PDF Printing 600 dpi - Murdoch University · - Mr Stephan Frodsham, Department of Commerce and...

Toegewijd aan

mijn ouders en Lucas

Abstract

Use of bauxite refining residue to reduce the mobility of heavy metals in municipal

waste compost.

PhD thesis by

Harrie Hofstede

Due to the adverse environmental impact of landfills and the lack of space for nearby

population centres an unprecedented interest has developed in waste recycling with the

objective to reduce the volume of waste disposed. Generally organic matter represents the

largest fraction in the domestic waste stream including food, garden and paper waste.

In the past efforts have been made to process this organic fraction into muniapal compost.

However contamination of the compost with heavy metals has in many cases resulted in the

lack of suitable markets and subsequent closure of compost facilities. A study was

undertaken and aimed at reducing the concentration and mobility of heavy metals in

municipal compost.

Bauxite refining residue ha; a high capacity to immobilise metals in soils through

precipitation, cation exchange and chemisorption (Fe- and Al- oxides).

The first step in the study was to assess the metal adsorption capacity of red mud by

equilibrating red mud with metal solutions. Metal removal from solution proved very high.

Subsequently, the effect of red mud addition to municipal compost was studied in relation

to metal mobility. In particular the interaction of metals with the mobile soluble organic

fraction, the humic and fulvic acids, was investigated. It was found that most metals

remained in the insoluble humin fraction and the metals in solution remained complexed to

the soluble organic fraction. Red mud appeared to be able to adsorp fulvic and humic acids

and thus indirectly immobilise the metals in solution. Red mud did not appear to be able to

transfer metals from the organic fraction to the mineral red mud fraction.

ft was kypothesised that, in order for the metals to be adsorped to red mud, the red mud

needed to be present in the organic waste prior to composting. Metal adsorption to red mud

is a rapid chemical reaction while metal complexation to the organic fraction takes a

number of weeks, since it must be sufficiently oxidised to contain functional groups

fn order to verify this hypothesis, an installation with seven incubators was developed

which allowed composting to be undertaken under computer controlled conditions and

monitored for temperature, airflow and carbon dioxide respiration. The incubators were

filled with 10 kg of a mixture of grass clippings and sawdust. The first incubator functioned

as a control. The contents of the rest of the incubators were spiked with the following

metals: Cd, Cr, Cu, Ni, Pb and Zn. In addition the contents of the 3rd - 7th incubators were

amended with an increasing percentage of red mud, respectively 10,20,25,30 and 40 % by

weight. After the mixture was composted, the metal mobility was reduced by approx. 80 -

99 %, depending on the metal. The mobility was assessed as leachable and plant available

in relation to the total metal content. Red mud did not affect the composting process if < 40

% red mud was added.

The next step was to compost municipal organic waste in a pilot plant (capacity 5 m3) using

batches with and without red mud. Mixed waste was collected from 150 households and

the glass, metal and plastic fractions were removed bx- manual sorting. The rest was

composted.

The red mud - compost had a relatively lower metal content and a reduced metal mobility

compared to compost without red mud. The red mud - compost also had a 300 times higher

pH buffer capacity and 90 O/O less soluble organic matter.

The addition of red mud prior to composting was found to reduce the concentration and

mobility of metals in compost, improve the quality of compost as a soil conditioner,

increased the resistance of the organic fraction against further breakdown and this process

thus adds value to both red mud and organic waste.

I would like to acknowledge the assistance and support of the following persons, who in

many different ways provided assistance and support in carrying out this research effort.

- Associate Professor Goen E. Ho for supervision and intellectual stimulation.

- Ms Hillary Capolingua for personal support and regular distractions.

- Mr Don Glenister, Alcoa of Australia, for taking an interest in the research and

provision of financial support.

- Mr Stephan Frodsham, Department of Commerce and Trade, WA Government for

support and financial assistance.

- Mr Wally Piscetek, City of Perth, for his enthusiasm and provision of engineering

and financial support.

- Technical staff at Environmental Science for construction of equipment and

challenging technical discussions.

- Ms Marcia Hawdon, who is now an expert in deciphering and digihsing my

handwriting.

Appendix 3.Ia Raw data of the adsorption experiment for individual metals with red mud gypsum, including initial (Ci) and final (Ce) metal concentration in mg/l, solubility product (Ks), amount of metal adsorbed (q in mg/100 g), and the calculated amount adsorbed according to the Langmuir and Freundlich equations.

Ci pH Ce Ks q q Langmuir q Freundlich Cadmium

0 8.31 0.00 0.0 0 0 0 50 8.37 0.04 6.5E-24 24.98 28.65 30.15

100 8.35 0.07 1.2E-23 49.965 47.67 46.84 150 8.32 0.10 2.0E-23 74.95 64.91 62.03 200 7.89 0.18 2.7E-22 99.91 103.87 98.54 400 8.2 0.50 1.8E-22 199.75 199.80 220.28

Chromium Copper Lead

pH Ce q pH Ce q pH Ce q 8.32 0 0 8.32 0 0 8.31 0 0 8.25 0 25 8.32 0 25 8.3 0 25 8.11 0 50 8.29 0 50 8.07 0 50 8 0 75 8.23 0 75 8.29 0 75 7.95 0 100 8.16 0 100 8.3 0 100 7.71 0 200 8.01 0 200 8.26 0 200 Nickel

pH Ce Ks q q Langmuir q Freundlich 8.34 0 0 0 0 0 8.3 0.06 2.6E-23 24.97 25.6 27.41 8.27 0.14 6.9E-23 49.93 55.21 53.41 8.18 0.19 1.4E-22 74.905 71.55 67.93 8.15 0.27 2.3E-22 99.865 94.82 89.59 7.88 0.86 2.6E-21 199.57 201.77 223.06

Zinc 8.32 0 0 0 0 0 8.29 0.01 4.0E-24 24.99 18.66 24.07 8.25 0.04 1.9E-23 49.98 65.14 63.45 8.21 0.04 2.3E-23 74.98 65.14 63.45 8 17 0 08 5 6E-23 99 96 111 41 103 02

Appendix 3.Ib Raw data of the adsorption experiment for individual metals with acid neutralised red mud including pH, initial (Ci) and final (Ce) metal concentration in mg/l, solubility product (Ks), amount of metal adsorbed (q in mg/100 g), and the calculated amount adsorbed according to the Langmuir and Freundlich equations.

metal Ci pH Ce Ks q q Langmuir q Freundlich Cd 0 5.65 0 0 0 0 0

50 5.92 0.78 1.0E-17* 24.61 11.69 27.26 100 5.8 3.97 8.9E-17* 48.02 44.08 45.84 150 5.75 10.61 3E-16* 69.70 76.52 62.76 200 5.56 24.38 1.6E-15* 87.81 101.81 81.87 400 5.5 142 1.3E-14* 129.00 129.04 143.75

Cr 6.13 0 0 0 0 0 5.63 0 0 25 0 0 5.43 0 0 50 0 0 5.12 0 0 75 0 0 5.03 0.25 3.9E-21* 99.875 158.73 98.11 4.46 9.9 7.9E-18* 195.05 194.92 190.14

