- 期刊
畜牧廢水中陰陽離子濃度組成與其導電度之關聯性探討
Relationship between Species of Ionic Equivalent Concentrations and Electrical Conductivity in Livestock Wastewater
摘要
畜牧廢水長期以來都是台灣主要的環境污染負荷之一，放流後影響灌溉水質，尤以導電度值為最引人關心。本文蒐集台灣及世界各國有關畜牧廢水處理後之成分，並以導電度（EC）為主要探討對象，從陰、陽離子組成推估其理論之導電度值，再與量測值做比較。結果得知水中量測導電度值與理論計算所得之導電度值的誤差平均為6.79%（標準偏差為4.84%，n=24），兩者呈現高度線性相關（y=0.999x, R^2=0.979）。水中離子強度與導電度值成正比，當水中離子電荷總濃度介於20~26 mEq L^(-1)時導電度值為1.0 dS m^(-1)；而一般畜牧廢水之放流水導電度值約3.0 dS m^(-1)，水中離子電荷總濃度範圍多介於56~64 mEq L^(-1)。分析顯示國內養豬場放流水中以碳酸氫根（HCO_3^-）與有機酸根（CH_3COO^-）在所反應的理論導電度值為最大約占總導電度值的32%，其次是銨根離子（NH_4^+）約占24%，再者為鎂（Mg^(2+)）、鉀（K^+）與氯離子（Cl^-）各占約7%；澳洲畜牧廢水中則以碳酸氫根與有機酸為最大約占總導電度值的34%，其次是氯離子約16%，而鈉（Na^+）、鉀與銨根離子各有12%左右的貢獻度。本文發現台灣與國外畜牧廢水中各種離子濃度及組成特性不盡相同，主因養殖管理及廢水處理方式不同所致，因而造成陰、陽離子濃度及組成之差異，進而影響水中導電度值。
並列摘要
Livestock waste has long been one of Taiwan's major pollution loading, and the effluents impact irrigation water quality, especially in electrical conductivity (EC) is the most compelling concern. In this paper, the ingredients of livestock wastewater effluents were collected from Taiwan and around the world’s treatment study. The goal is to explore the accuracy of theoretical values of EC estimated from the composition of its anions and cations as compared with the measured values. The results displayed high linear correlation between measured and calculated EC (y=0.999x, R^2=0.979, p ＜ 0.01), and the average error was 6.79% (standard deviation 4.84%, n=24). Conductivity of the water is proportional to the ionic strength, the total concentration of ions in water ions ranged 20~26 mEq L^(-1) reflect the EC about 1.0 dS m^(-1); while, in general, livestock wastewater effluent's EC around 3.0 dS m^(-1), means the total ionic charge in wastewater concentrations ranged between 56~64 mEq L^(-1). The results also showed that the dominated ion species in wastewater is bicarbonate(HCO_3^-) which reflects about 32% of EC, secondly ammonium (NH_4^+) attributing about 24% of the total EC and magnesium (Mg^(2+)), potassium (K^+) and chlorine (Cl^-) ions account for 7% of the total EC respectively in the effluents of pig farms in Taiwan. In Australia, the bicarbonate and acetate predominated in the effluent pond reflect the most magnitude of EC, about 34% of the total EC, secondly chlorine ion offers about 16% and ammonium, potassium and sodium(Na^+) ions account for 12% respectively. This study indicated that the differences of ionic concentrations and species influenced obviously by their farm management and wastewater treatment methods and also reflected the magnitude of the EC in the aqueous solution.