole carbon sources used for fat production, the highest yield of 48.63 mg/100 mL broth was achieved with mannitol after 72 h incubation. Carboxyl methyl cellulose was the poorest carbohydrate for fat production. The agricultural waste materials greatly improved fat production by Aspergillus nidulans. Levels of 44.62, 43.99 and 43.1 mg/100 mL broth were achieved with corn cob, rice husk and potato peels after 72 h incubation.  Mannitol also caused the best sterol production by the fungus. Monosodium glutamate and corn steep liquor were the best nitrogen sources for the production of fat and caused the production of 64.36 and 64.27 mg/100 mL broth respectively. Urea and potassium nitrate did not support good fat production by the fungus. Hydrolyzed potato peels supported high yields of sterol as compared to mannitol. Increased fat production was accomplished through the addition of 0.1 to 0.5% sodium acetate. Maximum fat yield of 168.67 mg/100 mL broth occurred after 72 h in medium in which acetate concentration was 0.4%. This level was significantly higher than that of the control which had only 34.82 mg/100 mL broth of fat after 72 h. Acetate addition also caused reasonable increases in sterol synthesis higher than the control.

Open Access Original Research Article

Impact of Automobile Repair Activities on Physicochemical and Microbial Properties of Soils in Selected Automobile Repair Sites in Abuja, Central Nigeria

Christopher I. Ekeocha, Christopher I. Nwoko, Lynda O. Onyeke

Chemical Science International Journal, Page 1-15
DOI: 10.9734/CSJI/2017/36065

This research is aimed at evaluating the impact of activities carried out in automobile repair sites on quality of soils in the area. To achieve this target, soil samples were collected from five sampling points in each of the three selected sites (Apo, Kugbo and Zuba) to a depth range of 0 -15 cm using a stainless hand dug auger. Results of analyses of physicochemical properties pH, % porosity, electrical conductivity, particle size distribution, sulphate, chloride, nitrate and microbial contents of the soil samples indicate that most of the values exceeded those of control values. Levels of heavy metals in soils were determined using Automated Atomic Absorption Spectrophotometer (AAS). The results of the analysis revealed a decreasing trend in heavy metal contents (mg/kg) in soil in the three studied automobile repair sites as follows; Apo site: Cu (7668) > Zn (5360) > Cr (1174) > Fe (467) > Pb (333) > Ni > (196) > Cd (10.6); Kugbo site: Zn (1587)  > Cu (1043) > Cr (783) > Ni (234) > Fe (217) > Pb (170)  > Cd (9.47) and Zuba site: Zn (1190) > Cr (767) > Cu (512) > Fe (279) > Pb (250) > Ni (127) > Cd (10.4). Comparative analysis reveals that values of the studied heavy metals have exceeded those of control values and background values of some international regulatory bodies. Pearson’s correlation analysis reveals that some of the heavy metals had very strong correlations with one another and with some of the physicochemical properties of the soil. This indicates that the studied heavy metals have the same origin, mutual dependence and identical behaviors.

Open Access Original Research Article

Evaluation of Elemental Pollution in Roadside Dust Northeast of Nairobi Major Highway and at Thika Town, Kenya

E. G. Maina, A. N. Gachanja, M. J. Gatari

Chemical Science International Journal, Page 1-7
DOI: 10.9734/CSJI/2017/35744

Aims: To evaluate the level of elemental pollution in roadside dust.

Study Design: Dust samples were collected along Thika highway at Roysambu and at Thika town.

Place and Duration of Study: Department of chemistry, government of Kenya laboratories, from July to December 2016.

Methodology: Dust samples were collected at Roysambu bus terminal along Thika highway and at Kwame Nkruma road in Thika town. The samples were prepared for analysis according to USEPA method 3050B and analysis of Al, B, Na, Mn, Cr, Cu, Pb, Co, Mg, Fe, Ni, Ca and Zn in the samples was carried out using an inductively coupled plasma optical emission spectrophotometer. The results obtained showed that there was moderate pollution by Pb and Mn, while the samples were extremely polluted by B as computed using the index of geoaccumulation. Metals Cr, Mn, Pd and Zn were in levels similar to those reported around the world.

Conclusion: These results showed that roadsides along the highway are more polluted than those inside the town, which is probably due to the high vehicular number. In addition, heavy metals may pose a health hazard to people exposed to roadside dust, which is not in line with the sustainable development goals (SDGs) 3 and 11.

Open Access Original Research Article

Preparation, Microstructure and Performance of Activated FA / TiO2-WO3 Composite Photocatalyst

Mande Qiu, Yanlong Cui, Qingjiao Han

Chemical Science International Journal, Page 1-7
DOI: 10.9734/CSJI/2017/35086

The goal of this article was to preparation Fly ash(FA)/TiO2-WO3 Composite Photocatalyst based activation and modify of FA  surface using simple chemical method. The FA carrier and catalysts were investigated through XRD, SEM/EDS and BET. The photocatalytic efficiency of composite photocatalyst was evaluated by degradation of methyl orange under UV irradiation. The results confirmed that the H2SO4 activation altered the surface structure and composition of FA, the specific surface area increased from 8.2 m2/g (Raw ash) to 15.5 m2/g (activation FA). The surface modification of FA was conducive to supporting photocatalysts powder by tetrabutyl titanate sol treating. The loading composite photocatalyst showed the higher photocatalytic degradation efficiency under UV irradiation. The decolorization efficiency can reach 97% when the TiO2-WO3 loading amount is wt5% in 30 min. The composite photocatalysts compared with raw FA, activitied FA and modified FA, The results revealed that the photocatalytic degradation play main role after adsorption equilibrium. Furthermore, the photocatalytic mechanism and carrier effect were preliminary discussed.

Open Access Original Research Article

Economical and Simple Preparation of Oleyl Bromide from Commercially Available Olive Oil

Marcelo D. Preite, Francisco J. Castillo, Claudia M. Urbina, Rodrigo E. Faúndez, Juan M. Manriquez, Ivonne A. Chávez

Chemical Science International Journal, Page 1-7
DOI: 10.9734/CSJI/2017/36289

The objective of this work was to get access to a cheap and easy to scale source of oleyl bromide. Starting from commercial olive oil, and using economical reagents and conditions, the conversion was achieved in 5 steps (saponification, distillation, esterification, reduction and bromination), with a good overall yield (30%), providing a good quality final product, which showed a purity of at least 95%, by NMR.