Treatment of palm oil mill secondary effluent (POMSE) using ultrafiltration and nanofiltration membranes

Malaysian palm oil industry has grown rapidly over the last few decades, to becoming the world’s largest producer and exporter of palm oil. This success story however, comes with a greater challenge and equally required more sacrifices in order to maintain the tempo. In the year of 2004, it has been recorded that 26.7 million tons of solid biomass and approximately a 30 million tons of palm oil mill effluent (POME) were generated from 381 palm oil mills in Malaysia [1]. Although different kind of wastes are generated in the palm oil mills, the perceived harmful waste among all the waste generated is the palm oil mill effluent (POME) due to its associated harm if discharged into the environment untreated [2]. POME is a colloidal suspension originating from mixture of sterilizer condensate, separator sludge and hydro cyclone wastewater in a ratio of 9:15:1 respectively [3]. It is a brownish colored, thick liquid that is containing high amount of oil, solids, and grease with high Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) values. Table 15.1 describes the characteristic of POME obtained from Malaysian Palm Oil Board

Nanofiltration of hazardous Congo red dye: performance and flux decline analysis

The effectiveness of nanofiltration (NF) for dye wastewater treatment has been well established. However, detailed study on the fouling phenomena during the NF of dye is still limited. This paper provides the understanding on the performance and fouling phenomena of the polypiperazine amide nanofiltration (PA–NF) membrane for the treatment of hazardous Congo red (CR) dye. The 20 mg L−1 dye at pH 9 was successfully 100% removed with minimum flux decline under the specific conditions: room temperature (25 ◦C) and trans-membrane pressure 5 bar. In addition, the membrane retained more Na2SO4 (62–91%) than NaCl (14–31%), owing to the ion size and negative charges on the membrane surface. The experimental results showed that fouling was the significant reason of the membrane flux decline which principally caused by the favourable/irreversible adsorption. Mechanisms ofthe PA–NF membrane fouling were investigated using the linearized forms according to Wiesner and Aptel equations. It had been found that the fouling mechanisms were influenced by the solution pH and concentration. Under 20 mg L−1 of initial CR concentration at pH 9, the decline of permeate flux was due to standard blocking mechanism during the initial filtration. The cake formation took place rapidly at the second stage of filtration which contributed to the relatively constant permeate flux decline

Polyethersulfone/HFO mixed matrix membrane for enhanced oily wastewater rejection

The recent growth of oil and gas industry has led to the increase of oily wastewater release. Membrane technology has been in the spotlight in recent advancement to treat the oily wastewater. Fouling due to surfactant adsorption and/or oil droplets plugging the pore has become one of the major hindrances in most of the research on oily wastewater treatment. In this work, self-synthesized hydrous ferric dioxide nanoparticles (HFO NPs) via chemical precipitation method were incorporated in polyethersulfone (PES) to fabricate a novel nanocomposite mixed matrix membranes (MMMs) for ultrafiltration (UF). The morphologies and physicochemical properties of prepared HFO NPs and MMMs were characterized using Scanning Electron Microscopy (SEM) and Transmission electron microscope (TEM), contact angle goniometer, before further subjected to water permeation test and oil rejection test. It was found that contact angle of membrane decreased remarkably with an increase in HFO nanoparticle loading from 70° to 38° at which proved its improved hydrophilicity which led to a significant rise in permeate flux, achieving 168.06 L/m2h bar in comparison to 63.67 L/m2h bar shown by the plain PES membrane. Total rejection of oil (100% rejection) demonstrated by the MMMs has confirmed the superior potential of PES/HFO UF membrane for total purification of oily wastewater especially to be reused in oilfield and refinery processes as well as to be released to the environment

Electrochemical strategy for grown ZnO nanoparticles deposited onto HY zeolite with enhanced photodecolorization of methylene blue: Effect of the formation of Si O Zn bonds

