Water Odor Research Articles

Ions Speciation at the Water–Air Interface

In typical aqueous systems, including naturally occurring sweet and salt water and tap water, multiple ion species are co-solvated. At the water-air interface, these ions are known to affect the chemical reactivity, aerosol formation, climate, and water odor. Yet, the composition of ions at the water interface has remained enigmatic. Here, using surface-specific heterodyne-detected sum-frequency generation spectroscopy, we quantify the relative surface activity of two co-solvated ions in solution. We find that more hydrophobic ions are speciated to the interface due to the hydrophilic ions. Quantitative analysis shows that the interfacial hydrophobic ion population increases with decreasing interfacial hydrophilic ion population at the interface. Simulations show that the solvation energy difference between the ions and the intrinsic surface propensity of ions determine the extent of an ion's speciation by other ions. This mechanism provides a unified view of the speciation of monatomic and polyatomic ions at electrolyte solution interfaces.

Electronic nose application for detecting different odorants in source water: Possibility and scenario

The problem of taste and odor (T&O) in drinking water is a widespread societal concern and highlights substantial challenges related to the detection and evaluation of odor in water. In this study, the portable electronic nose PEN3, which is equipped with ten different heated metal sensors, was applied to analyze its applicability, feasibility and application scenarios for the detection of typical odorants, such as 2-methylisobornel (2-MIB), geosmin (GSM), β-cyclocitral, β-ionone, and other T&O compounds in source water, while avoiding uncertainties and instability related to manual inspection. All the T&O compounds could be effectively differentiated by principal component analysis (PCA). Linear discriminant analysis (LDA) showed that the odors varied greatly between different samples and could be effectively distinguished. As the odorant concentration increased, the sensor response intensity of the primary identification sensors R6 and R8 increased with a significant positive correlation. For Microcystis aeruginosa, an algae that produces odorants, PCA could distinguish the odors of algae at a series of densities at different concentrations. The responses of R10 showed a significant increase with increasing algae density, implying the production of more aliphatic hydrocarbons and other odor compounds. The results indicated that the electronic nose could provide a promising alternative to traditional unstable and complex detection methods for the detection of odorous substances in surface water and early warning of odor events. This study aimed to provide technical support for rapid monitoring and early warning of odorants in source water management.

Remediation of the black-odor water body by aquatic plants with plant growth-promoting Rhizobacteria: Lab and pilot tests

To explore an effective, environmental, rapid operating method to repair black and odor water bodies, water samples and sediment samples collected from a polluted municipal lake in Daqing, China, were directly tested in transparent barrels (10 L). Seven groups of optimizing parameters obtained the optimal operating method, and the max removal rate of COD, NH4+-N, NO3−-N, and TP were achieved (89.18%, 59.65%, 69.50%, and 75.61%) by using aquatic plants with plant growth-promoting Rhizobacteria (PGPR). To further verify the method's effectiveness, lager scale tests were conducted based on a water tank (216 L), and similar removal rates were obtained within 48 h. The water quality index and microbial community structure analysis revealed the mechanisms of the interaction among plants, microorganisms, and pollutants and the main biological processes during water body remediation. Finally, the cost of water body remediation by using this method was estimated.

Physical Water Quality and Intestinal Protozoa Contamination on Household Water in Ajung District, Jember Regency

Intestinal protozoa infections are still a major health problem in worldwide. The prevalence of intestinal protozoa infections are relatively high in countries facing lack of safe drinking water and lack of suitable sanitation facilities. Lack of sanitation facilities, open defecation, and contamination of environmental feces can make water quality worse, both in terms of physically, chemically, and biologically. Physical water quality is poor when the household water used daily does not meet the standard parameters of the physical water quality standard. The purpose of this study was to determine the relationship between physical water quality and intestinal protozoa contamination in household water in Ajung District, Jember Regency. This type of research is an observational analytic study with a cross sectional research design. The research method used is the correlation method, namely the relationship between physical water quality and intestinal protozoa contamination in household water. The population in this study is household water in Ajung District, Jember Regency. Data analysis consisted of univariate analysis to see the distribution and percentage of temperature, total dissolves solid, color, odor, and intestinal protozoa contamination in household water, and then bivariate analysis using the Chi-square test to analyze physical water quality and intestinal protozoa contamination. The conclusion is there is a relationship between physical water quality and intestinal protozoa contamination in household water.

