The doctoral thesis „Using of nanofiber filter for air filtration“ is focused on application of nanofiber filter for air filtration under demanding conditions of water supply facilities. The main aim of the filter application is to decrease the secondary contamination of the indoor environment of the water accumulation tanks. The nanofiber filters are distinguished by high filtration efficiency of pollutants, dust particles and organic impurities. The contaminants don´t have to be unhealthy but they can be used for spore and microorganisms delivery to the system. They are served frequently as a reproduction substrate of microorganisms. All these factors negatively affect the water quality. The research includes formation of suitable testing methodology, pilot unit construction and operation, short-term testing and evaluation of nanofiber filters and commonly used filters and long term testing and verification of nanofiber filter attributes and quality. Furthermore the filter´s characteristics and filtration efficiency for characteristic pollutants were evaluated. Short-term and long-term experimental testing proved suitability of nanofiber filters use in water supply facilities. Interception of reported pollution indicators was reported on similar or higher level for application of nanofiber filter than for application of commonly used filter. Measured values of higher pressure difference of nanofiber filter were indicated as still adequate for use in water supply facilities. No operation difficulties, failures neither filter´s damage were reported during testing of nanofiber filters.

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I takt med att vattenbristen ökar har flera länder börjat använda avsaltning, en innovation som framställer rent men mineralfattigt vatten, för att möta vattenbehoven. Detta kandidatarbete ämnar att bidra med vidare kunskap kring avsaltat dricksvatten med bakgrund till tidigare forksning. Detta görs med hänsyn till tre ämnesområden där frågeställningarna är följande:  Vilka är de fundamentala processerna vid framställning av avsaltat dricksvatten? Vad finns det för hälsorisker med regelbunden konsumtion av avsaltat dricksvatten?  Hur bidrar olika faktorer till att kostnader i samband med avsaltat dricksvatten ökar och/eller minskar?  Denna studie fann att allt avsaltat dricksvatten går igenom tre grundläggande processer; förbehandling, avsaltning och remineralisering. Hälsoriskerna i samband med regelbunden konsumtion av avsaltat dricksvatten var; elektrolytavvikelse som kan leda till t.ex. cancer, 6 % större risk för ischemisk hjärtsjukdom, sköldkörtelproblem och ökad benskörhet. De olika faktorerna som bidrar till att kostnader i samband med avsaltat dricskvatten ökar och/eller minskar är:  Teknologins utveckling (Kostnader har minskat)  Bättre membranfilter (Kostnader har minskat)  Saltlaksavfall miljöpåverkan (Svårt att avgöra kostnder för)  Hälsopåverkan (Kostnader har ökat)  Val av vattenkälla (Påverkar kostnader för avsaltning)  Val av avsaltningsmetod (Påverkar kostnad för avsaltning)  Val av re-mineralisering (Påverkar kostnad för avsaltning)  Anläggningens storlek/kapacitet (Påverkar kostnad för avsaltning)  Val av energikällor (Påverkar kostnad för avsaltning)  Användandet av ERD (Kostnader har minskat)  Eftersom produktionen och konsumtionen av avsaltat dricksvatten förutspås öka bör myndigheter, såsom WHO, införa riktlinjer specifikt för avsaltat dricksvatten och dess mineralinnehåll. Dessutom har denna litteraturstudie kommit fram till slutsatsen att hälso- och miljöaspekter bör sammanvävas på ett bättre sätt med det avsalttade dricksvattnet. / As water scarcity increases, several countries have turned to the use of desalination, an innovation that produces clean but mineral-poor water in order to satisfy the water demands. This bachelor’s thesis aims to provide the reader with further knowledge about desalinated drinking water with background to previous research. This is done with regard to three questions:  What are the fundamental processes in the production of desalinated drinking water?  What are the health risks of regular consumption of desalinated drinking water?  How do various factors contribute to costs increasing and/or decreasing in relation to desalinated drinking water?  This study found that all desalinated drinking water goes throught three fundamental processes; pre-treament, desalination and remineralization. The healthrisks found in realtion to regular consumtion of desalinated drinking water was; electrolyte deviation which can lead to e.g. cancer, a 6% increase of iscehmic heart disease, poor thyroid condition and increased osteoporisis. The different factors that contribute to the costs of desalination increasing and/or decreasing are:  Technology development (costs have decreased) Better membrane filter (costs have decreased) Saline waste environmental impact (difficult to determine costs for) Health impact (costs have increased) Choice of water source (affects cost of desalination) Choice of desalination method (affects cost of desalination Choice of re-mineralization (affects cost of desalination) Plant size / capacity (affects desalination cost) Choice of energy sources (affects cost of desalination) Use of ERD (costs have decreased)  In addition as the production and consumtion of desalinated drinking water is predicted to increase, authorities, such as the WHO, should introduce guidelines specifically for desalinated drinking water and its mineral content. Furthermore, this literature study has come to the conclussion that health and enviorment components should be better interwoven with the production of desalinated drinking water.

