Effect Of Water Hardness Research Articles

Effect of water hardness and surfactant on the particle coverage and distribution of plant protection products granules

The paper presents a study done to determine how particles of different plant protection products (fungicides) are distributed onto treated surfaces when their solutions are prepared with water of different hardness and addition of surfactant. A total of fifteen plant protection products were studied, all in the same concentration of 0.3% with four type of solutions: only distilled water, distilled water plus a wetting agent – the organosilicone surfactant – Silwet L-77, very hard tap water (hardness = 196.9 ррm СаСО3, 11 °dH) and very hard tap water plus wetting agent. The observations and images were made via light microscope with magnification 200X and 3MP digital camera. The images were analyzed for a percent distribution, and spreading of particles by ImageJ software. The results showed that the distribution, and coverage of particles onto treated surfaces can be different even at application of similar plant protection products. The variations in the properties were observed when the solutions were made with waters with different hardness and a wetting agent was added to the solutions. Contrary to the common perception that hard water can reduce the effectiveness of pesticides towards pests, according to the distribution and coverage of particles onto treated surfaces, in some cases hard water can even enhance these properties of the pesticide solutions. Keywords: plant protection products, distribution, coverage, wetting agent, water hardness

The Effect of Water Hardness and pH on the Efficacy of Peracetic Acid and Sodium Hypochlorite against SARS-CoV-2 on Food-Contact Surfaces.

Sodium hypochlorite (NaOCl) and peracetic acid (PAA) are commonly used disinfectants with a maximum recommended concentration of 200 ppm for food-contact surfaces. The objectives of this study were to assess the effect of pH and water hardness on NaOCl and PAA efficacy against SARS-CoV-2 on stainless steel (SS). The two disinfectants were prepared at 200 ppm in water of hardness 150 or 300 ppm with the final pH adjusted to 5, 6, 7, or 8. Disinfectants were applied to virus-contaminated SS for one minute at room temperature following the ASTM E2197 standard assay. SARS-CoV-2 infectivity was quantified using TCID50 assay on Vero-E6 cells. In general, increasingly hard water decreased the efficacy of NaOCl while increasing the efficacy of PAA. Hard water at 300 ppm significantly increased virus log reduction with PAA at pH 8 by ~1.5 log. The maximum virus log reductions were observed at pH 5 for both NaOCl (~1.2 log) and PAA (~2 log) at 150 and 300 ppm hard water, respectively. In conclusion, PAA performed significantly better than NaOCl with harder water. However, both disinfectants at 200 ppm and one minute were not effective (≤3 log) against SARS-CoV-2 on contaminated food-contact surfaces, which may facilitate the role of these surfaces in virus transmission.

Effects of water hardness on the flavor and antioxidant activity of Ishizuchi dark tea

Ishizuchi dark tea, a traditional Japanese post-fermented tea, has attracted considerable attention for its bioactivity. In this study, the effect of water hardness on Ishizuchi dark tea infusions was analyzed. Sensory testing revealed that the teas brewed in hard water were less sour in taste than those brewed in soft water. The most abundant organic acid found in the tea infusions was lactic acid, with a constant concentration of 4 mmol L−1, regardless of water hardness. The pH of the tea infusions increased from 4 to 5 with increasing water hardness, and a similar increase in pH was observed with increasing concentrations of Ca2+ (or Mg2+) and HCO32− in an aqueous solution of 4 mmol L−1 lactic acid. The antioxidative activity of the tea infusion was clearly independent of water hardness. Therefore, hard water is suitable for brewing Ishizuchi dark tea because tea brewed in hard water has a less sour taste, which is more favored, while maintaining the same degree of antioxidative ability.

Impacts of water hardness on coagulation-UF-NF process using aluminum salts

Surface water supplemented with reclaimed water can effectively alleviate water shortage. In this study, an integrated coagulation ultrafiltration-nanofiltration (CUF-NF) process was explored to treat reclaimed water. The effects of water hardness and different aluminum salts on the CUF-NF process were specifically investigated focusing the flocs size, membrane fouling, removal of organic matter, and disinfection by-product formation potential (DBPs-FP). Moreover, the treatment performance of two coagulants (i.e., AlCl3 and PACl25) were also compared. Results showed that the increased water hardness remarkably improved the UF membrane flux in CUF process (i.e., 51.4% to 188.3%), however, a slightly reduced flux (up to 29.5%) was noticed for NF membrane. In addition, parallel factor (PARAFAC) analysis showed that higher water hardness contributed to higher removal efficiencies of humic- (up to 40.6%) and protein-like substances (up to 60.6%), together with the reduction of total DBPs-FP (i.e., total trihalomethanes; 52.6% and total haloacetic acids; 20.4%). Furthermore, 2D-COS-FTIR also revealed the correlation between water hardness and the functional groups in UF/NF fouling layers. Overall, this work not only provides insight into the impacts of water hardness and different aluminum salts on CUF-NF processes treating surface water, but also provides new insights into the formulation of hardness standards for reclaimed water.