Cu 6 0 0 0 0 0 5.87 0.09 2.6E-18 24.955 5.79 29.33 5.74 0.46 2.4E-17 49.77 25.8 45.58 5.56 1.79 2.1E-16 74.11 68.83 65.81 5.37 5.88 1.7E-15 97.06 114.93 90.76 4.9 80.6 2.0E-13* 159.7 157.83 184.16

Pb 6.13 0 0 6 0 25 5.92 0 50 5.93 0 75 5.24 0 100 5.55 0 200

* near or exceeds Ks value

metal Ci pH Ce Ks q q Langmuir q Freundlich Ni 0 6.14 0 0 0 0 0

50 6.03 12.79 1.90E-16 18.605 12.73 18.42 100 5.96 40.02 8.20E-16 29.99 27.79 30.06 150 5.89 71.36 2.02E-15 39.32 36.75 38.53 200 5.82 105 4.10E-15 47.5 42.34 45.47 400 5.5 263.9 4.49E-14* 68.05 52.54 67.54

Zn 6.12 0 0 0 0 0 5.96 1.4 2.57E-17 24.3 11.45 26.54 5.86 7.57 2.21E-16 46.215 42.86 44.06 5.72 20.39 1.13E-15* 64.805 70.45 59.33 5.62 45.84 4.03E-15* 77.08 89.29 75.67 5.44 187 3.77E-14* 106.5 106.52 115.42


Appendix 3.Ic The raw data of the preferential metal adsorption experiment with red mud gypsum, including pH, initial (Ci) and final (Ce) metal concentration in mg/l, solubility product (Ks), amount of metal adsorbed (q in mg/100 g), and the calculated amount adsorbed according to the Langmuir and Freundlich equations.

Ci pH Ce Ks q q Langmuir

q Freundlich

Cadmium

0 8.32 0 0 0 0 0

8.5 8.3 0.02 4.5E-24 4.24 5.85 5.7

17 8.22 0.03 9.7E-24 8.49 9.74 10.64

25.5 8.17 0.03 1.2E-23 12.74 9.74 10.64

34 8.17 0.03 1.2E-23 16.99 9.74 10.64

68 8 0.07 6.2E-23 33.97 40.68 39.19

Chromium Copper Lead Ce q Ce q Ce q

0 0 0 0 0 0 0 4.25 0 4.25 0 4.25 0 8.5 0 8.5 0 8.5 0 12.75 0 12.75 0 12.75 0 17 0 17 0 17 0 34 0 34 0 34

Nickel

Ce Ks q q Langmuir q Freundlich

0 0 0 0 0

0 0 4.25 0 0

0 0 8.5 0 0

0 0 12.75 0 0

0.01 7.8E-24 17 27.85 17

0.11 1.9E-22 33.95 33.75 34.1

Zinc

Ce Ks q q Langmuir q Freundlich 0 0 0 0 0 0 0 4.25 0 0 0 0 8.5 0 0

Appendix 3.Id The raw data of the preferential metal adsorption experiment with acid neutralised red mud including pH, initial (Ci) and final (Ce) metal concentration in mg/l, solubility product (Ks), amount of metal adsorbed (q in mg/100 g), and the calculated amount adsorbed according to the Langmuir and Freundlich equations.

Cadmium Ci pH Ce Ks q q langmuir q Freundlich

0 6.03 0 0 0 0 0 8.5 5.82 0.1 2.0E-18* 4.20 2.15 4.89 17 5.7 0.49 1.7E-17* 8.26 7.65 7.89

25.5 5.61 1.43 7.7E-17* 12.04 13.46 10.88 34 5.53 3.05 2.4E-16* 15.48 17.03 13.66 68 5.17 24.87 1.0E-14* 21.57 21.45 25.65

Chromium Copper Lead

Ce q Ce q Ce q 0 0 0 0 0 0 0 4.25 0 4.25 0 4.3 0 8.5 0 8.5 0 8.5 0 12.75 0 12.75 0 12.8 0 17 0 17 0 17 0 34 0 34 0 34 Nickel

Ce Ks q q langmuir q Freundlich 0 0 0 0 0 1.94 7.6E-17 3.28 3.27 4.21 5.67 3.8E-16 5.665 5.07 4.62 13.93 1.4E-15* 5.785 6.11 4.99 20.36 3.0E-15* 6.82 6.39 5.16 59.6 4.6E-14* 4.2 6.84 5.66

Zinc

Ce Ks q q langmuir q Freundlich 0 0 0 0 0 0.13 4.6E-18 4.185 2.01 4.88 0.78 4.7E-17 8.11 7.65 7.64 1 98 1 8E-16 11 76 11 6 9 64

Appendix 3.II

The constants for the Langmuir (K, Q) and Freundlich (k, n) equation for the individual

and the mixed isotherms, including the correlation coefficient (r2) for RMG and RMA for

individual and mixed metal concentrations (0 - 400 mg/l).

0-400 ppm Langmuir Freundlich

Q K r2 k n r2

ind - RMG

Cd 416.67 1.85 0.94 380.19 1.27 0.97

Ni 416.67 1.09 0.95 251.19 1.27 0.98

Zn 384.62 5.10 0.87 602.56 1.43 0.96

ind - RMA

Ni 83.33 0.02 0.98 6.17 2.33 1

Zn 112.36 0.08 0.99 23.99 3.33 0.98

Cd 135.14 0.12 1 29.51 3.13 0.98

Cu 163.93 0.41 0.99 56.23 3.7 0.96

Cr 196.08 17.00 0.99 125.89 5.56 1.00

Mix - RMG

Zn 34.48 460.32 0.95 125.89 2.33 1

Ni 34.48 420.29 0.99 64.57 3.45 1

Cd -29.41 -8.29 0.29 2344.23 0.65 0.83

Mix - RMA

Zn 17.54 1.00 1 8.13 4 0.93

Ni 7.14 0.44 0.99 3.98 11.63 0.15

Cd 22.22 1.07 1 9.77 3.33 0.95

Appendix 3.IIIa The raw data of the adsorption experiment with a solution/red mud gypsum ratio of 5 including pH, initial (Ci) and final (Ce) metal concentration in mg/l, solubility product (Ks), amount of metal adsorbed (q in mg/100 g red mud), and the calculated amount adsorbed according to the Langmuir and Freundlich equations. Metal Ci pH Ce Ks q q

