Arsenic mobility and speciation in a contaminated urban soil are affected by different methods of green waste compost application.
Application of green waste compost (GWC) to brownfield land is now common practice in soil restoration. However, previous studies have demonstrated both beneficial and detrimental effects on arsenic and metal mobility. In this paper, trace element behaviour was investigated following GWC application, either as surface mulch to, or mixed into soil from a previously described brownfield site in the U.K. Significant differences in arsenic mobility were observed between treatments. Mulching caused most disturbance, significantly increasing soil pore water As, together with Fe, P, Cr, Ni and dissolved organic carbon, the latter was a critical factor enhancing As mobilization. Arsenate was the main inorganic As species in soil pore water, increasing in concentration over time. An initial flush of potentially more toxic arsenite decreased 4 weeks after compost application. Biological processes appeared to play an important role in influencing As mobility. The results point to the necessity for careful management of As-contaminated soils.
Hartley
William
W
Liverpool John Moores University, Faculty of Science, Byrom Street, Liverpool L3 3AF, UK. w.hartley@ljmu.ac.uk
Dickinson
Nicholas M
NM
Riby
Philip
P
Leese
Elizabeth
E
Morton
Jackie
J
Lepp
Nicholas W
NW
D001151:Arsenic / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000378:metabolism*; D014131:Trace Elements / Q000032:analysis; D006113:United Kingdom
D012987:Soil; D012989:Soil Pollutants; D014131:Trace Elements; D001151:Arsenic