| Popis: |
Increasing interest in urban drainage green infrastructure brings attention to grass swales and filter strips (GSGFS) and their role in stormwater management. While the understanding of the hydrology and hydraulics of these stormwater control measures is adequate for current needs, there are knowledge gaps in understanding the water quality processes in GSGFS and such a finding motivated preparation of the review paper that follows. The review revealed that most of the empirical studies of GSGFS flow quality focused on the removal of pollutants associated with road runoff, and particularly solids, with relatively few studies addressing nutrients, traffic associated hydrocarbons, oxygen demanding substances, chloride, and faecal indicator bacteria. The reported results suffer from limitations caused by experimental conditions often representing a steady flow used to irrigate GSGFS and generate runoff, non-submerged flows, no lateral inflows along swale side slopes, constant dosing of solids, emphasis on larger-than-typical solids, incomplete descriptions of experimental conditions, and limited attention to experimental uncertainties. Besides settling, other treatment processes, like adsorption/desorption, plant uptake, chemical precipitation and microbial degradation are often acknowledged, but without attempting to quantify their effects on flow quality. The modelling of GSGFS flow quality would be beneficial for an improved understanding of green urban drainage infrastructure, but currently it is infeasible without a better knowledge of stormwater quality processes in GSGFS facilities. |
Full Text from ScienceDirect