| dc.description.abstract | Handwashing with soap/detergent and clean water has become increasingly vital as a result of the
Covid-19 pandemic. Handwashing wastewater contains high quantities of surfactants due to the
use of soap and/or detergents. Handwashing with soap/detergent and clean water is vital for human
hygiene and infectious disease prevention. The wastewater generated is costly to treat because of
the surfactants present, which can quickly clog conventional low-cost filtration systems. As a
result, the wastewater is mostly discharged into the environment leading to several detrimental
effects. This study sought to develop a low-cost composite adsorbent from eggshells and zeolite
for removal of surfactants from handwashing wastewater. The raw materials and the composite
were characterized by X-ray fluorescence, scanning electron microscopy, Fourier-transform
infrared spectroscopy, and Brunauer-Emmett-Teller (BET) surface area analyses. Preparation
conditions including the percentage of eggshells in the composite (30%, 50%, 70%), calcination
time (1 h, 2 h, and 3 h), and calcination temperature (300 oC, 400 oC, and 500 oC) were optimized
using the Box-Behnken design of design expert software. The considered responses were
Methylene blue number (MBN), BET surface area (SBET) and mean pore diameter (MPD). The
optimal preparation conditions were established to be 31.57 %, 1.43 h and 310.94 oC for eggshells
percentage in the composite, calcination time, and calcination temperature, respectively. This led
to the maximized MBN, SBET, and MPD of 94.51 mg/g, 25.92 m2
g
-1
and 10.01 nm, respectively.
The calcined sample prepared at optimum conditions was subsequently applied for removal of
chemical oxygen demand (COD) as an indicator of surfactants in handwashing wastewater. The
COD removal percentage of 87.82%. The EZC production process was found to be viable as was
established at Uganda shillings 40,800 which was low in comparison with commercial granular
activated carbon. | en_US |
