1. 1School of Natural Resources, Copperbelt University, Kitwe, Zambia
Ecological restoration of mining generated wastelands using biochar technology: A potential contribution to sustainable mining in Zambia
1Stephen Syampungani, 2Olusegun Yerokun, 1Concilia Monde 1Wilson Moono, Nancy Chileshe & Nalukui Matakala
1School of Natural Resources, Copperbelt University, Kitwe, Zambia
2Zambia Open University, Lusaka

2. Preparation for mining Primary forest/woodland Tailings dam/Wasteland
Degraded site
Preparation for mining
Primary forest/woodland ?
Tailings dam/Wasteland
Stunted vegetation

3. Background Zambia has a mining history spanning over 90 years
Largest copper deposits in Africa_Zambia
6% of known copper reserves globally
48% Zambia not geologically surveyed
Global consumption & demand for most of the minerals_Projected increase
Positive
More employment/jobs???
Massive infrastructure
More money???
Massive ecological foot print: Through generation of wastelands:i) wasterocks, ii) overburden materials & iii) tailings

4. Background: Some issues
Mining generated wastelands:
An environmental problem & wastage of land
For example, Copperbelt alone
9,125 ha of wasteland
contains 791 million tons of tailings
and 20,146 ha
Contain 1,899 million tons of overburden materials
Additional 388 & 279 ha
contain 77 million tons & 40 millions of wasterock and slag respectively

5. Background: Some issues
Mining industry expanding in the recent past
New deposits of copper and other minerals such nickel, coal being discovered in many parts of the country;
Northwestern,
Central &
Southern Provinces
More areas will be affected as need for more dumping ground will increase_
More mining generated wastelands

6. Background: some issues
More and more generated wastelands remain un-vegetated /poor /stunted vegetation for many years
Poor vegetation
Limited woody plants
i) High toxicity arising from heavy metals
ii) Surface and ground water contamination

7. Background: Concepts
Attempts to re-vegetate wastelands has recorded more failures
Recorded success:
Species selection based on ability to grow and adaptation
Not ability to immobilize heavy metals
No classification of species into classes based on functional traits
Excluders
And accumulators
Therefore, postponement of environmental problem_approach

8. Approach in biochar technology application
Determination of heavy metal concentration
Cu, Co,Ba, Ni, As,Zn, Pd, Cr, V, Cd
& physical properties
CU= 12,237.33± mg/kg (Tailing samples )
± mg/kg (Overburden samples)
Cd=0.60±0.23mg/kg and 0.25±0.13mg/kg on tailings and overburden material,
Pollution load factor=
8.97 and 5.84 on the tailings and overburden material, respectively
Acidity (mean pH) =
6.0 and 4.7 for the tailings and overburden material, respectively

9. The sites have high pollution load index And are high contaminated
Conclusion
The sites have high pollution load index
And are high contaminated
Very low porosity and no humus
The need for soil amendment
biochar technology that enhance heavy metal immobilization

10. Reduced leaching on nitrogen
Increased CEC in the soil
Moderation of soil acidity
Increased water holding capacity
Increased number of soil beneficial biota
Heavy metal immobilization & sequesteration

11. Biochar sources and soil amendments
Biochar is partially corbonized organic waste:
Wood chips
Sawdust (100,000 m3
Corncobs
Chicken manure
Various proportions of biochar and effect on soil are being studied

12. BIOCHAR TECHNOLOGY AND SPECIES CLASSIFICATION
Biochar technology to be enhanced by classification of species:
Accumulators/hyperaccumulators
Excluders

13. Accumulators vs excluders
Accumulars=
absorbs metals
and tend to accumulate heavy metals
When dead heavy metals flows back into the ecosystem
Excluders
Exclude heavy metals from being absorbed
Immobilize & sequester them

14. ssyampungani@yahoo.com; syampungani@cbu.ac.zm
THANK YOU
Contact information: