1
Open pit quarries potentially represent physical risks to safety of
OPEN PIT QUARRY RESTORATION TO BIO-VIABLE LAND
Isomar Latorre1, Imiraily Hernandez1, Arelys Fonseca2, and Sangchul Hwang2
1Department of Civil Engineering and Surveying, University of Puerto Rico, Mayagüez, PR 2 Department of Chemical Engineering, University of Puerto Rico, Mayagüez, PR
Introduction Statistical ExperimentGermination Experiment
The experiment purpose is toth t lit th tMeasure Parameters:
Conclusions
Until now, not concentration of cadmium is detected inpeople and stock due to dangerous vertical pit walls or deepwater. Also, they can be a possible source of environmentalpollution from water accumulation unless properly drained.Therefore, a need exists to develop an economical andenvironmentally sound restoration. Since industrial revolutiondemands and costs for construction-grade sand and gravel hassubsequently increased. For this reason, coal combustionbyproduct (CCPs) aggregates were propose as a potentialbackfilling material.
Future Studies and DevelopmentAfter a statistical design optimization the temporal and spatial fate and transport phenomena will be tested.
S t 1 S d if t i l ill b ll t d d k d it d d t fl ill b
measure the water quality thatis infiltrated in each column bya statistical design.
Variable Parameters:
High and Low Rainfall Intensity
Vmax=60mL Vmin= 30mL
CCPs size
A(9.53cm-4.75cm)
B(4.75cm-2.36cm)
Volumetric ratio of the CCPs t t il
Measure Parameters:
If pumpkin and beans seedsgerminate spraying it water that wasfilter with CCPs aggregate.
Observe the germination behaviorwith high an low rainfall intensity.
the water samples.High concentrations of lead were found in water
samples in comparison with EPA standards for potablewater. Doubts arise with respect to the precedence ofthis heavy metal, if it is caused for the CCPs aggregateor an external source.
Obj ti
Test the feasibility of CCPs as a potential backfilling materialto restore Santa Isabel open pit quarry to bio-viable land.
Assess the potential risks in relation to contamination of soiland groundwater associated with a CCPs (Agremax).
Project Location
Columns Set-up System 1: Sandy aquifer materials will be collected and packed on-site and groundwater flow will be
simulated by pumping the local groundwater at an average linear velocity.
Ground water pump
System 2: Increasing the site soil length, measure water quality
P
System 3: Increasing top soil, CCPs, bottom soil, and site soil length measure water qualityindependently, when comes out of each material. This will be at different temperatures and different soils
to top soil
Reactors Top Soil (in) CCPs (in) Bottom Soil (in) Site Soil (in) CCPs Size Rain Intensity
R1 8 4 4 10 A High
R2 8 4 4 10 A High
R3 8 4 4 10 A Low
R4 8 4 4 10 A Low
R5 8 4 4 10 B High
R6 8 4 4 10 B High
R7 8 4 4 10 B Low
R8 8 4 4 10 B Low
R9 4 8 4 10 A High
R10 4 8 4 10 A High
The following table present how the columns were filled and which parameters change of each one.Bottom Soil
CCPs
Site Soil
Top Soil
Objectives
Germination with Water from CCPs Aggregate
Top Soil/CCPs/Bottom Soil Site Soil
Aquifer Sand
Site Soil
Soils
Santa Isabel Open Pit Quarry
Analysis and Monitoring
CCPs
depe de t y, e co es out o eac ate a s be at d e e t te pe atu es a d d e e t so sfor site specific cases evaluation.
Data will be analyze using a general linear analysis of variance (ANOVA) model.
The water quality will be measured in different aspects as pH, heavy metals concentrations, totalorganic carbon concentrations, and total heterotrophic bacteria (THB) counts.
R11 4 8 4 10 A Low
R12 4 8 4 10 A Low
R13 4 8 4 10 B High
R14 4 8 4 10 B High
R15 4 8 4 10 B Low
R16 4 8 4 10 B Low
Preliminary Results
The control reactor instead CCPs has Isabela sand.
The following graphics present weekly pH, turbidity, lead concentrations, andcadmium concentrations behavior of each reactor.
All reactors are filled with gravel and top soil.The experiment has
2 reactors with bean seeds2 reactors with pumpkin seeds1 control reactor without seeds
Water collected from the reactor with Agremax is add 3 times weekly.
V max= 105 mL, V min= 15 mLUV light approx. 10 hours per day, 20 W.
Top Soil CCPs Bottom Soil Site Soil
Site Soil Aquifer Sand Site Soil
0123456789
10
0 5 10 15 20
Water pH
3/17/2008 3/24/2008 3/26/2008 3/31/2008 4/4/2008
0.0
5.0
10.0
15.0
20.0
25.0
0 5 10 15 20
Turbidity of Water
3/17/2008 3/24/2008 3/26/2008 3/31/2008 4/4/2008
0 400Lead Concentrations
0 000Cadmiun Concentrations
Weekly Measures:Amount of water percolated to the system.Water pH Water TurbidityLead and Cadmium Concentrations
Coamo Lake(Top Soil)
Analysis and MonitoringAgremax
Mixture of fly and bottomashes with waterMain chemical components:
SiO2 + Al2O3 + Fe2O3Lime (Cao), SO3
Obtained from a local coalburning power plant
Guayama Bay(Bottom Soil)
Statistical Experiment
Germination Experiment
Native grass species to Santa Isabel will be sampled on site and planted in the pot systems.
Plant experiment will be expanded to a feasibility study in use of mango trees.Baby Mango Trees Experiment
Plant Type: Tropical Fimbry and Baby MangoPlant Amount: Less, much
Germination experiments will be conducted with mango seeds. Subject to natural weather environments;survival, physiology, and growth dynamics of the grasses, seeds, and trees will be assessed inconjunction to the spatial and temporal biochemical characteristics of leachate.
Monitored factors will be the pH, heavy metals and TOC concentrations, germination percentage, THB counts,health of plants and photosynthetic pigments leaves concentrations.
A k l d t
-0.050
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0 5 10 15 20
3/17/2008 3/24/2008 3/26/2008 3/31/2008
-0.090
-0.080
-0.070
-0.060
-0.050
-0.040
-0.030
-0.020
-0.010
0.000
0.000 5.000 10.000 15.000 20.000
3/17/2008 3/24/2008 3/26/2008 3/31/2008
This research has been supported by Natural Resource Agency. Assistance and help provided by the members of environmental engineering laboratory are greatly appreciated. Especially acknowledgments to Imiraily Hernandez, Melvin Gonzalez, Ricardo Munoz, and Mahmmud Yousef.
Dr. Sangchul Hwang, Assistant Professor
Department of Civil Engineering, UPRM
787-832-4040 ext. 3454; [email protected] Meter Atomic Absorption Spectrometry Turbidity Meter
Santa Isabel Site Soil
p
Seeds for Germination Studies
Acknowledgments
Point of Contact
For the water from CCPs aggregate analyze:Water pH Lead and Cadmium Concentrations
Beans
Mango
Pumpkin