【摘要】：由于重金屬的致毒性、來源廣、非生物降解性及生物累積性,已經(jīng)引起人們的廣泛關(guān)注。我國(guó)專門為此制定了《“十三五”生態(tài)環(huán)境保護(hù)規(guī)劃》,將重金屬污染的預(yù)防與治理提上議事日程。本研究以殼聚糖為微膠囊囊壁,以納米四氧化三鐵修飾腐殖酸、納米羥基磷灰石修飾腐殖酸以及介孔分子篩修飾腐殖酸三種復(fù)合吸附劑為囊芯,采用復(fù)合凝聚法制備復(fù)合微膠囊吸附劑,并將其分別用于水溶液中Cd(Ⅱ)的去除。制備的復(fù)合微膠囊采用傅里葉紅外、X射線衍射、掃描電子顯微、比表面積等手段進(jìn)行表征,并考查實(shí)驗(yàn)條件對(duì)重金屬離子吸附量和去除率的影響,并開展了吸附動(dòng)力學(xué)和吸附等溫研究。具體內(nèi)容如下:(1)復(fù)合微膠囊吸附劑Fe_3O_4/HA@CS對(duì)Cd(Ⅱ)的吸附實(shí)驗(yàn)表明,吸附最佳pH=7,且去除率為97%;平衡吸附時(shí)間為60min,復(fù)合吸附劑對(duì)Cd(Ⅱ)的平衡吸附量為48.5mg/g。吸附動(dòng)力學(xué)研究表明,吸附機(jī)理可能既包含化學(xué)吸附過程,也包含物理吸附。吸附等溫研究表明,Langmuir等溫吸附模型可以很好地描述Fe_3O_4/HA/CS吸附Cd(Ⅱ)的過程。(2)復(fù)合微膠囊吸附劑HAP/HA/CS在pH=7時(shí)對(duì)Cd(Ⅱ)吸附效果最佳,去除率達(dá)95%,比單一HAP的去除率提升了16.8%;吸附等溫研究表明,Freundlich等溫吸附模型可以很好地描述HAP/HA/CS吸附Cd(Ⅱ)的過程。(3)復(fù)合微膠囊吸附劑CS/HA/MCM在pH=7時(shí)對(duì)Cd(Ⅱ)的去除率達(dá)到84%以上,與單一的MCM-41相比提升了12%;吸附過程在40min達(dá)到吸附平衡,吸附容量為92.6mg/g,比單一的MCM-41、HA/MCM分別提升了3.5%和3.1%。吸附過程符合準(zhǔn)二級(jí)動(dòng)力學(xué)模型,且Langmuir等溫吸附模型可以很好地描述CS/HA/MCM吸附Cd(Ⅱ)的過程。
[Abstract]:Due to the toxicity of heavy metals, extensive sources, non-biodegradability and bioaccumulation, people have attracted wide attention. In order to prevent and control heavy metal pollution, China has formulated the "Thirteenth five year Plan for Ecological Environment Protection", which puts the prevention and treatment of heavy metal pollution on the agenda. In this study, chitosan was used as microcapsule wall, nano-ferric oxide as humic acid, nano-hydroxyapatite as humic acid and mesoporous molecular sieve as capsule core. The composite microcapsule adsorbents were prepared by complex coagulation method and were used for the removal of Cd (鈪，

本文編號(hào)：2209974