Swimming Pool Water Treatment Research Articles

Nanofiltration treatment of swimming pool water in the aspect of the phenolic micropollutants elimination

Nanofiltration treatment of swimming pool water in the aspect of the phenolic micropollutants elimination

Contemporary aspects in the assessment of quality and treatment of swimming pool water

Recent reports in the literature relate to the identification of various substances in the pool water, including low-molecular weight pharmaceuticals that can react with chlorine residues contributing to the formation of a large group of irritant and toxic compounds. These substances are not covered by standard monitoring. As part of this work, the authors present information on the methods for assessing the quality of the swimming pool water. Common processes used in swimming pool water treatment systems were described. Previous experience of the authors in the use of a detailed assessment of the quality of the swimming pool water on the basis of toxicity tests was presented. The authors have researched the application of pressure driven membrane filtration for the improvement of the efficiency of the swimming pool water treatment.

Impact of the UV Lamp Power on the Formation of Swimming pool Water Treatment By-Products

Abstract The operation of swimming pools requires a constant monitoring of water quality parameters and protection of water against pathogens. This is implemented by various disinfection methods, among which the most commonly used are based on chlorine action supported by ozone or UV irradiation. The paper presents the comparison of the effectives of organic micropollutants decomposition occurring in swimming pool water during UV irradiation emitted by a 15 and 150 W UV lamp. The tests were conducted on real swimming pool water collected from a sport basin. The identification and the determination of micropollutants concentration were performed by the use of gas chromatography GC-MS (EI) preceded by solid-phase extraction SPE. It was shown that the concentration of micropollutants decreases with the increase in the irradiation time of pool water. The 150 W UV lamp allowed for an over 33% removal of micropollutants from the group of pharmaceuticals compounds (except for caffeine) and more than 76% decrease of other compounds, which belong to the group of personal care products additives, food additives and phthalates. In addition, it has been demonstrated that during the irradiation of such complex water matrixes as swimming pool water, a significant number of micropollutants degradation by-products were formed, which are not found in water before UV irradiation.

Pore diffusion limits removal of monochloramine in treatment of swimming pool water using granular activated carbon.

Overall apparent reaction rates for the removal of monochloramine (MCA) in granular activated carbon (GAC) beds were determined using a fixed-bed reactor system and under conditions typical for swimming pool water treatment. Reaction rates dropped and quasi-stationary conditions were reached quickly. Diffusional mass transport in the pores was shown to be limiting the overall reaction rate. This was reflected consistently in the Thiele modulus, in the effect of temperature, pore size distribution and of grain size on the reaction rates. Pores <2.5 times the diameter of the monochloramine molecule were shown to be barely accessible for the monochloramine conversion reaction. GACs with a significant proportion of large mesopores were found to have the highest overall reactivity for monochloramine removal.

Test of precoat filtration technology for treatment of swimming pool water.

The technical performance of a precoat filter was compared with that of a traditional sand filter. Particle concentration and size distribution were measured before and after the filtration of swimming pool water. Both the sand and precoat filters could reduce the particle concentration in the effluent. However, higher particle removal efficiency was generally observed for the precoat filter, especially for particles smaller than 10 μm in diameter. Adding flocculant improved the removal efficiency of the sand filter, resulting in removal efficiencies comparable to those of the precoat filter. Three powders, i.e., two types of perlite (Harbolite® and Aquatec perlite) and cellulose fibers (Arbocel®), were tested for the precoat filter, but no significant difference in particle removal efficiency was observed among them. The maximum efficiency was reached within 30-40 min of filtration. The energy required for the pumps increased by approximately 35% over a period of 14 days. The energy consumption could be reduced by replacing the powder on the filter cloth. The sand filter was backwashed once a week, while the powder on the precoat filter was replaced every two weeks. Under these conditions, it was possible to reduce the water used for cleaning by 88% if the precoat filter was used instead of the sand filter.