Public Perception of Drinking Water Quality in Bekasi City, Indonesia

The study of public perceptions regarding drinking water quality is essential for understanding how people choose and manage safe drinking water for consumption. Understanding public perceptions and the actual drinking water quality can also help to ensure the right policies to improve water quality and minimize possible risks. This study aims to analyze the association between public perceptions and the actual drinking water quality in Bekasi City, Indonesia. This study was conducted in three urban villages (Jatiluhur, Jatirangga, Sumur Batu) in Bekasi City, Indonesia, in the dry season (September-October 2021). The survey was conducted by distributing questionnaires and collecting groundwater samples at point-of-use for drinking (n=51 households). Drinking water samples were analyzed for pH, TDS, Total Coliform, and Escherichia coli. Among 51 households, 100% of respondents answered that the drinking water was safe and had good taste, 5% answered that there was a problem with the appearance (color/particles), and 2% of respondents answered that there was an odor in the drinking water consumed. Logistic regression was performed, and the result shows that measured drinking water quality does not significantly contribute to public perception of drinking water quality

PHYSICAL WATER QUALITY CONTAMINATED BY SOIL-TRANSMITTED HELMINTHS IN SUMBERSARI DISTRICT, JEMBER REGENCY

Introduction: Soil-Transmitted Helminth (STH) or worm infection is an infection caused by intestinal nematode worm group that can be infectious through the soil medium. One straightforward transmission route is through contaminated water consumption as water is needed daily. This study aims to know the association between quality of physical water and STH contamination in the Sumbersari District, Jember Regency, water sources. Methods: This research is an analytical observational study with a cross-sectional design. Data was obtained from water physical quality inspection and STH contamination in the water laboratory. The 30 samples were taken purposively. Results and Discussion: The results of the data analysis of the association between water temperature and STH contamination showed a p-value of 0.014, the association between watercolor with STH contamination showed a value of 0.566, and the association between odor and TDS of water with STH contamination was not analysed. Statistics analysis results showed a significant association between the quality of water physics and STH contamination in the water sources in Sumbersari District, Jember Regency, with a score of 0.022. Conclusion: The physical quality of water has a positive correlation with STH contamination in water sources in Sumbersari District, Jember Regency.

The effect of pH on taste and odor production and control of drinking water

Abstract There is general agreement that pH is an important parameter in many drinking water treatment and control processes such as taste and odor (T&O) control. However, pH is not usually targeted as a primary control parameter and its effects on T&O are often overlooked in favor of other treatment issues. When it comes to T&O control, treatment alternatives typically focus on oxidation and adsorption processes. Whether within these processes or separately, pH plays an important role and the effects on T&O should be considered. For example, pH plays a role in the speciation of odorous chemicals in the environment, some of which arise in wastewater treatment and others from the occurrence of metals in water. During blooms of algae and cyanobacteria in surface water, pH is an important parameter affecting water quality and T&O. Finally, as pH is important for the sample preservation and analysis of T&O compounds, pH is important in the fate and control of T&O. The objective of this article is to better understand the various ways that pH can influence T&O production, control, and analysis of odorants in water and encourage advancement in the state of the science of pH optimization for T&O control.

Effective catalytic hydrodechlorination removal of chloroanisole odorants in water using palladium catalyst confined in zeolite Y

Chloroanisoles is a class of odorous pollutants commonly identified in drinking water. In the present study, we confined noble metal palladium (Pd) in the micropores of zeolite Y (ie-Pd@Y) using an ion exchange method, and applied it for the catalytic hydrodechlorination removal of chloroanisoles (represented by 2,4,6-trichloroanisole/TCA) in water. Pd supported on zeolite Y surface (im-Pd/Y, prepared by conventional impregnation method) was used as the benchmarking catalyst. The characterization results revealed that ie-Pd@Y had smaller Pd particle size and higher Pdn+/Pd0 ratio than im-Pd/Y. The catalytic hydrodechlorination of TCA followed a concerted dechlorination pathway and the Langmuir-Hinshelwood model. The ie-Pd@Y catalysts with different Pd loadings exhibit excellent catalytic activities with more than 95% of TCA removed within 30 min, which is far superior to the im-Pd/Y catalysts (27–70%). Moreover, due to the confinement effect of zeolite Y, ie-Pd@Y displayed enhanced catalytic stability as compared with im-Pd/Y. The initial activity of ie-Pd@Y was more than 20 times higher than that of im-Pd/Y after five reaction cycles. Additionally, with the assistance of sieving effect, ie-Pd@Y displayed much stronger capability against the interference from dissolved organic matter than im-Pd/Y. The present results demonstrate that the confined catalysts ie-Pd@Y can be applied in liquid phase catalytic hydrogenation to effectively eliminate halogenated odorants in waters.

