生物吸附劑的制備及其對水中有機(jī)污染物的吸附性能研究
發(fā)布時間:2018-12-10 17:58
【摘要】:本文選用農(nóng)林廢棄物-玉米芯和糠醛渣為研究對象,對其進(jìn)行化學(xué)改性之后制備出新的吸附劑來分別吸附含染料廢水和含酚類廢水。通過對吸附劑投加量、p H、吸附平衡時間、吸附質(zhì)初始濃度、溫度等因素以及吸附熱力學(xué)和動力學(xué)的研究,考察了吸附劑對水中有機(jī)污染物質(zhì)的吸附性能。結(jié)果如下:1.用磷酸對玉米芯進(jìn)行改性,改性玉米芯吸附劑對水中亞甲基藍(lán)和羅丹明B的平衡吸附量較未改性玉米芯吸附劑吸附量高。改性玉米芯吸附劑對亞甲基藍(lán)(100 mg/L)吸附的最佳條件為:投加量為0.05 g,p H為6.0,溫度為25℃,吸附平衡時間60 min,平衡吸附量為99.06 mg/g;對羅丹明B(100 mg/L)吸附的最佳條件為:投加量為0.15 g,p H為2.0,溫度為25℃,吸附平衡時間140 min,平衡吸附量為33.12 mg/g。最佳條件下的去除率均達(dá)99%以上。用偽一級動力學(xué)、偽二級動力學(xué)和Elovich方程擬合了吸附過程的動力學(xué),結(jié)果顯示,吸附過程是一個快速進(jìn)行的過程,偽二級動力學(xué)方程能較好擬合吸附過程,為計(jì)量置換機(jī)制。用Langmuir、Freundlich等溫吸附方程擬合了等溫吸附平衡線,考察了溫度對吸附平衡的影響,分析了吸附的熱力學(xué),表明Langmuir方程更適合描述吸附平衡,溫度升高有利于吸附的進(jìn)行,吸附過程的?H0、?S0均為正值,熵變(?S0)是吸附過程的驅(qū)動力。2.研究了化學(xué)法對工業(yè)糠醛渣改性制備吸附劑的條件,考察改性吸附劑對水溶液中苯酚及對硝基酚的吸附特性。結(jié)果表明,糠醛渣經(jīng)Zn Cl2活化、600℃下炭化后制取的吸附劑對水溶液中苯酚及對硝基酚吸附性能最佳。對苯酚溶液(150 mg/L)的吸附最佳條件為:投加量為0.2 g,p H值為6.0,溫度為25℃,吸附平衡時間120 min,平衡吸附量為18.55 mg/g;對對硝基酚溶液(200 mg/L)的最佳條件為:投加量為0.1 g,p H值為4.0,溫度為25℃,吸附平衡時間60 min,平衡吸附量為49.36 mg/g。最佳條件下的去除率均達(dá)98%以上,吸附性能均顯著優(yōu)于未改性吸附劑。用偽一級動力學(xué)和偽二級動力學(xué)對吸附動力學(xué)進(jìn)行了擬合,結(jié)果表明吸附過程符合偽二級動力學(xué)方程,且是快速吸附的過程。由Langmuir和Freundlich方程對苯酚和對硝基酚的等溫吸附線進(jìn)行擬合,其中Langmuir方程擬合結(jié)果更佳,平衡吸附量隨著溫度的升高而減少,吸附為放熱物理吸附過程。3.通過比較未改性和改性糠醛渣吸附劑的紅外光譜、電鏡掃描、熱重、XRD衍射分析和BET表征,發(fā)現(xiàn)用Zn Cl2活化制得吸附劑表面孔結(jié)構(gòu)排列較為整齊,含有較多的O-H,C-O-C,-C(O)-O-C等官能團(tuán),而用H3PO4活化制得吸附劑雖然也含有Zn Cl2活化吸附劑表面基團(tuán),但明顯還有芳環(huán)或者醇酮型(羰基和酚羥基)結(jié)構(gòu)存在。所有改性吸附劑表面均存在大量的類石墨微晶,比表面積亦有了顯著增大。
[Abstract]:In this paper, corn cob and furfural residue were selected as the research objects. After chemical modification, new adsorbents were prepared to adsorb dyestuff wastewater and phenolic wastewater respectively. The adsorption performance of adsorbent for organic pollutants in water was investigated by studying the adsorption equilibrium time of adsorbent dosage of, p H, initial concentration of adsorbent, temperature and adsorption thermodynamics and kinetics. The results are as follows: 1. The adsorption capacity of modified corncob adsorbent for methylene blue and Rhodamine B in water was higher than that of unmodified corncob adsorbent. The optimum conditions for the adsorption of methylene blue (100 mg/L) by modified corncob adsorbent are as follows: the dosage of 0.05gpH is 6.0, the temperature is 25 鈩,
本文編號:2370982
[Abstract]:In this paper, corn cob and furfural residue were selected as the research objects. After chemical modification, new adsorbents were prepared to adsorb dyestuff wastewater and phenolic wastewater respectively. The adsorption performance of adsorbent for organic pollutants in water was investigated by studying the adsorption equilibrium time of adsorbent dosage of, p H, initial concentration of adsorbent, temperature and adsorption thermodynamics and kinetics. The results are as follows: 1. The adsorption capacity of modified corncob adsorbent for methylene blue and Rhodamine B in water was higher than that of unmodified corncob adsorbent. The optimum conditions for the adsorption of methylene blue (100 mg/L) by modified corncob adsorbent are as follows: the dosage of 0.05gpH is 6.0, the temperature is 25 鈩,
本文編號:2370982
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