模擬褐地土壤重金屬安定化之可行性研究

Feasibility of Heavy Metal Immobilization in Simulated Brownfiled Soil

陳玟潔(Wen-Jie Chen)

指導教授 ： 薩支高

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2011年)

https://doi.org/10.6346/NPUST.2011.00066

摘要

本研究目的為探討以改良劑安定遭重金屬(銅、鋅、鉛、鎘及鉻)污染現地場址及模擬褐地土壤之可行性及最佳操作條件。實驗以四種不同改良劑(水泥、腐植土、稻殼炭及堆肥)添加於供試土壤中進行土壤安定化處理。先以吸附(安定化)試驗探討改良劑之吸附效果，次以管柱酸雨淋洗試驗模擬現地處理情形，找出最佳處理添加配比，再利用序列萃取觀察管柱試驗前後土壤中各型態重金屬分佈情形，最後以健康風險評估判斷本試驗污染土壤處理前後對人體健康造成之可能危害程度。
結果顯示改良劑能有效降低溶液中重金屬釋出，管柱試驗結果指出添加5%改良劑於供試土壤中，能有效降低滲出液各重金屬濃度，其中以水泥處理土壤最能有效安定重金屬。
在管柱試驗前後進行供試土壤重金屬型態分析，在管柱淋洗前之供試土壤中發現添加改良劑後之樣品，原本以弱鍵結型態之重金屬部分可轉變為強鍵結型態，而經淋洗後之土壤多以弱鍵結型態為主，與pH值受淋洗液影響，使重金屬溶解度上升所致。
最後以第一層次健康風險評估計算得知，以高濃度(六種重金屬均高於10倍管制標準)供試土壤M10之危害指數經添加改良劑後皆小於1，顯示添加改良劑能有效安定重金屬於土壤中，並降低污染土壤對人體健康之危害。

關鍵字

重金屬安定化 ； 吸附 ； 淋洗 ； 序列萃取 ； 健康風險評估

並列摘要

The aim of this study is to evaluate the feasibility and optimal operation on heavy metals (Cu, Zn, Pb, Cd, and Cr) contaminated (real contaminated site and simulated high metal concentration brownfield) soil’s stabilization. Four amendments (cement, humic substance, rice husk charcoal and compost) and soils were individually preceded adsorption/stabilization test. A series of acid rain leaching test with different treatments (amendments and/or percentage) in soil columns were then used to find the best deal. The sequential extraction procedure (SEP) was used to identify heavy metal forms in soils before and after the leaching tests. Finally, we estimated human health hazard of heavy metals contaminated soils by using the health risk assessment.
The adsorption test results indicate that soil amendments can reduce heavy metals concentration in solution. Soil column leaching tests verify the 5% amendments addition can reduce heavy metals in leachate from contaminated soil. Among all, the most effective amendment is cement.
During the column tests, the SEP showed some weak-bonded metal forms were transform to strong-bonded metal forms right after amendments addition. After leached by 10 folds of soil water space simulated acid rain, heavy metal in soil existed in weak-bonded metal forms. The water pH influenced.
Finally, after calculated by using the first level of health risk assessment for M10 soils (all heavy metals are spiked 10 times higher than the standard) with 5% amendments addition, the hazard index become lower than 1. The amendments addition can surely stable heavy metals in soil and reduce contaminated soil hazard human health.

並列關鍵字

heavy metals stabilization ； absorption ； leaching ； sequential extraction ； health risk assessment

參考文獻

行政院環境保護署環境檢驗所(2011)，土壤酸鹼值(pH 值)測定方法-電極

行政院環境保護署(2006)，土壤及地下水污染場址健康風險評估評析原則

陳松甫，2003，碳化農業廢棄物改良水田重金屬污染之可行性研究，碩

國立中央大學，環境工程研究所，桃園，第 11-24 頁。

碩士論文，國立台灣大學，農業化學研究所，台北，第 5-7 頁。