Effect of Water Hardness on Acute Aquatic Toxicity of Fatty Acid Salts.

The acute aquatic toxicity of anionic surfactants, including fatty acid salts, changes depending on water hardness. Generally, the acute aquatic toxicity of Daphnia magna is caused by the adsorption of surfactants and other substances. Despite the low environmental risk, the effect of water hardness on the acute aquatic toxicity of soap should be discussed to improve the assessment accuracy. Previously, we evaluated the effects of water hardness and the presence of an adsorbent on the acute aquatic toxicity of soap by performing an immobility test using D. magna in accordance with Japanese Industrial Standards (JIS) K 0229. Immobility was low at 50 ppm and a higher water hardness was indicated owing to the loss of interfacial activities caused by the formation of insoluble fatty acid calcium or magnesium complexes (soap scum). In the current study, we evaluate the effects of water hardness on the acute aquatic toxicity of C10, C12, C14, C16, and C18 saturated and C18:1 unsaturated fatty acid sodium salts. The EC50 is measured via an immobility test in accordance with JIS K 0229 using D. magna, and the surface tension is measured as an indicator of surface activity. Results show that the EC50 and surface tension curves change with water hardness in single and mixed solutions. C18:1 indicates the least change and the highest surface activity. Moreover, immobility change is not observed when C18:1 is filtered, whereas the immobility of other solutions decreased significantly. This implies the effect of soap scum on immobility, such as the clogging of gills by soap scum. Based on quantitative analysis, the percentage of C18:1 that transformed soap scum to its initial concentration exceeds 80%. This implies that calcium deficiency under 5 and 25 ppm water hardness affects the immobility of larval D. magna. The effects of soap scum clogging and calcium deficiency on D. magna should be considered before assessing the soap.

Effects of water hardness on the toxicity of heavy metals to Daphnia magna

The paper presents a comparative study of the toxicity of chromium and molybdenum, carried out in hard aquarium 0,14⁰Clark and soft natural 8,2⁰Clark waters. A decrease in water hardness leads to an increase in the acute toxicity of metals, which is expressed in a decrease in the values of semi-lethal concentrations by 3 times for molybdenum and 25 times for chromium.The results obtained show that the toxicity of metals can differ significantly in waters with different hydrochemical compositions. The data presented in the work can be used in the development of regional MPC standards.

The effect of water hardness on atopic eczema, skin barrier function: A systematic review, meta-analysis.

Hard domestic water has been reported to worsen atopic eczema (AE) and may contribute to its development in early life. To review the literature on the relationship between the effect of water hardness (high calcium carbonate; CaCO3 ) on (a) the risk of developing AE, (b) the treatment of existing AE and (c) skin barrier function in human and animal studies. We systematically searched databases (MEDLINE, Embase, Cochrane CENTRAL, GREAT and Web of Science) from inception until 30/6/2020. Human and animal observational and experimental studies were included. The primary outcomes were risk of AE and skin barrier function. Studies were meta-analysed using a random effects model. Evidence certainty was evaluated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Sixteen studies were included. Pooled observational data from seven studies on 385,901 participants identified increased odds of AE in children exposed to harder versus softer water (odds ratio 1.28, 95% CI 1.09, 1.50; GRADE certainty: very low). Two mechanistic studies in humans reported higher deposition of the detergent sodium lauryl sulphate in those exposed to harder versus softer water. Two randomized controlled trials comparing water softeners with standard care did not show a significant difference in objective AE severity with softened water (standardized mean difference 0.06 standard deviations higher, 95% CI 0.16 lower to 0.27 higher; GRADE certainty: moderate). There was a positive association between living in a hard water (range: 76 to>350mg/L CaCO3 ) area and AE in children. There is no evidence that domestic water softeners improve objective disease severity in established AE. There may be a role of water hardness in the initiation of skin inflammation in early life, but there is a need for further longitudinal and interventional studies.