Assessment of the possibility of using flocculation to improve properties of ultrafiltration membranes used in the purification of swimming pool water system washings

The paper presents the possibility of using an in-line mode flocculation–ultrafiltration system for the purification of backwash water from flushing the beds of pressure filters used in the indoor swimming pool water treatment circulation. The effect of flocculation operational conditions (the flocculant dose in the range from 16 to 240 mg/dm 3 and the process temperature of 8–30°C) on the transport-separation properties of ultrafiltration membranes has been examined. To establish the effectiveness of the conducted processes, the contaminant retention coefficients, among others, were determined (based on the measurements of turbidity and UV254 ultraviolet absorbance). A significant influence of the flocculation process operational parameters on the performance of ultrafiltration was noted. With increasing flocculant dose, the efficiency of contaminant removal in the ultrafiltration process increased simultaneously. Moreover, the change in the temperature conditions of the flocculation process had a fundamental effect on the transport properties of the ultrafiltration membranes. The most advantageous temperature for conducting the processes was considered to be 21°C. Under those conditions, all flocculant doses contributed to a significant improvement in the transport properties of the ultrafiltration membranes. High values of the contamination retention coefficients and the permeate volumetric flux were obtained already at a flocculant dose of 80,160 and 240 mg/dm 3 .

Effects of UV-based treatment on volatile disinfection byproducts in a chlorinated, indoor swimming pool

Ultraviolet (UV) irradiation and chlorination are commonly used together in treatment of swimming pool water because they function as complementary disinfectants and because UV-based processes have been shown to promote photodecay of chloramines. However, UV-based treatment also has the potential to promote formation of some disinfection byproducts (DBPs). As a result, the overall effects of UV irradiation with chlorination on swimming pool chemistry remain unclear. To address this issue, a three-year study was conducted in a chlorinated, indoor swimming pool under three different operating conditions: conventional chlorination (1st year) which served as a control, chlorination augmented by MP UV irradiation (2nd year), and chlorination augmented by LP UV irradiation (3rd year). Water samples were collected from the pool for measurement of pH, temperature, total alkalinity, free and combined chlorine, eleven volatile DBPs, and urea concentration. After installation of MP UV, the concentrations of most volatile DBPs decreased; similar effects were observed after inclusion of LP UV. Collectively, these results imply an overall improvement in water quality as a result of the inclusion of the both UV systems. In general, MP UV was more efficient than LP UV for reducing the concentrations of most of the volatile DBPs measured in this pool. However, a need exists to standardize the application of UV systems in recreational water settings.

Assessment of the possibility of recycling backwashing water from the swimming pool water treatment system

Assessment of the possibility of recycling backwashing water from the swimming pool water treatment system

Secondary formation of disinfection by-products by UV treatment of swimming pool water

Formation of disinfection by-products (DBPs) during experimental UV treatment of pool water has previously been reported with little concurrence between laboratory studies, field studies and research groups. In the current study, changes in concentration of seven out of eleven investigated volatile DBPs were observed in experiments using medium pressure UV treatment, with and without chlorine and after post-UV chlorination.Results showed that post-UV chlorine consumption increased, dose-dependently, with UV treatment dose. A clear absence of trihalomethane formation by UV and UV with chlorine was observed, while small yet statistically significant increases in dichloroacetonitrile and dichloropropanone concentrations were detected. Results indicate that post-UV chlorination clearly induced secondary formation of several DBPs. However, the formation of total trihalomethanes was no greater than what could be replicated by performing the DBP formation assay with higher chlorine concentrations to simulate extended chlorination. Post-UV chlorination of water from a swimming pool that continuously uses UV treatment to control combined chlorine could not induce secondary formation for most DBPs. Concurrence for induction of trihalomethanes was identified between post-UV chlorination treatments and simulated extended chlorination time treatment. Trihalomethanes could not be induced by UV treatment of water from a continuously UV treated pool. This indicates that literature reports of experimentally induced trihalomethane formation by UV may be a result of kinetic increase in formation by UV. However, this does not imply that higher trihalomethane concentrations would occur in pools that apply continuous UV treatment.The bromine fraction of halogens in formed trihalomethanes increased with UV dose. This indicates that UV removes bromine atoms from larger molecules that participate in trihalomethane production during post-UV chlorination.Additionally, no significant effect on DBP formation was observed due to photo-inducible radical forming molecules NO3− (potentially present in high concentrations in pool water) and H2O2 (added as part of commercially employed DBP reducing practices).

