Influence of Various Passivators for Nickel Immobilization in Contaminated Soil of China

Abstract

In agricultural field, nickel (Ni) contamination has become a serious concern/threat all over the world due to its hazardous effects on ecosystem and food chain. An incubation study was conducted to investigate the simultaneous efficiency of rice straw (RS) and its derived biochar (BI), calcium carbonate (calcite), zeolite (ZE), and triple superphosphate (TSP) on the stabilization of Ni in contaminated soil. Various chemical extraction techniques, including the sequential extraction (BCR), leaching toxicity (TCLP) test, and single CaCl 2 extraction, were performed. The results revealed that greater reduction in acid-soluble fractions of Ni was observed by 45%, 65.1%, 42.1%, 55.7%, and 33.9% with RS, BI, ZE, calcite at 2%, and TSP 0.5% application rate, respectively. Similarly, TCLP and CaCl 2-extractable Ni were significantly decreased by 49.8% and 97.5% with 2% BI application rate, respectively. The soil pH, EC, and organic matter were significantly improved with the incorporation of RS, BI, ZE, TSP, and calcite amendments. Overall, among all the amendments, the incorporation of BI and calcite was considered to be the best option for Ni immobilization and thereby reducing its mobility in Ni contaminated soil. These findings suggest that RS biochar and calcite can be used as Ni stabilizers in contaminated agricultural soils.

Effects of biochar-based materials on nickel adsorption and bioavailability in soil

“…10. According to related literatures 42,43 with Ni(II) to form metal complexes, which reduced the migration and transformation of heavy metal ions in the environment 45 The results have proved that more carboxyl groups were bound to Ni(II) in BC materials, while more Ni(II) were bound to hydroxyl groups on the surface of BC-NaHA and BC-HA materials, which was the same as the results reported in the literature 46 . This result was consistent with the results of FT-IR, SEM, EDS, BET analysis.…”

“…The increased content of nickel oxidizable state components can be attributed to the formation of nickel complexes with organic functional groups present in the sorbent 43 , 44 . In addition, the largest immobilization of Ni in soil was the transformation from the acid-soluble fraction of Ni to residual Ni 44 , 45 . Therefore, the conversion of acid-soluble nickel components into residual components is an effective way for nickel to be solidified in soil.…”

Assessing the Impact of a Hydropower Plant on Changes in the Properties of the Sediment of the Bystrzyca River in Poland

“…A higher concentration of fine-grained fractions favors the sorption of various impurities (Buyang et al, 2019). In addition, the upstream damming conditions are conducive for the accumulation of large loads of various substances, and water zones with limited flow significantly lower sediment transport capacity are created, in contrast to the zones downstream damming, where the current is rapid and hydraulic bounce occurs (Ali et al, 2019;Tomczyk & Wiatkowski, 2020). Moreover, various studies have proved that mainly sand fractions pass through the damming thresholds, not clay and silt, which show strong sorption capacity (Yao et al, 2015;Bao et al, 2020).…”

“…In the first group of methods, pollutants travel from the solid phase to the sediment solution, while in the second group, they are retained in the solid phase (recommended methods) by changing the properties of the sediment (methods not recommended due to the risk to the environment) or a combination of these two methods (Ou et al, 2018;Chen et al, 2020). Considering Ni and Zn, using synthetic zeolites with high sorption capacity (in the form of briquettes that immobilize easily soluble forms of metals accumulated in the sediment) (Ali et al, 2019;Cataldo et al, 2021;Szerement et al, 2021), phytoremediation using plants that accumulate large amounts of such elements in their tissues without a noticeable phytotoxic effect (hyperaccumulators, e.g., energy willow) (Giordani et al, 2005;Sainger et al, 2014;Wu et al, 2021), and electrokinetic methods using the electric field generated by the flow of current, as a result of which the pollutants travel toward the appropriate electrodes on which they precipitate (Saleem et al, 2011;Hawal et al, 2021;Kamal et al, 2021), are recommended.…”