Heavy metals and dyes used in technological applications have a detrimental influence on human health and the environment. The most used methods for removing pollutants depend on high-cost materials. Therefore, this research was conducted on cost-effective alternatives derived from natural resources and food waste. Herein, we designed a composite hydrogel based on sodium alginate/coffee waste (Alg/coffee) as adsorbent for the removal of organic and inorganic pollutants from aquatic solutions. The selectivity study displayed that Alg/coffee is more effective in adsorbing Pb(II) and acridine orange dye (AO). Adsorption of Pb(II) and AO was studied at concentration range of 0–170 mgL⁻¹ and 0–40 mgL⁻¹. Adsorption data of Pb(II) and AO reveals their fitting to Langmuir-isotherm and pseudo-second-order-kinetic models. The findings demonstrated that Alg/coffee hydrogel are more effective than coffee powder itself with an adsorption (%) approaching 98.44 % of Pb(II) and 80.53 % of AO. Real sample analysis reveals the efficiency of Alg/coffee hydrogel beads in Pb(II) adsorption. The adsorption cycle was examined four times providing high efficiency toward Pb(II) and AO. Desorption of Pb(II) and AO was easily performed using HCl eluent. Thus, Alg/coffee hydrogel beads could be promising adsorbent for the removal of organic and inorganic pollutants.

技术应用中使用的重金属和染料对人类健康和环境产生有害影响。最常用的去除污染物的方法依赖于高成本的材料。因此，这项研究是针对从自然资源和食物垃圾中提取的具有成本效益的替代品进行的。在此，我们设计了一种基于海藻酸钠/咖啡废物（Alg/咖啡）的复合水凝胶作为吸附剂，用于去除水体溶液中的有机和无机污染物。选择性研究表明，Alg/咖啡对 Pb(II) 和吖啶橙染料 (AO) 的吸附效果更佳。研究了浓度范围为 0–170 mgL ^-1和 0–40 mgL ^-1时 Pb(II) 和 AO 的吸附。Pb(II) 和 AO 的吸附数据揭示了它们对 Langmuir 等温线和准二级动力学模型的拟合。研究结果表明，海藻/咖啡水凝胶比咖啡粉本身更有效，其吸附量 (%) 接近 98.44% 的 Pb(II) 和 80.53% 的 AO。真实样品分析揭示了藻类/咖啡水凝胶珠吸附 Pb(II) 的效率。吸附循环经过四次检查，提供了对 Pb(II) 和 AO 的高效率。使用 HCl 洗脱液可以轻松解吸 Pb(II) 和 AO。因此，藻类/咖啡水凝胶珠可能成为去除有机和无机污染物的有前景的吸附剂。