Field trials to assess the use of Fe-bearing industrial by-products for stabilisation of Cu As soil

Field trials to assess the use of iron-bearing industrial

by-products for stabilisation of chromated copper arsenate-contaminated soil

Sofia Lidelöw a,⁎,Daniel Ragnvaldsson b ,Per Leffler b ,Solomon Tesfalidet c ,

Christian Maurice a,1

a

Division of Waste Science and Technology,LuleåUniversity of Technology,SE-97187Luleå,Sweden

b

Division of NBC-Defence,Swedish Defence Research Agency,SE-90182Umeå,Sweden

c

Department of Chemistry,UmeåUniversity,SE-90187Umeå,Sweden

Received 20March 2007;received in revised form 9July 2007;accepted 12July 2007

Available online 4September 2007

Abstract

Two industrial by-products with high iron contents were tested for their effectiveness in the stabilisation of arsenic and trace

metals in chromated copper arsenate (CCA)-contaminated soil.Steel abrasive (SA;97%Fe 0)

and oxygen scarfing granulate (OSG;

69%Fe 3O 4)were applied at levels of 1%and 8%(w/w)respectively to two soils with different organic matter contents.Field lysimeter measurements indicated that SA and OSG treatments decreased the arsenic concentration in pore water by 68%and 92%,respectively,for the soil with low organic matter content,and by about 30%in pore water of soil with high organic matter content.At pH ≤6,the amended soil with low organic content contained elevated levels of manganese and nickel in their pore water,which were sufficient to induce cytotoxic effects in L-929mouse fibroblast cells.The industrial by-products have significant potential for soil amendment at field-scale,but caution is required because of the potential release of their chemical contaminants and their reduced capacity for sorption of arsenic in organic-rich soils.©2007Elsevier B.V .All rights reserved.

Keywords:Remediation;Iron oxides;CCA;Arsenic;Leaching;Toxicity

1.Introduction

Chemical stabilisation is a remediation technique whereby an additive (‘ameliorant ’)is incorporated and mixed with a contaminated soil.The objective is to induce chemical reactions such as sorption,co-precipitation,or complex formation,all of which reduce the mobility and bioavailability of the targeted soil contaminants.

Iron oxides can effectively sorb many trace elements in soil and have thus been considered for the remediation of soils contaminated with mixtures of metals and arsenic (As)resulting from industrial activities such as mining,wood impregnation,or pesticide use (Hartley et al.,2004;Kumpiene et al.,2006;Mench et al.,2003;Moore et al.,2000;Warren et al.,2003).The efficiency of remediation treatments depends on the intrinsic properties of the soil,the sorption capacity of the iron ameliorant,and the environmental conditions to which the treated soil is exposed.For example,the occurrence of reducing conditions induced by flooding or the

Science of the Total Environment 387(2007)68–78

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Corresponding author.Tel.:+46920491468;fax:+46920492818.E-mail address:soli@ltu.se (S.Lidelöw).1

Present address:Ramböll Sverige AB,SE-97126Luleå,Sweden.0048-9697/$-see front matter ©2007Elsevier B.V .All rights reserved.doi:10.1016/j.scitotenv.2007.07.018

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