Assessing the combination of iron sulfate and organic materials as amendment for an arsenic and copper contaminated soil. A chemical and ecotoxicological approach.
The efficiency of combining iron sulfate and organic amendments (paper mill sludge, olive mill waste compost and olive tree pruning biochar) for the remediation of an As- and Cu-contaminated soil was evaluated. Changes in As and Cu fractionation and solubility due to the application of the amendments was explored by leachate analysis, single and sequential extractions. Also, the effects on Arrhenatherum elatius growth, germination of Lactuca sativa and toxicity to the bacteria Vibrio fischeri were assessed. The combination of iron sulfate and the organic amendments efficiently reduced As solubility and availability through the formation of amorphous iron oxides, while organic matter did not seem to mobilize As. At the same time, copper fractionation was strongly affected by soil pH and organic matter addition. The soil pH significantly influenced both As and Cu mobility. Within all the amendments tested, FeSO4in combination with compost showed to be the most suitable treatment for the overall remediation process, as it reduced As and Cu availability andenhanced soil nutrient concentrations and plant growth. In sipte of contradictory trends between chemical analyses and ecotoxicity tests, we can still conclude that the application of organic amendments in combination with reactive iron salts is a suitable approach for the remediation of soils contaminated by Cu and As.
Department of Agricultural Chemistry and Food Sciences, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain. Electronic address: teresa.fresno@uam.es.
Teresa
T
Fresno
Department of Agricultural Chemistry and Food Sciences, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Eduardo
E
Moreno-Jiménez
Department of Agricultural Chemistry and Food Sciences, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Jesús M
JM
Peñalosa
D001151:Arsenic / Q000737:chemistry* / Q000633:toxicity; D002606:Charcoal / Q000737:chemistry*; D003300:Copper / Q000737:chemistry* / Q000633:toxicity; D005296:Ferrous Compounds / Q000737:chemistry*; D018525:Germination / Q000187:drug effects; D007220:Industrial Waste; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D031658:Olea; D010209:Paper; D006109:Poaceae / Q000187:drug effects / Q000254:growth & development; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry* / Q000633:toxicity; D014733:Vibrio / Q000187:drug effects
D005296:Ferrous Compounds; D007220:Industrial Waste; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; C020748:ferrous sulfate; D003300:Copper; D001151:Arsenic
Leaching; Organic by-products; Sequential extraction; Toxicity; Trace elements