Water flow and storage in fractured, unsaturated sulphur blocks

作者：Birkham T K^*; Hendry M J; Barbour S L; Carey S K; Lawrence J R; Lewko R

来源：Canadian Geotechnical Journal, 2011, 48(5): 810-825.

DOI：10.1139/T10-105

• sulphur blocks
• dye tracer
• infiltration
• hydrophobic
• fractured
• acidic drainage

Water is a primary control on the generation of acidic (H(2)SO(4)) effluent from commercial-scale sulphur (S(0)) blocks. Although clean S(0) is strongly hydrophobic, microbial colonization of fracture faces and friable S(0) generates localized hydrophilic conditions. Infiltration occurs preferentially along discrete fractures and in areas of friable S(0). Surface evaporation rates are low (mean 0.2 mm/day), and >90% of rainfall infiltrates and rapidly drains from the blocks. A conceptual model to describe the flow and storage of water at the base of S(0) blocks was developed and tested. The S(0) blocks were represented as a hydrophilic equivalent porous medium, and lateral drainage through the base of the blocks was quantified using a two-dimensional numerical model. Specific yield (S(y)) and saturated hydraulic conductivity (K(s)) values were estimated to be similar to 4%-7% and similar to 1 x 10(-2) m/s, respectively, by comparing measured and modelled pore-water pressure head and outflow responses to rainfall events. Given that commercial-scale S(0) blocks are constructed in a similar manner worldwide, the results of this study are considered widely applicable in designing S(0) block storage facilities that minimize water availability and H(2)SO(4) production in S(0) blocks.

• 出版日期2011-5