Comparative study of acid-treated and alkali-treated carbonised Kapok–fibres for oil/water absorption system

Abstract

Kapok predominantly utilized as an adsorbent in removing wastewater such as dye, oil and heavy metals. However, a comparative study between acid-treated and alkali-treated carbonized Kapok fibers has not been carried out in detail. In this study, as-made Kapok fibers were carbonized and subsequently undergo acid (HCL) and alkali (NaOH) treatment. The resultant treated Kapok fibers were characterized using Fourier transform infrared (FTIR) spectroscopy, Elemental Analyzer (EA) and Thermogravimetric Analysis (TGA). As-made carbonized Kapok fibers were tested with oil/water absorption model system. A reduction of band intensity at 1740 cm−1 and 1245 cm−1 occurred for NaOH treated sample compared with HCL. The composition of carbon in Kapok fiber increased after carbonization treatment using NaOH (62.42%) and HCL (66.15%) compared with untreated (0.17%). For oil/water absorption system, the result indicated that HCL-treated Kapok fibre was the highest absorption on 28.10 gg−1 diesel, 27.28 gg−1 petrol and 39.84 gg−1 for used vegetable oil respectively in comparison with NaoH-treated and as-made carbonized Kapor fibers. In conclusion, modification of the surface of carbonized Kapok fibers could significantly alter its textural properties which could enhance its oil absorptive behavior.

The preliminary study of oil removal using lemon peel waste

“…For untreated adsorbent, the lemon peel was collected then rinsed with tap water and dried under the sunlight for 48 hours to remove some of the moisture. Next, it was put in the oven for one hour at 70 °C to remove the residual moisture in the peels (Abdullah et al, 2016;Abdullah et al, 2019;Azlin et al, 2019). After that, it was ground by using into powder.…”

“…The use of natural organic adsorbents was widely used because of their greater adsorption capacities, eco-friendliness and cost effectiveness. Natural adsorbents are not only biodegradable when disposed, but more efficient than chemical adsorbent as they showed a greater adsorption capacity (Abdullah et al, 2016;Abdullah et al, 2019;Azlin et al, 2019).…”

Modification Strategies of Kapok Fiber Composites and Its Application in the Adsorption of Heavy Metal Ions and Dyes from Aqueous Solutions: A Systematic Review

“…loss of moisture contributed to a 5% weight decrease at temperatures between 20-78 °C [49,65]. The weight of KF decreased to 77% at 235-405 °C because of the degradation of cellulose and lignin, with only 11% of the original weight remaining when it reached 800 °C [49,66].…”

“…Alkaline pre-treatment on fibers, on the other hand, involves a concentrated aqueous solution with a strong base [87] such as sodium hydroxide, potassium hydroxide, or calcium oxide. Abdullah et al [65] pretreated KF with HCl and NaOH to remove wax, lignin, and impurities. The FTIR (Figure 5) of treated KF showed a higher broad absorption band at 3410 cm −1 than raw KF [65].…”

“…compounds [65,89]. Raw KF recorded around 2-3.5 mg weight loss that occurred between 237 °C and 367 °C because of dehydration and breaking down of cellulose and lignin.…”