Journal Article

Rice Straw as a Natural Sorbent in a Filter System as an Approach to Bioremediate Diesel Pollution

Siti Hajar Taufik, Noor Azmi Shaharuddin, Alyza Azzura Azmi, Faradina Merican, Peter Convey, Khalilah Abdul Khalil, Siti Aqlima Ahmad, Farah Eryssa Khalid, Azham Zulkharnain, Nur Nadhirah Zakaria

2021

Overview

Rice straw, an agricultural waste product generated in huge quantities worldwide, is utilized to remediate diesel pollution as it possesses excellent characteristics as a natural sorbent. This study aimed to optimize factors that significantly influence the sorption capacity and the efficiency of oil absorption from diesel-polluted seawater by rice straw (RS). Spectroscopic analysis by attenuated total reflectance infrared (ATR-IR) spectroscopy and surface morphology characterization by variable pressure scanning electron microscopy (VPSEM) and energy-dispersive X-ray microanalysis (EDX) were carried out in order to understand the sorbent capability. Optimization of the factors of temperature pre-treatment of RS (90, 100, 110, 120, 130 or 140 °C), time of heating (10, 20, 30, 40, 50, 60 or 70 min), packing density (0.08, 0.10, 0.12, 0.14 or 0.16 g cm−3) and oil concentration (5, 10, 15, 20 or 25% (v/v)) was carried out using the conventional one-factor-at-a-time (OFAT) approach. To eliminate any non-significant factors, a Plackett–Burman design (PBD) in the response surface methodology (RSM) was used. A central composite design (CCD) was used to identify the presence of significant interactions between factors. The quadratic model produced provided a very good fit to the data (R2 = 0.9652). The optimized conditions generated from the CCD were 120 °C, 10 min, 0.148 g cm−3 and 25% (v/v), and these conditions enhanced oil sorption capacity from 19.6 (OFAT) to 26 mL of diesel oil, a finding verified experimentally. This study provides an improved understanding of the use of a natural sorbent as an approach to remediate diesel pollution.

• Publisher: MDPI AG
• Subject: absorption / agricultural wastes / diesel fuel / Efficiency / Effluents / Morphology / oil absorption efficiency / oils / one-factor-at-a-time (OFAT) / Pollution / reflectance / response surface methodology / response surface methodology (RSM) / Rice / rice straw / rice straw; sorption capacity; oil absorption efficiency; morphology; spectroscopic analysis; one-factor-at-a-time (OFAT); response surface methodology (RSM) / Scanning electron microscopy / Seawater / Sorbents / sorption capacity / spectral analysis / spectroscopic analysis / spectroscopy / Spectrum analysis / temperature / Variance analysis / X-radiation