Villaescusa Isabel, Fiol Núria, Martínez María, Miralles Núria, Poch Jordi, Serarols Joan
Departament d'Enginyeria Química, Agrària i Tecnologia Agroalimentària, Universitat de Girona, Avda Lluis Santaló, Girona 17003, Spain.
Water Res. 2004 Feb;38(4):992-1002. doi: 10.1016/j.watres.2003.10.040.
In the present work, the usefulness of grape stalks wastes generated in the wine production process has been investigated for the removal of copper and nickel ions from aqueous solutions. The sorption process was relatively fast and equilibrium was reached after about 60 min of contact. The influence of pH, sodium chloride and metal concentration on metal removal has been studied. Uptake showed a pH-dependent profile. Maximum sorption for both metals was found to occur at around pH 5.5-6.0. An increase of sodium chloride concentration caused a decrease in metal removal. Langmuir isotherms, at pH 6.0, for each metal were used to describe sorption equilibrium data. Maximum uptake obtained was 1.59x10(-4) mol of copper and 1.81x10(-4) mol of nickel per gram of dry sorbent. Sorption of copper and nickel on grape stalks released an equivalent amount of alkaline and alkaline earth metals (K+, Mg2+, Ca2+) and protons, indicating that ionic exchange is predominantly responsible for metal ion uptake. Fourier transform infrared (FTIR) spectrometry analysis indicated that lignin C-O bond might be involved in metal uptake. Equilibrium batch sorption studies were also performed using a two metal system containing (Cu(II)+Ni(II)). In the evaluation of the two metal sorption system performance, single isotherm curves had to be replaced by three-dimensional sorption isotherm surface. In order to describe the isotherm surface mathematically, the extended-Langmuir model was used. Nickel was found to be much more sensitive to the presence of copper than copper is to the presence of nickel.
在本研究中，对葡萄酒生产过程中产生的葡萄茎秆废料用于从水溶液中去除铜离子和镍离子的效用进行了研究。吸附过程相对较快，接触约60分钟后达到平衡。研究了pH值、氯化钠和金属浓度对金属去除的影响。吸附呈现出pH值依赖性特征。发现两种金属的最大吸附量出现在pH值约为5.5 - 6.0时。氯化钠浓度的增加导致金属去除量减少。在pH值为6.0时，使用每种金属的朗缪尔等温线来描述吸附平衡数据。每克干吸附剂获得的最大吸附量为1.59×10⁻⁴摩尔铜和1.81×10⁻⁴摩尔镍。铜和镍在葡萄茎秆上的吸附释放出等量的碱金属和碱土金属（K⁺、Mg²⁺、Ca²⁺）以及质子，表明离子交换是金属离子吸附的主要原因。傅里叶变换红外（FTIR）光谱分析表明木质素C - O键可能参与了金属吸附。还使用含有（Cu(II)+Ni(II)）的双金属体系进行了平衡批量吸附研究。在评估双金属吸附体系性能时，单一等温线曲线必须被三维吸附等温线表面所取代。为了从数学上描述等温线表面，使用了扩展朗缪尔模型。发现镍对铜的存在比铜对镍的存在更为敏感。
