Wastewater filtration and re-use: an alternative water source for London.

摘要: The rapid growth and climate of the Greater London region have contributed towards large deficits in water supply. Inexpensive, energy-efficient sustainable resource schemes are increasingly sought as a means to boost Here, we propose small-scale recycling scheme whereby tertiary-treated wastewater is pumped Cretaceous chalk Basin. By taking advantage natural filtration properties underlying chalk, contaminants can be effectively attenuated over relatively short length scales result pure water. problem approached from four different scales. First, define two localities where such pumping might operate; regions which combine thick unsaturated zone high transmissivity, both essential ensure maximum contaminant removal minimum environmental impact. Secondly, effects fluid into Chalk at quantified using finite-difference groundwater flow model. We show that rivers impose regular regime, whereas pre-existing abstraction wells will lead less predictable results. Thirdly, consider effect fractures on channelling within rock mass. digitising fracture map based upon outcrop measurements exposed Kent coast similar beneath London, quantify transport patterns after injection. Imbibition matrix (and therefore filtration) occur pressure gradients highest, for instance around disconnected tips. Finally demonstrate efficacy by injecting an analogue 'effluent' through core. ICP-AES analysis recovered solution shows (viz. suite heavy metals) arrested or removed small time- length-scales. Numerical analytical solutions fit data poorly, shedding some light importance hydrodynamic dispersion aqueous chalk.