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This paper reports the production of biodiesel from Pongamia pinnata seed oil via single step process. The efficiency of deep eutectic solvents (DESs) synthesized from the mixture of choline chloride and para toluene solfonic acid (PTSA), was used with silica support (So-DES) and without support (Un-DES) as heterogeneous and homogeneous catalysts, respectively. The oil esterification with methanol and methyl tert-butyl ether as solvents was conducted. From the results, the optimum reaction conditions for esterification of P. pinnata seed oil with Un-DES are; catalyst loading 1 (wt%/v), reaction time was 120 min and temperature was 343 K. maximum total acid number (TAN) reduction obtained under these conditions was 0.57 mg/KOH/g and a corresponding biodiesel conversion of 97.53 %. The optimal reaction conditions for esterification with So-DES using methanol as solvent are; temperature of 353 K, catalyst loading was 5 (wt%/v) and reaction time was 240 min. The optimum TAN reduction obtained under these conditions was 1.42 mg/KOH/g with corresponding biodiesel conversion of 89.3 %. Catalysts reuse was between four to seven reuses for Un-DES and So-DES respectively. Physico-chemical properties studies indicated that, viscosity, density and calorific values were within acceptable standard limits. It could be concluded that, DES synthesized from choline chloride and PTSA either with or without supporting material, could effectively produce biodiesel with acceptable fuel quality via single step process.

The need for green based technologies to provide both affordable and environmentally sustainable energy and the ever increasing energy demand of the nations across the globe has led the way for economy based energy research. In this research work, Gossypium arboreum seed oil biodiesel production was optimized using a five-level-three-factor central composite rotatable design model of response surface methodology to study the synergistic and antagonistic effects of the catalyst concentration, reaction temperature and time, using base catalyzed transesterification process. The results indicated suitable vegetable oil properties for a single step transesterification reaction. In addition, the least square reduced cubic model used produced the optimal percentage yield for the optimization, yielding a predicted yield of 94.93±6.92% for catalyst concentration of 0.53% by weight of the oil, 60°C for 105 m. The fuel properties of the samples showed linear regression values of 0.980 and 0.933 for viscosity and specific gravity respectively. The model reliability tests conducted were found to be impressive and conclusively can be for the optimization of the oil under stated conditions.

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The sequential extraction of Cd, Cr, Ni, Pb, Cu, and Zn in atmospheric dust particles collected along ten high traffic roads in Kano metropolis was carried out. Analyses of metals in the extracts were done using flame atomic absorption spectrometry (FAAS). The samples analyzed for metals indicated high levels of Cd, Cr, Ni, Pb, Cu, and Zn in the atmospheric dust samples. The sequential extractions that showed significant amount of Cd were associated with CO 3 2− and Fe-MnO fractions especially during the dry seasons. For Cr and Ni, their occlusion in crystal lattice of the soil fraction exhibited the highest percentage. Pb in the particulate dust samples is significantly associated with the carbonate bound fraction with range of 8.81-64.69% across the season. The behaviour of Cu is quite different from other metals in that percentage fractions are higher in the organic bound. As for Zn, significant amounts were associated with the residue fractions ranging from 0.96 to 87.50% across the seasons. This study revealed contamination of the particulate dust with Cd and Pb; this implies health risks to human, living or carrying out daily activities along the corridors of these roads.

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