Abstract:
The high cost and complexity of existing techniques used to remove heavy metal ions from water
have necessitated developing and implementing cost-effective and socially acceptable options that
can be applied at the household level. This work examined the ability of ceramic water filters
impregnated with silver nanoparticles to remove Lead and Chromium ions from water. Ceramic
water filters were fabricated using locally sourced materials to filter water samples spiked with
known concentrations of Lead and Chromium ions. The filters were categorized into two categories;
without silver nanoparticles (control filters) and filters impregnated with silver nanoparticles using
two application methods; dip-soak method and paint-method. The study assessed the effects of the
addition of silver nanoparticles, application method of silver nanoparticles, initial water temperature,
and initial metal ion concentration on the performance of the different sets of filters. It was observed
that the addition of silver nanoparticles improved the ability of ceramic water filters to remove Lead
and Chromium ions from water. The relative amounts of Lead and Chromium ions removed in the
dip-soaked filters were higher (12.58% and 15.43%) than in the control filters (5.64% and 7.40%).
The study also showed that the application method of silver nanoparticles influenced the ability of
the filters to remove Lead and Chromium ions. The adsorption of Lead was higher in the Paint method filter (14.45%) compared to the Dip-Soaked filter (12.58%), whereas the adsorption of
Chromium was higher in the Dip-Soaked filter (15.43%) than in the Paint-Method filter (14.22%).
The effect of initial water temperature, over the range of 24 °C to 84 °C, was insignificant since the
cumulative percentage for the three sets of filters was less than 1%. Further, the initial metal ion
concentration had a significant impact on the adsorption capacities of the ceramic water filters. In
the control filters (without AgNPs), the relative amounts of Lead and Chromium ions removed
decreased with an increase in initial metal ion concentration. However, for the Dip-soaked and
Paint-method filters, the relative amounts increase with an initial increase in initial metal ion
concentration up to a saturation point (0.6g/l), after which it decreases. Surface morphology studied
using a Scanning electron Microscope (SEM) showed an excellent surface binding between the
clay particles and silver nanoparticles. Therefore, ceramic water filters impregnated with silver
nanoparticles offer a practical, low-cost, and socially acceptable alternative for removing heavy
metal ions from water at the household level.