Integrating ultrafiltration (UF) membranes in lieu of traditional media filters within conventional surface water coagulation-flocculation-sedimentation processes is growing in popularity. UF systems are able to produce low turbidity filtered water that meets newer drinking water standards. For typical drinking water applications, UF membranes require periodic chemically enhanced backwashes (CEBs) to maintain production; and citric acid is a common chemical used for this purpose. Problems may arise when the backwash recycle stream from a citric acid CEB is blended with raw water entering the coagulation basin, a common practice for conventional surface water plants. Citric acid is a chelating agent capable of forming complexes that interfere with alum or ferric chloride coagulation. Interference with coagulation negatively affects settled water quality. Acetic acid was investigated as a potential substitute for citric acid in CEB applications. A jar testing study was conducted to compare the impacts of both citric acid and acetic acid on the effectiveness of aluminum sulfate (alum) and ferric chloride coagulants. Citric acid was found to adversely affect coagulation at lower acid to coagulant (A/C) molar ratios than acetic acid, and a coagulation interference threshold was identified for both acids based on settled water turbidity goals recommended by the U.S. Environmental Protection Agency (EPA). Pilot testing was conducted to assess the viability of acetic acid as a UF CEB chemical. Acetic acid CEBs maintained pilot performance in combination with sodium hypochlorite CEBs for filtering a raw California surface water. It is believed that this is the first ultrafiltration membrane process application of acetic acid CEBs for municipal potable water production in the United States.

This study evaluated the effects of orthophosphate (OP) inhibitor addition on iron, copper, and lead corrosion on coupons exposed to different blends of groundwater, surface water, and desalinated seawater. The effectiveness of OP inhibitor addition on iron, copper, and lead release was analyzed by statistical comparison between OP treated and untreated pilot distribution systems (PDS). Four different doses of OP inhibitor, ranging from zero (control) to 2 mg/L as P, were investigated and non-linear empirical models were developed to predict iron, copper, and lead release from the water quality and OP doses. Surface characterization evaluations were conducted using X-ray Photoelectron Spectroscopy (XPS) analyses for each iron, galvanized steel, copper, and lead/tin coupon tested. Also, a theoretical thermodynamic model was developed and used to validate the controlling solid phases determined by XPS. A comparison of the effects of phosphate-based corrosion inhibitor addition on iron, copper, and lead release from the PDSs exposed to the different blends was also conducted. Three phosphate-based corrosion inhibitors were employed; blended orthophosphate (BOP), orthophosphate (OP), and zinc orthophosphate (ZOP). Non-linear empirical models were developed to predict iron, copper, and lead release from each PDS treated with different doses of inhibitor ranging from zero (control) to 2 mg/L as P. The predictive models were developed using water quality parameters as well as the inhibitor dose. Using these empirical models, simulation of the water quality of different blends with varying alkalinity and pH were used to compare the inhibitors performance for remaining in compliance for iron, copper and lead release. OP inhibitor addition was found to offer limited improvement of iron release for the OP dosages evaluated for the water blends evaluated compared to pH adjustment alone. Empirical models showed increased total phosphorus, pH, and alkalinity reduced iron release while increased silica, chloride, sulfate, and temperature contributed to iron release. Thermodynamic modeling suggested that FePO4 is the controlling solid that forms on iron and galvanized steel surfaces, regardless of blend, when OP inhibitor is added for corrosion control. While FePO4 does not offer much control of the iron release from the cast iron surfaces, it does offer protection of the galvanized steel surfaces reducing zinc release. OP inhibitor addition was found to reduce copper release for the OP dosages evaluated for the water blends evaluated compared to pH adjustment alone. Empirical models showed increases in total phosphorus, silica, and pH reduced copper release while increased alkalinity and chloride contributed to copper release. Thermodynamic modeling suggested that Cu3(PO4)2·2H2O is the controlling solid that forms on copper surfaces, regardless of blend, when OP inhibitor is added for corrosion control. OP inhibitor addition was found to reduce lead release for the OP dosages evaluated for the water blends evaluated compared to pH adjustment alone. Empirical models showed increased total phosphorus and pH reduced lead release while increased alkalinity, chloride, and temperature contributed to lead release. Thermodynamic modeling suggested that hydroxypyromorphite is the controlling solid that forms on lead surfaces, regardless of blend, when OP inhibitor is added for corrosion control. The comparison of phosphate-based inhibitors found increasing pH to reduce iron, copper, and lead metal release, while increasing alkalinity was shown to reduce iron release but increase copper and lead release. The ZOP inhibitor was not predicted by the empirical models to perform as well as BOP and OP at the low dose of 0.5 mg/L as P for iron control, and the OP inhibitor was not predicted to perform as well as BOP and ZOP at the low dose of 0.5 mg/L as P for lead control. The three inhibitors evaluated performed similarly for copper control. Therefore, BOP inhibitor showed the lowest metal release at the low dose of 0.5 mg/L as P for control of iron, copper, and lead corrosion.

