Functionalization and Formation of Drinking Water Filter Rod from Lignite with Zeolite, Bentonite, and Local Clay

摘要

A drinking water filter rod was functionalized and formed from a starting mixture of lignite, zeolite, bentonite, and clay. The formation of the filter was studied focusing on the effects of zeolite dosageand sintering temperature in a reducing atmosphere. Borax was also added to the starting mixtures for melting point reduction.The sintered filterswere characterized by XRD, FTIR, and SEM-EDS.The percent drying shrinkage, percent firing shrinkage, percenttotal shrinkage,percentmass yield, percentfixed carbon, and hardnessof filters weremeasured. The results showed that the firing shrinkage, the total shrinkage and hardness increased with increasing sintering temperature. The hardness of sintered filters ishigher thanthe limitof theThai Industrial Standards Institute. On the other hand, mass yield and fixed carbon decreased with increasing sintering temperature. The starting materials mixture of45wt% lignite, 30wt% zeolite, 10wt% bentonite, 10wt% local clay, and5wt% boraxwas used with sintering temperatures ranging from 400 °Cto 600°C. The functional surface groups of the sintered filter exhibited a high content of aluminosilicates and carbon, whichwere derived from all starting materials. The macropores of sintered filterhad dimensions of the channels between particles in the range of 0.2-2 pm.