Absorbance based water quality indicators as parameters for treatment process control with respect to organic substance removal

The removal of per-and polyfluoroalkyl substances (PFASs) presents a challenge for drinking water providers. Guidelines for PFAS concentrations in final drinking water are regularly updated to ever-decreasing values, and conventional drinking water treatment plants are not designed to remove PFASs. Currently, the most frequently used removal technique, adsorption to granular activated carbon (GAC), is often considered challenging. High-pressure membranes, such as nanofiltration (NF), have been shown to remove PFASs efficiently. However, the creation of a waste stream comprised of at least 10% of the feedwater volume is recognized as a major drawback of this technique. In this study, a NF pilot plant was operated at a drinking water treatment plant in the city of Uppsala, Sweden, for six months. NF removed up to >98% of PFASs and fulfilled other water quality targets, such as the removal of uranium-238, dissolved organic carbon (DOC), and mineral hardness from the raw water. The concentrate from the pilot plant was treated with two different GAC materials and two different anion exchange (AIX) resins in column tests, where the superior performance of AIX over GAC was observed in terms of PFAS removal. PFAS adsorption curves for GAC were found to superimpose each other for the two water types if normalized to the specific throughput of DOC. The application of the freely available PHREEQC model revealed improvement possibilities in terms of resin properties. A cost analysis using the column test results compared GAC filtration to the combination of NF with adsorption materials. Treatment costs were found to be largely dependent on the PFAS drinking water treatment goals and concentrate discharge requirements, which highlight the economic consequences of prevailing guidelines for drinking water and discharge to the environment. The results of this study provide both the scientific community as well as drinking water providers with important insights into the application of NF for PFAS removal during drinking water treatment as well as that mechanistic and economic aspects of NF treatment and the management of the resulting concentrate.

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“…Separate regressions were used for AIX and GAC effluents as well as for feedwater (Figure S.2 in the SI). , …”

Section: Methodsmentioning

confidence: 99%

The Price of Really Clean Water: Combining Nanofiltration with Granular Activated Carbon and Anion Exchange Resins for the Removal of Per- And Polyfluoralkyl Substances (PFASs) in Drinking Water Production

Franke

Ullberg

McCleaf³

et al. 2021

ACS EST Water

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“…Previous literature studies have highlighted the correlation between UV 254 and other parameters such as TOC, COD, and BOD (chemical and biological oxygen demand). 43 In this analysis, UV 254 was also found to track TOC measurements of different oil-in-water emulsions containing aromatic type oils as demonstrated in Table 7 .…”

Section: Resultsmentioning

confidence: 86%

Protocol for Preparing Synthetic Solutions Mimicking Produced Water from Oil and Gas Operations

et al. 2021

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Produced water (PW) is the water associated with hydrocarbons during the extraction of oil and gas (O&G) from either conventional or unconventional resources. Existing efforts to enhance PW management systems include the development of novel membrane materials for oil–water separation. In attempting to evaluate these emerging physical separation technologies, researchers develop various formulations of test solutions aiming to represent actual PW. However, there is no clear scientific guideline published in the literature about how such a recipe should be prepared. This article develops a protocol for preparing synthetic solutions representing the characteristics and behavior of actual PW and enabling the performance comparisons of different oil–water separation membranes at the bench scale level. In this study, two different brine recipes were prepared based on salts present in actual PW, crude oil was used as the hydrocarbon source, and a surfactant was added to disperse the oil into the aqueous phase. The recipe is accessible to the wider scientific community and was proven to be reproduceable, homogenous, stable, and comparable to actual PW field samples through analytical monitoring measurements and bench scale evaluations.

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“…According to authors as Weishaar et al (36) and Gerrity et al (17) , the measurement of UV absorbance has taken a new significance for the drinking water industry, due to offer a promising tool due to minimal equipment, expertise, faster response times, and lower costs to supplement existing analytical methods based on liquid or gas chromatography and mass spectrometry, being an important complement to operate a drinking water treatment plant (20) , due to allow a real time monitoring of processes performance.…”

Section: Evaluation Of the Uv Absorbance Spectrummentioning

confidence: 99%

“…These factors demonstrate the need for alternative procedures (18) . Different pollutants have different chemical structure, and the absorbance occurs at different wavelengths (19) ; the organic compounds absorb UV light (wavelength λ: 190 -380 nm) proportionally to their concentration, which is a useful parameter for the qualitative estimation of organic substances, in addition to offering advantages such as versatility, low cost (18,3) and the simplicity of measurement (20) .…”

Section: Introductionmentioning

confidence: 99%

Applicability of UV absorbance as an indicator of Atrazine presence into risk management of water supply watersheds

Lozada

Barba-Ho

Fuentes-López

et al. 2021

inycomp

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The type of hazards and hazardous events in watersheds, depend on land uses around them. Atrazine is an organic pollutant widely applied as a pesticide and it is a potential chemical hazard present in water sources, which cause water pollution and negative effects on aquatic life and human health, due to its high solubility and persistence in soil. However, for developing countries, monitoring and quantification of atrazine can be complex and costly; thus, to contribute to establishing strategies for risk assessment in water supply watersheds, it was evaluated the potential use of an easy, rapid and low-cost technique such as ultraviolet (UV) absorbance to identify the presence of atrazine. It was conformed distilled and surface water samples doped with Atrazine, and there were correlated with the UV typical spectrum indicator of organic material presence (wavelength λ: 200 - 300 nm). The optimal λ range was 203 - 223 nm to identify this substance at levels possible to be found in surface sources, being UV223 more adequate than UV254, which is more used to identify the presence of natural organic matter, which shows that UV223 is a complementary tool to chemical risk assessment for atrazine in drinking water supply systems.

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Absorbance based water quality indicators as parameters for treatment process control with respect to organic substance removal

Cited by 14 publications

References 16 publications

The Price of Really Clean Water: Combining Nanofiltration with Granular Activated Carbon and Anion Exchange Resins for the Removal of Per- And Polyfluoralkyl Substances (PFASs) in Drinking Water Production

The Price of Really Clean Water: Combining Nanofiltration with Granular Activated Carbon and Anion Exchange Resins for the Removal of Per- And Polyfluoralkyl Substances (PFASs) in Drinking Water Production

Protocol for Preparing Synthetic Solutions Mimicking Produced Water from Oil and Gas Operations

Applicability of UV absorbance as an indicator of Atrazine presence into risk management of water supply watersheds

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