Open Access Original Research Article

Sythesis of Nano Zerovalent Iron Supported Sawdust (NZVI/SD) and Its Application for Removal of Arsenic (III) from Aqueous Solution

Tasrina R. Choudhury, Snahasish Bhowmik, M. S. Rahman, Mithun R. Nath, F. N. Jahan, B. A. Begum, Mohammad Nurnabi

Chemical Science International Journal, Page 1-12
DOI: 10.9734/CSJI/2020/v29i130152

Sawdust supported nano-zerovalent (NZVI/SD) iron was synthesized by treating sawdust with ferrous sulphate followed by reduction with NaBH4. The NZVI/SD was characterized by SEM, XRD, FTIR and Chemical method. Adsorption of As (III) by NZVI/SD was investigated and the maximum uptake of As (III) was found at pH value of 7.74 and equilibrium time of 3 hrs. The adsorption isotherm modelling revealed that the equilibrium adsorption data were better fitted with the Langmuir isotherm model compared with the Freundlich Isotherm model. This study revealed that the maximum As (III) ions adsorption capacity was found to be 12.66 mg/g for using NZVI/SD adsorbent. However, the kinetics data were tested by pseudo-first-order and pseudo-second-order kinetic models; and it was observed that the adsorption data could be well fitted with pseudo-second-order kinetics for As (III) adsorption onto NZVI/SD depending on both adsorbate concentration and adsorption sites. The result of this study suggested that NZVI/SD could be developed as a prominent environment-friendly adsorbent for the removal of As (III) ions from aqueous systems.

Open Access Original Research Article

Emulsion Liquid Membrane Extraction of Bisphenol A with Three-dimensional Spiral Plate-type Microchannel

Diliyaer Hamiti, Zhengdong Ma, Meixiu Wei, Yadong Pu, Xiao Chen

Chemical Science International Journal, Page 13-20
DOI: 10.9734/CSJI/2020/v29i130154

The extraction of BPA (Bisphenol A) from aqueous solutions was performed using A set of three-dimensional spiral plate-type microchannel (3D-SPM) by emulsion liquid membrane (ELM). In the continuous extraction experiments, the effect of the flow rate ratio of emulsion to external aqueous phase ratios, Qe/Qa and height of microchannel, H and plate numbers, P, on the BPA extraction was studied. It was found that the less the height of microchannel is, the more extraction efficient it is. By increasing the plate number, the extraction efficiency and the distribution coefficient increase. The optimum performance was investigated by changing the flow rates of Qa and Qe. When using the flow rate ratio Qe/Qa of 7:1 in a 3D-SPM with a plate number of 9 and a height of 100 µm, 97% maximum depletion of BPA was obtained in 7.9 Seconds. These results show that 3D-SPM can intensify the ELM extraction process of BPA, which provides an optional technology for the disposal of BPA.

Open Access Original Research Article

Sorption of Pb2+, Cu2+ and Zn2+ from Aqueous Solution Using a Blended Membrane of Immobilized Karkashi (Sesame Leaves) and Sodium Alginate

Ibrahim Maradona, J. H. Kanus, M. Suleman Stephen

Chemical Science International Journal, Page 21-29
DOI: 10.9734/CSJI/2020/v29i130155

Sorption techniques are widely used to remove heavy metal ions from large volume of aqueous solutions, this plays a vital role in controlling environmental pollution. Herein, the sorption of Pb2+, Cu2+ and Zn2+ with blended membrane of sodium alginate (Na-Alg) and immobilized karkashi leaves (IKAL) from aqueous solution was investigated at optimum conditions for effectiveness. Sorption capacities of the membrane for Pb2+, Cu2+ and Zn2+ were found to be 86.80, 40.60 and 39.55% respectively. The sorption behavior with respect to initial pH, ionic strength, temperature, contact time and initial metal ion concentration was investigated for optimum sorption conditions. Maximum sorption was found to occur at pH 3.0 for all the metal ions studied. Results showed that metallic ion uptake by the blended membrane declined with increase in ionic strength. This trend was also observed at an increased temperature of 50ºC for Pb2+, Cu2+ and 40ºC for Zn2+. Increase in initial metal ion concentration led to increase in metal ion uptake.

At the end of the chemical remediation, the blended membrane was found to be effective to some extent, with the reaction being exothermic.

