本研究採集某一TFT-LCD光電業實廠廢水與放流水為分析對象,以鯉魚、水蚤、米蝦三種生物毒性試驗與Microtox®毒性分析儀檢測廢水毒性,配合水質分析數據,評估廢水毒性之來源類別與物種對毒性之敏感度。 由敏感度試驗結果發現,pH值範圍5.5-9.0三種生物存活率皆為100%,故無敏感度之差異;而氯離子濃度在0-10000mg/L試驗範圍中顯示,最敏感度之物種為水蚤;氨氮濃度在0-500mg/L試驗範圍中,敏感度最高亦為水蚤;而重金屬銦、鉬、鎵濃度在0-1.0mg/L試驗範圍中,則以米蝦最為敏感。 放流水之三種生物毒性結果與水質分析皆符合法規訂定之生物毒性管制標準;而製程廢水之毒性特性試驗共四組,以A組水樣為例,以pH調整、pH調整/過濾、pH調整/曝氣方法,對2%、1%、0.5%、0.25%四個不同濃度之廢水進行毒性特性分離,以硫代硫酸鈉氧化還原、EDTA螯合、活性碳吸附、陽離子交換樹脂吸附、沸石吸附方法,對2%、1%、0.5%三組不同濃度之廢水,進行毒性特性分離。結果顯示,各分離方法處理後之廢水毒性與處理前之基礎毒性試驗結果比較,大部分都未有毒性降低之現象,唯EDTA金屬螯合分離步驟中,加入濃度15.86g/L之EDTA溶液0.0125mL至10ml測試體積含2%、1%、0.5%廢水中,EDTA水中濃度為19.8mg/L時,廢水A毒性減低約50%,此結果可假設廢水之最大毒性因子可能為重金屬類;廢水B之毒性特性試驗結果顯示,添加硫代硫酸鈉至廢水中,水中硫代硫酸鈉濃度為162.5mg/L時,廢水毒性減低85%,可假設廢水之最大毒性因子可能為氧化性物質;廢水C之毒性特性試驗結果顯示,以原始pH之廢水進行曝氣後,廢水毒性減低43%,可假設廢水之最大毒性因子可能可經由氣提去除;廢水D之毒性特性試驗結果顯示,添加微量陽離子交換樹脂0.125g/L,廢水毒性減低52%,可假設廢水之最大毒性因子可能為可被樹脂交換之離子類物質。
Four TFT-LCD process wastewaters and effluents from two industry factories were collected and analyzed for their chemical and toxic properties. Three bioassessment test and Microtox® were used to indentify the source of toxicity and the sensitivity between different species. In sensitivity test, at pH 5.5 to 9, the survival rates of all three speices were 100%, so the species have equal sensitivity; At chloride ion concentration range of 0 to 10000 mg/L, the most sensitive species was Daphnia magna; At ammonia concentration range of 0 to 5000 mg/L, Daphnia magna was also the most sensitive species;At indium, molybdenum amd gallium heavy metal test range of 0 to 1.0 mg/L, the most sensitive speices was Neocaridina denticulate. In effluents biotoxicity results, all samples’ toxicity level were under the regulation of toxicity control standard. In toxic characteristic test, we used pH adjustment, pH adjustment/filtration, pH adjustment/aeration, oxidant reduction, EDTA chelation, activity carbon adsorption, cation ion exchange resin adsorption and zeolite adsorption to treat four process wastewaters. We observed that the toxicity of wastewater sample A was significantly reduced by EDTA chelation addition; the toxicity of wastewater sample B was significantly reduced by oxidant reduction addition; the toxicity of wastewater sample C was significantly reduced by filtration and the toxicity of wastewater sample D was significantly reduced by cation ion exchange resin addition.