Langmuir q

Langmuir, Ce = 0

q Freundlich

Cd 0 8.12 0 0.0E+00 0 0 0 100 8.18 0.12 4.7E-23 49.94 40.11 54.18 200 8.26 0.36 9.7E-23 99.82 106.65 101.5 500 8.05 1.26 8.9E-22 249.37 261.71 207.66 800 7.67 4.04 1.6E-20* 397.98 436.32 404.11 1000 7.79 7.1 1.7E-20* 496.45 501.71 557.74 Cr 0 8.35 0.01 0.0E+00 -0.005 -0.01 0 16.87 100 8.25 0.03 4.8E-32 49.985 -0.05 88.87 61.43 200 8.20 0.07 1.6E-31* 99.965 -0.17 190.37 166.45 500 8.00 0.06 5.3E-31* 249.97 -0.13 166.59 138.85 800 7.88 0.12 2.5E-30* 399.94 -0.93 296.05 313.82 1000 7.78 0.21 8.6E-30* 499.895 0.56 443.88 606.19 Cu 0 8.21 0.06 0.0E+00 -0.03 -0.08 0 24.12 100 8.20 0.15 5.3E-23 49.925 -0.26 114.93 80.52 200 8.23 0.15 4.6E-23 99.925 -0.26 114.93 80.52 500 8.15 0.27 1.2E-22 249.865 -0.70 198.94 174.5 800 8.02 0.47 3.8E-22 399.765 -7.41 325.49 361.87 1000 8.03 0.71 5.5E-22 499.645 2.20 458.61 622.71 Pb 0 8.49 0.01 1.1E-23 -0.005 -0.02 0 51.9 100 8.49 0.01 1.3E-22 49.995 -0.02 73.53 51.9 200 8.51 0.02 3.4E-22 99.99 -0.03 134.23 98.02 500 8.44 0.06 5.9E-21 249.97 -0.22 298.5 268.56 800 8.40 0.09 5.9E-20 399.955 -2.36 374.99 389.57 1000 8.31 0.12 3.9E-19 499.94 0.61 430.09 507.24 * near or exceeds Ks value

Metal Ci pH Ce Ks q q

Langmuir q

Langmuir, Ce = 0

q Freundlich

Ni 0 8.35 0.06 0.0E+00 -0.03 14.48 5.7 26.87 100 8.31 0.60 9.3E-25 49.7 0.15 51.51 69.03 200 8.25 1.22 1.7E-24 99.39 0.14 94.3 92.34 500 7.94 5.00 7.0E-24 247.5 0.13 240.38 164.61 800 7.81 27.4 1.3E-23 386.3 0.13 406.56 330.54 1000 7.69 105 2.6E-23 447.5 0.13 458.9 573.24 Zn 0 8.27 0.04 1.0E-23 -0.02 -0.08 30.83 46.67 100 8.33 0.06 1.2E-23 49.97 -0.12 45.06 58.53 200 8.29 0.12 2.8E-23 99.94 -0.24 83.75 86.21 500 8.15 0.73 3.3E-22 249.635 -1.89 296.3 236.4 800 8.10 1.51 8.5E-22 399.245 -6.47 399.26 354.81 1000 7.99 3.67 3.4E-21 498.165 19.38 493.78 582.72

Appendix 3.IIIb The raw data of the adsorption experiment with a solution/red mud gypsum ratio of 100 including pH, initial (Ci) and final (Ce) metal concentration in mg/l, solubility product (Ks), amount of metal adsorbed (q in mg/100 g red mud), and the calculated amount adsorbed according to the Langmuir and Freundlich equations. Metal Ci pH Ce Ks q q Langmuir q Freundlich Cd 0 7.12 0 0.0E+00 0 0 0 100 6.67 7.3 3.0E-18* 927 326.97 875.68 200 6.29 53.3 1.2E-16* 1467 1575.49 1639.51 500 5.96 253 2.7E-15* 2470 3019.95 2679.7 800 5.85 470 8.4E-15* 3300 3404.6 3257.9 1000 5.92 622 8.0E-15* 3780 3532.81 3558.99 Cr 0 7.04 0 0.0E+00 0 0 0 100 7.06 0.03 1.8E-28* 999.7 1084.22 1121.34 200 7.03 0.06 4.3E-28* 1999.4 2017.52 1808.61 500 6.70 0.16 1.1E-26* 4998.4 4366.96 3557.27 800 6.60 0.53 7.5E-26* 7994.7 8525.59 8125.41 1000 6.49 0.75 2.3E-25* 9992.5 9696.94 10323.7 Cu 0 7.46 0 0.0E+00 0 0 0 100 7.29 0.122 2.9E-21 998.78 885.32 1074.21 200 7.22 0.266 8.6E-21 1997.34 1809.36 1852.76 500 6.96 1.45 1.6E-19 4985.5 6509.77 6065.19 800 6.85 1.81 3.2E-19 7981.9 7364.67 7082.63 1000 6.96 2.99 3.2E-19 9970.1 9307.66 10060.91 Pb 0 7.35 0 0.0E+00 0 0 0 100 7.44 0.13 1.3E-18* 998.7 1247.31 1296.06 200 7.50 0.15 2.5E-18* 1998.5 1469.07 1572.57 500 7.28 0.38 9.4E-18* 4996.2 4888.49 5522.56 800 7.03 0.54 1.4E-17* 7994.6 8884.59 8879.13 1000 6.93 0.55 1.9E-17* 9994.5 9209.68 9102.05 * near or exceeds Ks value

Metal Ci pH Ce Ks q q Langmuir q Freundlich Ni 0 7.11 0 0.0E+00 0 0 0

100 7.09 21.4 1.5E-21 786 355.85 706.3 200 7.24 85.3 1.3E-21 1147 1130.36 1262.74 500 7.26 348 9.3E-21 1520 2513.28 2279.71 800 7.24 470 4.2E-20 3300 2802.24 2586.55 1000 7.24 651 6.8E-20 3490 3083.39 2965.97

Zn 0 7.33 0 0.0E+00 0 0 0 100 7.17 2 8.1E-20 980 306.09 854.73 200 6.88 17.6 2.7E-18 1824 2125.3 2296.88 500 6.56 108 7.3E-17* 3920 5867.62 5239.38 800 6.61 118 6.3E-17* 6820 6043.19 5454.58 1000 6.58 192 1.2E-16* 8080 6902.94 6805.51


Appendix 3.IV The constants of the Langmuir and Freundlich equations for metal adsorption onto red mud gypsum in a solution to solid ratio of 5 and 100 respectively.

ratio Langmuir Freundlich 5 r2 Q K r2 k n

Cd 0.98 625.00 0.57 0.99 181.97 1.75 Cr 0.25 0.18 -6.99 0.8 3801.89 0.85 Cu 0.23 0.62 -1.96 0.88 977.24 0.76 Pb 0.20 0.13 -10.54 0.99 3548.13 1.09

Pb* 0.71 27.32 183.92 Ni 0.14 0.13 -16.82 0.9 85.11 2.44

Ni* 1.00 476.19 0.20 Zn 0.12 5.08 -0.37 0.98 281.84 1.79

Zn* 0.99 591.72 1.37

100 Cd 0.96 4000.00 0.01 0.98 467.74 3.17 Cr 0.98 14492.75 2.70 0.97 12589.25 1.45 Cu 0.79 15625.00 0.49 0.98 4677.35 1.43 Pb 0.56 -9433.96 -0.90 0.96 20417.38 0.74 Ni 0.61 4166.67 0.00 0.84 194.98 2.38 Zn 0.71 8928.57 0.02 0.93 623.73 2.2

*Calculation of constants for the Langmuir equation assuming Ce = 0, ie. no desorption taking place.

