本文關(guān)鍵詞： 貝殼粉 鎘污染 吸附 賦存形態(tài)　出處：《沈陽農(nóng)業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：目前,重金屬污染受到國(guó)內(nèi)外的廣泛關(guān)注。鎘(Cd)作為典型的重金屬污染物,具有較強(qiáng)的生物毒性。向鎘污染水體和土壤中投加吸附材料是修復(fù)鎘污染的有效措施之一。貝殼是水產(chǎn)品的副產(chǎn)物,具有資源豐富、成本低廉和無污染等特征。本文通過吸附試驗(yàn)及恒溫培養(yǎng)試驗(yàn),就扇貝以及蟶子殼粉對(duì)水體中鎘的吸附特征與污染土壤鎘存在形態(tài)的影響進(jìn)行了研究。主要研究結(jié)論如下:供試扇貝及蟶子殼粉對(duì)水體中Cd2+均具有較強(qiáng)的吸附能力。隨著貝殼粉用量的增加,供試貝殼粉對(duì)水體中Cd2+的吸附量先快速降低后達(dá)到平穩(wěn);隨著Cd2+溶液初始pH值(1～6)的升高,吸附量逐漸增大;隨著Cd2+溶液初始濃度的增加,吸附量逐漸增大;在吸附開始0～2h內(nèi)吸附量快速增加,在吸附后期2～72h逐漸趨于不變。對(duì)于400℃扇貝殼粉(400ss)、天然扇貝殼粉(ss)和400℃蟶子殼粉(400rcs)來說,Freundlich等溫吸附模型能夠更好地?cái)M合吸附過程,R2在0.944～0.993之間,對(duì)于天然蟶子殼粉(rcs)來說,Langmuir和Freundlich兩種模型均能較好地?cái)M合吸附過程,R2均大于0.966;在貝殼粉對(duì)Cd2+的吸附過程中,溫度升高能夠促進(jìn)吸附,表明吸附為吸熱的過程;通過對(duì)比三種吸附動(dòng)力學(xué)模型(準(zhǔn)一級(jí)、準(zhǔn)二級(jí)以及顆粒內(nèi)擴(kuò)散模型),發(fā)現(xiàn)400ss、ss、400rcs和rcs對(duì)Cd2+的吸附動(dòng)力學(xué)過程與準(zhǔn)二級(jí)動(dòng)力學(xué)最為相符,R2達(dá)到0.999。對(duì)于不同來源貝殼粉而言,rcs的吸附效果遠(yuǎn)遠(yuǎn)高于400ss、ss和400rcs,qe 達(dá)到 485.32mg/g。添加400ss、ss、400rcs和rcs對(duì)土壤pH值升高均具有一定程度的貢獻(xiàn),培養(yǎng)50d后,ss1～ss5、rcs1～rcs5、400ss1～400ss5 和 400rcs1～400rcs5(貝殼粉施加比例為風(fēng)干土質(zhì)量的1%～5%)分別比CK高0.99～1.09、1.03～1.12、1.00～1.05和1.03～1.10個(gè)單位,所有處理與CK相比均存在顯著差異(p0.05),同時(shí)不同添加比例間均存在顯著差異(p0.05);在0～50d的培養(yǎng)期間,添加貝殼粉均能夠使土壤有效態(tài)鎘的含量下降,且添加比例越大降低效果越明顯,在培養(yǎng)50d后,ss5、rcs5、400ss5和400rcs5處理的土壤有效態(tài)鎘含量分別為5.46、5.37、5.51和5.51mg/kg。隨著培養(yǎng)天數(shù)延長(zhǎng)或者貝殼粉添加比例越大,可交換態(tài)鎘向碳酸鹽結(jié)合態(tài)鎘、鐵錳氧化物結(jié)合態(tài)鎘、有機(jī)物結(jié)合態(tài)鎘和殘?jiān)鼞B(tài)鎘轉(zhuǎn)化的程度越大。不同來源貝殼粉對(duì)土壤鎘賦存形態(tài)的影響不同,添加rcs對(duì)鎘污染土壤的修復(fù)效果優(yōu)于400rcs,ss優(yōu)于400ss,表明在修復(fù)鎘污染土壤時(shí)焙燒兩種天然貝殼粉至400℃無必要;在培養(yǎng)50d后,所有處理中rcs5對(duì)鎘污染土壤的修復(fù)效果最佳,與CK相比,可交換態(tài)鎘含量降低了 28.51%,碳酸鹽結(jié)合態(tài)鎘、鐵錳氧化物結(jié)合態(tài)鎘、有機(jī)物結(jié)合態(tài)鎘以及殘?jiān)鼞B(tài)鎘含量依次升高了50.19%、16.08%、29.74%以及 32.68%。
[Abstract]:At present, heavy metal pollution has attracted wide attention both at home and abroad. Cadmium (CD) is a typical heavy metal pollutant. The addition of adsorbent materials to cadmium contaminated water and soil is one of the effective measures for remediation of cadmium pollution. Shells are by-products of aquatic products and rich in resources. The characteristics of low cost and no pollution. In this paper, adsorption test and constant temperature culture test are carried out. The effects of scallop and clam shell powder on the adsorption characteristics of cadmium in water and the forms of cadmium in contaminated soil were studied. The main conclusions are as follows: both scallop and clam shell powder have strong adsorption energy for Cd2 in water. With the increase of shell powder, With the increase of initial pH value of Cd2 solution, the adsorption capacity increased gradually, and the adsorption capacity increased with the increase of initial concentration of Cd2 solution, and the adsorption capacity increased with the increase of initial concentration of Cd2 solution. The adsorption capacity increased rapidly within 2 hours after the beginning of adsorption. For 400 鈩，

本文編號(hào)：1508144