Abstract:
The discharge of organics and nutrients rich rice mill wastewater into an
aquatic ecosystem ultimately affects ecosystem functioning. Bio-sorption is a
viable technique for rice mills for onsite wastewater treatment. This study
aimed to produce waste derived bio-sorbent from banana stem to treat rice mill
wastewater. The banana stem was washed thoroughly, shade dried and ground
using a kitchen blade grinder and sieved using 500μm siever. The feed water
was collected from a rice mill functioning in the Vavuniya town area and the
initial COD, phosphates and nitrates were determined as 840.87±23.32 ppm,
12.32±0.11 ppm and 5.63±0.23 ppm respectively. Adsorption isotherm was
conducted for varying dose of biosorbent(1- 6 g/L) and the adsorption kinetics
was conducted for different contact times (30 -180 min). The bio-sorbent
reduced 61.6 % COD, 52.1 % nitrates and 22.2 % phosphates at the dosage of
4 g/L biosorbent at 150 min. Based on the t-test, banana stem is effective in
reducing organics, nitrate, and phosphate (p-value < 0.05). This study
emphasizes that the banana stem has the potential to remove contaminants
from wastewater.
