title: Olive mill waste biochar: a promising soil amendment for metal immobilization in contaminated soils.
abstract: The potential use of biochar from olive mill waste for in situ remediation of metal contaminated soils was evaluated. Biochar was mixed with metal contaminated soil originating from the vicinity of an old zinc smelter. Soil-biochar mixtures were equilibrated for 30 and 90 days. At these time points, Ca(NO3)2 exchangeable metals were determined, and effects of the biochar amendment on soil toxicity were investigated using plants, bacteria, and earthworms. Bean (Phaseolus vulgaris) growth, metal content, antioxidative enzymes activities, and soluble protein contents were determined. Furthermore, effects on soil microbial communities (activity, diversity, richness) were examined using Biolog ECOplates. After 120 days of soil-biochar equilibration, effects on weight and reproduction of Eisenia foetida were evaluated. With increasing biochar application rate and equilibration period, Ca(NO3)2 exchangeable metals decreased, and growth of bean plants improved; leaf metal contents reduced, the activities of antioxidative stress enzymes decreased, and soluble protein contents increased. Soil microbial activity, richness, and diversity were augmented. Earthworm mortality lowered, and their growth and reproduction showed increasing trends.
authors.affiliation: Dipartimento di Scienze e Tecnologie, Università Degli Studi di Napoli "Parthenope", Via Ammiraglio Ferdinando Acton, 38, 80133, Napoli, Italy, amine.hmid@uniparthenope.it.
authors.forename: Amine
authors.initials: A
authors.lastname: Hmid
authors.forename: Ziad
authors.initials: Z
authors.lastname: Al Chami
authors.forename: Wouter
authors.initials: W
authors.lastname: Sillen
authors.forename: Alain
authors.initials: A
authors.lastname: De Vocht
authors.forename: Jaco
authors.initials: J
authors.lastname: Vangronsveld
mesh_terms: D000818:Animals; D017610:Calcium Compounds; D002606:Charcoal / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D019216:Metals, Heavy / Q000032:analysis / Q000302:isolation & purification* / Q000633:toxicity; D009566:Nitrates; D031658:Olea / Q000737:chemistry*; D009835:Oligochaeta / Q000187:drug effects / Q000254:growth & development; D027805:Phaseolus / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development; D018515:Plant Leaves / Q000737:chemistry; D011506:Proteins / Q000032:analysis; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000302:isolation & purification* / Q000633:toxicity; D013997:Time Factors
chemical_list: D017610:Calcium Compounds; D019216:Metals, Heavy; D009566:Nitrates; D011506:Proteins; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; C059948:calcium nitrate