| 摘要: | 本研究主要目的為探討含氟廢水在不同氯化鈣的加藥順序對氟化鈣結晶結構物組成型態差異，以固定鈣氟比為 1.0，酸鹼值為 7.0 時將氟化鈣沉澱，利用化學混凝沉降的方式，並添加不同劑量的助凝劑與混凝劑，探討其最佳處理劑量、氟化鈣顆粒在混凝後晶體絮凝的實密度、載體空隙的大小，晶體的晶核再成長亦是影響氟化鈣結晶大小因素與氟離子去除效率。實驗結果顯示，先加氯化鈣再調 pH 水樣較先調pH再加氯化鈣清澈，由電子顯微鏡(SEM)圖片所示先加氯化鈣再調 pH 時氟化鈣晶體結構較為實密完整並可發現攪拌槽底部有結晶物生成。以聚丙烯酸(PAA)為混凝劑，在劑量為 10 mg/L時可得較佳氟離子去除效果，此時水樣中懸浮固體物(SS)與濁度有顯著下降趨勢；以聚氯化鋁(PACl)為混凝劑，於劑量為 15 mg/L時亦得較佳氟離子去除效果，水樣中聚氯化鋁去除膠體穩定主要機制為吸附及電性中和與沉澱拌除，而沉澱拌除是利用氫氧化鋁膠羽的生成並增加顆粒碰撞的機會，當顆粒夠大時，會使顆粒凝絮在一起並予以沉降，以增加去除效率。含氟廢水大多以PACl搭配PAA來處理，先以PACl去穩定後，再添加PAA使膠羽能有效成長，以增加水樣中的固液分離效能，使之能有效沉澱，懸浮固體物與濁度有顯著下降趨勢，造成此趨勢是水樣中PAA或PACl藥劑在分段加藥時膠羽的形成從電性中和與架橋機制的凝聚方式轉變為為沉澱拌除捕集形式。The main purpose of this study was to investigate the fluoride wastewater in the order of different calcium chloride dosing of calcium fluoride crystal structure and configuration differences, fixed calcium fluoride than 1.0, the pH value of 7.0, precipitated calcium fluoride, chemical coagulation and sedimentation way, and add different doses of coagulant aid coagulant, to investigate the optimal treatment dose, the density of the particles of calcium fluoride crystal flocculation after coagulation carrier the size of the gap, the crystal grain nuclear re-growth factors also affect the size of the calcium fluoride crystals with fluoride ion removal efficiency.The experimental results show that the first plus calcium chloride and then adjusted to pH water samples clear than the first pH adjustment coupled with calcium chloride, and by electron microscopy (SEM) images shown before adding calcium chloride and then adjusted to pH fluoride calcium crystal structure is real dense complete and can be found at the bottom of the stirred tank crystals generated. Better fluoride ion removal coagulant, polyacrylic acid (PAA) in a dose of 10 mg / L, then there is a significant downward trend in water samples of suspended solids (SS) and turbidity; using poly aluminum chloride (PACl) as coagulant, at a dose of 15 mg / L may also better fluoride ion removal, water samples poly aluminum chloride to remove the colloidal stability of the main mechanism for the adsorption and electrical and the precipitation mix In addition, while the precipitation mix in addition to aluminum hydroxide floc formation and to increase the chance of collision of the particles, when the particles are large enough to cause the particles flocculation together and settlement, in order to increase the removal efficiency.To handle most of the fluorine-containing wastewater PACl with PAA, first PACl to stabilize, and then add the PAA floc effective to grow, to increase the performance of solid-liquid separation in water samples, so that it can effectively precipitate, suspended solids and turbidity degree, there is a significant downward trend, this trend is caused by the the water samples PAA or PACl Pharmacy segment dosing the floc formation from electrical and bridging mechanism cohesion into precipitation mix in addition to capturing the form. |
