以改質氧化鎂穩定劑去除含鉛污染之地下水場址

地下水中鉛（lead, Pb）污染主要源自於人為因素居多，如任意棄置含鉛物品（蓄電池、鉛管及油漆等）導致之洩漏、汽油及焚化爐燃燒以及工業行為致生洩漏事件等因素。鉛對人體是一種累積性毒物，當藉由食物鏈攝取過量，不僅會誘發牙齒與骨骼等方面疾病，亦會藉由血液傳輸引發內源性鉛中毒。本研究主要以台灣鉛蓄電池製造業中以鉛錠鑄製、基（極）板、濃硫酸、鉛合金及其他塑膠製裝設品等原料，生產汽車／機車用蓄電池及電氣車／產業用蓄電池造成之地下水鉛污染進行探討。研究場址廢水處理場區由於使用之地下儲槽及設備因年久失修，地下儲槽因有破損洩漏之情形，故於全場區執行土壤及地下水改善作業之同時進行廢水場區改建工程，將舊有之地下儲槽及設備全數更新及地上化，以阻斷污染之洩漏。本研究以改質氧化鎂穩定劑（surface modification magnesium oxide immobilized agent, SMIA）進行實驗室批次與現地投藥試驗。SMIA為一緩釋藥劑，其具有強親和力及吸附力，且在寬pH值範圍內有強靜電吸引力，故於處理成效上能有優異表現，且經多項現地受污染地下水驗證，SMIA能針對水中特定金屬（如鉛、氟、砷等）與半導體業產生之矽酸高效去除，擁有優異處理成效。經由批次試驗結果顯示，添加0.6 g/L SMIA於現地污染水樣中經過2小時後，水中初始鉛濃度由0.446 mg/L（超出第二類地下水體管制標準約4.5倍）降至0.023 mg/L，明顯已低於法規規範之第二類地下水體監測標準（0.05 mg/L），且放置1個月其水中鉛濃度仍符合第二類地下水體法規標準，表示鉛無再釋出之跡象。藉由現地投藥試驗結果顯示，水中初始鉛濃度由0.824 mg/L（超出第二類地下水體管制標準約8.2倍）經1個月後降至0.008 mg/L，表示藥劑對於水中鉛污染物去除確實具有顯著處理成效。因此，以SMIA進行地下水中鉛污染整治工作，藥劑不但不會造成環境二次污染且整治過程亦能藉由緩釋及即效之特性達到污染控制目的，確實具有實場應用潛力。

關鍵字

改質氧化鎂穩定劑；地下水鉛污染；鉛蓄電池製造業

並列摘要

Lead pollution in groundwater is mainly caused by human factors, such as leakage caused by arbitrary disposal of lead-containing materials (batteries, lead pipes, paint, etc.), burning of gasoline, incinerator operation, and leaks caused by industrial activities. Lead is ubiquitous in daily life and acts as a cumulative poison for the human body. Excess accumulation of lead in human beings via the food chain induces teeth and bone diseases and causes endogenous lead poisoning through blood transmission. This study focuses on groundwater lead pollution caused by the lead storage battery manufacturing industry in Taiwan. A surface modification magnesium oxide immobilized agent (SMIA) was used to conduct laboratory batch and on-site testing. SMIA is a slow-release agent with strong affinity, adsorption, electrostatic attraction over a wide pH range. Therefore, it shows an excellent performance in the treatment of contaminated water samples; its efficacy has been verified by treating a number of contaminated groundwater samples on-site. SMIA is aimed at removing specific metals (such as lead, fluorine, arsenic, etc.) from water, with excellent treatment results being obtained. The batch test results showed that after adding 0.6 g/L of SMIA to the onsite polluted water sample for 2 hr, the initial lead concentration in the water decreased from 0.446 mg/ L (approximately 4.5 times exceeding the regulatory standard) to 0.023 mg/L, which is significantly lower than the monitoring standard (0.05 mg/L). Moreover, the lead concentration water still met the regulatory standard one month after the treatment. The results of the in-situ field tests showed that the initial lead concentration in water decreased from 0.824 mg/L (approximately 8.2 times the regulatory standard) to 0.008 mg/L after one month, indicating that the agent has a significant effect on the removal of lead pollutants in water. This suggests that the use of SMIA to remediate lead pollution in groundwater does not cause secondary pollution to the environment. Additionally, the remediation process using SIMA can also help achieve pollution control through the characteristics of slow release of the agent with immediate effect, indicating its high potential for field applications.