The Influence of the Filtration Bed type in the Pool Water Treatment System on Washings Quality

Abstract

This paper presents the influence of the type of filtration beds, used in swimming pool water treatment systems, on the quality and the possibility of reuse of washings. The research covered 4 pool cycles with sand, sand and anthracite, glass and diatomaceous beds. The degree of contamination of washings was assessed on the basis of physical, chemical and bacteriological tests. The possibility of washings drainage into the natural environment was considered, and the results of the research were compared with the permissible values of pollution indicators for wastewater discharged to water or ground. A direct management of washings from the analysed filters proved impossible mainly due to the high content of TSS (total suspended solids) and free chlorine. Washings were subjected to sedimentation and then the supernatant was stirred intensively. As a result of these processes, the quality of washings was significantly improved. This allowed planning to supplement the pool water installations with systems for washings management.

Water loss in swimming pool filter backwashing processes in the Balearic Islands (Spain)

“…The second section reported the swimming pool treatment, including information about the type of disinfection system and the filtration bed type. The bed type influences the backwashing quality (Wyczarska-Kokot & Lempart, 2019). Finally, different aspects related to the backwashing process, including the existence of a written protocol, the basis applied to the procedure, the time expended, the size and appropriateness of the used equipment, and the monitoring of the process, were also included.…”

“…This solution is widespread, but research to increase the filtration efficiency resulted in multi-layer filters, whose filter bed consists of two or three layers of various materials. The filling of multi-layer filters is usually gravel, quartz sand, anthracite or activated carbon (Wyczarska-Kokot & Lempart, 2019). The consequent filter clogging after the filtration process causes a pressure loss over time (de Deus et al, 2020).…”

“…That generates a high amount of backwash water, which is discharged usually to the sanitary sewer system. The backwashing from swimming pool systems may constitute 20% to even 70% of the total wastewater volume, depending on the size of the swimming pool and the water treatment technology applied (Wyczarska-Kokot & Lempart, 2019).…”

“…Besides, the European Commission published in 2015 the Circular Economy Strategy, with an action plan that includes a specific mention to this requirement of reuse the water. This need to save water, together with the increase of prices associated with water and sewage, leads to increased research for new solutions in the ambit of water and sewage management by the designers and owners of swimming pools (Wyczarska-Kokot & Lempart, 2019). In this sense, the potential opportunities to reuse backwash water is a stimulating and widely studied subject (Lewis et al, 2015).…”

Physico‐chemical processes

“…Wyczarska‐Kokot and Lempart (2019) applied four different types of filter media (sand, sand and anthracite, glass, and diatomaceous beds) for testing the possibility of swimming pool water reuse for washings. The washing water quality was compared with wastewater discharge pollution guidelines before drainage into the natural water bodies.…”