Comparison of chloramine concentration in swimming pool water depending on swimming pool intended use

Swimming pool water is a mixture of supplementary water added to a closed pool circuit (usually from water supply system) and water from a pool basin, constantly purified and disinfected because of its pollution caused by bathing people. In public swimming pools, in accordance with hygiene guidelines, disinfection by chlorine compounds is required. The most commonly used is sodium hypochlorite disinfectant. The disinfectant properties of chlorine are related to its ability to oxidize organic and inorganic compounds, and the result of water chlorination is the formation of disinfection by-products (DBP). Among the most troublesome DBPs for bathers and service facility of the swimming-pool are chloramines. Chloramines are responsible for the so-called syndrome of swimmers irritation, dry skin, irritation of the mucous membranes of the nose, throat and eyes. They give the pool water and the air in the pool hall a characteristic odor and have mutagenic properties. Therefore, analyzing chloramines concentrations and taking actions, in the field of pool water treatment, in order to reduce them are very important. The primary purpose of this paper is to present the distribution of chloramines concentrations (monochloramine and dichloramine) in the pool water, depending on the pool intended use (school training pool, sports pool, pool for children to play, pool with hydromassage and water tunnel). The analysis of the results of research takes into account the swimming pool water treatment systems, exploitation parameters and the number of people bathing. The comparison of parameters (physical, chemical and bacteriological) defining the quality of the pool water, with particular emphasis on the chloramines concentrations, allows to assess the efficiency of the treatment system and the usefulness of the water to swim and bathe in relation to DIN 19643 standards.

Research on Swimming Pool Water Treatment Based on Embedded System

This paper mainly designs the outdoor swimming pool circulation purification system, introduced the circulation mode selection, calculation of water cycle, and we proposed water purification treatment measures. After filtration and disinfection of swimming pool water, which achieve the "Hygienic standard for swimming place" (GB9667-1996) that regulations on "the quality and hygiene standards" artificial swimming pool, which can be recycled.

Photolysis of inorganic chloramines and efficiency of trichloramine abatement by UV treatment of swimming pool water

Trichloramine, one of the three inorganic chloramines (mono-, di- and trichloramine), is a problematic disinfection by-product in recreational pool water since it causes skin and eye irritations as well as irritations of the respiratory tract. The most commonly used chloramine mitigation strategy in pool water is UV treatment. Experiments with membrane inlet mass spectrometry (MIMS) confirmed that inorganic chloramines are effectively degraded by UV irradiation with low-pressure (LP) and medium-pressure (MP) mercury lamps (apparent quantum yields (QY): NH2Cl = 0.50 (LP) and 0.31 (MP) mol einstein−1, NHCl2: 1.06 (LP) and 0.85 (MP) mol einstein−1). Trichloramine showed the fastest depletion with a quantum yield slightly above 2 mol einstein−1 in purified (LP and MP) and pool water (MP). This high quantum yield can partly be explained by reactions involving OH radicals (purified water) and the reaction of trichloramine with moieties formed during UV irradiation of pool water. The presence of free chlorine affects trichloramine degradation (QY: ∼1.5 mol einstein−1) since it scavenges OH radicals and competes with trichloramine for reactive species (e.g. organic amines).Measurements in a pool facility revealed that the installed UV reactors degraded trichloramine by 40–50% as expected from laboratory experiments. However, trichloramine reduction in the pools was less pronounced than in the UV reactors. Model calculations combining pool hydraulics with formation/abatement of trichloramine showed that there was a fast trichloramine formation in the pool from the residual chlorine and nitrogenous precursors. The main factors influencing trichloramine concentrations in pool water are the free chlorine concentration and the UV treatment in combination with the recirculation rate through the water treatment system.

