Heavy Metal Immobilization in Contaminated Soils using Phosphogypsum and Rice Straw Compost

Abstract

The application of soil amendments to immobilize heavy metals is a promising technology to meet the requirements for environmentally sound and cost-effective remediation. The present study was carried out to evaluate the result of phosphogypsum (PG) used alone and in combination with compost (CP) at a mix ratio of 1:1 wet weight ratio (PG + CP) at 10 and 20 g dry weight kg À1 dry soil, on heavy metal immobilization in contaminated soil and on canola growth. The results revealed that the Pb, Cd and Zn uptake of canola plants was reduced by the application of PG alone and when it was mixed with CP as compared with untreated soil. At an application rate of 10 g dry weight kg À1 dry soil of (PG + CP) the dry weight of canola plants increased by 66·8% was increased in comparison with its weight in the untreated soil. The addition of PG alone resulted in more pronounced immobilization of heavy metal as compared with PG mixed with CP. Plant growth was improved with CP addition, but heavy metals immobilization was the greatest in PG alone treatments. Results suggest that PG may be useful for the immobilization of heavy metals in contaminated soils.

Progresses in restoration of post-mining landscape in Africa

“…There are several ways by which the mobility of heavy metals can be modified, including synthetic chelators, rhizosphere microbes, and biochar in combination with organic residues (Sarwar et al 2017). For instance, addition of phosphogypsum alone resulted in more immobilization of heavy metals (zinc, nickel, lead and cadmium) than did a combined soil treatment of phosphogypsum and rice straw composite but the latter treatment significantly improved biomass production of canola (Mahmoud and Abd El-Kader 2015). Soil microorganisms associated with plants, mycorrhizal fungi and plant growth promoting bacteria, have the potential to influence heavy metal availability and uptake by plants in the rhizosphere (Rajkumar et al 2012;Seth 2012).…”

The immediate effectiveness of barley straw mulch in reducing soil erodibility and surface runoff generation in Mediterranean vineyards

“…This then is a quick and efficient strategy to reduce soil losses and increase infiltration. The straw should also have a positive effect on soil quality as it will improve soil organic matter, soil biological activity and infiltration rates (Brevik, 2009b;Lieskovský and Kenderessy, 2014;Mahmoud and Abd El-Kader, 2015;Mwango et al, 2015).…”

Effects of spent mushroom compost application on the physicochemical properties of a degraded soil

“…The rate of decomposition of organic amendments and SOC remains in the long term varies with the intrinsic quality of the amendment (Lashermes et al, 2009;Novara et al, 2015). Soil organic matter content is one of the most important soil quality indicators of soil recovery (Mahmoud and Abd El-Kader, 2015;Parras-Alcántara et al, 2015;Pulido Moncada et al, 2015) and is a good sign for soil quality (Gelaw et al, 2015). The quality of soil organic matter, soil structure, microbial activity, and rainfall intensity are, in fact, important parameters that should be evaluated and correlated to assess the fate of carbon during transportation .…”