Appendix 4.I The solubilisation of cadmium, lead, zinc, nickel and copper in a water extract of compost amended with increasing amounts of red mud (RM) or red mud gypsum (RMG).

added (g) pH [Cd]* Ks@ Cd [Cd]# [Pb]* Ks Pb [Pb]# [Zn]* Ks Zn [Zn]# [Ni]* Ks Ni [Ni]# [Cu]* Ks Cu [Cu]# RM 0 7.52 0.03 2.7e-20 0 1.17 6.2e-19 0 0.68 1.1e-18 0.82 0.69 1.3e-18 0 0.61 1.1e-18 0.71

1 7.67 0.02 4.3e-20 0 1.17 1.2e-18 0 0.37 1.2e-18 0.41 0.69 2.6e-18 0 0.52 1.8e-18 0.56 2 7.77 0.02 6.8e-20 0 1.12 1.9e-18 0 0.24 1.3e-18 0.26 0.73 4.3e-18 0 0.46 2.5e-18 0.53 3 7.86 0.02 1.0e-19 0 1.12 2.8e-18 0 0.16 1.3e-18 0.18 0.85 7.6e-18 0 0.41 3.4e-18 0.46 4 7.91 0.02 1.3e-19 0 1.12 3.6e-18 0 0.14 1.4e-18 0.22 0.81 9.1e-18 0 0.39 4.1e-18 0.55 5 7.99 0.02 2.0e-19 0 1.12 5.2e-18 0 0.10 1.5e-18 0.13 0.81 1.3e-17 0 0.37 5.5e-18 0.44

RMG 0 7.52 0.03 2.7e-20 0.00 1.17 6.2e-19 0 0.68 1.1e-18 0.82 0.69 1.3e-18 0 0.61 1.1e-18 0.71

1 7.68 0.02 4.0e-20 0.00 1.17 1.3e-18 0 0.37 1.3e-18 0.42 0.81 3.2e-18 0 0.51 1.8e-18 0.57 2 7.83 3 7.88 0.03 1.5e-19 0.00 1.22 3.4e-18 0 0.19 1.7e-18 0.23 0.98 9.6e-18 0 0.51 4.6e-18 0.61 4 7.93 0.02 1.3e-19 0.00 1.26 4.4e-18 0 0.15 1.7e-18 0.27 1.06 1.3e-17 0 0.46 5.3e-18 0.59 5 7.96 0.03 1.9e-19 0.00 1.22 4.9e-18 0 0.13 1.6e-18 0.18 1.11 1.6e-17 0 0.46 6.1e-18 0.54

* Concentration in compost-red mud extracts # Concentration after humic acid removal @ Ks is the solubility product of the metal hydroxide in each sample.

Appendix 4.II The solubilisation of cadmium, lead, zinc, nickel and copper and humic acid adsorption in water extracts of compost after two hours equilibrating with increasing amounts of red mud (RM) or red mud - gypsum (RMG).

RM added (g) pH [Cu]* Ks@ Cu [Cu]# [Zn]* Ks Zn [Zn]# [Ni]* Ks Ni [Ni]# [Pb]* Ks Pb [Pb]#

0 7.68 0.61 2.2E-18 0.66 0.9 3.2E-18 0.9 0.31 1.2E-18 0 0.8 8.8E-19 0 1 8.38 0.32 2.9E-17 0.41 0.05 4.4E-18 0.06 0.44 4.3E-17 0 0.7 1.9E-17 0 2 8.53 0.24 4.3E-17 0.36 0.06 1.1E-17 0.07 0.44 8.6E-17 0 0.6 3.3E-17 0 3 8.58 0.21 4.8E-17 0.33 0.05 1.1E-17 0.06 0.44 1.1E-16 0 0.6 4.2E-17 0 4 8.62 0.18 4.9E-17 0.3 0.05 1.3E-17 0.06 0.44 1.3E-16 0 0.7 5.9E-17 0 5 8.77 0.19 1.0E-16 0.3 0.04 2.1E-17 0.06 0.44 2.6E-16 0 0.8 1.3E-16 0

* Concentration in compost-red mud extracts # Concentration after humic acid removal @ Ks is the solubility product of the metal hydroxide in each sample.

Appendix 4.III

Data of the column leaching experiment for nickel, copper and zinc.

red mud red mud - gypsum

pore volume [Ni] mg/l mgs pore volume [Ni] mg/l mgs

0.08 0.33 2.55 0.11 0.24 2.55

0.29 0.54 10.95 0.31 0.37 7.15

0.54 1.21 29.22 0.54 0.86 19.11

0.87 2.43 77.46 0.89 1.40 47.33

1.17 1.25 36.22 1.22 0.38 12.11

1.45 0.53 14.34 1.51 0.12 3.36

1.69 0.33 7.65 1.77 0.10 2.51

1.85 0.27 4.17 1.94 0.10 1.64

2.16 0.20 5.99 2.31 0.08 2.86

2.49 0.13 4.14 2.72 0.00 0.00

2.66 0.10 1.64 3.32 0.00 0.00

2.99 0.10 3.19 3.92 0.00 0.00

3.38 0.07 2.64 5.32 0.00 0.00

3.63 0.07 1.69 7.65 0.00 0.00

4.12 0.00 0.00 9.39 0.00 0.00

4.58 0.00 0.00

7.10 0.00 0.00

9.60 0.00 0.00

Total (mg) 201.87 98.63


pore volume [Cu] mg/l mgs pore volume [Cu] mg/l mgs

0.08 0.28 2.16 0.11 0.31 3.29

0.29 0.38 7.71 0.31 0.22 4.25

0.54 0.31 7.49 0.54 0.35 7.78

0.87 0.64 20.40 0.89 0.38 12.85

1.17 1.16 33.62 1.22 0.17 5.42

1.45 0.80 21.64 1.51 0.05 1.40

1.69 0.42 9.74 1.77 0.00 0.00

1.85 0.35 5.41 1.94 0.00 0.00

2.16 0.26 7.79 2.31 0.00 0.00

2.49 0.15 4.78 2.72 0.00 0.00

2.66 0.13 2.13 3.72 0.00 0.00

2.99 0.24 7.65 6.29 0.00 0.00

3.38 0.17 6.40 8.00 0.00 0.00

3.63 0.06 1.45 9.39 0.00 0.00

4.12 0.04 1.89

4.58 0.07 3.11

5.63 0.00 0.00

7.77 0.00 0.00

9.60 0.00 0.00

Total leached 143.37 34.99


pore volume [Zn] mg/l mgs pore volume [Zn]

mg/l

mgs

0.08 0.12 0.93 0.11 0.08 0.85

0.29 0.24 4.87 0.31 0.12 2.32

0.54 0.82 19.80 0.54 0.21 4.67

0.87 2.14 68.22 0.89 0.30 10.14

1.17 2.09 60.57 1.22 0.33 10.52

1.45 1.07 28.94 1.51 0.12 3.36

1.69 0.80 18.55 1.77 0.11 2.76

1.88 0.68 12.48 1.94 0.10 1.64

2.16 0.49 13.25 2.31 0.13 4.65

2.49 0.34 10.84 2.72 0.12 4.75

2.66 0.31 5.09 2.92 0.11 2.13

2.99 0.24 7.65 3.32 0.10 3.86

3.38 0.32 12.06 3.72 0.07 2.70

3.63 0.18 4.35 4.32 0.07 4.06

4.12 0.09 4.26 4.85 0.07 3.58

4.58 0.07 3.11 5.32 0.08 3.63

5.01 0.07 2.91 5.81 0.05 2.37

5.63 0.06 3.59 6.29 0.05 2.32

6.36 0.06 4.23 7.01 0.05 3.48

7.10 0.06 4.29 7.65 0.05 3.09

8.58 0.05 7.15 8.00 0.04 1.35

9.60 0.05 4.93 8.45 0.04 1.74

8.77 0.04 1.24

9.09 0.04 1.24

9.39 0.05 1.45

Appendix 5.I

COMPUTER PROCESS CONTROL PROGRAM

'Temperature/Valve control program

'If the temperature > 55degC a solenoid valve

'is turned open else the valve is closed

'

