Sorption kinetics and leachability of heavy metal from the contaminated soil amended with immobilizing agent (humus soil and hydroxyapatite).
Release of heavy metals onto the soil as a result of agricultural and industrial activities may pose a serious threat to the environment. This study investigated the kinetics of sorption of heavy metals on the non-humus soil amended with (1:3) humus soil and 1% hydroxyapatite used for in situ immobilization and leachability of heavy metals from these soils. For this, a batch equilibrium experiment was performed to evaluate metal sorption in the presence of 0.05 M KNO(3) background electrolyte solutions. The Langmuir isotherms applied for sorption studies showed that the amount of metal sorbed on the amended soil decreased in the order of Pb(2+)>Zn(2+)>Cd(2+). The data suggested the possibility of immobilization of Pb due to sorption process and immobilization of Zn and Cd by other processes like co-precipitation and ion exchange. The sorption kinetics data showed the pseudo-second-order reaction kinetics rather than pseudo-first-order kinetics. Leachability study was performed at various pHs (ranging from 3 to 10). Leachability rate was slowest for the Pb(2+) followed by Zn(2+) and Cd(2+). Out of the metal adsorbed on the soil only 6.1-21.6% of Pb, 7.3-39% of Zn and 9.3-44.3% of Cd leached out from the amended soil.
Chaturvedi
Pranav Kumar
PK
Ecotoxicology Section, Industrial Toxicology Research Centre, Post Box No. 80, M.G. Marg, Lucknow 226001, India.
Seth
Chandra Shekhar
CS
Misra
Virendra
V
D019342:Acetic Acid / Q000737:chemistry; D000327:Adsorption; D002104:Cadmium / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D007700:Kinetics; D007854:Lead / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry; D012987:Soil; D012989:Soil Pollutants; D018505:Waste Management / Q000379:methods; D015032:Zinc / Q000737:chemistry*
D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D012972:Sodium Hydroxide; D017886:Durapatite; D015032:Zinc; D019342:Acetic Acid