玉米秸稈生物炭對五氯苯酚吸附行為及吸附動力學研究

賈丹 卓孔友 谷東巖

摘要 [目的]研究玉米秸稈生物炭對五氯苯酚的靜態(tài)吸附特性。[方法]探討吸附劑量、溶液pH、吸附時間等參數(shù)對吸附的影響，用Langmuir和Freundlich等溫式研究吸附平衡過程。[結(jié)果]酸性條件有利于玉米秸稈生物炭吸附劑對五氯苯酚的吸附，吸附過程在30 min即可達到平衡，玉米秸稈生物炭對五氯苯酚的吸附更符合Freundlich等溫式。吸附動力學研究表明，吸附過程更符合準二級動力學模型，吸附速率常數(shù)為0.015 9 g/（mg·min）。吸附過程是吸熱的，升高溫度有利于吸附。[結(jié)論]玉米秸稈生物炭可用于吸附五氯苯酚。

關(guān)鍵詞 玉米秸稈生物炭；五氯苯酚；吸附動力學；吸附平衡

中圖分類號 S181文獻標識碼 A文章編號 0517-6611（2018）01-0071-03

Abstract [Objective]To study the adsorption removal of pentachlorophenol from aqueous solution by corn stalk biochar.[Method]Experiments were carried out as function of adsorbent dosage，pH and contact time.The adsorption isotherms were modeled with Langmuir and Freundlich.[Result]The results showed that it was favorable for the adsorption of pentachlorophenol from aqueous solution by corn stalk biochar under acid conditions.The adsorption process was fast，and it reached equilibrium in 30 min contact time.The date fitted well with the Freundlich isotherms.The kinetic data were analyzed using pseudo-first-order and pseudo-second-order models.The pseudo-second-order model was the best for the adsorption pentachlorophenol by corn stalk biochar and the adsorption rate constant is 0.015 9 g/（mg·min）.The sorption process was endothermic and raising temperature is favourable for it.[Conclusion]Biochar corn straw can be used for the adsorption of pentachlorophenol.

Key words Corn stalk biochar；Pentachlorophenol；Adsorption kinetic；Adsorption equilibrium

五氯苯酚是氯代酚的一種，是持久性有機污染物之一，具有生物累積性和強毒性，在動植物體內(nèi)富集率高，可對動物的肝、肺、腎臟及神經(jīng)系統(tǒng)造成損傷。五氯苯酚可以作為木材防腐劑、殺蟲劑、除草劑等農(nóng)藥進入環(huán)境，可以通過直接排放進入環(huán)境水體，還能通過飲用水或者紙漿漂白廢水中合成化合物的氯代反應間接合成。 五氯苯酚的廣泛使用已經(jīng)造成世界范圍的土壤和水體受到污染。因此，去除水體中的五氯苯酚具有重要的現(xiàn)實意義[1-2]。各種含酚廢水處理技術(shù)（如氧化、生物降解、溶劑萃取、反滲透和吸附等）用于從酚污染水體中去除酚類污染物[3-5]。其中，吸附法無論是在實驗室研究還是在實際工業(yè)處理中都是最有效的技術(shù)之一。常用的吸附劑是活性炭，但是商業(yè)活性炭成本高，再生困難。……