復(fù)合污染條件下改性殼聚糖對抗生素的絮凝脫除研究
發(fā)布時間：2019-01-30 08:07
【摘要】：水是人類賴以生存的重要資源。隨著抗生素的大量生產(chǎn)和濫用,各種抗生素物質(zhì)進入到水環(huán)境中,對人類健康造成了巨大的威脅。傳統(tǒng)的水處理劑對抗生素污染物處理效果甚微。針對不同復(fù)合污染條件下抗生素的賦存形態(tài)特征,本文選取了具有成本低、可再生、來源廣泛等特點的殼聚糖為基材,以2-氯-4,6-二甲氨基-1,3,5-三嗪、色氨酸和酪氨酸為改性試劑,制備了多類改性殼聚糖絮凝劑(BDAT-CTS、Ctrp和Ctyr),系統(tǒng)地考察了復(fù)合污染條件下多種因素(包括:水體pH、絮凝劑投加量、共存懸浮無機顆粒物、共存溶解型無機污染物、以及共存天然有機質(zhì)等)等對抗生素的絮凝脫除性能的影響,并對不同絮凝劑對不同污染體系的絮凝機理進行深入分析。結(jié)果表明:(1)在重金屬Cu(Ⅱ)共存條件下,BDAT-CTS對四環(huán)素TC有良好的絮凝脫除效果。對于Cu(Ⅱ)-TC復(fù)合污染水體的絮凝凈化中,電中和作用是主要的絮凝機理。帶正電的絮凝劑BDAT-CTS和帶負電的羥基絡(luò)合銅離子通過靜電吸引作用結(jié)合;同時,BDAT-CTS上帶正電的芳環(huán)與TC中帶負電的芳環(huán)結(jié)構(gòu)還存在較強的ππ相互作用。因此,BDAT-CTS、Cu(Ⅱ)、TC三者通過兩兩相互作用緊密結(jié)合,促進了絮體的形成,并實現(xiàn)了四環(huán)素的高效脫除。(2)在懸浮顆粒物高嶺土和天然溶解有機物腐殖酸共存條件下,不同結(jié)構(gòu)的氨基酸改性絮凝劑Ctrp和Ctyr對三種典型抗生素NOR、SDZ、TYL均表現(xiàn)出較好的絮凝效果。其中,含有負電性的苯酚基的Ctyr更有利于通過ππ電子給體-受體作用(EDA)絮凝帶正電的NOR和TYL;而含有正電性的吲哚基團的Ctrp對SDZ的絮凝脫除效果更佳。此外,在與原料殼聚糖和商用絮凝劑聚合氯化鋁的對比實驗中發(fā)現(xiàn),在絮凝劑投加量、絮凝效率和環(huán)境友好性上,Ctrp和Ctyr均具有優(yōu)勢顯著。(3)基于兩種絮凝劑Ctrp/Ctyr對含共存污染物kaolin和HA的三種抗生素NOR、SDZ、TYL體系的研究基礎(chǔ)上,進一步考察在Ca(Ⅱ)、Cu(Ⅱ)復(fù)合影響下對抗生素絮凝脫。通過U30*(307)均勻設(shè)計表設(shè)計實驗,運用DesignExpert軟件進行響應(yīng)曲面圖分析和最優(yōu)條件擬合,發(fā)現(xiàn):調(diào)節(jié)kaolin、HA、Ca(Ⅱ)、Cu(Ⅱ)和絮凝劑的濃度可以實現(xiàn)對抗生素污染物NOR、SDZ的進一步脫除。這可為真實水體中對抗生素的脫除提供指導(dǎo)。綜上所述,通過改性殼聚糖基從而進行不同結(jié)構(gòu)的修飾,可對多種復(fù)合污染的抗生素污染水體表現(xiàn)出較為理想的絮凝脫除效果;而多因素污染物的復(fù)合研究,從而探究物質(zhì)遷移轉(zhuǎn)化的規(guī)律,對真實水體的處理中有著良好的應(yīng)用意義。
[Abstract]:Water is an important resource for human survival. With the mass production and abuse of antibiotics, a variety of antibiotic substances enter the water environment, which poses a great threat to human health. Traditional water treatment agents have little effect on the treatment of antibiotic pollutants. In view of the morphological characteristics of antibiotics under different complex pollution conditions, chitosan with the characteristics of low cost, renewable and wide source was selected as the base material. A variety of modified chitosan flocculants (BDAT-CTS,Ctrp and Ctyr),) were prepared with tryptophan and tyrosine as modification reagents. The effects of co-existing suspended inorganic particles, co-dissolved inorganic pollutants and co-existing natural organic matter on the flocculation and removal performance of antibiotics were discussed. The flocculation mechanism of different flocculants on different pollution systems was also analyzed. The results showed that: (1) under the condition of coexistence of heavy metal Cu (鈪，
本文編號：2417927
[Abstract]:Water is an important resource for human survival. With the mass production and abuse of antibiotics, a variety of antibiotic substances enter the water environment, which poses a great threat to human health. Traditional water treatment agents have little effect on the treatment of antibiotic pollutants. In view of the morphological characteristics of antibiotics under different complex pollution conditions, chitosan with the characteristics of low cost, renewable and wide source was selected as the base material. A variety of modified chitosan flocculants (BDAT-CTS,Ctrp and Ctyr),) were prepared with tryptophan and tyrosine as modification reagents. The effects of co-existing suspended inorganic particles, co-dissolved inorganic pollutants and co-existing natural organic matter on the flocculation and removal performance of antibiotics were discussed. The flocculation mechanism of different flocculants on different pollution systems was also analyzed. The results showed that: (1) under the condition of coexistence of heavy metal Cu (鈪，
本文編號：2417927
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