土壤学报
土壤學報
토양학보
ACTA PEDOLOGICA SINICA
2010年
1期
64-70
,共7页
王强%刘双营%黄玉明%肖广全%魏世强
王彊%劉雙營%黃玉明%肖廣全%魏世彊
왕강%류쌍영%황옥명%초엄전%위세강
水钠锰矿%Cr(Ⅲ)%吸附解吸%氧化
水鈉錳礦%Cr(Ⅲ)%吸附解吸%氧化
수납맹광%Cr(Ⅲ)%흡부해흡%양화
Birnessite%Cr(Ⅲ)%Adsorption and desorption%Oxidation
采取等温吸附热力学方法,探讨了锰氧化合物(水钠锰矿)对Cr(Ⅲ)离子的吸附解吸和氧化特征及温度、pH等因素对其影响.研究结果表明,随着Cr(Ⅲ)初始加入量的增加,总铬吸附量逐渐增大,用Langmuir方程可以很好地描述吸附等温线数据;达到反应平衡时,水钠锰矿对Cr(Ⅲ)离子的氧化量与加入初始Cr(Ⅲ)的浓度呈极显著线性正相关,而水钠锰矿对Cr(Ⅲ)的氧化率,随初始Cr(Ⅲ)浓度增加而减小;温度是影响水钠锰矿对Cr(Ⅲ)的吸附和氧化的重要因素,35℃时的吸附量显著低于25℃时的吸附量,而35℃时的氧化量、氧化率明显高于25℃时的氧化量、氧化率,表明升温对吸附反应不利,而对氧化反应有利;溶液酸度对于Cr(Ⅲ)的吸附和氧化有着不同的影响,随着pH的升高,Cr(Ⅲ)离子氧化量、氧化率增大,然而,水钠锰矿对总Cr的吸附量则随着pH的升高而减小,表明pH的升高有利于氧化反应,而对吸附反应不利.
採取等溫吸附熱力學方法,探討瞭錳氧化閤物(水鈉錳礦)對Cr(Ⅲ)離子的吸附解吸和氧化特徵及溫度、pH等因素對其影響.研究結果錶明,隨著Cr(Ⅲ)初始加入量的增加,總鉻吸附量逐漸增大,用Langmuir方程可以很好地描述吸附等溫線數據;達到反應平衡時,水鈉錳礦對Cr(Ⅲ)離子的氧化量與加入初始Cr(Ⅲ)的濃度呈極顯著線性正相關,而水鈉錳礦對Cr(Ⅲ)的氧化率,隨初始Cr(Ⅲ)濃度增加而減小;溫度是影響水鈉錳礦對Cr(Ⅲ)的吸附和氧化的重要因素,35℃時的吸附量顯著低于25℃時的吸附量,而35℃時的氧化量、氧化率明顯高于25℃時的氧化量、氧化率,錶明升溫對吸附反應不利,而對氧化反應有利;溶液痠度對于Cr(Ⅲ)的吸附和氧化有著不同的影響,隨著pH的升高,Cr(Ⅲ)離子氧化量、氧化率增大,然而,水鈉錳礦對總Cr的吸附量則隨著pH的升高而減小,錶明pH的升高有利于氧化反應,而對吸附反應不利.
채취등온흡부열역학방법,탐토료맹양화합물(수납맹광)대Cr(Ⅲ)리자적흡부해흡화양화특정급온도、pH등인소대기영향.연구결과표명,수착Cr(Ⅲ)초시가입량적증가,총락흡부량축점증대,용Langmuir방정가이흔호지묘술흡부등온선수거;체도반응평형시,수납맹광대Cr(Ⅲ)리자적양화량여가입초시Cr(Ⅲ)적농도정겁현저선성정상관,이수납맹광대Cr(Ⅲ)적양화솔,수초시Cr(Ⅲ)농도증가이감소;온도시영향수납맹광대Cr(Ⅲ)적흡부화양화적중요인소,35℃시적흡부량현저저우25℃시적흡부량,이35℃시적양화량、양화솔명현고우25℃시적양화량、양화솔,표명승온대흡부반응불리,이대양화반응유리;용액산도대우Cr(Ⅲ)적흡부화양화유착불동적영향,수착pH적승고,Cr(Ⅲ)리자양화량、양화솔증대,연이,수납맹광대총Cr적흡부량칙수착pH적승고이감소,표명pH적승고유리우양화반응,이대흡부반응불리.
Cr(Ⅲ) adsorption, desorption and oxidation by birnessite was studied in this paper. Results show that amount of total Cr(Ⅲ) increased with the amount of Cr(Ⅲ) added, and the adsorption process could be well described with the Langmuir equation. The concentration of Cr(Ⅵ) resulting from oxidation of Cr(Ⅲ) showed an extremely significant positive linear relationship with the initial concentration of Cr(Ⅲ) added, while the oxidation rate did a reverse one. Moreover, effects of pH, temperature on the adsorption and oxidation processes were also examined. The adsorption at 308.2 K was remarkably lower than at 298.2 K, while the oxidation and oxidation rate at 308.2 K were obviously higher than at 298.2 K, which suggest that high temperature favored oxidation, but disfavored adsorption. This finding could also be proved by thermodynamic parameters (ΔG°and ΔH°) of the adsorptive process. Adsorption decreased with increasing pH of the adsorption solution, while the oxidation and oxidation rate increased. The results indicated that high pH favored oxidation, but disfavored adsorption.