1. The Study on Adsorption Capability of Heavy Metal Ions from Aqueous Solution by Oyster Shell Powder Geotechnical & Geoenvironmental Lab., Seoul Natl. Univ. Ph.D Candidate XUXIN

2. Contents 1 Introduction 2 Materials and Methods 3 Results and Discussions 4 Conclusions and Follow-up research plan

3. 1 Introduction Large amounts of oyster shells are produced as a byproduct of shellfish farming in coastal regions without beneficial use options. Large amounts of oyster shells discharging from the restaurant as waste Cause the environmental problem. The recycling of the abundant oyster shells into the useful materials can be the method to reduce the oyster shells wastes. Producing: 282000 ton Recycling: fertilizer - 161000 ton oyster cultivation - 44000 ton Landfill & stacked : 77000 ton (2014 standard) Necessity of adsorption of heavy metal from aqueous solution by OSP

4. 1 Introduction Possibility of adsorption of heavy metal from aqueous solution by OSP AdsorbentCu 2+ Pb 2+ Cd 2+ Zn 2+ Ni 2+ reference Chabazite3.106.006.705.504.50 Kaolinite1.180.120.321.25 Flyash+wollastonite1.18 7.3 Fly ash1.392.82 Chitosan3.4 2.4 Blast-furnace slag7.55.53.1 Oyster shell powder4.268.86.22 This study Hsu, Ting-Chu. "Experimental assessment of adsorption of Cu 2+ and Ni 2+ from aqueous solution by oyster shell powder." Journal of hazardous materials171.1 (2009): 995-1000. Adsorption capacities of heavy metal on various low-cost adsorbents

5. 1 Introduction Adsorption mechanism of heavy metal from aqueous solution by OSP In the presence of CaCO 3, upon higher Cd addition, CdCO 3 (PbCO 3 ) was attained by divalent cation exchange. Solid solutions could be achieved by the following equation. CaCO 3 +Cd 2+ → CdCO 3 +Ca 2+ CaCO 3 +Pb 2+ → PbCO 3 +Ca 2+ CaCO 3 + H 2 O → Ca 2+ + CO 3 2- CO 3 2- + H 2 O → HCO 3 - +OH - M n+ + n(OH) - → M(OH) n M : Metal The following chemical reactions are involved in the conversion of CaCO 3 to heavy metal compounds

6. 2 materials and methods Waste oyster shell powder( OSP) (1) The WOS were washed and heated at 95 0 C for 5h using distilled water to remaining materials (2) The WOS were dried at 105 0 C for 72h and then pulverized using a mortar and pestle. (3)The pulverized WOS were passed through a #16 sieve(1.18mm) no passed a #20 sieve(0.85mm) to obtain a homogeneous size. Heavy metal contaminated solution (1)Cd, Cu,Pb (nitrate salt) + DI water  heavy metal solution (2) pH of the solution adjusting to 5.5-6.0 by adding amounts of dilute NaOH or HNO 3 solution.

7. 2 materials and methods Experiment methods and Equipment

8. 3 Results and Discussions Effect of contact time (60mg/L, 40mL, OSP 0.5g, Room temp. pH 5.5~6) Time(min) 1030603009001440 Cd 32.7530.3529.2024.336.037.70 Cu 43.3240.6139.4532.4824.9722.14 Pb 51.2338.6932.260.7350.42350.9738

9. 3 Results and Discussions Effect of initial concentration ( 40mL, OSP 0.5g, Room temp. pH 5.5~6, 24h) C 0 (mg/L) 20406080100120 Cd 1.732.846.7014.7535.9242.25 Cu 0.98129.9926.2643.6355.2767.56 Pb 0.8352.134.326.939.7313.31

10. 3 Results and Discussions Effect of temperature ( 60mg/L, 40mL, OSP 0.5g, pH 5.5~6, 24h) Temperature(°C) 814162325 Cd 36.4232.2830.4327.1325.35 Cu 40.3138.3537.2535.9134.39 Pb 44.6737.4230.2316.565.88

11. 3 Results and Discussions Effect of pH (60mg/L, 40mL, OSP 0.5g, Room temp., 24h) pH 234567 Cd 20.3114.318.938.628.839.30 Cu 26.8125.2224.5923.7922.930.704 Pb 4.313.672.311.310.9140.873

12. 3 Results and Discussions Langmuir model Freundlich model Adsorption isotherm

13. 4 Conclusion and Follow-up research plan Conclusion 1 As the contact time increased the amount of adsorbed and removal ratio also increased and will reach a plateau at some time. 2 On increase the initial solute concentrations, the total metal uptake increased and the removal ratio decreased. 3 As the temperature increased the amount of adsorbed and removal ratio also increased.The amount of absorbed Pb with the biggest increasing. 4 Metal uptake increased with increasing pH and reached maximum in the of 6 for both metal ions. 5 The capacity of OSP adsorbed heavy metal ions: Pb > Cd > Cu.

14. 4 Conclusion and Follow-up research plan Follow-up research plan OSP at higher initial metal concentration adsorption behaviourCompetitive heavy metal sorption by OSP OSP

15. 4 Conclusion and Follow-up research plan Smart PRB Turner, Matthew, et al. Permeable Reactive Barriers: Lessons Learned/New Directions. INTERSTATE TECHNOLOGY REGULATORY COOPERATION WASHINGTON DC, 2005. Sampling Parameters Water level pH Temperature Redox potential Dissolved oxygen Alkalinity Turbidity salinity