Effect of water hardness on coffee composition and coffee preference by university students

Effect of water hardness on coffee composition and coffee preference by university students

The effects of water hardness on the growth, metabolic indicators and stress resistance of largemouth bass Micropterus salmoides

Water hardness varies regionally and optimal levels for fish are often species specific. It is generally assumed that largemouth bass, Micropterus salmoides, require elevated water hardness, but this has not yet been investigated. In this two-part study, M. salmoides juveniles were subjected to 100, 200, 400 and 600 mg/l CaCO3 (by CaCl2 additions) and the survival, growth, ammonia-N excretion/oxygen consumption rates, biochemical composition and ion-regulatory enzymes were measured after one month. Afterwards, fish were subjected to a sudden salinity shock test (SSST) at 10 ppt. In experiment 2, M. salmoides juveniles were subjected to 50 or 400 mg/l CaCO3 for one month and measured for the above-mentioned parameters. In experiments 1 and 2, both feed intake and feed conversion ratio (FCR) significantly decreased at 400 mg/l CaCO3, compared to 50 or 100 mg/l CaCO3, however, hardness had no significant effect on survival or growth. There was no significant effect to gill Na+/K+-ATPase or H+-ATPase activities; however, survival to SSST was significantly less at 50 or 100 mg/l than the other treatments. At 400 mg/l CaCO3, ammonia-N excretion/oxygen consumption rates were significantly less compared at 50 mg/l CaCO3, indicating greater energy expenditure at lower water hardness. These results demonstrate that while high water hardness substantially improves stress resistance in M. salmoides juveniles, they do not require high water hardness for optimal growth.

The synergistic toxicity of Cd(II) and Cu(II) to zebrafish (Danio rerio): Effect of water hardness

We have evaluated the interactive toxicity of Cu(II) and Cd(II) in water with different hardness levels using adult zebrafish (Danio rerio). Zebrafish were exposed to Cd(II) (0.2–22 μM) or Cu(II) (0.1–8 μM) in single or binary exposures in very soft, moderately hard or very hard water. The whole body burdens of Cd(II) and Cu(II) reflect the net effect of biouptake and elimination, mortality was the indicator of toxicity, and whole body major ion content was measured to assess ion regulatory functions. Cu(II) was found to be more toxic than Cd(II) for zebrafish, and Cu(II) and Cd(II) exhibited a significant synergistic effect. The toxicity of metal ions increased upon decreasing the ionic strength of the exposure medium, probably due to elevated competition between metal ions with other cations in hard water and increased activity of Ca2+ pathways in soft water treatments. Whole body metal accumulation and the accumulation rate of both Cu and Cd increased as the metal ion concentration in the exposure medium increased. Nevertheless, neither parameter explained the observed synergistic effect on mortality. Finally, we observed a significant loss of whole body Na+ in fish which died during the metal exposure compared to surviving fish, irrespective of exposure conditions. Such an effect was not observed for other major cations (K+, Ca2+ and Mg2+). This observation suggests that, under the applied exposure conditions, survival was correlated to the capacity of the organism to maintain Na+ homeostasis.

Effects of water hardness on the toxicity of heavy metals to Daphnia magna

Effects of water hardness on the toxicity of heavy metals to Daphnia magna

The effect of water hardness on the toxicity of graphene oxide to bacteria in synthetic surface waters

Graphene oxide (GO), used in a wide variety of applications, is increasingly being introduced into aquatic environments; this situation calls for research on GO toxicity to assess its environmental risks. In this study, the toxic effect of GO to E.coli was studied before and after its aggregation equilibrium in the synthetic surface waters (the soft water, moderately hard water, and hard water) to reveal the effects of GO aggregation and solution hardness. The cytotoxicity of GO increased with increasing solution hardness while decreased after GO aggregation. The 3 h 50% inhibitory concentration (IC50) values of dispersed GO in the soft water, moderately hard water, and hard water were 12.2 ± 2.2, 8.5 ± 1.5, and 4.0 ± 1.0 mg/L, respectively. After 24 h shaking (aggregation equilibrium) in the synthetic surface waters, the dispersed GO aggregated and the 3 h IC50 values of GO aggregates in the three synthetic waters were 40.3 ± 6.9, 15.9 ± 2.2, and 7.5 ± 1.5 mg/L, respectively. The dispersed GO sheets wrapped E. coli cells and cut the cell membrane, resulting in the disruption of cell membrane and the cell inactivation. With increasing water hardness, the heteroaggregation between GO sheets/aggregates and E. coli cells was enhanced, resulting in the increase of toxic effect. The GO aggregates could also entrap E.coli cells while exhibited limited effect on cell membrane disruption without sharp edges, thereby causing the lower toxic effect compared with the dispersed GO sheets. These outcomes shed new light on the assessment of ecological effects of GO.

