Remediation of Petroleum and HeavyMetals- Contaminated Soilby Plants and Nanoparticle Productsfrom Plants and Algal Extract

Increased global industrialization has led to the release of several pollutants, including total petroleum hydrocarbons (TPHs) and heavy metals (HMs), which are detrimental to all living forms and have a major impact on the balance of ecosystems. The present study assessed the potential use of six plant species as phytoremediators and four different kinds of silver nanoparticles (AgNPs) to remove TPHs and HMs from soil. The soil was treated artificially with five doses of TPHs, including D1 5000, D2 10000, D3 15000, D4 20000, and D5 25000 mg kg<sup>−1</sup>, respectively, with four replications for 180 days and the same doses for control without plants. The plant species examined were <i>Cyperus rotundus</i>, <i>Hordeum vulgare</i>, <i>Hordeum disticum</i>, <i>Triticum aestivum</i>, <i>Triticum durum</i>, and <i>Medicago polymorpha</i>, with different types of AgNPs synthesized from <i>Nostoc</i> sp., <i>Cladophora glomerata</i>, <i>Nasturtium officinale</i> and <i>Thymus vulgaris</i>. Results indicated significant differences among doses and plant species for the removal of TPHs and HMs in soil. Generally, more Removal percentage (R%) of TPHs and HMs among all doses were obtained by <i>C. rotundus</i>. The trend for HMs R% in the investigated soils was in descending order of Fe > Pb > Mn> Zn > Cr > Ni. Four distinct types of nanoparticles showed significant variation in R% of TPHs and HMs in soil after adding 50 mg and 100mg of AgNPs for each sample soil, N-AgNPs were the best AgNPs to eliminate HMs except Pb there were CG-AgNPs. By increasing the concentration of TPHs and HMs, the efficiency of AgNPs for remediation was decreased.