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Návrh rekonstrukce přivaděče surové vody pro úpravnu vody / Reconstruction proposal of raw water supply for water treatment plantPasnichenko, Dmytro January 2021 (has links)
This diploma thesis deals with the assessment of the technical condition of the raw water supply Dnipro-Mykolaiv for water treatment plant Inhulets in Ukraine and the reconstruction proposal of the section of this supply. Specifically, it is a 300 m long section of the steel pipeline DN 1 400 of the first row of the sypply near the Myrné village in Bilozerka Raion (district), Kherson Oblast (province), Ukraine, which is in a state of disrepair. As part of this work is an an evaluation of the current technical condition of the pipeslines of the first and second rows of the suplly. Subsequently, the design of the reconstruction of the section is then carried out using selected remediation technology.
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Kontaminace životního prostředí musk sloučeninami / Contamination of environment of musk compoundsTobková, Lenka January 2015 (has links)
Synthetic musk compounds are artificial organic substances commonly used as fragrant constituents of personal care products as parfums, cosmetics, detergents, in-house cleaning and washing agents. Given their large area of applications and their ability to be persistent, they leaked into all parts of ecosystem, especially aquatic one. There have been a big focus on studiyng these compounds, their properties and fate in the different parts of ecosystems in the last years. The aim of master's thesis was carry out the determination of five representatives (habanolide, exaltolide, ambrettolide, musk MC4 and ethylene brassylate) of macrocyclic musk compounds in waste water samples from influent and effluent of three water treatment plants (WWTP Brno-Modřice, WWTP Lednice and WWTP Mikulov). One of the main tasks was to perform a method optimisation for the determination of selected musk compounds in waste water and evaluation and interpretation of the results. Solid phase microextraction (SPME) technique was used for the extraction of analytes, consequently gas chromatography-mass spectrometry was used for analysis of selected analytes. Following evaluation the removal efficiency of musk compounds in the waste water treatment plant was assessed.
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Provozně technický stav objektů separace na úpravnách vody / Operational and Technical Condition of Separation Equipment in Water Treatment PlantsPešout, Jakub January 2015 (has links)
The goal of this thesis was to determine the operational and technical parameters of the separation objects in water treatment. The first part is a theoretical and provides basic information on this issue. The second part contains the evaluation criteria created by the obtained information for individual objects and gained in practice by personal visits of selected treatment plants of water. In the last part we can find application of these criteria in water treatment in practice. There is also included the final evaluation of the researched condition.
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Hodnocení technického stavu úpraven vody / Evaluation of the Technical State of Water Treatment PlantsPřecechtěl, Karel January 2016 (has links)
The subject of this thesis is to create evaluation criteria of technical condition of water treatment plants. The thesis is divided into four parts. In the first part of this thesis are presented evaluation systems by performance indicators drinking water treatment plants, which are then applied in real time. There are detailed descriptions of individual performance indicators. Each evaluation conducted certain period of time. After the expiry of the period under review was to evaluate and create charts to display results. In the next chapter the thesis focuses on the identification data. First, it was necessary to find out all necessary information about the water treatment plant. Necessary information means information relating to building construction, human resources, mechanical parts, technological equipment and other entities with links to the operation of the water treatment plant. All these data were sorted for better overview and facilitate setting evaluation indicators. The third part of this thesis is focused on the development of indicators that are used to determine the current status of the water treatment plant. As a first step was established 19 indicators used to evaluate the condition of the entire water treatment plant. Followed by a description of the individual indicators and then determine the individual evaluation criteria. In the last part of this thesis was carried out by the proposed criteria on selected water treatment plants. They were selected three water treatment plants located in the Czech Republic, which held a personal tour of each water treatment plant. This was followed by an overall assessment of the technical condition of water treatment plants.
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Propuesta del uso de agua residual de las plantas de tratamiento de Carapongo, San Antonio de Carapongo y Santa Clara para elaboración de concreto premezclado f'c = 210 kg/cm2 y disminución del uso de agua potable en Lima Metropolitana / Proposal of the use of residual water from the treatment plants of Carapongo, San Antonio de Carapongo and Santa Clara for the elaboration of ready-mix concrete f'c = 210 kg/cm2 and reduction of the use of potable water in Metropolitan LimaVerde Bravo, Sharlys Alberth, Aranibar Huayhua, Aderly 23 November 2021 (has links)
En Lima metropolitana falta agua potable en determinados lugares y el suministro no es uniforme. Asimismo, las proyecciones que se presentan para el futuro marcan un déficit por mucha demanda poblacional y cambio climático. Ante esta situación, es fundamental buscar medidas que aporten al ahorro del agua potable, y la industria del concreto premezclado en la ciudad ha presentado un crecimiento vertiginoso en los últimos años a excepción del 2020 por el Covid-19 con gran demanda de agua potable. Ante la problemática planteada, es factible usar aguas residuales provenientes de plantas de tratamientos para elaborar concreto premezclado.
