Bonemeal Additions as a Remediation Treatment for Metal Contaminated Soil

Abstract

The ability of bonemeal additions (finely ground, poorly crystalline apatite, [Ca 10 (PO 4 ) 6 OH 2 ]) to immobilize pollutant metals in soils and reduce metal bioavailability through the formation of metal phosphates has been evaluated. Leaching column experiments were carried out on contaminated soils with pH varying between 2.7 and 7.1. Monitoring of leachates over a three month period indicated that bonemeal additions resulted in the immobilization of metals and an increase in the pH of the column leachate, the soil pore water and the soils themselves. Analytical scanning electron microscopy of the bonemeal treated soil at the end of the experiment revealed that Pb and Zn were associated with phosphorus. X-ray diffraction identified several newly formed phases in the bonemeal treated soil at the end of the experiments that had peaks of similar intensity and positions as reference Pb and Ca-Zn phosphates. Batch experiments and subsequent extraction of metals from controls and bonemeal amended soils using 0.01 M CaCl 2 and DTPA indicated that bonemeal additions reduced the availability of the metals in the soils.Bonemeal amendments appear to have potential as a remediation treatment for metal contaminated soils.

Effect of bone char application on Pb bioavailability in a Pb-contaminated soil

“…4) except at the highest application rates. This result agrees with those reported by Cheung et al (2001), and Hodson et al (2000). However, the pH values of both E-4 and C-4 treatments were the highest among the treatments (Fig.…”

“…In particular, its potential to adsorb both cationic and anionic metal species including radionuclides from radioactive wastes and contaminated water supplies is now being examined. Recently, the ability of bone meal addition to immobilize pollutant metals in soils has also been reported (Hodson et al, 2000). In the present study, bone char was used in pot experiments and sequential extraction was employed to investigate the effects of bone char application on bioavailability of Pb in a smelter-contaminated soil from Hunan Province, south China.…”

Determination of adsorption efficiency based on cation exchange capacity related to red earth, bone meal and pulverised fly ash as ameliorants to lead contaminated soils

“…Thus the efficacy, low-cost and potential adsorbancy properties of red earth justified its use in this study as one of the ameliorants of choice. Bone meal contains lead, but at low concentrations < 0.2 ppm (Hodson et al, 2000). According to the information supplied by John Hall Ltd, the bonemeal (sterilised to ensure that it is free of risk from BSE and pathogens) contained 3.5 wt.…”

“…Bone meal was an ideal choice as an ameliorant (to remediate metal contaminated lands) due to its low-cost, readily available, high P content and the ability to release P without the risk of high solubility (without causing excessive P runoff e.g. K 2 HPO 4 ) associated with other P forms (Valsami-Jones, 2000). The high solubility of most P source means that the eutrophication risk would be associated with such treatment (Hodson et al, 2000).…”

“…K 2 HPO 4 ) associated with other P forms (Valsami-Jones, 2000). The high solubility of most P source means that the eutrophication risk would be associated with such treatment (Hodson et al, 2000). In addition to mineral P sources such as Pyromorphites, rock apatite have also been successfully trialled (Ma et al, 1993), but rock apatite is highly insoluble (Nriagu, 1984) and so might not release P sufficiently and rapidly to remediate contaminated soil on an acceptable time scale.…”