Efficiency of lime, biochar, Fe containing biochar and composite amendments for Cd and Pb immobilization in a co-contaminated alluvial soil. (February 2020)

• Record Type: Journal Article
• Authors: Hamid, Yasir; Tang, Lin; Hussain, Bilal; Usman, Muhammad; Gurajala, Hanumanth Kumar; Rashid, Muhammad Saqib; He, Zhenli; Yang, Xiaoe
• Is Part Of: Environmental pollution. Volume 257(2020)
• Publication Date: 2020-02
• Subjects: Metals immobilization -- Composite amendments -- FTIR -- SEM-EDS -- Speciation -- Alluvial soil; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.113609
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Present study reports the laboratory and field scale application of different organic and inorganic amendments to immobilize cadmium (Cd) and lead (Pb) in a co-contaminated alluvial paddy soil. For that purpose, lime, biochar, Fe-biochar and two composite amendments (CA) composed of biochar, lime, sepiolite and zeolite (CA1: composite amendment 1) and manure, lime and sepiolite (CA2: composite amendment 2) were firstly tested in an incubation experiment to ameliorate Cd and Pb co-contaminated alluvial soil. It was observed that liming and CA2 elevated the soil pH and reduced DTPA extractable Cd and Pb in the incubated soil leading to higher metal immobilization. Therefore, efficiency of lime and CA2 was further investigated in field conditions with mid rice as the test crop to evaluate field scale immobilization and precise application rate for the tested soil type. DTPA and CaCl2 extractable Cd (46 and 51%) and Pb (68 and 70%) in field soil were decreased with applied treatments. Speciation of Cd and Pb also promoted conversion of metal exchangeable contents to less-available forms. Activated functional groups on amendments' surface ( _ OH bonding, C _ O and CO, -O-H, Si–O–Si, carboxylic and ester groups) sequestered metals by precipitation, adsorption, ion exchange or electro static attributes. Application of lime at 2400 kg/acre (T4) and CA2 at 1200 kg/acre was more effective in reducing rice shoot and grains metal contents. Moreover, obtained results in terms of pH, extractable content, speciation and yield, and microanalysis of amendments highlights the remarkable efficiency of lime and composite amendment to sorb Cd and Pb providing the key evidence of these amendments for metals immobilization and environmental remediation. Considering these results, lime and CA2 are potential amendments for co-contaminated rice field especially in context of alluvial soil. Graphical abstract: Image 1 Highlights: Inorganic, organic and composite amendments decreased the DTPA extractable metals. Lime addition elevates incubated and field soil pH. Cd and Pb speciation reduced exchangeable form of metals. Lime and CA2 were effective in reducing metal availability in alluvial soil. Abstract : Inorganic and organic additives have potential to remediate metal polluted sites but their composite application was more helpful in reducing Cd and Pb availability in co-contaminated alluvial soil.