Solubility of heavy metals in a contaminated soil: Effects of redox potential and pH

被引:344
作者
Chuan, MC [1 ]
Shu, GY [1 ]
Liu, JC [1 ]
机构
[1] NATL TAIWAN INST TECHNOL,DEPT CHEM ENGN,TAIPEI 10772,TAIWAN
关键词
heavy metals; solubility; redox potential; pH; soil;
D O I
10.1007/BF00282668
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
To assess the mobilities of Pb, Cd, and Zn from a contaminated soil, the effects of redox potential and pH value on metal solubilities were investigated. Both redox potential and pH were found to greatly affect heavy metal solubility in the soil. Results showed that the soil suspension under continuous oxygen aeration for 21 days resulted in increases of redox potential from 290 to 440 mV and pH value from 6.9 to 7.0, respectively. Soluble concentrations of Pb, Cd, and Zn varied with time, and were all lower than 1 mg kg(-1). When the soil suspension was aerated with nitrogen, final redox potential was -140 mV, and pH value of 7.1. The soluble metal concentrations were slightly higher than those aerated with oxygen. The equilibrium solubility experiments were conducted under three different pH values (3.3, 5.0, 8.0) and three redox potential (325, 0, -100 mV). Results showed that metals were sparingly soluble under alkaline conditions (pH = 8.0). Metal solubilities were higher when under slightly acidic conditions (pH = 5.0), and increased drastically when pH was kept at 3.3. When solubilities were compared under same pH values, it was observed that metal solubilities increased as redox potential decreased. Generally speaking, acidic and reducing conditions were most favorable for metal solubilization, and the effect of pH was more significant than that of redox potential. It was proposed that heavy metals were mostly adsorbed onto Fe-Mn oxyhydroxides. The pa-dependent metal adsorption reaction and the dissolution of Fe-Mn oxyhydroxides under reducing conditions was the mechanism controlling the release of heavy metals from soils.
引用
收藏
页码:543 / 556
页数:14
相关论文
共 39 条
[1]   MODELING SELENIUM TRANSPORT IN STEADY-STATE, UNSATURATED SOIL COLUMNS [J].
ALEMI, MH ;
GOLDHAMER, DA ;
NIELSEN, DR .
JOURNAL OF ENVIRONMENTAL QUALITY, 1991, 20 (01) :89-95
[2]  
[Anonymous], 1990, HEAVY METALS SOILS
[3]   MULTIPLE-SITE ADSORPTION OF CD, CU, ZN, AND PB ON AMORPHOUS IRON OXYHYDROXIDE [J].
BENJAMIN, MM ;
LECKIE, JO .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1981, 79 (01) :209-221
[4]   SURFACE IONIZATION AND COMPLEXATION AT OXIDE-WATER INTERFACE .2. SURFACE PROPERTIES OF AMORPHOUS IRON OXYHYDROXIDE AND ADSORPTION OF METAL-IONS [J].
DAVIS, JA ;
LECKIE, JO .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1978, 67 (01) :90-107
[5]   SURFACE-IONIZATION AND COMPLEXATION AT THE OXIDE-WATER INTERFACE .3. ADSORPTION OF ANIONS [J].
DAVIS, JA ;
LECKIE, JO .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1980, 74 (01) :32-43
[6]   SURFACE IONIZATION AND COMPLEXATION AT OXIDE-WATER INTERFACE .1. COMPUTATION OF ELECTRICAL DOUBLE-LAYER PROPERTIES IN SIMPLE ELECTROLYTES [J].
DAVIS, JA ;
JAMES, RO ;
LECKIE, JO .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1978, 63 (03) :480-499
[7]   DISTRIBUTION AND MOBILITY OF SELENIUM AND OTHER TRACE-ELEMENTS IN SHALLOW GROUNDWATER OF THE WESTERN SAN-JOAQUIN VALLEY, CALIFORNIA [J].
DEVEREL, SJ ;
MILLARD, SP .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 1988, 22 (06) :697-702
[8]   EFFECT OF REDOX POTENTIAL ON LEACHING FROM STABILIZED SOLIDIFIED WASTE MATERIALS [J].
DUSING, DC ;
BISHOP, PL ;
KEENER, TC .
JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION, 1992, 42 (01) :56-62
[9]   CONSTRUCTION AND EVALUATION OF A REFERENCE ELECTRODE ASSEMBLY FOR USE IN MONITORING INSITU SOIL REDOX POTENTIALS [J].
FARRELL, RE ;
SWERHONE, GDW ;
VANKESSEL, C .
COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS, 1991, 22 (11-12) :1059-1068
[10]   ASSESSMENT OF LONG-TERM METAL MOBILITY IN HEAT-PROCESSING WASTES [J].
FORSTNER, U ;
CALMANO, W ;
KIENZ, W .
WATER AIR AND SOIL POLLUTION, 1991, 57-8 :319-328