Nanoparticles of electrogenerated zinc-supported HY zeolite (EGZnO/HY) catalyst were prepared by a simple electrochemical method. The interaction between zinc species and HY support during the electrolysis was found to affect the EGZnO/HY structure. In addition to the formation of EGZnO nanoparticles (<30 nm in size) that distributed on the surface of HY support, an isomorphous substitution of Al with Zn also occurred in the aluminosilicate framework to result in a Si O Zn bonds. The photoactivity of EGZnO/HY was tested on the decolorization of methylene blue (MB). An amount of 0.375 g L−1 of 1 wt% EGZnO/HY was found to be the optimum dosage for 10 mg L−1 MB, which resulted in 80% of maximum decolorization after 6 h of contact time at pH 3 under fluorescent light (420 nm). Increasing the EGZnO loading led to additional formation of Si O Zn bonds and lessened the number of EGZnO nanoparticles, which then reduced the photodecolorization percentage of MB.The photocatalytic reaction was follows the first-order Langmuir–Hinshelwood model, and gives partially mineralization. The photocatalyst was still stable after five cycling runs with no Zn leaching

Effect of various zinc oxide nanoparticles in membrane photocatalytic reactor for Congo red dye treatment

The utilisation of titanium dioxide (TiO2) in a coupling system membrane photocatalytic reactor (MPR) has been widely investigated. However, there have been very few studies regarding the zinc oxide (ZnO) photocatalyst in MPR, although it has been shown to provide better efficiency than TiO2 in certain cases, mainly for dye photodegradation. In this study, the influence of ZnO nanoparticles in MPR has been investigated for Congo red (CR) dye treatment. Four types of ZnO were synthesised via the precipitation of oxalic acid and zinc acetate solutions. The X-ray diffractometry (XRD) and transmission electron microscopy (TEM) results showed that precipitation is a valuable method for producing the smallest particle size (7–30 nm) of ZnO without any agglomerations, especially under stirring conditions in the presence of PVP (ZnO-PVP-St). As expected, the ZnO-PVP-St presented the great potential in MPR in terms of the highest photodegradation efficiency and lesser membrane flux decline, which was supported by the FESEM results. From the EDX analysis, it was confirmed that the small amount of ZnO-PVP-St did not pass through the membrane pores to the final stream. It was believed that the other remaining ZnO was reused in the photocatalytic reactor, for the continuous process of MPR. Due to the effective surface area of ZnO-PVP-St and adsorption of UV light, the optimum photocatalyst loading for the system was 0.3 g L1 under 20 mg L1 dye concentration and pH 7 of the initial CR dye solutio

Synergistic effects on process parameters to enhance enzymatic hydrolysis of alkaline oil palm fronds

Due to an increasing demand for more sustainable and renewable resources, there has been strong interest in utilizing biomass as a source for cleaner production of energy and chemicals. In this work, the lignocellulosic elements of oil palm frond (OPF) biomass were assessed as an alternate sugar feedstock for biofuel and bioproducts production. At present, long hydrolysis times and high enzymatic loadings hinder commercialisation and large-scale utilisation of enzymatic hydrolysis of lignocellulosic biomass. Thus, various process parameters of enzymatic hydrolysis of alkaline OPF fibre were investigated in an attempt to improve process performance. In this study, OPF biomass was pretreated with 4.42% NaOH at 100 °C for 58.31 min, resulting in significant disruption as characterised by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). Alkaline pretreatment of OPF biomass improved enzymatic biodegradability, and glucan recovery by the Cellic Ctec2 enzyme was more effective than the conventional Celluclast 1.5 L cellulase enzyme. Synergistic effects of stirring speed, surfactant Triton X-100 loading, and β-glucosidase supplement on enzymatic hydrolysis were assessed using statistical experimental design. Under optimal conditions (450 rpm, 1.31%, and 0.14 pNPGU/FPU), 88% conversion of glucan was obtained from alkaline OPF, which is equivalent to the conversion from commercial cellulose (microcrystalline cellulose, MCC). Enzymatic hydrolysis of pretreated OPF was further improved at high agitation speeds. Synergy between agitation speed and surfactant loading interactions with β-glucosidase supplement enhanced glucose production due to the efficient mixing and availability of cellulose to be adsorbed by cellulase

