Remediation of copper contaminated soil by using different particle sizes of apatite: a field experiment

Abstract

The particle size of apatite is one of the critical factors that influence the adsorption of heavy metals on apatite in the remediation of heavy metal contaminated soils using apatite. However, little research has been done evaluating the impact of different particle sizes of apatite on immobilization remediation of heavy metal polluted soils in field. In this study, the adsorption isothermal experiments of copper on three kinds of apatite was tested, and the field experiment by using different particle sizes apatite [nano-hydroxyapatite (NAP), micro-hydroxyapatite (MAP), ordinary particle apatite (OAP)] at a same dosage of 25.8 t/ha (1.16 %, W/W) was also conducted. Ryegrass was chosen as the test plant. The ryegrass biomass, the copper contents in ryegrass and the copper fractionations in soil were determined after field experiments. Results of adsorption experiments showed that the adsorption amounts of copper on OAP was the lowest among different particles. The adsorption amounts of copper on MAP was higher than NAP at high copper equilibrium concentration (>1 mmol L−1), an opposite trend was obtained at low copper concentration (<1 mmol L−1). In the field experiment, we found that the application of different apatites could effectively increase the soil pH, decrease the available copper concentration in soil, provide more nutrient phosphate and promote the growth of ryegrass. The ryegrass biomass and the copper accumulation in ryegrass were the highest in MAP among all treatments. The effective order of apatite in phytoremediation of copper contaminated field soil was MAP > NAP > OAP, which was attributed to the high adsorption capacity of copper and the strong releasing of phosphate by MAP.

Effects of goethite on the fractions of Cu, Cd, Pb, P and soil enzyme activity with hydroxyapatite in heavy metal-contaminated soil

“…48 Resin-P is freely exchangeable P and can be used as a good indicator of the short-term P loss potential in soil, which causes the eutrophication in aquatic ecosystem. 49 In previous studies, application rates of HAP were 1-5%, 3,17,18 and our recent study show that the phosphorus in effluents is higher than the Class Five limit (0.4 mg L À1 ) mandated by the Chinese National Quality Standards for Surface Waters (GB 3838-2002) in 1% HAP treated column. 50 Fortunately, application of goethite decreased resin-P and NaHCO 3 -Pi in the presence of HAP.…”

“…1 Chemical immobilization method could reduce heavy metals mobility and bioavailability by binding toxic heavy metals or changing their chemical speciation, and it has been widely implemented for heavy metals contaminated soils. 2,3 Phosphate compounds, liming materials, organic composts, biochar, and metal oxides, have been applied to date to treat heavy metal-contaminated soils. 1,3 Moreover, soil amendments have different immobilization efficiency for various heavy metals (Cu, Cd, Pb, As, etc.)…”

“…2,3 Phosphate compounds, liming materials, organic composts, biochar, and metal oxides, have been applied to date to treat heavy metal-contaminated soils. 1,3 Moreover, soil amendments have different immobilization efficiency for various heavy metals (Cu, Cd, Pb, As, etc.) and soils with different characteristics.…”

Remediation of heavy metals in contaminated soil by using nano‐bentonite, nano‐hydroxyapatite, and nano‐composite

“…Application of NMs improved yield growth and components of peanut as stated in the presented data (Table 5). This finding may be mainly due to the improved physical and chemical properties of soil and availability of different nutrients, particularly phosphorus (Amira et al, 2016;Ling et al, 2017;Xing et al, 2016).…”

<p>Effect of a dentifrice containing different particle sizes of hydroxyapatite on dentin tubule occlusion and aqueous Cr (VI) sorption</p>

“…Therefore, Cr 6+ is an important index for water pollution control. HA is an excellent adsorbent that has strong adsorption capacity, and it has a good adsorption effect on removing heavy metal ions from contaminated water or soil 22–26. Previous studies have shown that the 600 nm HA dentifrice causes good occlusion of dentinal tubules and adsorption of Cr 6+ 27…”