Application of synthesized acetylated silica in the remediation of oily wastewater

Abstract

Acetylated materials have been applied successfully in oily water remediation with some degree of success. Many of these materials which have been acetylated are, however, from seasonal fruits and other plant parts. This work reports the successful acetylation of silica extracted from diatomaceous earth by refluxing silica and acetic anhydride using 1% N-bromosuccinimide as a catalyst. The functionalization was confirmed by the presence of absorption bands at 1406 cm −1 (C-O) and 1568 cm −1 (C = O) on an IR spectrum and the presence of C, Si, and increased amount of O on the EDX spectrum. The synthesized materials were applied in the optimization of the removal of oil from synthetic oily wastewater using response surface methodology giving a percentage oil removal of 99.7%. The optimum conditions for oil removal were as follows; 7867 mg/L oil concentration, with adsorbent dosage of 0.001 g and a duration of 21.6 h, and the adsorption capacity under these conditions was found to be 1039 mg/g. The outcomes proved that acetylated silica is an excellent material for oil adsorption and can therefore be used in oil spill clean-ups.

Facile Synthesis of Silica Composites with Oil Sorption Efficiency from a Vital Agricultural Waste of Corn Stalk Cultivated in Bishoftu, Ethiopia

“…The preparation of SYOWW was done according to Shoba et al [10] and Izevbekhai et al [11]. To achieve a homogeneous SYOWW solution, various concentrations (100, 200, 400,600, 800, and 1000 mg) of vacuum pump oil (Mobil, USA) and sodium dodecyl sulfate (0.01 g) were added to 1 L of distilled water and sonicated (probe sonication) for 15 min at 75% amplitude.…”

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

“…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…”

“…The reason for this is, as the dosage was increased, the number of binding sites were also increased and with increase in time, there was prolonged interaction between the oil molecules and the binding sites. 29,30,46 Comparison to other similar adsorbents…”