'The array specifies which connection of port E

'is used and what mode they are in i.e

'single-ended uni-polar mode A/D conversion

'

'Main program

'MaxRTNo = number of pt100 temperature probes

MaxRTNo=7

DIM DataChannel$(1:7),VOpen(1:7),D(1:7),CO2(1:7),Topen(1:7),T(1:7),Vn(1:7),T1(1:7)

cls

open"com1:300,n,8,2,rs,cs,ds,cd " as #1

MuxChannel$(1) ="M0"






MuxChannel$(MaxRTNo) ="M6"

call InitializeTimer

call initializeValvePosition(VPos)

for VP= 1 to 14

print " "

next VP

print "end"

end

Sub

testtemp(MChannel$(1),MaxRTNo,VOpen(1),VData(1),D(1),CO2(1),VPos, T(1))

RTNo = 0

for RTNo = 1 TO MaxRTNo

print #1,MChannel$(RTNo)

3 if input$(1,1) <> ":" then 3

print #1,"E0U?"

line input #1,echo$

line input #1,InputValue$

M = val(InputValue$)

7 if input$(1,1) <>":" then 7

if RTNo=1 then M=0.1183*M-11.17

if RTNo=2 then M=0.1098*M-8.4






InputValue=M

Vdata(RTNO)=m

if InputValue > 55 then

call OpenValve(RTNo-1)

if Vopen(RTNo) =0 then Topen(RTNo)=timer

Vopen(RTNo)=1

else

if Vopen(RTNo)=1 then

VOpen(RTNo)=0

end if

if RTNo=7 then

print date$,time$

for No= 1 to 7

print using "##.# ";Vdata(No);

next No

end if

next RTNo

end sub

Sub CloseValve(RT)

c$ = "A" + CHR$(48+RT) + "OFF"

print #1,c$

4 if input$(1,1) <> ":" then 4

end sub

Sub OpenValve(RT)

t$="A" + CHR$(48+RT) + "ON"

print #1,t$

5 if input$(1,1) <> ":" then 5

end sub

Sub InitializeTimer

input "What the date is today (mm-dd-yy)=",d$

date$=d$

input "What the time is now (hh:mm:ss)=", t$

time$=t$

end sub

Sub Rotate12Valve(VPos,VOpen(1),VData(1),D(1),CO2(1),T(1),Vn(1))

t&=timer/150

VPos=VPos+1

if VPos=8 then call datafile(Vdata(),D(),CO2(),T(),Vn())

else

call closeValve(7)

end if

if VPos=13 then VPos=1

end sub

Sub valve12

print #1,"E0U?"

line input #1,echo$

line input #1,Value12$

Value12=VAL(Value12$)

if 12thValue < 50 then

end sub

Sub initializeValvePosition(VPos)

input "Initial valve Position=", VPos

end sub

Sub O2data(VOpen(1),Vdata(1),D(1),CO2(1),VPos,Vn(1))

print #1, "D0?"

line input #1,echo$

line input #1,D$

D=val(D$)

D(VPos)=D*0.1894-0.6

80 if input$(1,1) <> ":" then 80

print #1, "D1?"

line input #1, echo$

line input #1, C$

print using " ##.# ";VPos,D(VPos),Vn(VPos)

end sub

Sub datafile(Vdata(1),D(1),CO2(1),T(1),Vn(1))

open "d3.bas" for append as #2

print #2, date$,time$,"(hours:minutes:seconds)"

print #2," Bin No. Vopen Temp O2 % CO2 % Topen(min)"

for bin = 1 to 7

T(bin)=T(bin)/60

print #2,using " # ";bin,Vn(bin);

print #2,using " ##.# ";Vdata(bin),D(bin),CO2(bin),T(bin)

T(bin)=0.0

next

close #2

print "this test" ,Vn(7)

end sub

Appendix 6.Ia

A univariate F-test with (1,6) degrees of freedom to test the significance of the effect of

time, during composting, on the mobility of heavy metals.

metal Hypoth.

SS

Error SS Hypoth.

MS

Error

MS

F Sign. of F

(α)

Chromium

CaCl2 1.06 0.05 1.06 0.01 123.03 0.00

DTPA 0.18 0.02 0.18 0.00 48.41 0.00

Cadmium

CaCl2 0.08 0.00 0.08 0.00 7123.36 0.00

DTPA 0.35 0.19 0.35 0.03 11.04 0.02

Copper

CaCl2 0.08 0.00 0.08 0.00 7123.36 0.00

DTPA 0.35 0.19 0.35 0.03 11.04 0.02

Nickel

CaCl2 10.35 0.19 10.35 0.03 326.27 0.00

DTPA 0.48 0.40 0.48 0.07 7.31 0.03

Lead

CaCl2 0.05 0.02 0.05 0.00 14.02 0.01

DTPA 4.44 0.84 4.44 0.14 31.61 0.00

Zinc

CaCl2 1430.20 4.98 1430.20 0.83 1721.59 0.00

DTPA 25.50 805.95 25.50 134.32 0.19 0.68

Appendix 6.Ib

Test of the significance of the effect of red mud addition on the mobility of heavy metals

using sequential sums of squares and simple regression. Repeated measures over time

(6) treated as replicates.

metal Sum of

Squares

Degrees

Freedom

Mean

Squares

F Sign. of F

(α)

Chromium

CaCl2 18.66 5 3.73 342.94 0

DTPA 94.25 5 18.85 10243.4 0

Cadmium

CaCl2 1.09 5 0.22 4356 0

DTPA 245.94 5 49.19 3044.42 0

Copper

CaCl2 1.09 5 0.22 4356 0

DTPA 245.94 5 49.19 3044.42 0

Nickel

CaCl2 66.51 5 13.3 3231.16 0

DTPA 1168.5 5 233.7 5367.6 0

Lead

CaCl2 7.96 5 1.59 105.6 0

DTPA 768.44 5 153.69 405.62 0

Zinc

CaCl2 40335.1 5 8067.02 7460.65 0

DTPA 957003.31 5 191400.66 6057.79 0

Appendix 6.IIa Leachable Metals

Appendix 6.IIa Leachable metals in mg/kg dry matter.