Risk perception from the consumption of untreated drinking water in a small island community.

A small island community in Malaysia uses gravity-fed drinking water, and rejected water treatment by the authorities. This study was conducted to evaluate the community's risk perception towards their untreated water supply by interviewing one adult per household in four out of eight villages on the island. The survey asked questions on risk perception, socioeconomic characteristics, and perception of water supply quality. Water samples were collected from a total of 24 sampling locations across the four villages, and 91.7% of them were positive for E.coli. The study surveyed 218 households and found that 61.5% of respondents agreed to some degree that the water is safe to drink without treatment, while 67.9% of respondents disagreed to some degree that drinking tap water is associated with health risks, and 73.3% of respondents agreed to some degree that it is safe to drink directly from taps that are fitted with water filters. Using factor analysis to group the risk perception questions and multivariable GLM to explore relationships with underlying factors, the study found that older respondents, lower income level, positive water odour perception and positive water supply reliability perception lowers risk perception. The village of residence also significantly affects the risk perception level in the model.

Phosphorus accelerate the sulfur cycle by promoting the release of malodorous volatile organic sulfur compounds from Microcystis in freshwater lakes

Volatile organic sulfur compounds (VSCs) released by algae are of great significance in sulfur cycle, climate regulation and biological information transmission, and they also caused taste and odor in freshwaters. However, the categories, sources, and environmental regulatory factors of VSCs in freshwaters were less known. Here, we show that eight common freshwater cyanobacterium Microcystis, which bloom in freshwaters over the world, are found to be important producers of VSCs. Dimethyl sulfide (DMS), dimethyl disulfide (DMDS) and isopropyl methyl sulfide (IPMS) are the main VSCs with the highest concentrations 184.81 nmol/L, 162.01 nmol/L and 101.55 nmol/L, respectively. The amount of VSCs released from those Microcystis varied greatly, M. elabens, M. panniformis and M. flos-aquae released the largest amount of VSCs (1260.52 nmol S/L, 1154.75 nmol S/L and 670.58 nmol S/L), and M. wesenbergii had the smallest release amount. We also found for the first time that phosphorus (P) was one of the important factors for the regulation VSCs from most Microcystis. P can elevate the release of DMS by promoting the biomass and DMS yields of most Microcystis in the range 0.05 mg/L to 0.5 mg/L. Similar results were also found in 16 lakes at three different spatiotemporal scales. Overall, we revealed that the common freshwater Microcystis were able to release diverse thioethers, and the major VSCs were significantly influenced by water P concentrations. In the context of global freshwater eutrophication and Microcystis bloom, freshwater cyanobacteria driven sulfur cycle and water odor will probably be further strengthened.

Geosmin과 2-MIB의 GC/MS 분석을 위한 전처리 방법 비교 연구

Geosmin and 2-methylisoborneol are representative odorous compounds that smells like mud or mold after rain, and are secondary metabolites generated by various organisms such as blue-green algae and actinomycetes. These substances, which are detected in raw water and purified water, are odor substances that have not been found to be harmful to the human, but induce an unpleasant taste and odor in tap water and cause distrust in drinking. Therefore, research on the cause and removal methods is continued, and a sensitive and accurate detection method is required. In this study, three pretreatment methods(LLE, SPE, HS-SPME) and SPME arrow were compared for the detection of Geosmin and 2-MIB. In the four methods, the limits of quantitation were 0.2-0.8 ng/L for Geosmin and 0.6-1.1 ng/L for 2-MIB. The accuracy and precision of all four methods met the target values for quality control, but the HS-SPME and the SPME Arrow showed the most satisfied results.

