Stabilization of cationic and anionic metal species in contaminated soils using sludge-derived biochar

This study compares the effectiveness of several chemical evaluation procedures to predict Cu, and Zn concentrkjghgfsdations in lettuce (Lactuca sativa 'Buttercrunch') grown on contaminated soils from the Montreal urban area. The plant growth assays were performed in the greenhouse using field-collected, non-spiked soils. The soils were characterized using several chemical extraction reagents, as well as electrochemical speciation of the soil solution free metal species. The chemical characterization was supplemented with labile metal pool determinations using anion exchange membranes treated with DTPA or EDTA. The results show that the more sophisticated electrochemical speciation and exchange resins procedures did not consistently improve predictions of metal uptake. We believe this is due to the minimization of metal solubility caused by the circumneutral or alkaline pH values and the relative homogeneity of the relatively small urban soil sample set that we used. The metal solubility and bioavailability in the soils tested were minimized by the particular chemical properties of the soils, obscuring any potential advantages from more discriminate soil chemical evaluation procedures. Nevertheless, the reported regressions (for 10 different methods) are valid estimates of Cu and Zn phytoavailability in contaminated urban soils. Key words: Lettuce, trace metals, bioavailability, chemical speciation, ion exchange membranes, contaminated soils, free ion

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HAZARDOUS WASTE CLASSIFICATION: REVIEW OF WORST CASE TO LESS WORST CASE METAL SPECIES WITH A WORKED EXAMPLE FOR A CONTAMINATED SOIL

Detritus ◽

10.31025/2611-4135/2021.14065 ◽

2021 ◽

pp. 4-24

Author(s):

Ian Bishop ◽

Pierre Hennebert

Keyword(s):

Contaminated Soil ◽

Contaminated Soils ◽

Metal Species ◽

Worst Case ◽

Metal Concentrations ◽

Worked Example ◽

The Uk ◽

Filter Cakes ◽

Technical Guidance

The classification of waste as either hazardous or non-hazardous, especially for mixtures such as contaminated soils, ashes, filter cakes and sludges, is not straight forward. In particular, as the laboratories can only measure total metal concentrations, both the European and the UK technical guidance state that if the classifier doesn’t know exactly which metal species is in their waste, then they should start from a worst case species and use lines of evidence to work towards a more reasonable (less hazardous) species. However, the guidance doesn’t define or list worst case nor less worst case species. While some authors have documented worst case species, this is only in relation to documenting the concentrations at which each hazard property is triggered for a given worst case species. This paper addresses this gap. It documents how to define both the worst case species and more importantly, lists less worst case species for 32 elements and 204 metal species; species based on those listed in the European legislation but also supplemented by species that haven’t (yet) been included in this legislation but are significant nevertheless. For each species, the paper tabulates the hazard property that triggers first, metal concentrations, conversion factors and other metadata, species by species, in descending order of hazard. Finally, to demonstrate how to use the data, either manually or by utilizing commercial software, the paper will give a worked example for a contaminated soil, showing how classifiers can use the list to help move from a worst case to a less worst case species.

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Remediation of Cr(VI)-Contaminated Soils by Washing with Low-Molecular-Weight Organic Acids Based on the Distribution of Heavy Metal Species

Environmental Engineering Science ◽

10.1089/ees.2021.0018 ◽

2021 ◽

Author(s):

Shaolin Tan ◽

Yi Xin ◽

Kun Liu ◽

Enzhi Zhang ◽

Shijie Li ◽

...

Keyword(s):

Heavy Metal ◽

Molecular Weight ◽

Organic Acids ◽

Contaminated Soils ◽

Metal Species ◽

Low Molecular Weight ◽

Heavy Metal Species

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Extraction of Metal Species from Contaminated Soils Utilizing Supercritical CO2and Ultrasound

Japanese Journal of Applied Physics ◽

10.1143/jjap.48.07gm17 ◽

2009 ◽

Vol 48 (7) ◽

pp. 07GM17 ◽

Cited By ~ 3

Author(s):

Ik-Beom Park ◽

Younggyu Son ◽

Il-Seok Song ◽

Kyung-Ho Na ◽

Jongchan Kim ◽

...

