Effect of basic washing parameters on the chemical composition of empty fruit bunches during washing pretreatment: A detailed experimental, pilot, and kinetic study

Parametric and kinetic study of washing pretreatment for K and Cl removal from rice husk

“…The leaching of K also depends on the temperature, whereas very weak dependency can be observed for Cl. A similar trend has been observed by previous researchers with empty fruit bunches [ 31 ]. Cl being extensively water-soluble [ 33 ] results in maximum removal despite the temperature.…”

“…However, beyond five minutes 65 °C and 75 °C washing temperatures show higher conductivity values compared to that of 50 °C. It has been reported that the secondary slow release is diffusion-limited [ 31 ] and therefore, it can be influenced by particle size, water temperature, and other washing parameters. Within the test duration of 90 min, the conductivity values are much similar in the 65 °C and 75 °C cases.…”

“…The overall leaching rate constant shows an increasing trend up to 50 °C followed by a drop. The secondary release of inorganic species is affected by the concentration of the inorganic species in the leachate [ 31 ] and at higher temperatures, this could be the reason to observe less overall leaching rate even though the initial leaching rate is high. In our previous studies of washing rice husk with tap water gave the same trend with a maximum at 50 °C [ 26 ].…”

“…Cl being extensively water-soluble [ 33 ] results in maximum removal despite the temperature. Due to its diffusion-limited secondary release [ 31 ], the temperature dependency of K is significant. Temperature dependency of K leaching has been observed by a previous study on rice husk washing conducted at three temperature levels and an L/S ratio of 80 for a 3 h duration [ 11 ].…”

“…The overall leaching rate constant shows an increasing trend up to L/S of 40 followed by a drop. As discussed before, the secondary release of inorganic species is affected by the concentration of the inorganic species in the leachate [ 31 ] and this could be the reason to observe less overall leaching rate at higher L/S ratios. The initial leaching rate is continuously increasing with the increase of L/S.…”