Response Surface Optimization of Oil Removal Using Synthesized Polypyrrole-Silica Polymer Composite

Abstract

The severity of oil pollution, brought about by improper management, increases daily with an increase in the exploration and usage of oil, especially with an increase in industrialization. Conventional oil treatment methods are either expensive or time consuming, hence the need for new technologies. The aim of this research is to synthesize polypyrrole-modified silica for the treatment of oily wastewater. Pyrrole was copolymerized with silica in the presence of ferric chloride hexahydrate by adding 23 mL of 117.4 g/dm3 ferric chloride hexahydrate drop wise to a silica-pyrrole mixture (1:2.3). The mixture was stirred for 24 h, filtered and dried at 60 °C for 24 h. The composite was then characterized using FTIR and SEM/EDX. A central composite model was developed in design expert software to describe the efficiency of oil removal using the polypyrrole-modified silica under the influence of initial oil concentration, adsorbent dosage and contact time. The synthesized adsorbent had FTIR bands at 3000–3500 cm−1 (due to the N-H), 1034 cm−1 (attributed to the Si-O of silica), 1607 cm−1 and 1615 cm−1 (due to the stretching vibration of C=C of pyrrole ring). The adsorption capacity values predicted by the central composite model were in good agreement with the actual experimental values, indicating that the model can be used to optimize the removal of oil from oily wastewater in the presence of polypyrrole-modified silica. The adsorbent showed excellent oil uptake when compared with similar materials. The optimum conditions for oil removal were 7091 mg/L oil concentration, 0.004 g adsorbent dosage and contact time of 16 h. Under these conditions, the percentage of oil adsorption was 99.3% and adsorption capacity was 8451 mg/g. As a result of the low optimum dosage and the lack of agitation, the material was found to be applicable in the remediation of field wastewater.

Fluidity Influencing Factors Analysis and Ratio Optimization of New Sealing Materials Based on Response Surface Method

“…In a case where the interaction of various additives to the ultrafine cement and their influences on its strength and expansibility are unknown, the single factor experiment method can be used in preliminary experiments to determine the optimal dosage ranges. Then, based on an analysis of the results, the Design-Expert 8.0.5 Trial software can be used to design an orthogonal experiment in order to accurately understand the influence of each factor on the performance of a composite expansion borehole sealing material [24][25][26]. In this study, after the completion of the orthogonal experiment, the Design-Expert 8.0.5 Trial software was used to calculate the variance and range of the experimental data, and the influence of the compound incorporation of various additives on the performance of the borehole sealing material was studied.…”

Synthesis and evaluation of the oil removal potential of 3-bromo-benzimidazolone polymer grafted silica gel

“…Silica extracted from diatomaceous earth in our previous study was used aer drying. 22,23 Sodium dodecyl sulphate, 3-bromo-1,2-benzenediamine, urea and ammonium persulphate were of analytical grade and obtained from Sigma-Aldrich (St Louis, USA), NaOH and HCl was obtained from Rochelle Chemicals (Johannesburg, South Africa). Milli-Q water from Millipore S.A.S (Molsheim, France) (18.2 ms cm À1 at 25 C) was also used in all dilutions.…”

“…The synthesized polymer was used in the optimization tests as described by Izevbekhai et al 29,30 Variable amounts of adsorbent were put in sealed tea bags and placed in a constant volume of SOWW. To test the effect of the tea bags, empty tea bags were sealed and used in similar experiments.…”

“…These large oil droplets become trapped in the pores of the adsorbent and settle at the base, leaving the water clear. 29,30,43 This could also be because of the introduction of new binding sites as the dosage is increased but as these get saturated, the adsorption capacity begins to reduce. [44][45][46] With adsorbent dosage, there is a slight increase in adsorption capacity as the adsorbent dosage is increased because of an increase in the binding sites.…”

“…This could be as a result of an increase in the number of positive interactions between the 3-bromo benzimidazolone polymer adsorbent and oil, as the adsorbent stayed in longer contact with the oily solution. 29,30,45 Effect of adsorbent dosage and time…”