Reduction of Fouling and Scaling by Calcium Ions on an UF Membrane Surface for an Enhanced Water Pre-Treatment

The control of fouling and scaling on heat and mass transfer surfaces is of major importance in processes as superficial water treatments, since it also improves the efficiency of the whole process from an energy saving point of view. The aim of the paper is to present the experimental results obtained in the inhibition of the fouling and scaling by calcium ions on an ultrafiltration membrane surface, by using citric acid as an additive. The last is an environmentally friendly additive−a so-called “green additive”, which may represent a reliable alternative to phosphorous and nitrogen based compounds typically used as inhibitors, since it has the characteristics of being non-toxic, non-bio accumulating, and biodegradable. The experimental plant is made of a tangential flow system on a lab scale equipped with a flat sheet ultrafiltration polymeric membrane, whose cut-off is 650 nm. In the first series of experiments, the effect of water hardness and its fouling effect due to calcium ions on membrane permeability has been measured in the range of potable waters. Then, the scaling effect of high calcium concentration in solution (supersaturated conditions) has been quantified by measuring the increase in weight of the membrane, with and without the addition of citric acid as an additive; moreover, the retarding effect of citric acid has been evaluated through the measurement of the induction times for the nucleation of calcium sulfate dihydrate (used as model scalant for fouling). Experiments have been carried out at two different supersaturation ratios (S = 2.25–2.60), at room temperature, in the absence of any additive, and with a citric acid concentration varying in the range 0.01 to 0.50 g/L. Experimental results have shown that the addition of citric acid in solution delays the induction times for gypsum crystals nucleation; moreover, it mitigates the phenomenon of membrane fouling and reduces the pressure drops by allowing an acceptable permeate flow for a longer duration.

Effect of water hardness, temperature, and tank wall color, on the effectiveness of swim bladder inflation and survival of Eurasian perch (Perca fluviatilis, L.) larvae reared under controlled conditions

The study shows how water temperature, water hardness, and color of tank affect the swim bladder inflation effectiveness (SBIE) and survival in Eurasian perch larvae in controlled conditions. Three separate experimental rearings (in 50-L tanks) were conducted, where (1) water temperature (12 days, 3000 ind./tank; 15, 20, and 25 °C), (2) water hardness (12 days, 4600 ind./tank; 15 °C; and 5, 10, and 15°n), and (3) tank wall color (20 days, 25,000 ind./tank; tanks with black and white walls; 15 °C) constituted tested variables. During all of the experiments, the photoperiod was 24 h (24L:0D), and the intensity of light was 1500 lx at the water surface. In experiments 1 and 2, perch larvae were not fed and in experiment 3, from 5-day post-hatch (DPH), they were fed ad libitum with Artemia sp. nauplii. In experiment 1, the highest SBIE was observed for larvae reared at 15 °C (20.6 ± 1.1%) for 20 °C and 25 °C; the maximum SBIE was significantly lower (8.4 ± 2.9% and 13.0 ± 5.8%, respectively; p < 0.05). The mortality trend was similar for all of the tested temperatures, although at higher temperatures, the larvae were seen to die sooner. In experiment 2, there were no statistical differences (p > 0.05) in mortality of larvae and in final SBIE. The results of experiment 3 clearly suggests that the white tanks caused a significant (p < 0.05) reduction in survival rate (4.9 ± 3.2% and 24.6 ± 6.4%, for white and black tanks, respectively) as well as SBIE (7.7 ± 2.7% and 32.9 ± 3.6%, for white and black tanks, respectively; p < 0.05). The outcomes indicate that Eurasian perch larval rearing at 15 °C in black tanks is preferred.

