Recent advances in the preparation of oil palm waste-based adsorbents for removal of environmental pollutants - a review [Kemajuan terkini dalam penyediaan penjerap berasaskan sisa kelapa sawit untuk penyingkiran bahan pencemar alam sekitar - sebuah ulasan]

The palm oil industry is an excellent source for huge quantities of highly useful biomass. Utilization of oil palm biomass-based materials for the removal of environmental pollutants appears to be a viable solution in the lights of promoting sustainable development. This article aims to review recent advances in the preparation of adsorbent from different parts of oil palm biomass for the removal of heavy metal and organic environmental pollutants from water. Physical and chemical factors that enhance the applicability of oil palm waste as adsorbents are also discussed. It is clear that each part of the oil palm biomass is potentially applicable as biosorbents for most environmental pollutants and the capability could be further enhanced through modifications in accordance with its intended pollutants. Modifications by chemical treatments such as acidic, basic or drying agent treatments under optimum dosages have been found to have significant effects on the selectivity of the analyte absorption. In general, basic treatment is more suitable for common pollutants such as metals, pesticide and basic dyes. Meanwhile, the acidic treatment is more suitable for non-polar organic pollutants such as phenols. Recent trends in the application of oil palm biomass as biosorbents are also discussed that together open new doors to sustainable development

Sol-gel based optically active phenolphthalein encapsulated nanomatrices for sensing application

In this work, synthesis and characterization of phenolphthalein-immobilized titania (T-phph) and silica–titania (ST-phph) nanomatrix is reported. The thin films are deposited by sol–gel method at low temperature. The effect of host–guest chemistry in matrices, on the surface structures, optical and sensing activity of the resultant thin films is studied. The phenolphthalein-immobilized fabricated nanoparticles/nanomatrices are analyzed by field emission scanning electron microscope, energy-dispersive X-ray spectroscopy, atomic-force microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, surface analysis, thermogravimetric analysis, and UV–Vis spectroscopy. Thermally stable and high surface area homogeneous nanoparticles, containing nanocrystalline anatase phase with low refractive index (1.58), low roughness (5.5 nm), and high transparency (95 %) are obtained for phenolphthalein-immobilized ST-phph nanomatrix. Moreover, smaller nanoparticles (56–121 nm) with good incorporation of dye and good response of sensing are obtained. The sensor response is optimized at pH 12 with 10.1 pKa value at 555 nm. Graphical Abstract: [Figure not available: see fulltext