Photocatalytic of Thiophene Desulfurization

Thiophene, found in the fuels is a heterocyclic five-membered ring consisting of sulfur as the heteroatom, with two pairs of electrons at the S atom along with a pair in the six-electron π-system and the others in the ring. Thiophene give negative impacts on living things and also the atmosphere. The presence of sulfur in fuels will lead to the emission of sulfur dioxide into the atmosphere and lead to atmospheric pollution such as acid rain. Thiophene is difficult to remove by using conventional desulfurization processes such as hydro-sulfurization (HDS). Thus, the photocatalytic process is the best alternative method available to degrade thiophene. The photocatalytic process only requires a minimal quantity of catalyst and the by product is almost zero or less harmful to the environment and living things. The process efficiency depends strongly on the chosen photocatalyst. ZnO/KCC provides great potential as the photocatalyst. Hence, this review paper focus on photocatalytic thiophene desulfurization using ZnO/KCC as the photocatalyst

The Optimization of RHS-polysulfone Membrane towards Operating Condition for Humic Acid Removal

This study investigates the effects of rice husk silica (RHS) as additive in the polysulfone membrane to enhance antifouling properties in membrane separation process. The performance (of what?) was evaluated in term of pure water flux (PWF), rejection and antifouling properties. The optimized of normalized flux (Jf /Jo) at different parameter in filtration (pH, ionic strength and tranmembrane-pressure) was carried out by using the response surface methodology (RSM). The results showed that the addition of 4 wt. % RHS give the highest flux at 300.50 L/m².hour (LMH). The highest rejection was found at 3 wt. % of RHS membrane with value 98% for UV254 and 96% for TOC. The optimal value of Jf/Jo&nbsp;was found at 0.62 with the condition of pH: 6.10, ionic strength: 0.05 mol/L and transmembrane-pressure: 2.67 bars. Optimize of RSM analysis from ANOVA also proved that the error of model is less than 0.05% which indicates that the model is significant

Photocatalytic activity of Zn0-PEG nanoparticles for palm oil mill secondary effluent (POMSE) treatment

Palm oil mill secondary effluent (POMSE) has a high color intensity, dissolve oxygen, turbidity, and an organic load of BOD which still not achieved the discharged requirement by the Department of Environment (DOE) and led to detrimental to the aquatic life. The photocatalytic degradation process is one of the promising methods in wastewater treatment due to its advantages. However, the study on PMSE treatment using the photocatalytic degradation process in the presence of ZnO-PEG nanoparticles (NPs) is still limited. Therefore, this study reports on the photocatalytic degradation of POMSE by using ZnO-PEG NPs. The ZnO-PEG NPs was characterized by using XRD and FTIR where the results show that there are no impurities present in the samples and presenting the nature and the chemical bonds of ZnO-PEG nanoparticle

The Photocatalytic Activity of Green Zinc Oxide Nanoparticles in The Treatment of Aerobically Palm Oil Mill Effluent

Traditional treatment of aerobically palm oil mill effluent (A-POME) is incapable of removing the colour and organic load that does not exceed the discharge standard limit to the stream channel. Green synthesis nanoparticles (NPs) provide a significant potential for substantial performance in the photocatalytic degradation of high-strength wastewater. Therefore, the current project's goal is to investigate the photocatalytic degradation performance of A-POME in the addition of green Zinc Oxide Cymbopogon Citratus (ZnO–CC) NPs in terms of chemical oxygen demand (COD), turbidity, and colour removal. The outcomes showed that pH 8 and a ZnO-CC NPs loading of 0.3g/L was ideal for the photocatalytic degradation of A-POME with a significant percentage reduction of turbidity (68.03%), colour (48.11%), and COD (75.4%). The equilibrium data revealed a better fit Langmuir-Hinshelwood models with higher R2 and K values of 0.9906 and 0.0225, respectively. Increased ZnO–CC NPs loading in alkaline medium aided in the breakdown of A-POME pollutants by increasing the surface area accessible for UV light adsorption during the photocatalytic process. Thus, the finding from this study can assist the palm oil mill sector in improving A-POME treatment to provide high-quality treated effluent