Department of Civil Engineering, National Institute of Technology Agartala, Tripura 700046, India.
Environmental and Water Resources Engineering Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India.
Ultrason Sonochem. 2021 Jul;75:105592. doi: 10.1016/j.ultsonch.2021.105592. Epub 2021 May 21.
The magnetic MgFeO nanoparticles (NPs) were fabricated via a facile co-precipitation technique and was comprehensively characterized by XRD, FTIR, SEM, EDX and VSM. The prepared NPs were used as catalyst in presence of ultrasound (US) irradiation to activate persulfate (PS) for generation of sulfate radicals (SO) for boosted degradation of toxic Brilliant Green (BG) dye. Preliminary experiments revealed that highest BG dye degradation efficiency of 91.63% was achieved at MgFeO catalyst dose of 1.0 g/L, PS dose of 300 mg/L, and initial dye concentration of 70 ppm within 15 min of US irradiation. However, only US, US in presence of PS oxidation and US in presence of MgFeO catalyst have shown 20.2%, 83.6% and 45.0% of BG dye removal, respectively. Furthermore, response surface methodology (RSM) based central composite design (CCD) was executed to investigate the effect of interaction between independent variables such as MgFeO catalyst dose (0.5-1.5 g/L), PS dose (150-350 mg/L), initial BG dye concentration (50-150 ppm) and US irradiation time (4-12 min). The RSM based quadratic model was used to predict the experimental data, and the prediction accuracy was confirmed by analysis of variance (R = 0.98). The established RSM model has predicted the optimum experimental conditions as MgFeO catalyst dose of 0.75 g/L, PS dose of 300 mg/L, initial dye concentration of 75 ppm and sonication time of 10 min. Subsequently, the treatment cost analysis was performed for all thirty experimental runs of CCD, and the RSM predicted response was found to be evidently optimum as this has delivered best economic condition (140 $/kg of BG removed) with respect to relative dye removal (%). COD removal and residual sulfate analysis have demonstrated satisfactory reduction of COD (90.31%) as well as sulfate ions (42.87 ppm) in the dye solution after treatment. Results of degradation pathway analysis portrayed the transformation of BG molecule (M/Z ratio 385) into simpler fractions with M/Z ratio of 193, 161, 73, and 61. Moreover, the toxicity analysis revealed that sono-catalytically activated PS system has efficiently reduced the toxicity level of BG dye from 93.9% to 5.13%.
通过简便的共沉淀技术制备了磁性 MgFeO 纳米颗粒（NPs），并通过 XRD、FTIR、SEM、EDX 和 VSM 进行了全面表征。将制备的 NPs 用作催化剂，在超声（US）照射下激活过硫酸盐（PS）以产生硫酸根自由基（SO），从而促进有毒亮绿（BG）染料的降解。初步实验表明，在 US 照射 15 分钟内，当 MgFeO 催化剂剂量为 1.0 g/L、PS 剂量为 300 mg/L、初始染料浓度为 70 ppm 时，BG 染料的最高降解效率达到 91.63%。然而，仅 US、US 存在 PS 氧化和 US 存在 MgFeO 催化剂时，BG 染料的去除率分别为 20.2%、83.6%和 45.0%。此外，还执行了基于响应面法（RSM）的中心复合设计（CCD），以研究独立变量（如 MgFeO 催化剂剂量（0.5-1.5 g/L）、PS 剂量（150-350 mg/L）、初始 BG 染料浓度（50-150 ppm）和 US 照射时间（4-12 min）之间的相互作用对实验数据的影响。使用基于 RSM 的二次模型来预测实验数据，并通过方差分析（R=0.98）验证预测的准确性。所建立的 RSM 模型预测了最佳实验条件，即 MgFeO 催化剂剂量为 0.75 g/L、PS 剂量为 300 mg/L、初始染料浓度为 75 ppm 和超声时间为 10 min。随后，对 CCD 的所有 30 个实验运行进行了处理成本分析，发现 RSM 预测的响应显然是最佳的，因为它提供了最佳的经济条件（每公斤 BG 去除 140 美元），相对于相对染料去除率（%）。COD 去除和残留硫酸盐分析表明，处理后染料溶液中的 COD（90.31%）和硫酸盐离子（42.87 ppm）得到了令人满意的降低。降解途径分析的结果表明，BG 分子（M/Z 比 385）转化为具有 M/Z 比 193、161、73 和 61 的更简单分数。此外，毒性分析表明，超声催化激活的 PS 体系有效地将 BG 染料的毒性水平从 93.9%降低到 5.13%。
