Wendy Tyrrell - Academia.edu (original) (raw)
Papers by Wendy Tyrrell
Underground mining has occurred in the Illawarra region for more than 150 years. Over time, commu... more Underground mining has occurred in the Illawarra region for more than 150 years. Over time, community expectations about the environmental effects of mining and other developments have changed dramatically. It is in this context that community, government, and environmental groups have raised concerns about the effects that mining can have on rivers and other natural features, residential property, and infrastructure, such as transmission lines, roads, and bridges. On natural features, these effects can include fracturing of the rock bedding in the river, water loss to the shallow sub-strata, gas release, rock falls, and vegetation dieback. In the past, mine planning has considered potential effects on engineered structures, however, the same attention has not been paid to the effects of mining on natural features. Through a Stakeholder Involvement Programme conducted by Illawarra Coal, it was identified that government and community stakeholders were seeking a more sensitive approa...
The large number of wetlands treating mining wastewaters around the world have mostly been constr... more The large number of wetlands treating mining wastewaters around the world have mostly been constructed in temperate environments. Wetlands have yet to be proven in low rainfall. high evaporation environments and such conditions are common in many parts of Australia. BHP Australia Coal is researching whether wetlands have potential in central Queensland to treat coal mining wastewaters. In this region. mean annual rainfall is < 650 mm and evaporation> 2 000 mm. A pilot-scale wetland system has been constructed at an open-cut coal mine. The system comprises six treatment cells. each 125 m long and 10 m wide. The system is described in the paper and some initial results presented. Results over the first fourteen months of operation have shown that although pH has not increased enough to enable; reuse or release of the water. sulfate reduction has been observed in parts of the system. as shown by the characteristic black precipitate and smell of hydrogen sulfide emanating from the wetlands. These encouraging signs have led to experiments aimed at identifying the factors limiting sulfate reduction. The fll'St experiment, described herein, included four treatments where straw was overlain by soil and the water level varied, being either at the top of the straw, at the top of the soil, or about S em above the soil. The effect of inoculating with sulfate-reducing bacteria was investigated. Two controls were included, one covered and one open, to enable the effect of evaporation to be determined. The final treatment consisted of combined strawlcattle manure overlain with soil. Results showed that sulfate reduction did occur, as demonstrated by pH increases and lowering of sulfate levels. Mean pH of the water was significantly higher after 19 days; in the controls, pH was < 3.3, whereas in the treatments, pH ranged from S.4 to 6.7. The best improvement in sulfate levels occurred in the straw/cattle manure treatment.
Underground mining has occurred in the Illawarra region for more than 150 years. Over time, commu... more Underground mining has occurred in the Illawarra region for more than 150 years. Over time, community expectations about the environmental effects of mining and other developments have changed dramatically. It is in this context that community, government, and environmental groups have raised concerns about the effects that mining can have on rivers and other natural features, residential property, and infrastructure, such as transmission lines, roads, and bridges. On natural features, these effects can include fracturing of the rock bedding in the river, water loss to the shallow sub-strata, gas release, rock falls, and vegetation dieback. In the past, mine planning has considered potential effects on engineered structures, however, the same attention has not been paid to the effects of mining on natural features. Through a Stakeholder Involvement Programme conducted by Illawarra Coal, it was identified that government and community stakeholders were seeking a more sensitive approa...
The large number of wetlands treating mining wastewaters around the world have mostly been constr... more The large number of wetlands treating mining wastewaters around the world have mostly been constructed in temperate environments. Wetlands have yet to be proven in low rainfall. high evaporation environments and such conditions are common in many parts of Australia. BHP Australia Coal is researching whether wetlands have potential in central Queensland to treat coal mining wastewaters. In this region. mean annual rainfall is < 650 mm and evaporation> 2 000 mm. A pilot-scale wetland system has been constructed at an open-cut coal mine. The system comprises six treatment cells. each 125 m long and 10 m wide. The system is described in the paper and some initial results presented. Results over the first fourteen months of operation have shown that although pH has not increased enough to enable; reuse or release of the water. sulfate reduction has been observed in parts of the system. as shown by the characteristic black precipitate and smell of hydrogen sulfide emanating from the wetlands. These encouraging signs have led to experiments aimed at identifying the factors limiting sulfate reduction. The fll'St experiment, described herein, included four treatments where straw was overlain by soil and the water level varied, being either at the top of the straw, at the top of the soil, or about S em above the soil. The effect of inoculating with sulfate-reducing bacteria was investigated. Two controls were included, one covered and one open, to enable the effect of evaporation to be determined. The final treatment consisted of combined strawlcattle manure overlain with soil. Results showed that sulfate reduction did occur, as demonstrated by pH increases and lowering of sulfate levels. Mean pH of the water was significantly higher after 19 days; in the controls, pH was < 3.3, whereas in the treatments, pH ranged from S.4 to 6.7. The best improvement in sulfate levels occurred in the straw/cattle manure treatment.