養豬廢水膠體中重金屬之分佈與分配性質研究

A study of the distribution and partition of colloidal metals in swine wastewater

黃虹株(Hung-Chu Huang)

指導教授 ： 謝季吟

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2015年)

https://doi.org/10.6346/NPUST.2015.00187

摘要

本研究為了解普遍存在於畜牧廢水中溶解性有機質(Dissolved Organic Matter, DOM)之特性與鋅(Zn)、銅(Cu)、鐵(Fe)、錳(Mn)、鎳(Ni)、鉛(Pb)和鉻(Cr)等金屬於顆粒態固體、膠體以及真溶解態之分配情形，即了解重金屬於不同基質與程序存在不同特性，藉以評估廢水處理效率之探討。結果顯示，各個廢水處理程序藉由溶解性有機碳回收率確認符合物理分離程序之穩定性。Zn、Cu、Ni、Mn、Fe、Cr等金屬於液相中較明顯被去除，而Pb則隨處理流程有增加之趨勢。懸浮顆粒物(Suspended Particulate Matter，SPM)中金屬濃度則與液相金屬濃度分布呈相反趨勢，可能與金屬吸附相轉移有關。經由DOC校正後之 Zn、Fe、Mn等金屬主要集中於0.45μm~100kDa；Cu主要分布於<100kDa之分子量，而Pb、Ni及Cr則主要分布於真溶解態(<1kDa)。

另外，不同重金屬在進流至出流之吸附能力不同而導致計算分配係數具差異，其中Zn、Mn、Fe等金屬分配係數穩定呈現LogKp > LogKd > LogKc1 > LogKc2；而Cu及Cr分配係數則轉變為LogKp > LogKd > LogKc2 >LogKc1，表示此兩金屬於放流水中較易吸附於小膠體；而Ni分配係數計算結果顯示為LogKp > LogKd > LogKc2 > LogKc1，表示進流水中較易吸附於膠體而非顆粒態固體，放流則以吸附於顆粒態固體居多；重金屬Pb分配係數計算結果為LogKd > LogKp > LogKc2 > LogKc1，即於進流水中較易吸附於小膠體，而在放流水中則較易吸附於真溶解態，大多與DOC校正後金屬濃度分布趨勢相符。
本研究亦針對厭氧污泥及放流污泥進行探討，得知經由處理程序可降低重金屬濃度，重金屬皆較易吸附於污泥。膠體中重金屬濃度與DOC相關性分析結果顯示， Zn、Cu、Ni、Mn及Cr濃度與DOC呈正相關，而Pb及Fe則無相關性。整體而言，本研究畜牧廢水處理廠水體中Zn 、Cu 、Ni、Mn 及 Cr 多以有機膠體態存在；而Pb和 Fe 則主要以無機膠體態存在。

關鍵字

畜牧廢水 ； 金屬 ； 分配係數 ； 膠體 ； 污泥

並列摘要

This study focused on evaluating and understanding the distribution (particulate solids, colloids, and dissolved) and removal efficiency of zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and chromium (Cr) in treated livestock wastewater in southern Taiwan. Wastewater treatment efficiency was evaluated with partition coefficients (Kp, Kd, Kc1, and Kc2) under different sections of the wastewater treatment process to understand the characteristics of physical separation.

The removal of all the subject metals except Pb in the liquid phase was dramatic during the treatment process, with the latter having a different trend. The distribution of metals in suspended particulates trended differently than in the water column, possibly related to metals adsorbing easily onto solids. The results, after dissolved organic carbon was normalized, showed that Zn, Fe, and Mn were mainly distributed in the 0.45 μm ~ 100 kDa fraction while Cu was distributed in the molecular weight <100 kDa fraction and Pb, Ni, and Cr were mainly within the truly dissolved (<1 kDa) fraction.

In addition, partition coefficients were calculated to demonstrate the adsorption capacity of different heavy metals from inflow to outflow. The adsorption tendency of Zn, Mn, and Fe appeared in the order of LogKp > LogKd > LogKc1 > LogKc2. The pattern of distribution of coefficients of Cu and Cr were transformed into the order of LogKp > LogKd > LogKc2 > LogKc1, showing that Cu and Cr were adsorbed onto small colloids. The calculated distribution coefficients were in the order of LogKp > LogKd > LogKc2 > LogKc1, indicating that Ni was readily adsorbed onto colloidal particulate solids in the inflow and onto particulate solids in the outflow. Pb is readily adsorbed onto small colloids in the inflow and adsorbed into the truly dissolved fraction in the outflow. The distribution tendency of metals after DOC was normalized were similar to previous results.

This study also revealed that metals in effluent sludge were lower than in anaerobic sludge after treatment. Metals were more readily adsorbed in anaerobic process sludge. Concentrations of heavy metals in colloids correlated well with DOC for Zn, Cu, Ni, Mn, and Cr, but there was no correlation between Pb and Fe. Overall, Zn, Cu, Ni, Mn, and Cr were adsorbed onto organic colloids whereas Pb and Fe were mainly adsorbed onto inorganic colloids in livestock wastewater.

並列關鍵字

Livestock Wastewater ； Metals ； Distribution Coefficient ； Colloids ； Sludge

參考文獻

賴佑昇，2014，「河川水樣微量金屬在液相與懸浮固體分配」碩士論文，國立屏東科技大學，環境工程與科學系，屏東。

Aldrich, A. P., Kistler, D., & Sigg, L. (2002). Speciation of Cu and Zn in drainage water from agricultural soils. Environmental Science & Technology,36(22), 4824-4830.

Amon, B., Kryvoruchko, V., Amon, T., & Zechmeister-Boltenstern, S. (2006). Methane, nitrous oxide and ammonia emissions during storage and after application of dairy cattle slurry and influence of slurry treatment. Agriculture, Ecosystems & Environment, 112(2), 153-162.

Basta, N. T., Ryan, J. A., & Chaney, R. L. (2005). Trace element chemistry in residual-treated soil. Journal of environmental quality, 34(1), 49-63.

Benoit, G., & Rozan, T. F. (1999). The influence of size distribution on the particle concentration effect and trace metal partitioning in rivers. Geochimica et