Developing early warning systems to predict water lead levels in tap water for private systems

Lead is a chemical contaminant that threatens public health, and high levels of lead have been identified in drinking water at locations across the globe. Under-served populations that use private systems for drinking water supplies may be at an elevated level of risk because utilities and governing agencies are not responsible for ensuring that lead levels meet the Lead and Copper Rule at these systems. Predictive models that can be used by residents to assess water quality threats in their households can create awareness of water lead levels (WLLs). This research explores and compares the use of statistical models (i.e., Bayesian Belief classifiers) and machine learning models (i.e., ensemble of decision trees) for predicting WLLs. Models are developed using a dataset collected by the Virginia Household Water Quality Program (VAHWQP) at approximately 8000 households in Virginia during 2012–2017. The dataset reports laboratory-tested water quality parameters at households, location information, and household and plumbing characteristics, including observations of water odor, taste, discoloration. Some water quality parameters, such as pH, iron, and copper, can be measured at low resolution by residents using at-home water test kits and can be used to predict risk of WLLs. The use of at-home water quality test kits was simulated through the discretization of water quality parameter measurements to match the resolution of at-home water quality test kits and the introduction of error in water quality readings. Using this approach, this research demonstrates that low-resolution data collected by residents can be used as input for models to estimate WLLs. Model predictability was explored for a set of at-home water quality test kits that observe a variety of water quality parameters and report parameters at a range of resolutions. The effects of the timing of water sampling (e.g., first-draw vs. flushed samples) and error in kits on model error were tested through simulations. The prediction models developed through this research provide a set of tools for private well users to assess the risk of lead contamination. Models can be implemented as early warning systems in citizen science and online platforms to improve awareness of drinking water threats.

Odor, Taste and Toxin Producing Cyanobacteria and Algae in Surface Waters of North Central Province

North Central Province, the largest province in Sri Lanka, consists of two main districts; Anuradhapura and Polonnaruwa with a semi-arid climate. During the present study, Padaviya Wewa, Tissa Wewa, Nuwara Wewa, Kala Wewa, Basawakkulama Wewa and Rajanganaya Wewa from Anuradhapura District and Parakrama Samudraya, Minneriya Wewa, Ambagas Wewa, Kaudulla Wewa, and Girithale Wewa from Polonnaruwa District were studied to evaluate the potential odor, taste and toxin-producing cyanobacteria and algae in the water sources, since there’s a lack of scientific data on plankton who are capable of producing odor, taste and toxins. The studied water bodies are being used for the purposes of drinking, fisheries and recreational activities. Sampling was done during November 2020 in triplicates and phytoplankton were observed under the microscope following Lugals’ sedimentation procedure. According to the observations, the total phytoplankton density (Cyanobacteria+Algae) was higher in the Anuradhapura District (1176.33±129.19 cells/L) than in the Polonnaruwa District (699.20±28.76 cells/L). The phytoplankton groups found in the studied water bodies belong to Bacillariophyta, Chlorophyta, Chrysophyta and Cyanophyta. The most abundant species was Microcystis sp. both in the Anuradhapura District (929±123.02 cells/L) and in the Polonnaruwa District (462±22.79 cells/L) and the species is responsible for producing the cyanotoxins, microcystin (MC) and anatoxins and also responsible for causing taste and odor in water. Except for Microcystis sp., Cylindrospermopsis sp. was found in high numbers (163.50±13.52 cells/L) in Anuradhapura, which produces the cyanotoxins cylindrospermopsin (CYN), anatoxin, and saxitoxin and also gives rise to taste and odor in water. Anabaena sp. found in Anuradhapura (89.00±5.15 cells/L) and Oscillatoria sp. found in Polonnaruwa (191.00±0.00 cells/L) were also responsible for the production of cyanotoxins such as, MC, CYN, saxitoxin, and anatoxin and add taste and odor to the water too. Further, Merismopedia sp. was found both in Anuradhapura (94.00±4.54 cells/L) and Polonnaruwa (118.40±12.39 cells/L), which is responsible of producing toxic lipopolysaccharides. Among the observed algal species, Dinobryon sp. was detected in low numbers in Polonnaruwa, which is also responsible for the occurrence of taste and odor in water. Based on the assessment of phytoplankton in the North Central Province, it is clear that, the surface water is not pleasant and healthy enough to provide safe drinking water to the community, especially, due to the presence of unpleasant taste, odor and cyanotoxins producing organisms.
 Keywords: North Central, Odor, Taste and toxins, Cyanobacteria, Algae

Interlaboratory comparison of the intensity of drinking water odor and taste by two-way ordinal analysis of variation without replication.

