Photocatalytic Degradation of Palm Oil Mill Effluent (POME) Waste Using BiVO4 Based Catalysts

Abstract

Disposal of palm oil mill effluent (POME), which is highly polluting from the palm oil industry, needs to be handled properly to minimize the harmful impact on the surrounding environment. Photocatalytic technology is one of the advanced technologies that can be developed due to its low operating costs, as well as being sustainable, renewable, and environmentally friendly. This paper reports on the photocatalytic degradation of palm oil mill effluent (POME) using a BiVO4 photocatalyst under UV-visible light irradiation. BiVO4 photocatalysts were synthesized via sol-gel method and their physical and chemical properties were characterized using several characterization tools including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), surface area analysis using the BET method, Raman spectroscopy, electron paramagnetic resonance (EPR), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The effect of calcination temperature on the properties and photocatalytic performance for POME degradation using BiVO4 photocatalyst was also studied. XRD characterization data show a phase transformation of BiVO4 from tetragonal to monoclinic phase at a temperature of 450 °C (BV-450). The defect site comprising of vanadium vacancy (Vv) was generated through calcination under air and maxima at the BV-450 sample and proposed as the origin of the highest reaction rate constant (k) of photocatalytic POME removal among various calcination temperature treatments with a k value of 1.04 × 10−3 min−1. These findings provide design guidelines to develop efficient BiVO4-based photocatalyst through defect engineering for potential scalable photocatalytic organic pollutant degradation.

Insight into Potassium Vanadates as Visible-Light-Driven Photocatalysts: Synthesis of V(IV)-Rich Nano/Microstructures for the Photodegradation of Methylene Blue

“…It was also observed that the increase in V 4+ content resulted in a slight increase of band gap energy (2.44 to 2.50 eV). 74 …”

“…It was also observed that the increase in V 4+ content resulted in a slight increase of band gap energy (2.44 to 2.50 eV). 74 To investigate the kinetics of the process, the ln(C/C 0 ) vs t plot was prepared (see Supporting Information Figure S2). The most probable is the pseudo-first-order kinetics according to the Langmuir−Hinshelwood model; 75 however, the mechanism of the photocatalytic degradation can be more complex.…”

“…Results revealed that the higher the V 4+ content was, the better were the degradation rates and reaction rate constant. It was also observed that the increase in V 4+ content resulted in a slight increase of band gap energy (2.44 to 2.50 eV) 74. To investigate the kinetics of the process, the ln(C/C 0 ) vs t plot was prepared (see Supporting Information FigureS2).…”

Recent Advances in Photocatalytic Oxidation of Methane to Methanol

“…Currently, photocatalytic technology has been widely applied to solve problems related to air pollution [ 10 ] and environmental remediation of water contaminants [ 11 ], including dyes degradation [ 12 ], organic pollutants removal [ 13 , 14 , 15 ], heavy metals removal [ 16 ], and oil degradation in wastewater [ 17 ]. In addition, photocatalytic technology provides alternative ways to produce renewable energy, including water splitting, CO 2 reduction, N 2 fixation, and, in particular, CH 4 oxidation to methanol [ 9 ].…”

“…In the photocatalytic process, bismuth-based material can be prepared as Bi 2 O 3 , Bi 2 MO 6 (M = Cr, Mo, and W), BiVO 4 , BiOX (X = Cl, Br and I), BiPO 4 , (BiO) 2 CO 3 , and pentavalent bismuthates [ 44 ]. Bismuth-based semiconductors are widely used as photocatalysts for many applications such as water splitting [ 48 ], pollutant degradation [ 14 ], CO 2 reduction/N 2 fixation [ 49 ], and organic synthesis ( Figure 14 ).…”