Keyword(s):

Contaminated Soils ◽

Metal Species

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Production and STEM examination of controlled-size silver clusters

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075488 ◽

1983 ◽

Vol 41 ◽

pp. 338-339

Author(s):

M. A. Listvan ◽

R. P. Andres

Keyword(s):

Cluster Size ◽

Metal Clusters ◽

Experimental Parameter ◽

Carbon Films ◽

Metal Species ◽

Silver Clusters ◽

Free Jet ◽

Size Dependent ◽

Cluster Properties ◽

Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

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Effect of chelants on the lead and copper uptake of maize from contaminated soils

Agrokémia és Talajtan ◽

10.1556/agrokem.62.2013.2.14 ◽

2013 ◽

Vol 62 (2) ◽

pp. 373-386 ◽

Cited By ~ 1

Author(s):

György Czira ◽

László Simon ◽

György Vincze ◽

József Koncz ◽

Gyula Lakatos

Keyword(s):

Contaminated Soils ◽

Copper Uptake

Magyarországon a robbanóanyaggal és lőszerszármazékokkal szennyezett területek kármentesítése környezetvédelmi és nemzetgazdasági érdek. Egy hazai lőtérről, illetve lőszer-megsemmisítő telepről vett talajban 900 mg·kg−1 ólom- és 133 mg·kg−1 rézszennyeződést mértünk. A fitoextrakció célja, hogy a növényi szervekbe helyezzük át a nehézfémeket, lecsökkentve ezzel a mobilis, toxikus elemkészletet a szennyezett talajokban. Megvizsgáltuk, hogy egy lőszerszármazékokkal szennyezett talajba, illetve ólommal mesterségesen elszennyezett talajba kijuttatott kelátképzőszerekkel (EDTA, EGTA, citromsav) indukálható-e, megnövelhető-e a növényi szervek Pb- és Cu-akkumulációja?Tenyészedény-kísérletünkben kukoricát neveltünk a fenti ólommal és rézzel elszennyezett lőtéri talajon, illetve a közelben gyűjtött szennyezetlen talajt mesterségesen szennyeztük el 100 mg·kg-1 ólommal. Míg a kontroll (kelátképzővel nem kezelt) szennyezett talajon fejlődő kukorica gyökerében 554 μg·g−1 ólom volt mérhető, addig az EDTA hatására a gyökerekben 4611 μg·g−1-ra (több mint nyolcszorosára), a hajtásokban pedig 158-ról 302 μg·g−1-ra (91%-kal) nőtt az ólomkoncentráció. Mindkét változás statisztikailag szignifikánsnak bizonyult. Az EGTA a Cufelvételt serkentette; a kontrollkultúrák gyökerében 516 μg·g−1, a kezelt kultúrákban viszont 1063 μg·g−1 értéket mértünk (ez kétszeres szignifikáns növekmény). A hajtásokban 69%-kal, 29,9-ról 50,7 μg·g−1-ra emelkedett a réztartalom, ez azonban nem bizonyult statisztikailag szignifikánsnak. A citromsav az ólom hajtásokba történő áthelyeződését nem indukálta, rézfelvétel-serkentő hatása csak a gyökerekben volt szignifikáns.Tenyészedény-kísérleteink alapján kijelenthető, hogy elsősorban az EDTA, illetve részben az EGTA a talajba kijuttatva mobilisabbá, könnyebben felvehetővé teszi az ólmot és a rezet, elősegítve ezzel e két toxikus elem növényekben történő akkumulációját. Szabadföldi körülmények között is feltételezhető, hogy a növények betakarításával a toxikus elemek egy része eltávolítható a szennyezett talajból.

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