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K d values of Cu, Cr, As in different soil matrix 1 Sung-Mo Kang, 2 Seung-Hun Shin, 1 Ja-Oon Koo ( 1 Korea Forest Research Institute, 2 Dong-Yang Timber.

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Presentation on theme: "K d values of Cu, Cr, As in different soil matrix 1 Sung-Mo Kang, 2 Seung-Hun Shin, 1 Ja-Oon Koo ( 1 Korea Forest Research Institute, 2 Dong-Yang Timber."— Presentation transcript:

1 K d values of Cu, Cr, As in different soil matrix 1 Sung-Mo Kang, 2 Seung-Hun Shin, 1 Ja-Oon Koo ( 1 Korea Forest Research Institute, 2 Dong-Yang Timber Co., LTD)

2 ● Preservative treated wood Purpose - Extend service life - Improve economic values - Protect forest

3 ● CCA consumption in Korea

4 ● Biocide use in Korea ACQ CUAZ CB-HDO

5 ● Treated wood and Environment Environmental Concerns =

6 ● Toxicity of CCA AS 2 O 5 & Cr +6  Poisonous 2. Respiratory disease, carcinogen, ulcer, skin irritation LD 50 (mg/kg) LC 50 (96hr) Carcinogen Asrat 15~293fish 64mg/L ○ Crrat 149~177Trout 69mg/L ○ (UNEP, 1994)

7 ● CCA debate Chemical fixation of CCA with wood component results in environmentally safe products. Treated wood will be eventually degraded and cause environment pollution.

8 Soil pollution standards and soil remediation criteria in Korea. Cu Soil pollution Agricultural : 6mg/kg Commercial/Industrial : 20mg/kg Soil remediation Agricultural : 15mg/kg Commercial/Industrial : 50mg/kg As Soil pollution Agricultural : 50mg/kg Commercial/Industrial : 200mg/kg Soil remediation Agricultural : 125mg/kg Commercial/Industrial : 500mg/kg ComponentCriteria Cr Soil pollution Cr 6+ (Agricultural) : 4mg/kg Cr 6+ (Commercial/Industrial ) : 12mg/kg Soil remediation Cr 6+ (Agricultural A area) : 10mg/kg Cr 6+ (Commercial/Industrial ) : 30mg/kg

9 ● Ban components of CCA   Ban CCA treated wood (Ministry of Environment Notice )   Voluntarily stop use CCA by Korea preservative industry

10 Mobility and retention of chromium, copper, and arsenic leached from In- service CCA-treated wood in soil

11 Mobility and retention of chromium, copper, and arsenic leached from In- service CCA-treated wood in soil Figure 1. Soil sampling methods

12 Figure 2. Cr, Cu and As levels in soil at selected distances. Mobility and retention of chromium, copper, and arsenic leached from In- service CCA-treated wood in soil

13 Figure 3. Cr, Cu and As levels in soil at selected depths. Mobility and retention of chromium, copper, and arsenic leached from In- service CCA-treated wood in soil

14 Mobility and retention of chromium, copper, and arsenic leached from In- service CCA-treated wood in soil Physical characteristics of tested soils. Sample Sand (%) Silt (%) Clay (%) Soil texture Bulk density (g/ml) Porosity Sandy loam SL Sand S

15 Figure 4. Cr, Cu and As levels in two different soils. Mobility and retention of chromium, copper, and arsenic leached from In- service CCA-treated wood in soil Sandy soil Sandy loam

16 Partition Coefficients ● Partition Coefficients Kow = C oct/C water Kom = C organic matter/C water Koc = C organic carbon/C water Kd = C solid/C water

17 ● Kd (soil-water partition coefficient) C soil = Conc. absorbed to soil matrix C water = Conc. in water CsCs CwCw (ml/g) =

18 ● K d (soil-water partition coefficient) High Kd Low water solubility Low water solubility Low biodegradation Low biodegradation Remain in soil Remain in soil

19 CrCuAs K d (ml/g) Values of the soil-water partition coefficient k d (Baes and Sharp, 1983; Baes et al, 1984; EPA, 1999; EPA 2005). DDT : 2,380ml/g Benzene : 0.198ml/g ● K d (soil-water partition coefficient)

20 ● Objective To measure adsorption characteristics of domestic soils for chromium, copper, and arsenic.

21 Physical and chemical characteristics of tested soils Soil texture, pH, Organic Matter (%) Bulk density, Porosity, Cation exchange capacity exchangeable cations ● Materials and Methods

22 4 different types of soil matrix [Soil, Soil:OM (8:2) Soil:OM (1:1) OM] Sorption affinities (ASTM D ) - -Standard solutions (Kanto chemical) - -Flame atomic absorption spectrometer (Shimadzu AA-6800) - - Distribution coefficient (Kd)

23 ● Materials and Methods SHIMADZU AA-6800 HVG HYDRIDE VAPOR GENERATOR

24 Physical characteristics of tested soils. Sample Sand (%) Silt (%) Clay (%) Soil texture Bulk density (g/ml) Porosity Soil SL ● Results and Discussion

25 Chemical characteristics of tested soils. ● Results and Discussion Sample pH (H 2 O) Organic Matter (%) Total Nitrogen (%) P 2 O 5 (mg/kg) Soil

26 CEC, exchangeable cations and base saturation of tested soils. ● Results and Discussion Sample CEC (cmol + /kg) Exchangeable cations (cmol + /kg) Base saturation (%) K+K+ Na + Ca 2+ Mg 2+ Sum of bases Soil

27 ● Results and Discussion KdKd Values of Kd for three metals in different soil matrix Figure 5. Values of Kd for three metals in different soil matrix.

28 ● Conclusions 1. Values of the distribution coefficient (Kd) Chromium > Arsenic > Copper in all 4 matrix. Chromium > Arsenic > Copper in all 4 matrix. 2. Different soil matrixes resulted in varying mobilities of CCA components. mobilities of CCA components. 3. The values of Kd for all three metals were lower in the soil without organic matter, lower in the soil without organic matter, but increased with organic matter contents. but increased with organic matter contents.

29 ● Conclusions 4. Further studies will be necessary to explain leaching behavior at different soil to explain leaching behavior at different soil characteristics. characteristics. 5. The mobility of metal components may be very limited to the surface area adjacent to CCA- limited to the surface area adjacent to CCA- treated wood due to their fairly large Kd. treated wood due to their fairly large Kd. 6. The metal components would be persistent and accumulated in the soil, resulting in high and accumulated in the soil, resulting in high chemical concentration in service area of chemical concentration in service area of treated wood. treated wood.


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