Metal Time (d) Control Blank 10% 20% 25% 30% 40% Time effectmean stand.dev. stand. error

Zinc 0 9.7 98.5 27.2 5.7 4.0 3.7 7.88.6 91.8 29.7 6.2 3.6 4.5 4.5 9.7 10.0 3.2

3 9.9 99.4 20.5 3.1 4.3 4.9 3.610.1 102.7 18.0 3.0 4.0 4.9 4.0 7.0 6.5 2.1

6 5.3 70.4 21.3 4.9 3.8 5.7 7.24.8 66.0 20.7 4.6 4.0 5.8 7.6 8.6 6.7 2.1

9 8.5 73.6 11.5 6.3 4.3 3.2 6.78.4 75.9 11.8 6.2 3.7 3.1 7.2 6.4 3.2 1.0

14 4.6 45.2 22.2 9.4 3.8 3.0 4.96.6 44.2 22.1 9.2 3.4 3.1 6.1 8.7 7.5 2.4

20 4.9 35.0 12.3 7.6 3.3 1.7 5.45.2 33.0 11.3 7.2 3.8 1.7 4.9 5.9 3.7 1.2

mud effect mean 7.2 69.7 19.1 6.1 3.8 3.8 5.8stand. dev. 2.2 25.5 6.2 2.0 0.3 1.4 1.5stand. error 0.6 7.4 1.8 0.6 0.1 0.4 0.4

Chromium 0 0.0 2.7 0.2 0.0 0.0 0.0 0.00.0 2.2 0.3 0.0 0.0 0.0 0.0 0.1 0.1 0.0

3 0.0 1.0 0.0 0.0 0.0 0.0 0.00.0 0.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

6 0.0 1.6 0.0 0.0 0.0 0.0 0.00.0 1.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

9 0.0 1.4 0.0 0.0 0.0 0.0 0.00.0 1.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

14 0.0 0.7 0.0 0.0 0.0 0.0 0.00.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

20 0.0 0.2 0.0 0.0 0.0 0.0 0.00.0 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0



Copper 0 1.5 7.9 4.1 2.8 1.9 2.4 1.84.2 15.8 10.1 6.2 6.1 6.1 4.9 4.6 2.6 0.8

3 3.0 13.3 5.4 2.0 2.8 3.4 4.83.0 19.5 5.3 2.0 2.8 3.5 4.8 3.7 1.3 0.4


6 2.9 9.9 7.3 3.0 4.0 4.2 9.02.4 10.0 7.4 3.1 3.7 3.8 9.2 5.5 2.4 0.8

9 3.4 8.5 4.8 3.6 4.2 2.0 8.53.0 8.6 4.8 3.4 3.9 2.2 8.6 4.6 2.3 0.7

14 2.1 4.5 6.1 5.3 3.7 2.7 6.82.6 4.3 6.1 5.6 3.7 2.8 6.1 4.9 1.5 0.5

20 3.5 4.0 5.0 5.4 3.7 2.0 6.53.6 4.2 5.6 5.4 3.5 2.5 6.4 4.6 1.6 0.5


Cadmium 0 0.0 0.5 0.0 0.0 0.0 0.0 0.00.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

3 0.0 0.7 0.0 0.0 0.0 0.0 0.00.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

6 0.0 0.3 0.0 0.0 0.0 0.0 0.00.0 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

9 0.0 0.5 0.0 0.0 0.0 0.0 0.00.0 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

14 0.0 0.1 0.0 0.0 0.0 0.0 0.00.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

20 0.0 0.0 0.0 0.0 0.0 0.0 0.00.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0



Nickel 0 0.0 5.9 1.5 0.0 0.0 0.0 1.10.0 5.2 1.7 0.0 0.0 0.0 1.1 0.5 0.7 0.2

3 0.0 4.1 0.4 0.0 0.0 0.0 0.10.0 3.8 0.3 0.0 0.0 0.0 0.1 0.1 0.1 0.0

6 0.0 3.1 2.6 0.0 0.0 0.8 3.30.0 3.6 2.5 0.0 0.0 0.6 3.3 1.3 1.4 0.5

9 0.0 2.5 0.5 0.0 0.0 0.0 2.30.0 2.6 0.3 0.0 0.0 0.0 2.2 0.5 0.9 0.3

14 0.0 0.4 1.3 0.0 0.0 0.0 0.70.0 0.5 1.2 0.0 0.0 0.0 1.1 0.4 0.6 0.2

20 0.0 0.0 0.2 0.0 0.0 0.0 0.80.0 0.0 0.1 0.0 0.0 0.0 0.7 0.2 0.3 0.1



Lead 0 0.2 0.4 0.2 0.1 0.1 0.1 0.10.5 0.5 0.4 0.1 0.1 0.1 0.1 0.1 0.1 0.0

3 1.3 1.3 0.4 0.1 0.2 0.2 0.21.3 1.3 0.5 0.1 0.4 0.4 0.4 0.3 0.1 0.0

6 0.5 1.4 0.7 0.2 0.2 0.2 0.20.7 1.3 0.7 0.4 0.4 0.4 0.4 0.4 0.2 0.1

9 0.5 1.3 0.8 0.2 0.2 0.2 0.20.7 1.6 0.2 0.1 0.4 0.4 0.4 0.3 0.2 0.1

14 0.2 1.0 0.2 0.2 0.2 0.2 0.20.1 1.4 0.4 0.1 0.2 0.2 0.2 0.2 0.1 0.0

20 0.7 1.0 0.2 0.1 0.2 0.2 0.20.8 0.8 0.2 0.2 0.2 0.2 0.2 0.2 0.0 0.0


Appendix 6.IIb Plant Available Metals

ix 6.IIb Plant available metals in mg/kg dry matter.

Metal Time (d) Control Blank 10% 20% 25% 30% 40% Time effectmean stand. dev. stand. error

0 37.5 450.3 195.5 123.4 127.4 121.9 109.9Zinc 33.9 496.5 222.8 127.1 134.9 121.3 102.4 138.6 38.8 12.3

3 34.7 523.8 238.3 68.1 125.5 123.6 80.533.9 542.7 217.7 73.2 124.4 117.9 81.2 125.0 59.0 18.7

6 27.6 456.6 315.6 88.9 127.8 147.9 132.629.5 423.0 321.5 96.7 132.0 154.0 134.7 165.2 83.3 26.3

9 36.4 458.7 198.0 110.6 160.1 91.9 129.236.4 408.3 200.1 106.4 159.9 87.9 128.2 137.2 40.8 12.9

14 34.3 330.6 275.7 149.4 142.7 130.5 104.742.7 362.1 286.2 100.9 141.8 133.7 110.6 157.6 67.1 21.2

20 41.5 349.5 238.7 155.7 143.1 116.0 105.741.9 349.5 238.7 157.6 146.9 109.9 114.5 152.7 49.2 15.6

mean 35.9 429.3 245.7 113.2 138.9 121.4 111.2mud effect stand. dev. 4.7 71.2 44.2 30.3 12.5 19.5 18.2

stand. error 1.3 20.6 12.8 8.7 3.6 5.6 5.2

0 0.1 5.1 0.0 0.0 0.0 0.0 0.0Chromium 0.2 5.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

3 0.3 3.3 0.0 0.0 0.0 0.0 0.00.2 3.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

6 0.9 3.6 0.0 0.0 0.0 0.0 0.00.6 3.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

9 0.1 2.5 0.0 0.0 0.0 0.0 0.00.0 2.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

14 0.0 1.8 0.0 0.0 0.0 0.0 0.00.0 1.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

20 0.1 1.5 0.0 0.0 0.0 0.0 0.00.2 1.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0



Copper 0 5.1 48.7 23.5 20.1 20.9 21.0 21.26.0 52.2 25.1 21.2 23.5 21.6 19.2 21.7 1.8 0.6

