Maintenance Of Drainage System Research Articles

Representation of Particulate Matter COD in Rainfall Runoff from Paved Urban Watersheds

For a half century, total suspended solids (TSS) has been the most commonly utilized particulate matter (PM) gravimetric index for wastewater. While TSS has been extended to urban runoff, runoff phenomena are unique. Runoff is unsteady and transports heterodisperse inorganic granulometry, giving rise to the PM index, suspended sediment concentration (SSC). With respect to PM-associated chemical oxygen demand (CODp) in runoff, it is hypothesized that, while the TSS method can represent effluent CODp, the SSC method is required to represent influent CODp. CODp and PM indices (TSS and SSC) for runoff events with mass balances and manual sampling are analyzed to investigate this hypothesis. This study examined a series of rainfall-runoff events captured from an instrumented fully paved urban catchment subject to traffic loadings in Baton Rouge, LA. Results indicate TSS generated substantial event-based mass balance errors for CODp and Δm p (mg/g) across a hydrodynamic separator (HS) as compared to SSC. TSS underestimates sediment-bound COD (>75 µm), a significant portion (maximum of 63% and median of 50%) of influent load. Negative bias by the TSS method for influent CODp load increases as the heterodisperse particle size distribution becomes coarser. Above a PM of 250 mg/L, underestimation of CODp by the TSS method is statistically significant. Utilizing the SSC method, CODp reduction by a HS upstream of a batch clarifier (BC) indicates that a HS does not provide CODp reduction, compared to a BC with 60 min of residence time. Representative PM and CODP assessment suggests frequent BMP and drainage system maintenance to ensure proper operation and reduce pollutant elution.

Drainage Problems in a Tropical Environment: Perspectives on Urban Quality Management

This research effort is an assessment of drainage problems in the tropical environment of Ilorin, Nigeria. In order to achieve the philosophy of the work, the following data have been sourced from direct fieldwork. Such data include drainage dimensions, types of wastes in drainage channels, problems of wastes and techniques for waste management. These data have been analyzed through the application of descriptive statistics and cross tabulations as a basic method of data analysis. The results of the finding include: (a) the dimensions of drainage channels are adequate to permit free flow of water bodies given a good culture of drainage system maintenance, (b) various types of waste materials but in different proportions have been found to be blocking the drainage channels, (c) the problems of drainage channels ranges from the occurrence of street flooding to environmental deterioration and the splashing of water on other road users; and (d) an obvious method for managing drainage channels is the adoption of environmental education with emphasis on the technique for drainage channel management.

(تصميم مجاري الأمطار في مدن الشرق الأوسط (تناول جديد

It is a tradition among the Arab designers not to consider the effect of sediments in their design of drainage systems which would give a wrong design, especially according to the lack of maintenance of drainage systems. Ignoring the effect of sediments leads to ignoring a major factor affecting the hydraulic roughness of the flow, where sediments increase the hydraulic roughness and also decrease the cross section of the sewers. The aim of this paper is to introduce a new approach to handle the design of storm sewers and also to include all hydraulic factors which affect the flow, these factors are: 1. Properties of sediments (diameter, shape and density). 2. Water properties (density, viscosity and temperature). 3. Flow characteristics (velocity, sediment concentration, sediment depth, gravitational force and depth of sediments) In order to achieve this model, laboratory tests (carried out by the author on a prototype at Salford Hydraulic Laboratory in Manchester).