在这项研究中,四种海藻的干生物量,即紫菜sp.,格racilariabursa-pastoris,裙带菜和海带。,筛选了它们从水溶液中去除亚甲基蓝(MB)染料的能力。采用Plackett-Burman设计(PBD)和Box-Behnken设计(BBD)的统计方法来优化不同的环境条件,以实现龙舌兰的最大MB去除百分比。利用FTIR对吸附前后的生物吸附剂进行了表征,XRD和SEM分析。此外,等温线,进行了动力学和热力学研究,以研究吸附剂的吸附行为。结果表明,与96.5%相比,江草达到了最高的染料去除效率(98.5%),裙带菜占93.5%和93.9%,紫菜。和海带sp.,分别。PBD分析表明,搅拌速度,pH值,发现和生物量剂量是影响将MB去除到龙须菜干燥生物量上的重要参数。根据BBD结果,在132rpm的搅拌速度下获得最大染料去除百分比(99.68%),pH为7,生物量剂量为7.5g/LFTIR,XRD和SEM分析显示了几种官能团参与吸附过程,并且在染料吸附之后,吸附剂的细胞表面形态发生了变化。吸附等温线比Langmuir更符合Freundlich模型(R2=0.9891),Temkin,还有Dubinin-Radushkevich模型.吸附动力学最好用伪二级模型(R2=0.9999)描述,表明染料离子和藻类生物量之间的化学相互作用。热力学参数表明,龙须菜干生物质对MB的吸附是自发的,可行,吸热和随机。这些结果表明,江草干生物量是一个有吸引力的,环保,从环境排放中去除MB染料的廉价和有效的试剂。
In this study, the dried biomass of four marine algae, namely Porphyra sp., Gracilaria bursa-pastoris, Undaria pinnatifida and Laminaria sp., were screened for their ability to remove methylene blue (MB) dye from aqueous solutions. Statistical approaches of the Plackett-Burman Design (PBD) and Box-Behnken Design (BBD) were applied to optimize different environmental conditions in order to achieve the maximum MB removal percentage by Gracilaria bursa-pastoris. The biosorbent was characterized before and after adsorption process using FTIR, XRD and SEM analysis. Additionally, isotherms, kinetics and thermodynamics studies were conducted to investigate the adsorption behavior of the adsorbent. The results showed that Gracilaria bursa-pastoris achieved the highest dye removal efficiency (98.5 %) compared to 96.5 %, 93.5 % and 93.9 % for Undaria pinnatifida, Porphyra sp. and Laminaria sp., respectively. PBD analysis revealed that the agitation speed, pH, and biomass dose were found to be the significant parameters affecting MB removal onto Gracilaria dried biomass. According to the BBD results, the maximum dye removal percentage (99.68 %) was obtained at agitation speed of 132 rpm, pH 7 and biomass dose of 7.5 g/L. FTIR, XRD and SEM analysis demonstrated the participation of several functional groups in the adsorption process and changes in the cell surface morphology of the adsorbent following the dye adsorption. The adsorption isotherms showed better fit to Freundlich model (R2 = 0.9891) than the Langmuir, Temkin, and Dubinin-Radushkevich models. The adsorption kinetics were best described by the pseudo-second-order model (R2 = 0.9999), suggesting the chemical interactions between dye ions and the algal biomass. The thermodynamic parameters indicated that the adsorption of MB onto Gracilaria dried biomass was spontaneous, feasible, endothermic and random. These results indicate that dried biomass of Gracilaria bursa-pastoris is an attractive, environmentally friendly, cheap and effective agent for MB dye removal from environmental discharges.