未经处理的制革废水含有大量有毒金属,染料,和其他污染物,对生态系统和公共卫生造成不利影响。在这项工作中,制备了海藻酸钙-聚乙烯醇-氧化石墨烯(CA-PVA-GO)复合材料,特别是Cr(Ⅲ)和Cl酸性紫54(AV54)染料,制革废水。FESEM,FTIR,和XRD分析用于表征GO和CA-PVA-GO。不同的操作变量,viz.pH(Cr(III)为3.0-5.5,染料为2-7),用量(0.164-2.46g/L),接触时间(10-60分钟),初始浓度(Cr(III)为39、65、98和201ppm,染料为21.5、38.5、54.5和61.75ppm),和温度(298、308、318和328K)进行了研究,以评估CA-PVA-GO复合材料的效率。发现Cr(Ⅲ)和AV54染料吸附的最佳条件为pH(5.0和3.0),用量(两者均为0.82g/L),和时间(45和60分钟),分别,去除率为35.35±1.43%,去除率为84.63±2.54%。通过Langmuir和Freundlich等温线分析了实验数据。Cr(Ⅲ)和AV54染料的最大吸附量(qm)分别为173.01和74.68mg/g,分别。对于AV54染料吸附,伪二级动力学模型比一级动力学模型更好地拟合(R2=0.981、0.995、0.92和0.995)。热力学分析表明,Cr(Ⅲ)和AV54染料的吸附过程是自发的和放热的。Cr(III)吸附的吉布斯自由能(ΔG)值在-7.433,-4.508,-2.626和-1.311kJ/mol下获得,而染料为-5.178、-4.867、-4.628和-4.555kJ/mol。对于Cr(III),ΔH和ΔS的值分别为-67.257和-0.198kJ/mol,对于染料去除为-10.852和-0.019kJ/mol。再生CA-PVA-GO复合材料成功重复使用。不同的物理化学参数,viz.,浓度,pH值,TDS,EC,铬革和染色废水的BOD5和COD,吸附前后进行了分析。制革废水中铬和染料的去除率分别为53.18%和93.91%,揭示开发的环保CA-PVA-GO复合材料可能是制革废水处理的有效吸附剂,并可能扩大到工业水平。
Untreated tannery wastewater contains a large amount of toxic metals, dyes, and other pollutants, which pose adverse effects on the ecosystem and public health. In this work, a calcium alginate-poly vinyl alcohol-graphene oxide (CA-PVA-GO) composite was prepared to remove metals and dyes, particularly Cr(Ⅲ) and CI acid violet 54 (AV54) dye, from tannery wastewater. FESEM, FTIR, and XRD analyses were applied to characterize the GO and CA-PVA-GO. Different operational variables, viz. pH (3.0-5.5 for Cr(III) and 2-7 for dye), dosage (0.164-2.46 g/L), contact time (10-60 min), initial concentration (39, 65, 98, and 201 ppm for Cr(III) and 21.5, 38.5, 54.5, and 61.75 ppm for dye), and temperature (298, 308, 318, and 328 K) were studied to evaluate the efficiency of the CA-PVA-GO composite. The optimum conditions for Cr(Ⅲ) and AV54 dye adsorption were found to be pH (5.0 and 3.0), dosage (0.82 g/L for both), and time (45 and 60 min), respectively, with 35.35 ± 1.43% and 84.63 ± 2.54% removal efficiency. The experimental data was analyzed through the Langmuir and Freundlich isotherms. The maximum adsorption capacity (qm) was observed at 173.01 and 74.68 mg/g for Cr(Ⅲ) and AV54 dye, respectively. The pseudo-second-order kinetic model was fitted better (R2 = 0.981, 0.995, 0.92, and 0.995) than first-order for AV54 dye adsorption. Thermodynamic analyses revealed that the Cr(Ⅲ) and AV54 dye adsorption processes were spontaneous and exothermic. The value of Gibbs free energy (ΔG) for Cr(III) adsorption was obtained at -7.433, -4.508, -2.626, and -1.311 kJ/mol, whereas it was -5.178, -4.867, -4.628, and -4.555 kJ/mol for dye. The values of ΔH and ΔS were -67.257 and -0.198 kJ/mol for Cr(III) and -10.852 and -0.019 kJ/mol for the dye removal. The regenerated CA-PVA-GO composite was reused successfully. Different physicochemical parameters, viz., concentration, pH, TDS, EC, BOD5, and COD of chrome tanning and dyeing effluents, were analyzed before and after the adsorption. The results of chromium and dye removal from tannery wastewater were 53.18% and 93.91%, revealing that the developed eco-friendly CA-PVA-GO composite could be an operative
adsorbent for tannery wastewater treatment and possibly scaled up to an industrial level.