Review of swimming-associated cryptosporidiosis and Cryptosporidium oocysts removals from swimming pools

In this paper, outbreaks of cryptosporidiosis in swimming pools in the last 20 years are summarized. Cryptosporidium oocysts are very resistant to many disinfectants, including chlorine, one of the most widely-used disinfectants in swimming pools. Ozone or UV is shown to inactivate Cryptosporidium, while not effective to newly introduced Cryptosporidium and bacteria because of no residual ozone or UV in the treated swimming pool water. Additionally, swimming pool sand filters or cartridge filters are not able to effectively remove Cryptosporidium (removal rate &amp;lt;50%). Above 99% Cryptosporidium removals are achieved in drinking water treatment, but swimming pool water treatment is different from drinking water treatment: no coagulation is performed prior to filtration in most US swimming pools, filtration rate is four to five times higher for swimming pool water treatment compared with drinking water treatment, and the input compounds and microorganisms from bathers continuously recirculate in the swimming pool. Moreover, up-to-date Cryptosporidium or Cryptosporidium surrogate removals from swimming pools are discussed, and alternative swimming pool treatment techniques are reviewed.

Effects of UV-Based Treatment on Water and Air Chemistry in Chlorinated, Indoor Pools

Effects of UV-Based Treatment on Water and Air Chemistry in Chlorinated, Indoor PoolsCombined UV/chlorine treatment is commonly used in treatment of swimming pool water because UV irradiation is known to be effective against (some) chlorine-resistant...Author(s)Mehrnaz Zare AfifiErnest R. Blatchley IIISourceProceedings of the Water Environment FederationDocument typeConference PaperPublisherWater Environment FederationPrint publication date Feb, 2013ISSN1938-6478DOI10.2175/193864713813503747Volume / Issue2013 / 2Content sourceDisinfection and Reuse SymposiumCopyright2013Word count401

Elucidating mechanisms of chlorine toxicity: reaction kinetics, thermodynamics, and physiological implications.

Industrial and transport accidents, accidental releases during recreational swimming pool water treatment, household accidents due to mixing bleach with acidic cleaners, and, in recent years, usage of chlorine during war and in acts of terror, all contribute to the general and elevated state of alert with regard to chlorine gas. We here describe chemical and physical properties of Cl(2) that are relevant to its chemical reactivity with biological molecules, including water-soluble small-molecular-weight antioxidants, amino acid residues in proteins, and amino-phospholipids such as phosphatidylethanolamine and phosphatidylserine that are present in the lining fluid layers covering the airways and alveolar spaces. We further conduct a Cl(2) penetration analysis to assess how far Cl(2) can penetrate the surface of the lung before it reacts with water or biological substrate molecules. Our results strongly suggest that Cl(2) will predominantly react directly with biological molecules in the lung epithelial lining fluid, such as low-molecular-weight antioxidants, and that the hydrolysis of Cl(2) to HOCl (and HCl) can be important only when these biological molecules have been depleted by direct chemical reaction with Cl(2). The results from this theoretical analysis are then used for the assessment of the potential benefits of adjuvant antioxidant therapy in the mitigation of lung injury due to inhalation of Cl(2) and are compared with recent experimental results.

THE STUDY OF THE O3/UV ADVANCED OXIDATION PROCESSES FOR A SWIMMING POOL WATER TREATMENT

The O3/UV advanced oxidation in an aqueous solution is one of the advanced oxidation processes that are the most intensely investigated in the last decade, notably owing to the high degree of applicability in the field of water treatment. This work aims at practically tackling with such a process by means of real scale studies performed on a pilot station, used for swimming pool water treatment and disinfection, simultaneously with numerically modeling the system. The experimental data obtained, compared to the information provided by the numerical modeling operations made, can constitute the departing point for drawing up a predictive pattern for such systems.

Swimming pool water treatment by ultrafiltration–adsorption process

Disinfection by-products are of great concern in swimming pool water where water treatment generally involves a disinfection step with chlorine. In fact, swimmers can contribute a large quantity of organic matter that can lead to the formation of chloramines, chloroform and chloroacetic acids. These compounds can lead to health problems among the staff and pool users, especially babies or little children. The water quality improvement and productivity performance of the hybrid process, ultrafiltration–adsorption, is investigated. An original work, this paper presents results obtained in a real pool system for the first time. An industrial unit was installed in a municipal swimming pool in Marseille (France) and the process was studied for more than 18 months. After a study on water quality according to pool usage (activity and number of swimmers), the influence of transmembrane pressure and filtration time on ultrafiltration performance was evaluated. Optimal ultrafiltration operating conditions were found to be at a transmembrane pressure (TMP) of 0.45 bar and a filtration time ( T f) of 60 min for the entire range of each water quality parameter studied. The filtration unit enabled water clarification, and the adsorption step limited the concentration of combined chlorine in water to 0.35 ppm, well below the limit given by the French legislation (0.6 ppm). Due to a succession of filtration and backwashes, permeability never decreased below 160 L h −1 m −2 bar −1. In spite of difficult conditions in terms of frequent pool usage and total chlorine concentration, the membranes have shown promising flexibility in this hybrid process.

Preparo da para-cloroanilina: um experimento simples, rápido e barato

Experiments simple, short and efficient for experimental disciplines in undergraduate courses in Chemistry are an excellent opportunity for students to consolidate the learning of theoretical concepts in classical chemical transformations. The use of a safe reagent, of low cost and easy access is the motivation for this communication, that describes the use of trichloroisocyanuric acid - a chlorinating agent used in the treatment of swimming pool water - for the chlorination of acetanilide, an intermediate in the preparation of para-chloroaniline.

Simulated Cryptosporidium removal under swimming pool filtration conditions

AbstractThere has been no information available on the removal of Cryptosporidium oocysts or oocyst‐sized particles under the sand filtration conditions normally used for swimming pool water treatment. A pilot sand filtration plant has therefore been constructed at The University of Wales Swansea and operated under swimming pool conditions (25 m/h downflow, 30°C, 1.5 mg/L free chlorine, pH 7.3 to 7.5, alkalinity 120–150 mg/L as calcium carbonate). Removal of fluorescent polystyrene particles of a size range (1–7 μm) similar to the size of Cryptosporidium oocysts (about 5 μm) without added coagulant was less than 50%. Removal of the particles under the operating conditions above but with the addition of either of the coagulants polyaluminium chloride (PAC) or aluminium sulphate was capable of giving better than 99% removal of the particles.

Swimming pool water—fractionation and genotoxicological characterization of organic constituents

Swimming pool water treatment in general includes flocculation, sand filtration, and subsequent disinfection with chlorine. The continuous chlorination and input of organic material by bathers in combination with recirculation of the pool water leads to an accumulation of disinfection by-products (DBPs) in the water. Several DBPs have been identified as human carcinogens and are thought to cause allergic asthma. Therefore, the elimination of DBPs is one major aim of pool water treatment. Using membrane filtration as an alternative treatment technology, DBPs can be removed more efficiently than with conventional treatment. In this study membrane filtration and genotoxicity testing were applied for the characterization of pool water constituents and for the identification of the necessary molecular weight cut off of the membrane for an efficient elimination. Two-step membrane filtration revealed that most of the DBPs (as adsorbable organically bound halogen, AOX) were present in the molecular weight fraction below 1000 g/mol. The fraction below 200 g/mol contained more than 30% of the AOX. The distribution of the dissolved organic carbon (DOC) across the fractions was similar to that of the AOX. The genotoxicity was found to be strongest in the low-molecular weight fraction. Thus, considerable DBP removal by membrane treatment requires membranes with low-molecular weight cut offs down to 200 g/mol. The comprehensive elimination of the genotoxic compounds requires further treatment steps.