Open Access Original Research Article

Determination of Compressive Strength and Combustibility Potential of Agricultural Waste Briquette

B. A. Thliza, F. I. Abdulrahman, J. C. Akan, Z. M. Chellube, B. Kime

Chemical Science International Journal, Page 30-46
DOI: 10.9734/CSJI/2020/v29i130156

This study evaluates the development of a substitute and alternative solid fuel in the form of briquette from agricultural wastes (rice husk, sawdust and cotton stalk charcoal). Four sets of briquette with different grades were produced using a discontinuous briquette production technology, where a single briquette is produced at a time in a closed mould. Some physical properties such as; Length of briquettes (170 mm), diameter of briquettes (50 mm), mass of briquettes (140-160 g), volume of briquettes (133.5 cm3), density of briquettes (1.05-1.20 gm3), texture of briquettes (rough), and colour of briquettes (brown, light brown and mud black), were investigated using physical methods of evaluation. The result of the proximate analysis (moisture 10.5-10.8%, ash 30.3-33.8%, volatile matter 20.5-25.9% and fixed carbon contents 45.2-52.6%. The burning potential tests carried out on the formed briquettes compared to that of firewood showed that firewood boils 5 litres of water in 60 minutes, while Rice husk, Sawdust, Cotton stalk charcoal blended with rice husk, and Sawdust briquettes boils the same volume of water in 35, 30, 20 and 25, minutes respectively. Compressive strength of the briquettes was determined as 155.9, 155.9, 158.1 and 158.1 KN/m2 for rice husk, sawdust, cotton stalk charcoal blended with rice husk and sawdust briquettes respectively. Energy dispersed x-ray fluorescence spectrometer (ED-XRF) analyses revealed the existence of minor and major elemental percentage compositions (Cl, Br, P, K, Ca, Ba, Cu, Zn, Fe, Mn and Si, Ti, V, Cr, Ni, Sr, Rb). Liebig’s and Kjeldahl’s methods of laboratory analyses confirmed the presence of organic elements (C, H, O, N and S) that contributes to the heating value, increase in ignitability, smooth combustion. It can, therefore, be concluded that briquettes produced in this research work provide a better alternative to firewood and charcoal energies, they are eco-friendly, having high heat intensity with smooth burning and are easy to handle, store and transport, they are very cheap, affordable to both rural and semi-urban dwellers.  

Open Access Original Research Article

Levels of Polycyclic Aromatic Hydrocarbons (PAHs) in Beers: Consumption and Public Health Concerns

V. N. Okafor, U. B. Uche, R. C. Abailim

Chemical Science International Journal, Page 47-59
DOI: 10.9734/CSJI/2020/v29i130157

Aim: The aim is to investigate some physicochemical properties of beers and polycyclic aromatic hydrocarbons contaminants in beer brewed with isomerized hop extract and in comparison with beers brewed with extracts from four Nigerian potential hop substitutes.

Study Design: Beers were brewed using isomerized hop extract and extracts from four Nigerian bitter vegetables. Analyses of physicochemical properties of the beers and for the presence of 16 specific target PAHs were carried out using their respective standard methods.

Place and Duration of Study: Analysis of physicochemical properties of the beers was done at Nigerian Breweries PLC, Enugu while analysis for PAHs was conducted at Central Laboratory, Nigerian Institute for Oceanography and Marine Research, Lagos between July, 2018 and November, 2019.

Methodology: Physicochemical properties of the beers (alcohol content, bitterness level, pH, specific gravity, colour) were determined using their respective standard methods. Gas chromatography/mass spectrometry was used in analyzing for PAHs [naphthalene, acenaphthylene, acenaphthene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene]. Four isotopically labelled PAHs (acenaphthene-d10, phenanthrene-d10, chrysene-d12 and perylene-d12) were used as internal standards.

Results: Alcohol content (%v//v) in the beer samples is A(5.20); B(4.28); C(4.40); D(4.43) and E(4.54), bitterness level in International Bitterness Units (IBU) is A(0.54); B(0.80); C(1.46); D(1.46) and E(0.08), pH is A(4.36); B(3.08); C(3.88); D(3.90) and E(3.87), specific gravity is A(10.06); B(10.00); C(10.00); D(10.06) and E(10.06), and beer colour is A(5.80); B(7.70); C(6.60); D(8.00) and E(7.40). All 16 EPA PAHs were not found in all the beer samples except pyrene which was detected in sample B at a concentration of 0.00402 mg/kg.

Conclusion: It is concluded that extracts from the four Nigerian bitter vegetables could be used as substitutes for isomerized hop extract and that consumption of beer produced using extract from G. kola poses great public health concerns.