A wastewater retention canal as a sewage network and accumulation reservoir

Abstract

The paper presents an innovative retention canal for storm sewage as a competitive solution in relation to the ones currently used. The principle of operation of the retention canal, the conditions of its use in a sewage network and the basis for dimensioning were presented. To demonstrate its versatility and retention efficiency, comparative studies on the example of a drained catchment were carried out. A linear network layout composed of 12 storm canals with the retention reservoir located at the network outlet was assumed. Based on the developed algorithm, simulation tests were performed with the use of the SWMM 5.1 program. On the basis of hydrodynamic modelling it was determined: (1) the required geometry of storm canals, (2) the geometry of damming partitions and (3) the process of wastewater accumulation in the retention canal. Having the results of simulation research for rainfalls with a duration of 10 to 100 minutes, the critical rainfalls for network and retention canal dimensioning were determined. The comparison of hydrographs of sewage outflow from the examined catchment is interesting. From the value of 3.62 m3/s in the network it decreases three times to just 1.16 m3/s at the outlet of the retention canal. The retention canal with diameters identical to those established for the network, allow achieving the sewage retention capacity, which corresponds to a capacity of 1,844 m3 for a multi-chamber retention reservoir. Thus, the retention canal fully replaces the operation of a network of certain geometry and retention reservoir. The results of the research allowed the formulation of a number of important conclusions, including conclusions on cognitive significance. The critical rainfall appointed for the design of the retention canal always lasts longer than that, determined for the sewage network design. The retention canal is suitable for widespread use in the canals of new and already existing storm sewage systems and combined sewage systems.*

Multi-Objective Optimization for Urban Drainage or Sewer Networks Rehabilitation through Pipes Substitution and Storage Tanks Installation

“…In the work of Cunha et al, only storage tanks were implemented as a strategy for flood reduction; Simulated Annealing was used as the optimization model. As an alternative solution, Dziopak [30] or Słyś [31] proposed the use of control devices, allowing storage in the channel themselves.…”

An Analysis of Stormwater Management Variants in Urban Catchments

“…For instance, in more than 90% of Chinese cities, flood risk management is based on the use of traditional engineering infrastructure [17] in the form of a traditional covered storm water drainage systems, which are designed to discharge urban discharges to the receiver as soon as possible. Additionally in Poland, as in many other European Union countries, traditional drainage systems that operate in a gravitational way are still the leading way of transporting rainwater [14] when draining urbanized areas. This approach results rainwater discharge that is characterized by a high peak flow value and a rapid rise of water in the receivers.…”

“…In order to ensure the maintenance of the living standards that are expected by residents, who are increasing in number, it is necessary to properly maintain, operate [7,8], and modernize a city's infrastructure [9,10] and to implement such in accordance with the principles of sustainable development [11,12]. In many cases, urban development is constrained by the possibilities of municipal infrastructure, especially the one used to drain wastewater and stormwater [13,14].…”

“…Outflows of stormwater from drainage systems to the surface of area usually occur in close proximity to drainage conduits, which have an insufficient hydraulic capacity. There are also cases where the flooding appears at a considerable distance from the overloaded conduit, and this is due to the specific shape of the catchment surface [14].…”

Decision Criteria for the Development of Stormwater Management Systems in Poland

“…As a consequence, the degree of implementation of nature-based solutions for stormwater management is low [4]. The problem of focusing on financial criteria concerns both the selection of a specific facility dedicated to stormwater management [5] and the selection of its dimensions [6]. This issue is present in many other countries [7].…”