Characterization and performance of rice husk as additive in green ceramic water filter fabricated by slip-casting

Abstract

Purpose The purpose of this study is to investigate the using of rice husk (RH) which is a green material derived from agricultural waste with the ability to absorb heavy metal. It has been used in wastewater treatment. In this research, a kaolin-based green ceramic water filter (CWF) incorporated with two different additives (RH and zeolite-based RH ash [RHA]) was successfully fabricated. Design/methodology/approach The weight ratio of kaolin:additive was varied (90:10, 80:20 and 70:30) and fabricated via the slip-casting technique. The green CWFs were dried (60°C for 1 h), followed by sintering (1,200°C). Findings The green CWF of kaolin:RH with a weight ratio of 70:30 showed the best properties and satisfactory performance with a porous cross-section microstructure, highest porous area (4.58 µm2), good structure, lowest shrinkage (8.00%), highest porosity (45.10%), lowest density (1.79 g cm−3), highest water absorption (55.50%) and hardness (241.40 Hv). This green CWF has also achieved good permeability (42.00 L m−2h−1) and removal of the textile dye (27.88%). The satisfactory characterization and good textile dye removal performance (75.47%) were also achieved from green CWF with kaolin:zeolite at a weight ratio of 80:20. Research limitations/implications This research is focused on green CWF and zeolite at a certain amount with the specific characterization analysis methods. Practical implications The use of low-cost waste materials to treat dye wastewater from agricultural by-products/wastes sources in treating the dye will enhance the using of green material. Social implications Avoiding the waste sludge that can pollute the environment can create a health issue. The use of low-cost waste materials to treat dye wastewater from agricultural by-products/wastes sources in treating the dye can avoid the waste sludge that can pollute the environment and create serious health issue. Originality/value All the kaolin-based green CWFs incorporated with two different additives (RH and zeolite-based RHA) fabricated using a simple slip-casting technique have shown the potential to be used as a filter in wastewater treatment applications.