Effect of water hardness on the interaction of cationic dye with anionic surfactants

ABSTRACTThe effect of water hardness causing ions on the critical micelle concentration (cmc) of surfactants was studied using conductivity measurement. Spectrophotometric and conductometric studies of dye and surfactant interaction under the influence of water hardness causing ions were also investigated. It was found that with increasing hardness in water, cmc of the surfactants tends to decrease. The change in the colour of the solution was observed as the degree of hardness increases. Hardness of water can consider as a major contributor of fading or change in colour during washing and cleaning of dyed material. Dye in a surfactant solution containing varying amount of hardness causing ions undergoes a blue shift in the visible region and red shift in ultraviolet region. The comparison between sodium dodecylsulphate (SDS) and saponin natural surfactant showed that turbidity was observed only in the aqueous solution of SDS in the presence of very hard water.

Effect of Water Hardness and pH on Adsorption Kinetic of Arsenate on Iron Oxide

Effect of Water Hardness and pH on Adsorption Kinetic of Arsenate on Iron Oxide

물의 경도가 빵의 제조적성에 미치는 영향

물의 경도가 빵의 제조적성에 미치는 영향

Effect of Water Hardness and pH Value on the Corrosion Behaviour of Copper in an Emulsion

Effect of Water Hardness and pH Value on the Corrosion Behaviour of Copper in an Emulsion

The Effect of Water Hardness on Surfactant Deposition after Washing and Subsequent Skin Irritation in Atopic Dermatitis Patients and Healthy Control Subjects

Living in a hard water area is associated with an increased risk of atopic dermatitis (AD). Greater skin barrier impairment after exposure to surfactants in wash products, combined with the high calcium levels of hard water and/or high chlorine levels, is a compelling mechanism for this increase. The purpose of this study was to investigate this mechanism in individuals with and without a predisposition to skin barrier impairment. We recruited 80 participants: healthy control subjects and AD patients with and without FLG mutations. The skin of each participant was washed with sodium lauryl sulfate in water of varying hardness levels and chlorine concentrations, rinsed, and covered with chambers to determine the effects of surfactant residues. Sites washed with hard water had significantly increased sodium lauryl sulfate deposits. These deposits increased transepidermal water loss and caused irritation, particularly in AD patients carrying FLG mutations. Aclear effect of chlorine was not observed. Water softening by ion-exchange mitigated the negative effects of hard water. Barrier impairment resulting from the interaction between hard water and surfactants is a contributory factor to the development of AD. Installation of a water softener in early life may be able to prevent AD development. An intervention study is required to test this hypothesis.

Acute toxicity of chlorpyrifos and carbosulfan to glochidia of the freshwater mussel Hyriopsis bialata Simpson, 1900.

The acute toxicity of carbosulfan and chlorpyrifos in formulated pesticides to glochidia (larvae) of the freshwater mussel (Hyriopsis bialata Simpson, 1900) was evaluated under static conditions in moderately hard dechlorinated tap water. Measured pesticide concentrations were 26 to 34% lower than nominal concentrations; therefore, all results are expressed in terms of measured active ingredient. Carbosulfan was relatively non-toxic to the mussel larvae with median effective concentrations (EC50) of carbosulfan at 24 and 48h greater than 0.10mg/L. The EC50s of chlorpyrifos at 24 and 48h were 0.083 and 0.078mg/L, respectively (measured concentrations). The 48-h EC50 of a combined exposure to a mixture of chlorpyrifos and carbosulfan at a constant ratio of 2.9:1 was 0.0142:0.049mg CP:CB/L. In a separate experiment, the effect of water hardness on carbosulfan, chlorpyrifos, or a combined exposure was assessed using glochidia exposed to either soft, moderately hard, or hard reconstituted water. There was no effect of water hardness on the survival of glochidia after 24- or 48-h exposure to carbosulfan. The chlorpyrifos 48-h EC50s in soft water, moderately hard water, and hard water were 0.18, 0.11, and 0.16mg/L, respectively. The data indicate that the lowest water hardness resulted in the highest survival of glochidia, whereas an increase to moderate water hardness resulted in significantly decreased survival of glochidia (F=15.5, P<0.05). The EC50s of a combined exposure at 48h in soft water, moderately hard water, and hard water were 0.124:0.044, 0.132:0.047, and 0.064:0.022mg CP:CB/L, respectively. The data indicate that the combined toxicity was lowest at low and moderate water hardness, whereas an increase to high water hardness resulted in a significantly decreased survival of glochidia. After 48h, the toxicity of the combined chlorpyrifos and carbosulfan exposure in soft and hard water was greater than that of chlorpyrifos alone.