Groundwater is an important source of fresh water on earth. A source that is also affected by climate change. Climate change is expected to influence both the groundwater quality and the groundwater level, where elevated levels of iron and manganese in the groundwater are to be expected. In Sweden guideline values are set for iron and manganese in drinking water, which means that waterworks that use groundwater as raw water must treat the water when the guidline values are exceeded. A common treatment step to remove iron and manganese is abiotic oxidation with a chemical oxidant. A relatively new method is biological oxidation where microorganisms oxidize the metals. Biological oxidation has proven to be a faster process than chemical oxidation and better adapted to variations in raw water quality. In this work the possibility of biological oxidation of iron and manganese at smaller groundwater plants with day-to-day production breaks has been studied. The study also concern how seasonal variations in raw water quality might affect the oxidation ability of the microorganisms. During the study a pilot filter for biological oxidation was constructed where the efficiency of the filter and the raw water quality was measured during a one-year test. After a short start-up time for iron oxidation the pilot filter reduced iron in the raw water up to 92 % and after a longer start-up time for manganese oxidation the pilot filter reduced manganese from the raw water up to 97 % during the rest of the test period. The results show that biological oxidation is possible at smaller groundwater plants despite production breaks. The results also show that biological oxidation is not affected by the vaiations i raw water quality that was measured during the test period. Furthermore, the results show that biological oxidation is equally efficient as the chemical oxidation, at the investigated groundwater plant, in terms of removing iron and even more efficient in terms of removing manganese. In addition the biological oxidation do not require pH adjustment or addition of any chemicals. The results indicate that biological oxidation of iron and manganese is a more favorable alternative to chemical oxidation in smaller groundwater plants on the impact of climate change on raw water quality.

I Sverige har ungefär 1,2 miljoner människor enskild dricksvattenförsörjning och en stor andel av dessa har problem med vattenkvalitet. En utvärdering av reningstekniker har inletts av företaget Ecoloop och Utvecklingscentrum för vatten och detta examensarbete fördjupar och följer upp de inledande resultaten från det projektet. Med hjälp av en litteraturstudie, modellering i Visual MINTEQ och fem fallstudier utvärderades reningsteknikerna jonbytarfilter och nanofilter avsett för enskild dricksvattenförsörjning med avseende på reduktion av föroreningarna bly och uran. Fallstudierna visar att jonbytarfilter kan fungera väl för att reducera uranhalter men en viss inkörningsperiod förekommer där bieffekter, exempelvis kemisk smak, kan förekomma samt att underhåll är viktigt för att fortsätta ha en hög reduktionsgrad. Fallstudierna kunde ej besvara ifall nanofilter är en lämplig reningsteknik för ändamålet att reducera halter av bly och uran under de gränsvärden som finns, eftersom de membranfilter som använts i fallstudierna visade sig ha för stor porstorlek för att kallas nanofilter. En slutsats är att det är viktigt att fortsätta med provtagning av vattnet även efter att ett filter installerats. Utöver det genomfördes intervjuer och en enkätundersökning som undersökte hur kommuner i Sverige arbetar för att möta enskilda brunnsägare i deras utmaningar med vattenkvalitet. Intervjuerna och enkätsvaren visar på en variation där några kommuner jobbar aktivt för att stötta de enskilda brunnsägarna med rådgivning, bidrag och förebyggande åtgärder medan andra kommuner är mer passiva och låter de enskilda ta eget ansvar för sitt vatten. / About 1.2 million people in Sweden rely on their own private drinking water supply for their daily needs and a large portion of those have problems with water quality. An evaluation of water treatment technology intended for private wells has been initiated by the companies Ecoloop and Utvecklingscentrum för vatten and this master’s thesis further develops and follows up the initial results. By conducting a literature review, doing modelling in Visual MINTEQ and carrying out five case studies the two water treatment techniques nanofilter and ion exchange are evaluated in the context of domestic water supplies with water quality problems caused by either lead or uranium. The case studies shows that ion exchange filters can reduce uranium in drinking water below the threshold value but with some initial side effects (i.e., chemical taste of the water). The case studies could not show if nanofilters are suitable to reduce lead or uranium from domestic water supplies, since the pore size was found to be too big for the membrane filters used in the case studies to be called nanofilters. This concludes that it is important to proceed with sampling of the water even after installing a filter for water treatment. Additionally, interviews and a survey were conducted which investigated how municipalities in Sweden are working to meet private well owners in their challenges with water quality. The answers from the interviews and the survey displays a variation where some municipalities are actively supporting the private well owners through counselling, grants, and preventive measures while other municipalities are more passive and leaves the individual well owners responsible to look after their water quality by themselves.

In this thesis I argue that access to an adequate quantity and quality of safe water in sustainable ways is a basic moral human right, one that has been legally recognized by the international community through UN Resolution 15/9. As a result of water’s being a basic moral human right, governments, institutions, and individuals are obligated to avoid depriving, protect from deprivation, and aid those deprived of access to safe drinking water. Using this as a foundation, I examine the Millennium Development Goals, the Sustainable Development Goals, and water pricing as strategies used to fulfill the right to safe drinking water. I also provide arguments in favour of (national and international) tax schemes that cover the cost of providing 50L of safe water per person per day. / Thesis / Master of Arts (MA)

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