|Abstract: ||本論文主要研究物化法回收處理含EDTA鍋爐清洗廢水。在檢測鍋爐清洗廢水後，發現COD濃度高達31,000 mg/L，經過AA分析金屬離子，其中以Fe離子的含量為最多，Fe濃度為1,950 mg/L，其次Zn濃度為230 mg/L、Cu濃度93 mg/L及少量的金屬離子。
實驗過程經過金屬沉降實驗、回收EDTA及氧化分解，最後以活性碳吸附。在金屬沉降實驗以添加氫氧化鈉幫助金屬離子沉降，金屬沉澱物乾重可得5.4 g/L，廢水中Fe含量由1,950 mg/L降至 3 mg/L，而EDTA回收部分，則以添加硫酸把帶Na型態的EDTA轉變為EDTA-4H型態回收，且回收EDTA後，COD濃度僅剩餘11,300 mg/L，然後利用氧化搭配活性碳吸附降解COD，最後可將COD處理約至1,780 mg/L，並使用RO進行處理，以縮短廢水處理的時間。
This article is focused on the physicochemical treatment and EDTA recycling of sewage containing EDTA from furnace washing. Testing revealed the COD concentration of sewage was 31,000 mg/L, and AA quantitative analysis for metal ions showed that the iron (Fe) species were the most abundant constituents (1,950 mg/L), followed by zinc (Zn, 230 mg/L), copper (Cu, 93 mg/L) and other metal ions in smaller amounts.
Metal deposition, EDTA recycling, oxidative decomposition and activated carbon absorption were applied in the experiment. Sodium chloride was added to promote the deposition of metal ions. The dry weight of the metal-containing deposit was 5.4 g/L. After treatment, the amount of iron species decreased from 1,950 mg/L to 3 mg/L. The recycling of EDTA was achieved by adding sulfuric acid, which converts disodium EDTA into EDTA-4H and can be easily recycled. Post-treatment COD concentration was 11,300 mg/L. By incorporating oxidative decomposition and activated carbon absorption, COD concentration can be decreased to 1,780 mg/L. The use of RO filtration technique may shorten the time for sewage processing.