Wastewater is a rich source of valuable chemicals of industrial importance. However, their economic recovery is crucial for sustainability. The objective of the present work is to recover hexavalent chromium (Cr VI) as a value-added transition metal from wastewater cost-effectively; the biosorbent derived from seed kernels of mango (M) and jackfruit (JF) were applied for removing the metal from simulated wastewater. The functional groups of the biomass were analysed with the help of Fourier transform infrared (FTIR) spectroscopy, micrographs were generated using a scanning electron microscope, and crystallinity was determined by an x-ray diffractometer (XRD). The concentration of Cr VI in wastewater was analysed by an inductively coupled plasma optical emission spectrometer (ICP-OES). Process parameters (pH, dose, contact time, temperature, and initial concentration) were optimized for efficient Cr VI adsorption using a response surface methodology-based Box–Behnken design (BBD) employing Design-software 6.0.8. The batch experiment at room temperature at pH 4.8 and Cr VI removal ∼94% (M) and ∼92% (JF) was achieved by using a 60-mg dose and an initial Cr (VI) concentration of 2 ppm in 120 min. The equilibrium Cr binding on the biosorbent was well explained using Freundlich isotherm (R² = 0.97), which indicated the indirect interactions between Cr (VI) and the biosorbent. Biosorption of Cr (VI) followed the pseudo-order and intra-particle diffusion models. The maximum adsorption capacity of the M and JF bio-adsorbent is 517.24 and 207.6 g/mg, respectively. These efficient, cost-effective, and eco-friendly biosorbents could be potentially applied for removing toxic Cr (VI) from polluted water.

废水是具有工业重要性的宝贵化学品的丰富来源。然而，他们的经济复苏对可持续性至关重要。目前工作的目标是从废水中经济高效地回收六价铬 (Cr VI) 作为一种具有附加值的过渡金属；来自芒果 (M) 和菠萝蜜 (JF) 种子核的生物吸附剂用于去除模拟废水中的金属。借助傅里叶变换红外 (FTIR) 光谱分析生物质的官能团，使用扫描电子显微镜生成显微照片，并通过 X 射线衍射仪 (XRD) 测定结晶度。通过电感耦合等离子体发射光谱仪（ICP-OES）分析废水中六价铬的浓度。工艺参数（pH、剂量、接触时间、温度、和初始浓度）通过使用设计软件 6.0.8 的基于响应面方法的 Box-Behnken 设计 (BBD) 优化以实现高效的 Cr VI 吸附。通过在 120 分钟内使用 60 毫克剂量和 2 ppm 的初始 Cr (VI) 浓度实现了室温下 pH 4.8 和 Cr VI 去除率约 94% (M) 和约 92% (JF) 的批量实验。使用 Freundlich 等温线很好地解释了生物吸附剂上的平衡 Cr 结合（电阻² = 0.97)，这表明 Cr (VI) 和生物吸附剂之间存在间接相互作用。Cr (VI) 的生物吸附遵循伪有序和颗粒内扩散模型。M和JF生物吸附剂的最大吸附容量分别为517.24和207.6 g/mg。这些高效、经济且环保的生物吸附剂有可能用于从污染水中去除有毒的 Cr (VI)。