3 4.4 48.1 26.4 8.2 17.4 16.8 10.84.4 47.6 23.8 7.7 18.1 16.2 10.6 15.6 6.3 2.0


6 5.0 38.5 33.8 7.8 17.3 20.5 18.65.2 40.1 33.9 7.8 18.3 22.0 18.7 19.9 8.8 2.8

9 6.5 33.0 20.4 10.6 25.9 10.4 17.86.6 33.9 20.5 10.6 25.4 9.8 17.9 16.9 6.3 2.0

14 6.6 23.5 32.0 17.3 18.9 17.1 13.65.3 24.1 31.5 16.9 20.4 17.1 13.1 19.8 6.6 2.1

20 8.0 25.1 25.4 18.1 22.4 15.3 12.18.4 25.1 24.6 18.0 23.3 15.2 13.4 18.8 4.8 1.5


Cadmium 0 0.0 6.7 4.4 2.1 3.2 1.7 3.60.0 7.5 4.0 2.1 3.5 1.8 3.6

3 0.0 6.1 4.0 1.1 1.9 1.8 1.7 3.0 1.0 0.30.0 6.0 3.9 1.3 2.0 1.8 1.7

6 0.0 8.6 4.3 2.3 3.4 4.0 5.3 2.1 1.0 0.30.0 8.4 4.1 2.4 3.5 3.6 5.4

9 0.0 8.9 4.4 2.2 2.6 2.6 1.9 3.8 1.0 0.30.0 8.8 4.4 2.3 2.7 2.3 2.0

14 0.0 8.6 4.6 3.4 2.7 2.7 1.6 2.7 0.9 0.30.0 8.4 4.6 3.6 2.7 2.6 1.6

20 0.0 7.2 4.3 4.1 3.1 2.7 2.7 3.0 1.1 0.30.0 7.3 4.5 4.0 3.2 2.8 2.6

3.4 0.7 0.2mud effect mean 0.0 7.7 4.3 2.6 2.9 2.5 2.8

stand. dev. 0.0 1.0 0.3 1.0 0.5 0.7 1.4stand. error 0.0 0.3 0.1 0.3 0.2 0.2 0.4


Nickel 0 0.0 17.1 7.9 4.3 3.8 3.9 3.00.0 18.5 7.4 4.3 4.0 3.8 2.3 3.9 1.2 0.4

3 0.0 17.2 7.2 1.2 3.0 4.0 1.90.0 16.8 8.1 0.9 3.1 3.9 1.9 2.5 3.8 1.2

6 0.0 15.1 8.3 2.9 3.7 5.9 5.50.0 14.7 8.5 2.9 4.4 6.5 5.7 4.7 1.9 0.6

9 0.0 13.2 6.6 2.6 5.3 2.2 4.90.0 13.0 6.7 2.5 5.3 2.1 5.0 3.7 1.1 0.4

14 0.0 14.3 8.1 4.3 4.0 4.2 3.10.0 13.7 8.1 4.2 4.3 4.0 3.0 3.9 3.7 1.2

20 0.0 10.7 8.0 5.7 3.9 3.3 2.20.0 10.5 7.6 5.6 4.2 3.3 2.6 3.9 3.8 1.2



Lead 0 9.8 11.2 8.0 8.1 10.8 8.7 11.59.2 12.4 8.8 8.0 13.9 9.0 10.7 9.7 1.9 0.6

3 11.3 17.7 14.9 6.5 9.5 6.3 6.310.5 18.1 13.7 6.3 9.3 6.1 6.3 8.5 3.3 1.0

6 7.1 21.3 14.0 7.5 11.0 9.5 13.48.8 22.9 13.9 7.6 11.5 10.2 13.7 11.2 2.5 0.8

9 9.0 20.1 13.5 7.5 10.0 8.7 7.59.2 19.4 13.9 7.8 9.8 8.1 7.1 9.4 2.5 0.8

14 8.7 16.1 16.1 9.0 10.3 7.3 5.89.7 16.2 15.9 9.7 11.3 7.1 5.3 9.8 3.8 1.2

20 15.4 14.7 13.0 11.7 11.8 7.3 6.814.4 15.4 13.0 11.8 11.3 8.0 7.5 10.2 2.5 0.8


Appendix 6.IIc Acid Extractable Metals

Appendix 6.IIc Acid extractable metals in mg/kg dry matter.


Zinc 0 103.1 613.7 334.7 232.3 203.4 214.4 195.5 236.1 56.8 25.43 81.1 642.0 369.8 155.1 260.6 296.9 224.9 261.5 80.1 35.86 83.7 642.0 642.8 229.1 280.1 384.0 342.0 375.6 160.6 71.89 170.9 655.7 388.2 258.5 329.4 205.5 284.3 293.2 69.5 31.114 81.6 595.8 695.3 270.1 281.1 255.9 275.9 355.6 190.1 85.020 101.6 485.6 345.2 345.2 296.9 265.4 281.6 306.8 36.7 16.4

mud mean 103.7 605.8 462.6 248.4 275.2 270.3 267.4effect stand. dev. 34.4 62.8 161.8 62.1 42.0 65.1 51.2

stand. error 14.0 25.6 66.1 25.3 17.2 26.6 20.9

Chromium 0 1.3 37.6 50.9 73.0 65.9 74.4 72.2 67.3 9.7 4.33 2.7 39.0 65.6 70.2 91.1 82.9 100.5 82.1 14.4 6.56 3.9 57.4 73.3 68.8 99.6 104.5 105.9 90.4 17.9 8.09 4.2 52.3 64.8 68.2 101.6 69.3 66.5 74.1 15.5 6.914 3.9 52.0 63.9 64.5 91.4 77.8 71.0 73.7 11.4 5.120 4.2 52.0 - 81.8 94.8 99.6 66.8 85.8 14.7 6.6


stand. error 0.5 3.3 3.3 2.4 5.3 5.8 7.3



Cadmium 0 0.2 8.9 6.9 2.8 3.7 2.8 5.4 4.3 1.8 0.83 0.2 9.2 6.6 1.4 3.4 4.2 4.8 4.1 1.9 0.86 0.2 14.5 7.2 4.0 4.9 8.2 13.3 7.5 3.7 1.69 0.2 13.8 8.7 4.1 4.6 3.9 3.7 5.0 2.1 0.914 0.2 13.1 8.5 7.0 4.0 3.6 3.7 5.4 2.3 1.020 0.2 13.1 8.7 6.0 4.3 5.4 6.4 6.2 1.7 0.7


stand. error 0.0 1.0 0.4 0.8 0.2 0.8 1.5

Copper 0 20.2 178.4 82.4 71.4 53.2 56.3 50.8 62.8 13.6 6.13 56.9 194.3 101.4 63.6 74.1 85.2 67.3 78.3 15.3 6.86 51.9 164.1 149.8 64.9 81.8 116.9 100.1 102.7 32.8 14.79 83.6 155.7 100.2 71.4 100.6 47.9 84.0 80.8 22.1 9.914 47.3 136.2 153.4 103.1 79.4 67.2 75.5 95.7 34.9 15.620 56.7 149.8 109.6 97.4 91.5 67.7 75.1 88.3 16.9 7.6


