Mohamed Hussein S, Soliman N K, Abdelrheem Doaa A, Ramadan Arwa A, Elghandour Ahmed H, Ahmed Sayed A
Basic Science Department, Nahda University, Beni-Suef, Egypt.
Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt.
Heliyon. 2019 Mar 7;5(3):e01287. doi: 10.1016/j.heliyon.2019.e01287. eCollection 2019 Mar.
Recently, a great attention has been given for applying a low-cost and effective adsorbents instead of expensive and dangerous chemical materials as a promising approach to treat wastewater. In this work, residue powder of brown macroalga (RPG), after extracting most of its active components by 70% methanol, was used as an adsorbent material for wastewater treatment. This work also reduces the costs of residue disposal. The adsorption ability of RPG is studied for removing Cd and Crfrom wastewater. We investigated metal adsorption isotherms and kinetics, the effect of initial metal concentration, contact time, adsorbent dosage, temperature, pH and the RPG reusability on metal ions removal. The results showed that the removal % generally increases with decreasing concentration of metal ions. RPG has higher metal removal percentages reaching 96.2% and 78.8% for Cd and Cr, respectively, with a maxiumum adsorption capacity of 96.46 and 31.52 mg/g for and Cr,respectively at pH 6.2, 50 mg, 25 °C and initial metal concentration of 100 mg/L. The metal ions removal % increased by increasing the dosage of adsorbent and it decreased after a certain limit. The metal removal % slightly changes with increasing temperature for Cd and decreased at high-temperature for Cr. The adsorption increased with increasing pH value from 3 to 5, and decreases at pH value of 6.2 then it increased again at pH 8. The removal % and adsorption capacity at pH 8 reaches 99.58%, 99.65%, 99.85 mg/g and 39.86 mg/g for Cd and Cr, respectively. The results also showed that RPG can be reused several times for metal ions removal. In addition, Tempkin isotherms and pseudo-second-order kinetic fit the adsorption of Cd and Cr well.
最近，人们高度关注应用低成本且有效的吸附剂来替代昂贵且危险的化学材料，将其作为一种有前景的废水处理方法。在这项工作中，棕色大型海藻的残留粉末（RPG），在通过70%甲醇提取其大部分活性成分后，被用作废水处理的吸附材料。这项工作还降低了残留物处置成本。研究了RPG对废水中镉和铬的吸附能力。我们研究了金属吸附等温线和动力学、初始金属浓度、接触时间、吸附剂用量、温度、pH值以及RPG的可重复使用性对金属离子去除的影响。结果表明，去除率通常随着金属离子浓度的降低而增加。RPG对金属的去除率较高，镉和铬的去除率分别达到96.2%和78.8%，在pH值为6.2、吸附剂用量50mg、温度25°C以及初始金属浓度为100mg/L时，镉和铬的最大吸附容量分别为96.46mg/g和31.52mg/g。金属离子去除率随着吸附剂用量的增加而提高，但在达到一定限度后会下降。镉的金属去除率随温度升高略有变化，而铬在高温下则下降。吸附率随着pH值从3增加到5而升高，在pH值为6.2时下降，然后在pH值为8时再次升高。在pH值为8时，镉和铬的去除率分别达到99.58%、99.65%、99.85mg/g和39.86mg/g。结果还表明，RPG可多次重复用于去除金属离子。此外，Tempkin等温线和准二级动力学很好地拟合了镉和铬的吸附过程。
