Similarly, urea treatments had slightly increased the lignin content of retted kenaf fibres across the varieties. However, there was a significant reduction in hemi-cellulose content of kenaf fibres retted in 1% urea solution compared with others. 2% urea retted fibres had the highest ash content (0.8- 1.05%) followed by 1% urea (0.71-0.96%) and least in control (0.61-0.85%). The protein content of the kenaf fibres was highest in 2% urea followed by 1% urea and least in control. Ifeken 400 fibre retted in 2% urea had the highest (95.35mg/kg) iron content followed by Ifeken Di-400 (94.00mg/kg) of 2% urea and least in Tianug-2 (86.80mg/kg) of control. The tensile strength of 2% urea retted fibres was significantly higher than that of 1% urea and control for all the tested varieties of kenaf fibres. It can be concluded that kenaf retting in 2% urea solution had produced fibres with promising physico-chemical and mechanical …show more content…
These values increased progressively with the retting in all the treatments (figure 8c).Urea treatments had higher amount of COD than control at the first three days of retting. There was rapid increase in COD of control at day 5 and 8.Chemical oxygen demand (COD) shows the oxygen equivalent of the organic matter content of each liquor that is prone to oxidation which can lead to water deterioration. Figure 8c: Chemical oxygen demand (COD) at different retting days. 3.6.4: Retting period
Complete and effective retting lasted for 7-8 days for all the urea treatments (1 and 2%urea) while control lasted for 14 days. 4.0: