Chloride pollution of groundwater and surface water resources is an environmental concern in many regions. While use of road salt for winter road maintenance is known to be a major source of chloride ...in the environment, limited research has investigated the environmental impacts of chloride discharged from water softeners, particularly in areas with hard water. A chloride budget was developed for the state of Minnesota to estimate the amount of chloride discharged from household water softeners as well as other domestic, agricultural, commercial, and industrial sources. The analysis used multiple data sources, including salt sales records and wastewater monitoring data, and used statistical, spatial, and survey methods to estimate chloride loading from major sources statewide. Annual chloride mass contributions were estimated for the following sources: household water softener use; human excretions; household product use; chloride concentrations in drinking water; atmospheric deposition; road salt use; dust suppressant use; fertilizer application; industrial discharge; and livestock excretions. A mass balance for 96 wastewater treatment plants with effluent monitoring data showed that across these facilities, discharge from water softeners was the largest chloride source. A statewide chloride budget found that road salt was the largest source of chloride to the environment, but that WWTPs and fertilizer were also substantial sources, discharging 221,300 t and 209,900 t annually. Water softeners were estimated to contribute 65% of the chloride discharged to all 613 municipal WWTPs statewide. Methods used in this analysis could be applied to other communities, watersheds, or states with similar conditions. The results of the analyses indicate that water softening is an important chloride source in areas with hard water and underscore the importance of identifying and characterizing chloride sources in less urban areas, where deicing salt may be a less important contributor and receiving water bodies are often lakes, reservoirs, and streams.
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•Estimated loading from commercial, industrial, agricultural and domestic sources•Wastewater facilities and fertilizer contributed 209,900 t and 221,300 t annually.•Road salt contributed 403,600 t chloride to environment per season.•Water softeners contributed 65% of wastewater facilities' chloride loading.•Results suggest softening is important chloride source in regions with hard water.
The graph shows the action of zeolite on the NAA heavy water. Display omitted
Square 1 - zeolite with sodium promotes ion exchange of calcium and magnesium present in water hard. ► Square 2 - water ...free of calcium and magnesium captured by zeolite. ► Square 3 - calcium and magnesium present in hard water withheld in the sites of adsorption.
Zeolite 4A (LTA) has been successfully synthesized by a hydrothermal method, where kaolin was used as silica and alumina source. The synthesized zeolite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), laser granulometry, and FTIR spectroscopy. XRD data from the Rietveld refinement method confirmed only one crystallographic phase. Zeolite A morphology was observed by SEM analysis, and it showed well-defined crystals with slightly different sizes but with the same cubic shape. Particle size distribution of the crystals was confirmed by laser granulometry, whereas FTIR spectroscopy revealed significant structural differences between the starting material and the final zeolite product used as water softener.
Background
Observational studies suggest an increased risk of eczema in children living in hard versus soft water areas, and there is, therefore, an interest in knowing whether softening water may ...prevent eczema. We evaluated the feasibility of a parallel‐group assessor‐blinded pilot randomized controlled trial to test whether installing a domestic ion‐exchange water softener before birth in hard water areas reduces the risk of eczema in infants with a family history of atopy.
Methods
Pregnant women living in hard water areas (>250 mg/L calcium carbonate) in and around London UK, were randomized 1:1 antenatally to either have an ion‐exchange water softener installed in their home or not (ie to continue to receive usual domestic hard water). Infants were assessed at birth and followed up for 6 months. The main end‐points were around feasibility, the primary end‐point being the proportion of eligible families screened who were willing and able to be randomized. Clinical end‐points were evaluated including frequency of parent‐reported doctor‐diagnosed eczema and visible eczema on skin examination. Descriptive analyses were conducted, and no statistical testing was performed as this was a pilot study.
Results
One hundred and forty‐nine families screened were eligible antenatally and 28% (41/149) could not have a water softener installed due to technical reasons or lack of landlord approval. Eighty of 149 (54%) were randomized, the primary end‐point. Two participants withdrew immediately after randomization, leaving 39 participants in each arm (78 total). Attrition was 15% (12/78) by 6 months postpartum. All respondents (n = 69) to the study acceptability questionnaire reported that the study was acceptable. Fifty‐six of 708 (7.9%) water samples in the water softener arm were above the hard water threshold of 20 mg/L CaCO3. At 6 months of age 27/67 infants (40%) developed visible eczema, 12/36 (33%) vs. 15/31 (48%) in the water softener and control groups, respectively, difference −15% (95% CI −38, 8.3%), with most assessments (≥96%) remaining blinded. Similarly, a lower proportion of infants in the water softener arm had parent‐reported, doctor‐diagnosed eczema by 6 months compared to the control arm, 6/17 (35%) versus 9/19 (47%), difference −12% (95% CI −44, 20%).
Conclusion
A randomized controlled trial of water softeners for the prevention of atopic eczema in high‐risk infants is feasible and acceptable. Trial registration: NCT03270566 (clinicaltrials.gov)
In the SOFTER trial, approximately half of eligible families were willing and able to be randomized to a water softener. There were less infants that had visible or parent‐reported doctor‐diagnosed eczema in the water softener group in comparison with the control group, which had their usual hard domestic water supply. Lastly, this pilot trial showed that a trial of water softeners for preventing eczema in high‐risk infants is feasible and acceptable.
Figure created with biorender
Observation of arsenic water treatment adsorption media in the treated water of several homes with high arsenic private wells led to the hypothesis that treatment media was escaping the treatment ...systems and entering the plumbing and drinking water. Our research at 62 homes identified that microparticles of arsenic water treatment media and/or water softener resin had escaped the treatment system in 71% of the homes. This is a potential health hazard as ingesting arsenic treatment media or water softener resin may lead to an elevated ingestion exposure to arsenic and other contaminants. Potential causes of media escape from the treatment systems include media observed to be smaller in size than specifications and media breaking into smaller pieces. One interim solution to media escape is installation of a post‐treatment sediment filter. New developments in media durability or treatment system design and maintenance may be needed to prevent media escaping into drinking water.
Practitioner Points
Arsenic in private wells is often treated with point‐of‐entry whole house adsorption systems.
Arsenic adsorption treatment media and/or water softener resin was observed in treated water at 44 of 62 homes inspected.
Water treatment media escaping into treated water is a potential hazardous exposure pathway.
Potential causes and solutions are discussed.
Investigation at 62 homes with high arsenic private wells identified that microparticles of arsenic water treatment media and/or water softener resin had escaped the treatment system and entered drinking water in 71% of the homes. Ingestion of these microparticles may lead to an elevated exposure to arsenic and other contaminants.
Water treatment in the magnetic field is not an officially recognized method of water softening. This method can be promoted as an alternative to water softening without potentially toxic chemical ...agents. The water softener device consisting of 3 pairs of permanent magnets made of neodymium was designed with the help of Solid Edge software. Numerical simulation was performed using ANSYS WORKBENCH finite element analysis software using the FluidFlow (CFX) module. With this analysis module the dynamic analysis of the fluid flow through a pipe was performed. Three numerical analyses of the water flow through a pipe with an internal diameter of 20 mm were performed at a pressure of 2 bars, namely: • the water flow without magnetic influences; • the water flow under the magnetic influence of the softener device positioned longitudinally with the pipe; • the water flow under the magnetic influence of the softener device positioned transversely with the pipe. The conclusions of these simulations can be the basis for future research in order to optimize this type of device.
There has been a large amount of scientific research carried out to date on the impact of salty backwash brine from domestic water softeners (WS) on domestic wastewater treatment plants (DWTPs). ...Experts and practitioners agree that the impact is harmful and there is still a need to look for new technologies. The study of the effect of an increased sodium chloride (NaCl) concentration after softener regeneration is important from the point of view of the operation of DWTPs and soil properties. This paper presents the results of a field study of the concentration of NaCl at the septic tank (ST) drainage point, into which the grey water from the regeneration of the water softener flowed. During the six-month measurements (recorded every 1 min), an increase in NaCl concentration was observed in the septic tank outflow, from an average NaCl concentration of 1.5 g·L−1—between regenerations—to an average concentration of 4.5 g·L−1—after water softener regeneration. The increased NaCl concentration decreased significantly up to 2 days after the water softener regeneration. Temperature changes in the treated wastewater were also measured—during the winter period, temperature differences of up to 10 °C per day were recorded. In the second part of the study, conducted on a semi-technical scale, the effect of brine from the regeneration of the water softener on the hydraulic conductivity (Ks) of the soil from the infiltration drain of the DWTPs studied was assessed. The Ks was determined by analysing the time it took the water to soak into the soil, using the Van Hoorn equation. The results and statistical analysis indicate an increased salt content in the soil absorbing the brine, which may have been influenced by the reduced absorption and capacity of the drain due to adverse physico-chemical changes.
A new integrated catchment model for salinity has been developed to assess the transport of road salt from upland areas in watersheds to streams using readily accessible landscape, hydrologic, and ...meteorological data together with reported salt applications. We used Fishkill Creek (NY) as a representative watershed to test the model. Results showed good agreement between modeled and measured stream water chloride concentrations. These results suggest that a dominant mode of catchment simulation that does not entail complex deterministic modeling is an appropriate method to model salinization and to assess effects of future applications of road salt to streams. We heuristically increased and decreased salt applications by 100% and results showed that stream chloride concentrations increased by 13% and decreased by 7%, respectively. The model suggests that future management of salt application can reduce environmental concentrations, albeit over some time.
► A new Integrated Catchment Model (INCA-Cl) is developed to simulate salinity. ► Road salt application is important in controlling stream chloride concentration. ► INCA-Cl can be used to manage and forecast the input and transport of chloride to the rivers.
A newly developed integrated catchment model for salinity can be used to manage and forecast the inputs and transport of chloride to streams.
Chemical treatment for the control of the spread of zebra mussels in watercraft is typically focused on the early life stages of the mussel. Adult mussels may be spread via attachment or entangling ...to gear that is brought on board. Sodium chloride is a chemical that has been recommended for use during some aquacultural practices as a mussel disinfectant. The effectiveness of three sodium chloride-based salts (high-grade sodium chloride, iodized table salt, and water softener salt) was examined for their use as an adult zebra mussel decontamination solution. High-grade sodium chloride and iodized table salt both caused complete mortality at 30.000 mg/l in 24 h. Water softener salt caused complete mortality at the same concentration at 48 h. Iodized table salt caused complete mortality at a lower concentration faster than the laboratory-grade sodium chloride. On the basis of the results of this study, iodized table salt may be an acceptable alternative to high-grade sodium chloride for decontamination of zebra mussels, costing much less and leading to an increase in spread-prevention effectiveness.
The properties of rice cooked in ion-exchanged water (2.5 mg/L of Ca2+ and 36.2 mg/L of Na+) and in tap water (15.7 mg/L of Ca2+ and 15.7 mg/L of Na+) were compared to clarify the effect of ion ...exchange by a domestic water- softener. The respective water content and rate of volume increase of the rice cooked in ion-exchanged water (ion-exchanged water rice) were 64.12% and 4.03-fold. These are significantly higher than the respective values of 62.03% and 3.83-fold for the rice cooked in tap water (tap water rice). The hardness of ion-exchanged water rice was significantly lower than that of tap water rice. The sensory evaluation judged the ion-exchanged water rice to be significantly softer and sweeter than the tap water rice. These results show that the water absorption and volume increase of rice were facilitated by cooking in ion-exchanged water from which Ca has been removed by the water- softener, giving softer rice. Scanning electron micrographs show starch granules on the surface of tap water rice, but not on ion-exchanged water rice.
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