Low-Temperature Solid-Phase Synthesis of Graphene Thin Films Usable in the Harsh Environment of Liquids Suresh Giri, Vikaskumar Pradeepkumar Gupta, Muzzammil Bin Ngatiman, Nur Sahiera Binti Abd Rohim, Naoko Yoshida, Jiaxin Yan, Daniel H. C. Chua, Wei Ming Lin, Toru Asaka, Yazid Yaakob, Hidetoshi Miyazaki, Kosuke Kurushima, Naomi Fukui, Mohd Zamri Mohd Yusop, Yong Yang, Masaki Tanemura Advanced Materials Technologies, 2026 The synthesis of graphene at lower temperatures remains challenging, along with the expansion of its application areas. Here we demonstrated the graphene synthesis on various substrates at and above 350°C by a solid phase reaction method. In this method, C‐rich Ni–C films are deposited on the substrates by conventional magnetron sputter deposition at room temperature with a binary target, followed by vacuum annealing. This resulted in phase separation of the multilayer graphene on top. The temperature dependence of graphene formation is investigated by high‐resolution transmission electron microscopy (TEM), in situ X‐ray diffraction (XRD) and Raman spectroscopy. Graphene thus synthesized on a stainless steel (SS) plate is successfully used to enhance the biofilm formation and the current generation by Geobacter species for use in microbial fuel cell application. As transfer‐free graphene can be synthesized directly on substrates irrespective of their material and shape, and is usable in harsh environment of liquid, this simple method is believed to be quite promising for a variety of applications.
MECHANISM OF MEMBRANE FOULING IN HYBRID MEMBRANE PHOTOCATALYTIC REACTOR FOR PALM OIL MILL SECONDARY EFFLUENT TREATMENT Yahaya Hawari, Muzammil Ngatiman, Rohaya Mohamed Halim, Hazim Sharudin, Hasannuddin Abd Kadir Jurnal Mekanikal, 2023 Palm oil mill secondary effluent (POMSE) is a byproduct of the biological treatment of palm oil mill effluent. This research aims to investigate the mechanism of membrane fouling in the treatment of POMSE using a hybrid membrane photocatalytic reactor (MPR). The effectiveness of MPR in POMSE treatment is currently limited due to membrane fouling on the membrane surface. This study focuses on understanding the various mechanisms of membrane fouling, including complete blocking, intermediate blocking, standard blocking, and cake filtration. The determination of each fouling mechanism is achieved through an analysis of normalized flux data employing the Wiesner and Aptel equation. The results demonstrate a high degree of model fitness (R2 = 0.9576) for MPR Run 3, confirming its effectiveness. Based on the (R2) values and the fitted parameter (Ks^(-1)), it is evident that, under varying pH levels, catalyst types, catalyst loading, and initial POMSE concentrations, the cake formation fouling mechanism prevails in MPR Run. In conclusion, this research holds promising potential for implementation in the wastewater treatment industry while ensuring compliance with environmental regulations.
Investigation of struvite crystals formed in palm oil mill effluent anaerobic digester Muzzammil Ngatiman, Mohammed Saedi Jami, Mohd Rushdi Abu Bakar, Vijaya Subramaniam, Soh Kheang Loh Heliyon, 2021 The formation of struvite crystals or magnesium ammonium phosphate (MgNH4PO4) in palm oil mill effluent (POME) occurs as early as in the secondary stage of POME treatment system. Its growth continues in the subsequent tertiary treatment which reduces piping diameter, thus affecting POME treatment efficiency. Hypothesis. The beneficial use of the crystal is the motivation. This occurrence is rarely reported in scientific articles despite being a common problem faced by palm oil millers. The aim of this study is to characterize struvite crystals found in an anaerobic digester of a POME treatment facility in terms of their physical and chemical aspects. The compositions, morphology and properties of these crystals were determined via energy dispersive spectroscopy (EDS), elemental analysis, scanning electron microscopy (SEM) and x-ray diffraction (XRD). Solubility tests were carried out to establish solubility curve for struvite from POME. Finally, crystal growth experiment was done applying reaction crystallization method to demonstrate struvite precipitation from POME. Results showed that high phosphorous (P) (24.85 wt%) and magnesium (Mg) (21.33 wt%) content was found in the struvite sample. Elemental analysis detected carbon (C), hydrogen (H), nitrogen (N) and sulfur (S) below 4 wt%. The crystals analysed by XRD in this study were confirmed as struvite with 94.8% struvite mineral detected from its total volume. Having an orthorhombic crystal system, struvite crystals from POME recorded an average density of 1.701 g cm−3. Solubility curve of struvite from POME was established with maximum solubility of 275.6 mg L−1 at pH 3 and temperature 40 °C. Minimum solubility of 123.6 mg L−1 was recorded at pH 7 and temperature 25 °C. Crystal growth experiment utilizing POME as the source medium managed to achieve 67% reduction in phosphorous content. This study concluded that there is a potential of harnessing valuable nutrients from POME in the form of struvite. Struvite precipitation technology can be adapted in the management of POME in order to achieve maximum utilization of the nutrients that are still abundant in POME. At the same time maximization of nutrient extractions from POME will also reduce pollutants loading in the final discharge.
Assessment of the effluent polishing plant using a ultrafiltration membrane installed at a palm oil mill NUMAN ABDUL HADI, YAHAYA HAWARI, MUZZAMMIL NGATIMAN, NOR FAIZAH JALANI, NOORSHAMSIANA ABDUL WAHAB, ROHAYA MOHAMED HALIM Environment Protection Engineering, 2019 Palm oil mills discharge raw effluent with high biochemical oxygen demand (BOD) of about 25 000 mg O2/dm 3 . Conventional effluent treatment system uses ponds with a long hydraulic retention time of about 55-85 days, but the reduction of BOD is usually halted at 100-250 mg O2/dm 3 . Further reduction of BOD to below 20 mg O2/dm 3 to meet regulation requirement needs further advanced treatment. This study evaluates the efficiency of an effluent polishing plant installed at a palm oil mill targeting final effluent BOD below 20 mg O2/dm 3 . Characteristic of the incoming and treated effluent, dissolved oxygen in the aeration ponds and the effluent flow rate of the treatment plant have been determined. Due to low process throughput at the mill, the polishing plant operated at only 60% of its designed capacity. Treatment of effluent showed reduction of BOD from 39.35.8 to 6.13.8 mg O2/dm 3 , i.e., a reduction by 80-94%. Colour -a newly proposed regulation parameter -was reduced from 108169 to 84560 ADMI, i.e., by 11-30%. This study indicates that while the treatment of effluent to reduce the BOD to below 20 mg O2/dm 3 is feasible, reduction of colour to less than 100 ADMI is not achievable.
Zero discharge treatment technology of palm oil mill effluent Journal of Oil Palm Research, 2013