Effects of Nanoscale Carbon Black Modified by HNO₃on Immobilization and Phytoavailability of Ni in Contaminated Soil

Abstract

A surface-modified nanoscale carbon black (MCB) as Ni adsorbent in contaminated soil was prepared by oxidizing the carbon black with 65% HNO 3 . The surface properties of the adsorbent were characterized by zeta potential analysis, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIRs). Batch experiments were conducted to evaluate the improvement of Ni 2+ adsorption by MCB. Greenhouse cultivation experiments were conducted to examine the effect of MCB on the DTPA-extractable Ni 2+ in soil, Ni 2+ uptake of ryegrass shoot, and growth of ryegrass. Results indicated that MCB had much lower negative zeta potential, more functional groups for exchange and complexation of cation, and more heterogeneous pores and cavities for the adsorption of cation than the unmodified parent one (CB). MCB showed enhanced sorption capacity for Ni ( max , 49.02 mg⋅g −1 ) compared with CB ( max , 39.22 mg⋅g −1 ). Greenhouse cultivation experiment results showed that the biomass of ryegrass shoot and the Ni uptake of the ryegrass shoot were significantly increased and the concentrations of DTPA-extractable Ni in soil were significantly decreased with the increasing of MCB amount. It is clear from this work that the MCB had good adsorption properties for the Ni and could be applied in the in situ immobilization and remediation of heavy metal contaminated saline-alkali soils.

A Comprehensive Evaluation System for the Stabilization Effect of Heavy Metal-Contaminated Soil Based on Analytic Hierarchy Process

“…Studies on the accumulation of heavy metals by crops have mainly focused on that which is above-ground, the edible parts and the roots. The level of heavy metal content in plants can reflect the available heavy metals in soil [ 35 ], which in turn can reflect the effect of stabilization. The biomass represents the health of the crop during the stabilization process.…”

Biofabricated nanomaterials in sustainable agriculture: insights, challenges and prospects

“…Seed germination, shoot and root lengths significantly increased in Brassica juncea when iron oxide (Fe 2 O 3 ) and NPs were applied in combination rather than alone. Cheng et al (2015) reported that modified carbon NPs oxidized with 65% HNO 3 increased the fresh weight of shoots in rye grass. SiO 2 NP application increased the shoot and root lengths, and dry and fresh weights of Cr-stressed hydroponically cultivated peas (Siddiqui et al 2020).…”