Reducing Availability of Some Heavy Metals in a Contaminated Soil Using Phosphate Rock and Bentonite Amendments

Abstract

The present work was carried out to assess the immobilization efficiency of some amendments induced some heavy metals in contaminated soil. Two types of amendments phosphate rock and bentonite were mixed with soil at different rates 1, 2, 4, 6 and 8 ton fed-1 , then incubated with soil samples at periods of 20, 30 and 60 days in three replicates, then seeded maize (Zea maize) after incubation of soil to monitoring reducing values of available heavy metals in plant and soil. The obtained data showed that:-Both applied phosphate rock and bentonite succeeded in reducing the availability of (Cu, Zn, Mn and Pb) as well as that phyto-availability to the grown plant of maize. Available heavy metal contents showed a tendency to decrease by increasing the applied amendment levels.-Lower values of available (Cu, Zn, Mn and Pb) could be obtained as a result of application of phosphate rock and bentonite at rates of 6 and 8 ton/fed., respectively, after 60 days of incubation.-The important role of phosphate rock and bentonite application for improving soil physical and chemical properties.-The previous beneficial effects of studied amendments were actually reflected on increasing the plants ability for improving the vegetative growth parameters, i.e., fresh weights and dry weights of shoots and roots yields, with similar parallel trends for the heavy metals immobilization in soil and uptake by plant organs (shoots and roots) .-Likewise, phytotoxicity of (Cu, Zn, Mn and Pb) alleviated rather easily by increasing the levels of phosphate rocks and bentonite at rates of 6 and 8 ton/ fed., respectively, after 60 days or incubation.

Remediation of a Soil Contaminated With Heavy Metals Using Some Seaweeds

“…The data in Table 9 show the moisture content values for the soils under study which markedly increased with increasing different rates (0.1, 0.2, 0.3, and 0.4 ton fed -1 ) of seaweeds, especially after red radish planting compared with control treatment. Data in Table9 show that soil moisture values (field capacity and saturation percent) were affected by application of different treatments of seaweedsat different rates; similar results were obtained by (Abd-Elhady, et al, 2010 andXiao, et al,2008).…”