Basta Altaf H, Lotfy Vivian F, Trens Philippe
Department of Cellulose and Paper, National Research Centre, 33 El Bohouth Street, Dokki, Giza PO 12622, Egypt.
Institut Charles Gerhardt des Matériaux de Montpellier, MACS/CNRS/ENSCM/UM, 240 avenue du Pr Emile Jeanbrau, 34296 Montpellier Cedex 5, France.
R Soc Open Sci. 2019 Jul 24;6(7):190579. doi: 10.1098/rsos.190579. eCollection 2019 Jul.
To recommend the beneficial effect of the pulping process on enhancing agro-wastes as precursors for the production of high-performance activated carbons (ACs), different pulping methods (alkali, sulfite and neutral sulfite) were applied on two available Egyptian agriculture by-products (rice straw and sugar cane bagasse), using the one-step pyrolysis method and HPO activating agent. The adsorption performance of the different prepared ACs was evaluated in terms of Iodine Numbers and their sorption properties for removing the methylene blue (MB) from aqueous solutions. The corresponding sorption processes were also analysed using Lagergren first order, pseudo-second order and intraparticle diffusion models. Data revealed that the applied pulping conditions were effective for removing the non-cellulosic constituents of agro-residues. This was demonstrated by the hydrogen/carbon and oxygen/carbon ratios, thermal stability and IR-measurements of the final pulps. These data were effective on the particular sorption properties of RS and SCB-based ACs. Interestingly, the pulping process is a profound modification of the SCB-based fibres, on which it induced a clear increase of the specific surface areas of the corresponding ACs even though they had an impact on the sorption of MB and iodine. These values are superior to the reported data on agro-based ACs with HPO activators. Pulping processes therefore play a dual role in the sorption properties of ACs. The first important role is the impact on the specific surface areas and the second impact is a profound modification of the surface chemistry of the ACs. Therefore, SCB-based ACs can be seen as an economical breakthrough product, and an alternative to the high-cost commercial ACs for the purification of industrial wastewaters.
为了推荐制浆工艺在增强农业废弃物作为高性能活性炭（AC）生产前驱体方面的有益效果，采用一步热解法和HPO活化剂，对两种埃及现有的农业副产品（稻草和甘蔗渣）应用了不同的制浆方法（碱法、亚硫酸盐法和中性亚硫酸盐法）。根据碘值及其从水溶液中去除亚甲基蓝（MB）的吸附性能，评估了不同制备的AC的吸附性能。还使用 Lagergren 一级、准二级和颗粒内扩散模型分析了相应的吸附过程。数据表明，所应用的制浆条件对于去除农业残留物中的非纤维素成分是有效的。最终纸浆的氢/碳和氧/碳比、热稳定性和红外测量结果证明了这一点。这些数据对基于稻草和甘蔗渣的AC的特定吸附性能有影响。有趣的是，制浆过程对基于甘蔗渣的纤维有深刻的改性作用，尽管它对MB和碘的吸附有影响，但它使相应AC的比表面积明显增加。这些值优于报道的使用HPO活化剂的农业基AC的数据。因此，制浆过程在AC的吸附性能中起着双重作用。第一个重要作用是对比表面积的影响，第二个作用是对AC表面化学的深刻改性。因此，基于甘蔗渣的AC可以被视为一种经济上的突破性产品，是用于工业废水净化的高成本商业AC的替代品。
