Abstract:
Maruthamunai is a hamlet located in the Eastern Province of Sri Lanka where
the dyeing industry plays a significant role. The discharge of dyeing effluent is a serious
problem in this area due to the pollution of the environment and the health of the
inhabitants. Hence, the treatment of effluent is necessary. There are various
technologies are available for the treatment process and most of them are costly. On
account of this, Ganem & Nawas, (2020) have proposed a simple treatment method
using a byproduct (charcoal) formed during the process itself. The objectives of
the previous study were to improve its applicability and efficiency using one color.
But in reality, there are different colors (different compounds) are released. Here
five different colored samples, namely blue, pink, orange, green, and brown were
collected and identified conditions, such as adsorbent (wood charcoal, 63 µm)
dosage, agitation speed, retention time, and pH, were optimized for each case. The
optimum conditions for each sample were as follows; for the blue color sample the
adsorbent dosage was 6.0 g/100 ml, agitation speed was 210 rpm, retention time
was 90 min, and pH was 7.00. For the pink color sample adsorbent dosage, agitation
speed, retention time and pH were 6.0 g/100 ml, 140 rpm, 90 min and 9.60
respectively. For the orange color sample 7.5 g/100 ml, 140 rpm, 60 min, and 1.00 were
adsorbent dosage, agitation speed, retention time, and pH respectively. For the green
color sample adsorbent dosage, 7.0 g/100 ml, agitation speed, 178 rpm, retention
time 90 min and pH, 2.00 and for the brown color sample 6.5 g/100 ml, 140 rpm, 120
min and 8.60 were the adsorbent dosage, agitation speed, retention time, and pH
respectively.The percentage color reduction was 98.93%, 98.26%, 97.08%,
98.61%, and 98.49% for samples blue, pink, orange, green, and brown respectively.
When the adsorbent particle size decreased the percentage of color reduction
increased. As per the results, wood charcoal can be used as a simple, cheap,
ecofriendly, and efficient adsorbent to remove any color (chemical compound) of
the effluent, subject to the optimum conditions mentioned.