stand. error 8.3 8.5 11.8 7.0 6.6 10.1 6.7



Nickel 0 1.9 34.0 14.8 8.7 7.7 8.0 6.8 9.2 3.2 1.43 1.9 28.6 13.6 5.9 10.5 14.1 8.4 10.5 3.5 1.56 2.3 31.8 27.6 9.8 11.7 20.1 18.0 17.5 7.1 3.29 4.0 34.2 17.6 10.3 14.8 7.0 12.9 12.5 4.1 1.814 2.3 29.0 26.0 18.7 11.9 11.0 10.3 15.6 6.7 3.020 2.8 30.4 19.2 16.9 12.4 10.8 11.9 14.2 3.6 1.6


stand. error 0.3 1.0 2.4 2.0 0.9 1.9 1.6

Lead 0 32.1 62.5 43.6 24.2 29.3 21.3 38.9 31.4 9.5 4.33 34.3 59.5 35.1 25.9 29.3 27.6 30.9 29.8 3.5 1.66 33.0 75.5 40.6 28.4 33.5 44.0 63.3 42.0 13.4 6.09 33.9 62.5 47.3 29.3 38.1 31.4 26.3 34.5 8.4 3.814 27.6 62.5 47.3 38.5 29.3 25.9 27.6 33.7 9.0 4.020 32.1 70.9 43.1 38.1 30.5 33.5 39.8 37.0 5.0 2.2


stand. error 1.0 2.5 1.9 2.5 1.5 3.2 5.6

Appendix 6.III

Development of the pH level in the various mixtures during the thermophilic stage of the

composting process.

Time (d) Control Blank 10 % 20 % 25 % 30 % 40 %

0 6.34 5.98 5.94 6.43 6.47 6.45 6.61

3 7.37 7.39 7.91 8.05 7.64 7.66 7.84

6 8.58 8.23 8.24 8.37 7.94 7.74 7.67

9 7.98 7.97 7.51 7.20 7.79 7.73 7.72

14 7.72 7.72 7.53 7.64 7.70 7.51 7.73

21 7.10 7.45 7.02 7.43 7.4 7.36 7.4

Appendix 6.IV

Solubilisation of organic matter during composting; Measured as the chemical oxygen

demand of a water extract expressed in mg O/L.


0 515 535 396 277 297 227 158

3 1338 3223 996 830 1006 547 410

6 2012 2246 879 1250 879 684 352

9 2830 2130 1095 2475 1272 690 740

14 2275 1854 851 927 649 496 354

20 3702 5420 2176 2595 840 572 387

Appendix 6.V

Total organic carbon (TOC) and total nitrogen (TN) over time as a function of red mud.

Time (d) Control Blank 10% 20% 25% 30% 40%

TOC

0 362 312 336 276 258 277 252

3 307 322 338 271 278 255 200

6 296 346 281 271 237 210 172

9 311 363 314 297 220 234 216

14 359 364 279 317 216 173 174

20 317 366 320 300 236 161 188

TN

0 14.2 14.9 13.7 10.3 9.2 9.4 11.5

3 14.4 14.9 11.7 9.7 7.4 6.3 5.9

6 13.4 15.7 13.8 11.7 8.6 9.2 8.0

9 16.5 16.1 11.7 10.3 5.9 9.6 8.4

14 14.9 14.6 12.0 10.2 7.4 8.3 7.3

20 17.6 14.4 13.3 9.3 8.3 4.2 7.4

Appendix 6.VI

The net weight of the substrate in the incubators as a function of time (in kg fresh

weight).


0 10.0 10.0 11.0 12.0 12.5 13.0 14.0

3 8.2 8.4 10.1 10.0 10.5 11.6 13.2

6 7.4 7.4 9.1 9.3 9.9 10.4 12.4

9 7.2 7.2 8.9 9.1 9.7 10.1 12.1

14 7.0 7.0 8.7 8.8 9.5 9.9 12.0

20 6.7 6.7 8.3 8.6 9.1 9.7 11.6

Appendix 6.VII The components of the mass balances of each bin. All data expressed in kg.

Bin Time Moisture Dry weight

Carbon as CO2

Evaporation

Sample Total

Control 0 5.87 4.13 0.00 0.00 0.00 10.00 3 5.11 3.19 0.08 0.82 0.10 8.30 6 4.73 2.87 0.21 1.26 0.20 7.60 9 4.17 3.33 0.28 1.86 0.30 7.50 14 3.96 3.44 0.39 2.12 0.40 7.40 20 3.91 3.29 0.42 2.23 0.50 7.20 Blank 0 6.11 3.89 0.00 0.00 0.00 10.00 3 5.17 3.31 0.09 1.00 0.10 8.48 6 4.73 2.87 0.22 1.50 0.20 7.60 9 4.19 3.31 0.31 2.08 0.30 7.50 14 3.96 3.44 0.41 2.36 0.40 7.40 20 3.92 3.28 0.44 2.46 0.50 7.20 10% 0 6.15 3.85 0.00 0.00 0.00 10.00 3 5.76 3.39 0.13 0.45 0.10 9.15 6 5.58 2.72 0.27 0.71 0.20 8.30 9 5.13 3.07 0.34 1.21 0.30 8.20 14 4.95 3.15 0.44 1.45 0.40 8.10 20 4.89 2.91 0.47 1.57 0.50 7.80 20% 0 5.75 4.25 0.00 0.00 0.00 10.00 3 4.29 3.81 0.11 1.51 0.10 8.10 6 3.93 3.57 0.23 1.92 0.20 7.50 9 3.57 3.83 0.28 2.32 0.30 7.40 14 3.38 3.82 0.37 2.56 0.40 7.20 20 3.31 3.79 0.40 2.67 0.50 7.10

Bin Time Moisture Dry

weight Carbon as CO2

Evaporation

Sample Total

25% 0 6.42 3.58 0.00 0.00 0.00 10.00 3 5.40 2.68 0.12 1.08 0.10 8.08 6 5.15 2.45 0.24 1.41 0.20 7.60 9 4.96 2.54 0.31 1.66 0.30 7.50 14 4.88 2.52 0.39 1.79 0.40 7.40 20 4.86 2.24 0.41 1.90 0.50 7.10 30% 0 6.25 3.75 0.00 0.00 0.00 10.00 3 5.79 2.81 0.10 0.46 0.10 8.60 6 5.30 2.05 0.20 0.95 0.20 7.35 9 4.62 2.48 0.27 1.63 0.30 7.10 14 4.34 2.56 0.35 1.91 0.40 6.90 20 4.23 2.47 0.37 2.02 0.50 6.70 40% 0 6.81 3.19 0.00 0.00 0.10 10.00 3 6.04 3.16 0.11 0.52 0.20 9.20 6 5.78 2.62 0.21 0.80 0.30 8.40 9 4.52 3.58 0.28 0.80 0.40 8.10 14 3.46 4.54 0.35 0.91 0.50 8.00 20 2.94 4.66 0.38 1.03 0.60 7.60

Date post:	07-Aug-2020
Category:	Documents
Upload:	others
View:	0 times
Download:	0 times

PDF Printing 600 dpi - Murdoch University · - Mr Stephan Frodsham, Department of Commerce and...

Documents