Laboratory experiments of sediment transport from bare soil with a rill [Expériences de laboratoire sur le transport des sédiments provenant d'un sol nu avec rigoles]

Mathematical models developed for quantification of sediment transport in hydrological watersheds require data collected through field or laboratory experiments, but these are still very rare in the literature. This study aims to collect such data at the laboratory scale. To this end, a rainfall simulator equipped with nozzles to spray rainfall was constructed, together with an erosion flume that can be given longitudinal and lateral slopes. Eighty experiments were performed, considering microtopographical features by pre-forming a rill on the soil surface before the start of each experiment. Medium and fine sands were used as soil, and four rainfall intensities (45, 65, 85 and 105 mm h-1) were applied in the experiments. Rainfall characteristics such as uniformity, granulometry, drop velocity and kinetic energy were evaluated; flow and sediment discharge data were collected and analysed. The analysis shows that the sediment transport rate is directly proportional to rainfall intensity and slope. In contrast, the volumetric sediment concentration stays constant and does not change with rainfall intensity unless the slope changes. These conclusions are restricted to the conditions of experiments performed under rainfall intensities between and 105 mm h-1 for medium and fine sands in a 136-cm-wide, 650-cm-long and 17-cm-deep erosion flume with longitudinal and lateral slopes varying between 5 and 20%. © 2013 © IAHS Press

Current Situation and Future Perspectives in Municipal Wastewater Treatment and Sludge Management in Turkey

Appropriate management of wastewater and sludge requires several systems. One of these systems is the collection of data about generation rates and characteristics of sludge. This paper aims to summarize the work done as a part of a threeyear project requested by the Turkish Ministry of Environment and Urbanization. Efforts involved preparation and evaluation of a detailed questionnaire for currently operated wastewater treatment plants (INWTPs) in Turkey, collection and confirmation of information from visits to large scale plants, calculation of theoretical sludge generation rates from data provided, and its comparison to reported sludge amounts