酒廠污泥吸附水中銅之研究

Removal of Copper from Aqueous Solution Using Wine Processing Waste Sludge

吳伊柔(Yi-Rou Wu) ； 劉鎮宗(Cheng-Chung Liu)

《國立宜蘭大學工程學刊》 5期 (2009/03) Pp. 75-98

https://doi.org/10.6176/BCE.2009.05.16

摘要

酒廠污泥（Wine Processing Waste Sludge）能有效吸附水中鎳、鉻、鉛等金屬，但對於吸附水中銅的效果則並不清楚。本研究目的主要為探究酒廠污泥吸附銅之機制，並以光學顯微鏡、元素分析儀（EA）、能量分散光譜儀（EDS）、紅外線（IR）等儀器研究污泥之型態與特徵。由紅外線的分析顯示羧基是酒廠污泥的主要官能基，以-COO^-及-COOM^+的形態存在。污泥有機質含量約38%，陽離子交換容量為625 cmolc kg^(-1)。污泥對銅之吸附較符合Langmuir等溫吸附模式及假二階吸附模式。在吸附穩定時，污泥吸附銅之ΔG°範圍為-20.69～-24.29 kJ mol^(-1)，而ΔH°和ΔS°分別為5.048 kJ mol^(-1)和91.05 kJ mol^(-1)，為物理性吸附，屬於自發性且吸熱的反應，故高溫時有利於吸附效果。污泥吸附銅的顆粒內部擴散係數隨溫度、銅濃度、污泥粒徑的增加而增強。銅對污泥粒子的總體擴散（bulk diffusion）約發生在反應期間的第0～3分鐘，第6～15分鐘為顆粒內部擴散，其後銅和污泥粒子間的質量傳送則趨近平衡。

關鍵字

銅 ； 污泥 ； 吸附 ； 顆粒內部擴散 ； 物理性分離

並列摘要

Wine processing waste sludge (WPWS) has been shown to be an effective sorbent for sorption of nickel, lead and chromium, but the sorption for copper (Cu) in aqueous solution by WPWS have not been conducted. The objective of this study was to explore the sorption mechanism of WPWS for Cu. The futher characteristics of WPWS were also determined by optical microscopy, elemental analyzer (EA), energy-dispersive spectrometry (EDS) and infrared (IR) machines. From IR analysis of WPWS revealed that carboxyl was the major functional group (-COO^- and -COOM^+). The sludge contained high organic matter (38%) and cation-exchange capacity (CEC, 625 cmolc kg^(-1)), The WPWS sorption isotherms of Cu are only well described by the Langmuir sorption isotherm. A pseudo-second-order sorption kinetic model describes successfully the kinetics of sorption of Cu onto WPWS at different operation parameters (i.e., temperature, initial Ni concentration, and particle size). Under the steady-state reaction conditions, the Gibb free energy (ΔG°) ranges from -20.69 to -24.29 kJ mol^(-1), and the ΔH° and ΔS° are 5.048 kJ mol^(-1)and 91.05 J mol^(-1) K^(-1), respectively, indicating that higher temperature favors spontaneous reaction for Cu sorption by WPWS. According to the thermodynamic sorption parameters under steady-state conditions, this sorption is a spontaneous and endothermic reaction. The intraparticle diffusion coefficients of Cu sorption increase with increase in temperature, Cu concentration and particle size of WPWS. The bulk diffusion of Cu^(2+) onto WPWS was observed when the sorption was conducted in 0-3 minutes and the intraparticle diffusion 6-15 minutes. After 20 minutes until the experiments ending, mass transfer of Cu to WPWS was slow down markedly near in equilibrium.

並列關鍵字

copper ； sludge ； sorption ； intraparticle diffusion ； physical separation