Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7044002 | Separation and Purification Technology | 2018 | 38 Pages |
Abstract
The bleaching operation of a kraft pulping process generates a large amount of effluents with high organic loads. The affinity of biomass-based fly ash as a low-cost adsorbent for reducing lignin concentration, chemical oxygen demand (COD) and turbidity of the bleaching effluents prior to a biological treatment process was studied in this work. The results showed that the optimized conditions for obtaining the maximum removals of lignin (81.6%) and COD (67.9%) were the fly ash dosage of 6â¯wt% in the effluent and the treatment time of 30â¯min and temperature of 30â¯Â°C. The results also showed that the settling rate of the fly ash in fly ash/effluent suspension systems increased as fly ash dosage increased. Charge neutralization played a key role at a low fly ash dosage (less than 2â¯wt%) for removing lignocellulosic flocs smaller than 10â¯Âµm, while complexion of small flocs to larger ones (with the size of 30-500â¯Âµm) occurred at the higher fly ash dosage in the effluent. Coagulation and adsorption were the main phenomena for the removals of COD, lignin and turbidity at a higher fly ash dosage and a prolonged treatment time.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Filtration and Separation
Authors
Weijue Gao, Pedram Fatehi,