A case study of ordinal data from human organoleptic examination (sensory analysis) of drinking water obtained in an interlaboratory comparison of 49 ecological laboratories is described. The recently developed two-way ordinal analysis of variation (ORDANOVA) is applied for the first time for the treatment of responses on the intensity of chlorine and sulfurous odor of water at 20 and 60 °C, which is classified into the six categories from 'imperceptible' to 'very strong'. The one-way ORDANOVA is used for the analysis of the 'salty taste' intensity of the water. A decomposition of the total variation of the ordinal data and simulation of the multinomial distribution of the data-relative frequencies in different categories allowed the determination of the statistical significance of the difference between laboratories in classifying chlorine or sulfurous odor intensity by categories, while the effect of temperature was not significant. No statistical difference was found between laboratories on salty taste intensity. The capabilities of experts to identify different categories of the intensity of the odor and taste are also evaluated. A comparison of the results obtained with ORDANOVA and ANOVA showed that ORDANOVA is a more useful and reliable tool for understanding categorical data such as the intensity of drinking water odor and taste.

Mathematical Modeling & Engineering Design of Wastewater Treatment Unit for Al-Kut Gas Filling Company

New talented treatment method without chemicals and with minimum operational cost was performed to treat industrial waste water discharged by a hydrostatic test performed on the gas bottles maintenance workshops to reuse it. A common method by Tarleton and Wakeman was used to select the general treatment philosophy, The implementation of this study was carried out on three stages, water sample analysis, simulates the proposed preliminary design and detailed engineering designing for the first stage, a sample of waste water was brought from Al-Kut Gas Filling Company - maintenance section and tested for settling, aeration, and filtration. The experiments showed that the most of sediments were insoluble but rather than suspended in water and can be removed by settling. Furthermore, aeration test showed that concentrated Thiophene odor in water was removed at 50 C of water with diffused air bubbling. On the other hand, filtration of using 10 Micron filter paper was achieved to eliminate the rest of tiny sedimentation. Secondly, general dimension of equipment was calculated by engineering design equation according to qualitative and quantitative analyses of waste water. Accordingly, a set of experiments of simulation using ANSYS V19.0 and Eulerian – Eulerian as mathematical model were performed for the 3D two phase flow sedimentation tank with capacity of 5 m3/hr to find the optimum sedimentation performance by testing of the modifications on the tank geometry (baffle depth, distance between baffle and inlet, hooper). Simulation results showed that the optimum tank geometry (0.86 m Baffle depth with inclined part, 2.5m distance between baffle and inlet, hooper within V type geometry W=1.67m/0.29 m, D=1.03 m and tank dimension (L=10m, W=2.5, H=2.5 with slope angle = 2o) with 49.5 volume % in sediment layer with a minimum sediment layer height. 
 The third stage included an accomplishment of the Preliminary and detailed engineering design of the entire unit by SOLIDWORKS software to be ready for prototyping.

Co-occurrence of odor-causing dioxanes and dioxolanes with bis(2-chloro-1-methylethyl) ether in Huangpu River source water and fates in O3-BAC process

