ASSESSING THE REMEDIATION OF A CONTAMINATED SOIL ECOSYSTEM WITH SOME RECENT CHEMO BIOLOGICAL TECHNOLOGIES THROGH BIOREMEDIATION INDEX

Abstract

In a soil ecosystem irrigated with low-quality water out at El-Rahway village, Giza Governorate, Egypt, a completely randomized field trial was carried out to assess the suitability of some soil biochemical remediation technologies on minimizing the inorganic contaminants hazards, their bioavailability as well as the relationship between potential toxic elements (PTEs) distribution in remediated soil ecosystem, the bioavailability index (BI) and pollutants uptake by cultivated hyperaccumulated plants. Turnip Brassica rapa and radish Raphanus sativus were separately cultivated in the contaminated after being enriched with elemental sulfur (T1), elemental sulfur fortified with a mixture of Thiobacillus Thiooxidans and Thiobacillus ferrooxidans (T2), rock phosphate impregnated with phosphate dissolving bacteria (PDB) (T3), bentonite inoculated with Pseudomonas fluorescence (T4), kaolinite associated with Pseudomonas fluorescence (T5), sulfur mixed with rock phosphate and inoculated with a mixture of Thiobacillus thiooxidans, Thiobacillus ferrooxidans and phosphate dissolving bacteria (PDB) (T6), a mixture of bentonite and kaolinite inoculated with Pseudomonas fluorescence (T7) and a combined mixture of bentonite, kaolinite and rock phosphate inoculated with Pseudomonas fluorescence and phosphate dissolving bacteria (PDB) (T8), as well as control treatments represented by cultivated untreated soil ecosystem.Results implied that the concentration of most contaminants was found in F6 (Residual form) in control cultivated, decreased, T1, T2, and increased in the treatments supplied with modified clay minerals. Results also emphasized that T8 is the best management practice in the remediation of targeted inorganic contaminants grown in a contaminated soil ecosystem cultivated with radish or turnip plants that showed the lowest values compared to other trailed treatments. The combination of phytoremediation and chemo-biological techniques was very effective in minimizing the hazards of PTEs bioavailability and the distribution of the inorganic contaminants, and BI was verified to be promising tools in evaluating soil remediation.