A study of chalcedonite coated with manganese dioxide

Prezentacja na temat: "A study of chalcedonite coated with manganese dioxide"— Zapis prezentacji:

1 A study of chalcedonite coated with manganese dioxide
Magdalena Michel Marta Tytkowska Faculty of Civil and Environmental Engineering Warsaw University of Life Sciences - SGGW, Poland XVth conference „Drinking Water” October 8-10, 2013 Trenčianske Teplice, Slovakia

2 Occurence of chalcedonite
sedimentary rock occurs in Poland in Inowłódz mined from „Teofilów” deposit two varieties of chalcedonite: consistent and compact (A) porous and pumice-like (B) A B [1]

3 Properties of chalcedonite
siliceous rock, almost homogeneous (SiO2 content exceeds 94%) [2] hydrophilic character [3] low specific surface area → m2/g [1-3] specific density → 2600 kg/m3 [4] total pore volume → cm3/g [1] and cm3/g [3] calculated porosity inside the grains → 0.10 [-] sphericity of grains → [4] porosity of filtration bed → [4]

4 Application of chalcedonite for water treatment
natural chalcedonite good filter material, useful for removal iron from underground water: large mass capacities of bed long filtration cycles (comparing with sand) [5] effectively removes manganese after long-time filtration (20-80 days) [5, 6] used as a base in nitrification biofilter for ammonium ion removal [7] very good MnO2 carrier - impregnation using various chemical methods [8] after MnO2 modification its sorptive and catalitic properties are comparable to greensand [9, 10] MnO2 modified chalcedonite can be used as a chemical active bed for effective iron and manganese removal [9, 10] modified chalcedonite

5 Aim of study to determine how multiple deposition of the MnO2 coat affects increase in the sorption capacity of chalcedonite Methods classic batch test – sorption of manganese(II) on: natural chalcedonite (NC) MnO2 coated chalcedonite; one, two, three and four times modified (MD1MC-MD4MC) to model the sorption data, the Langmuir isotherm equation was used to compare the sorption properties of materials, the qm constant was used

6 Results very good adjustment of the model to the experimental data (r ) favourable character of manganese(II) sorption process (RL ) modification significantly increases the sorption capacity of chalcedonite subsequent modifications also increase the sorption capacity, but the rate of change is decreasing qm [mg/g] δ qm [mg/g] 2.217 0.193 2.024 0.313 1.711 0.793 0.918 0.834 0.084 - Fig. 1. Langmuir isotherms of manganese(II) sorption on the tested materials

7 Results NC - light-beige grains, irregular surface, visible cracks
MD1MC - MnO2 deposited in clusters, incomplete coverage NC MD1MC MD2,3,4MC - continuous brown-black coat of MnO2, no differences in the grains’ appearance MD2MC MD3MC MD4MC

8 Conclusions natural chalcedonite has minimal sorption properties
its surface can be successfully modified with MnO2 single modification increases the sorption capacity eleven times double modification increases the sorption capacity twenty times further modifications increase the sorption capacity just twenty-four and twenty-six times in practice the use of single and double modification is sufficient

9 References [1] Michel M.M. 2011: Charakterystyka chalcedonitu ze złoża Teofi lów pod kątem możliwości wykorzystania w technologii uzdatniania wody i oczyszczania ścieków [Characteristics of chalcedonite from Teofi lów deposit for possible use in technology of water and wastewater treatment. Engl. summ.]. Gosp. Sur. Min. 27: 49–67. [2] Ratajczak T., Wyszomirski P. 1991: Charakterystyka mineralogiczno-surowcowa chalcedonitów spongiolitowych z Teofilowa nad Pilicą [Mineralogical and technological characteristics of spongolithic chalcedonites of Teofi lów on Pilica. Engl. summ.]. Gosp. Sur. Min. 7 (1): 65–84. [3] Tchórzewska D., Pabis J., Kosk I., Nieć M. 2001: Nowe zastosowania chalcedonitu jako sorbentu w procesie oczyszczania wód [The use of chalcedonite as a sorbent for water treatment. Engl. summ.]. Przegląd Geologiczny vol. 49 (4): 303–306. [4] Siwiec T. 2012: Graniczne wartości parametrów płukania wybranych złóż filtracyjnych. Gaz, Woda i Technika Sanitarna 1:13-17. [5] Sozański M.M., Jeż-Walkowiak J., Weber Ł., Szambelańczyk K. 2007: Badania w skali pilotowej i technicznej odżelaziania i odmanganiania wód podziemnych w procesie filtracji przez złoża chalcedonitowe [Pilot and full scale research on iron and manganese removal from groundwater in filtration process through chalcedonit sand. Engl. summ.]. Instal 10: 60–64. [6] Weber Ł., Szambelańczyk K. 2006: Badania technologiczne nad uzdatnianiem wody podziemnej na złożach chalcedonitowych na Stacji Uzdatniania Wody Nowy Folwark. Forum Eksploatatora 1 (22): 31–33. [7] Papciak D., Puszkarewicz A., Kaleta J. 2012: Porównanie skuteczności usuwania manganu(II) i azotu amonowego w procesie biofiltracji na złożach chemicznie aktywnych [Comparison of removal efficiency of manganese(II) and ammonium nitro gen in the biofiltration process on the chemically active beds. Engl. summ.]. Editors: Dymaczewski Z., Jeż-Walkowiak J. Materials of 10th International Conference Water Supply and Water Quality, Poznań, Poland. [8] Michel M.M. 2012: A study of application of chalcedonite as a manganese dioxide carrier. Ann. Warsaw Univ. of Life Sci.– SGGW, Land Reclam. 44 (1): 63–73. [9] Michel M.M. 2009: Odmanganianie wody podziemnej na modyfikowanym chalcedonicie. Gaz, Woda i Technika Sanitarna 4: 22–26. [10] Michel M.M. 2012: A study of application the modified chalcedonite for underground water treatment. Ann. Warsaw Univ. of Life Sci.– SGGW, Land Reclam. 44 (2): 91–100.

10 Thank you for your attention
Q&A PhD Eng. Magdalena Michel