In recent years, dioxanes and dioxolanes have been intermittently detected in water environment and have caused several offensive drinking water odor incidents worldwide. In this study, the co-occurrence of eight dioxanes, twelve dioxolanes and bis(2-chloro-1-methylethyl) ether was investigated in Huangpu River watershed to explore potential sources and contributions to septic/chemical odor. Totally 8 dioxanes and dioxolanes were detected in river, with 1,4-dioxane (212 −8310 ng/L) and 2,5,5-trimethyl-1,3-dioxane (n.d.−133 ng/L) as the dominated dioxanes, 2-methyl-1,3-dioxolane (49.5 −2278 ng/L), 2-ethy-4-methyl-1,3-dioxolane (n.d.−167 ng/L) and 1,3-dioxolane (n.d.−225 ng/L) as the major dioxolanes. Bis(2-chloro-1-methylethyl) ether was detected (n.d.−1094 ng/L) with significant correlation with dioxanes and dioxolanes, illustrating their similar polyester resin-related industrial origins. 2-Ethy-4-methyl-1,3-dioxolane, 2,5,5-trimethyl-1,3-dioxane and bis(2-chloro-1-methylethyl) ether with individual maximum odor activity value above 1, should contribute to septic/chemical odor in Huangpu River water. The increased concentrations of these chemicals in the downstream of some industrial areas illustrated the association with industrial discharge. Fates in a waterworks using the river water as source water were further explored. The adopting ozone-biological activated carbon treatment could permit a relatively high removal for bis(2-chloro-1-methylethyl) ether and 2,5,5-trimethyl-1,3-dioxane (> 80%), while limited removal for other chemicals. This study provides valuable information for the management of drinking source water and water environment.

Removal effect and mechanism of amphiphilic chitosan modified microbubbles on microcystis aeruginosa

Algal blooms in lake and reservoir water lead to water quality problems, including water odors, algal toxins, and disinfection byproducts. A novel dissolved air flotation process that incorporates positively charged bubbles (PosiDAF) can effectively remove algae in lakes and reservoirs. Chitosan, as a modified bubble agent in the PosiDAF process, has attracted extensive attention due to its natural nontoxicity and good flocculation properties. In this paper, three types of amphiphilic chitosan with different lengths of carbon chains were prepared via amphiphilic modification and were used as bubble modifiers to remove microcystis aeruginosa in the PosiDAF process. The effects of algae removal under different dosage of modifiers were compared, and the role of algal organic matter was investigated. Results showed that the water solubility of chitosan was markedly enhanced after amphiphilic modification, while thermal stability were decreased. When using butyl-N-2 hydroxypropyl trimethyl chitosan ammonium chloride (C4-HTCC), the effect of modified air flotation was the best, and the removal ratio of algae was 93.47% when the C4-HTCC dosage was 1.0 mg/L. The presence of AOM enhanced the overall effect of algae removal, and electrostatic attraction was the primary adhesion mechanism of the microbubble-amphiphilic chitosan-algal organic matter-algal cell system. In addition, adsorption bridging and net trapping also have positive effects on algae removal.

Tap Water Aesthetics: The Tail That Wags the Dog

Over the years, aesthetic problems have been a widespread nuisance that comes and goes and is forgotten until the problems arise again. The taste, odor, and appearance of water that consumers enjoy affects their perceptions of water safety and reliability.

The Status Quo of Causal Substance Exploration for Fishy Odor in Raw Water for Taps

The Status Quo of Causal Substance Exploration for Fishy Odor in Raw Water for Taps

Data Analytics Determines Co-occurrence of Odorants in Raw Water and Evaluates Drinking Water Treatment Removal Strategies.

A complex dataset with 140 sampling events was generated using triple quadrupole gas chromatography-mass spectrometer to track the occurrence of 95 odorants in raw and finished water from 98 drinking water treatment plants in 31 cities across China. Data analysis identified more than 70 odorants with concentrations ranging from not detected to thousands of ng/L. In raw water, Pearson correlation analysis determined that thioethers, non-oxygen benzene-containing compounds, and pyrazines were classes of chemicals that co-occurred, and geosmin and p(m)-cresol, as well as cyclohexanone and benzaldehyde, also co-occurred, indicating similar natural or industrial sources. Based on classification and regression tree analysis, total dissolved organic carbon and geographical location were identified as major factors affecting the occurrence of thioethers. Indoles, phenols, and thioethers were well-removed through conventional and advanced treatment processes, while some aldehydes could be generated. For other odorants, higher removal was achieved by ozonation-biological activated carbon (39.3%) compared to the conventional treatment process (14.5%). To our knowledge, this is the first study to systematically identify the major odorants in raw water and determine suitable treatment strategies to control their occurrence by applying data analytics and statistical methods to the complex dataset. These provide informative reference for odor control and water quality management in drinking water industry.