Se usó 4 tipos de aguas. Tres proveniente de las Plantas de Tratamiento de Agua Residuales (PTARs) de Santa Clara, Carapongo y San Antonio de Carapongo con sistema de tratamiento lodos activados, aireación y filtros de arena para la primera. Anaerobio-Aerobio para la segunda y lodos activados y aireación extendida para la tercera y agua potable del Laboratorio de Ensayo de Materiales (LEM-UNI) para elaborar concreto f'c=210 Kg/cm2
La investigación consta de 7 capítulos: En capítulo 1, se presenta el marco teórico que nos presenta las bases fundamentales empleadas. En el capítulo 2, se tiene los materiales y método utilizados donde de elaboraron 116 muestras en total para ensayos de compresión axial, tracción por compresión diametral, flexión en vigas y permeabilidad al agua. En el capítulo 3, los resultados de los objetivos específicos planteados y su interpretación. En el capítulo 4, las conclusiones finales. En el capítulo 5, las recomendaciones y en capítulo 6 se presenta las referencias consultadas. Finalmente, el capítulo 7 todos los anexos de la investigación.
Se llegó a la conclusión que es muy factible elaborar concreto con aguas residuales tratadas procedentes de las 3 PTARs, ya que presentaron un comportamiento óptimo al ser evaluados en sus propiedades físicas, mecánicas y de durabilidad. / In Metropolitan Lima, there is no water in certain places and the supply is not uniform. Also the projections that are presented to the future show a deficit due as a resulto of high population demand and climate change, is essential to look up some ways that contribute to the saving of drinking wáter and the premix concrete industry, in the city has presented dizzy groth in the last years except for 2020 due to the COVID 19 with high demand for drinking wáter. Face with the problem raised, it is very feasible to use wasteater from treatment plants to make premix concrete.
It was used four types of water. Three from Santa Clara, Carapongo and San Antonio de Carapongo wastewater treatment plants (PTARs) with a treatment system activated sludge, aeration and sand filters for the first. Anaerobic – Aerobic for the second and activated sludge and extended aeration for the third and drinking wáter from the material testing (LEM-UNI) to make concrete f'c=210 Kg/cm2
This research has 7 chapters: In the 1rst chapter presents us, the theorical framework is about the fundamental bases used. In the 2nd consists about materials and methods used where 116 samples in total were prepared for trials of axial compression, diametral compression traction, vending in beams and wáter permeability. In the 3rd chapter, the results of the specific objectives set and their interpretation. In the 4th last conclusions, in the 5th the recommendations and in the 6th the consulte references are presented. Finally, In the last chapter all the research annexes.
It was concluded that is very feasible to makeconcrete with treated wastewater from 3 PTARs, since they presente an optimal behavior when evaluated in their physical, mechanical and durability properties. / Tesis
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Úprava hydraulických poměrů v prostoru rozdělovacího objektu čtyř usazovacích nádrží na ČOV Brno-Modřice / Adjustment of hydraulic conditions in the area of the distribution object of four settling tanks at the Brno-Modřice WWTPŠenková, Monika January 2022 (has links)
The aim of this diploma thesis is to find a suitable adjustment of hydraulic conditions in the distribution object area of four settling tanks at the Brno-Modřice WWTP. Due to the WWTP capacity increase, there were changes in the hydraulic conditions at the distribution facility, which needed to be adjusted. To find a suitable hydraulic solution, a hydraulic physical model was created in the Laboratory of Water Management Research of the Institute of Hydraulic Engineering, Faculty of Civil Engineering, Brno University of Technology, where experimental tests were made.
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Strategic Assessment of Drinking Water Production Systems Environmental impacts from a Life cycle perspective : A case study of Norrvatten future drinking water production alternatives / Strategisk bedömning av dricksvattenproduktion. Miljöpåverkan ur ett livscykelperspektiv : En fallstudie av Norrvattens framtida alternative för dricksvattenproduktionAggarwal, Rahul January 2020 (has links)
Climate change is a global challenge that requires proactive action from municipalities, companies, and other organizations to prioritize sustainability in their daily operations. In the past few decades, life cycle assessment (LCA) approach has been successfully applied for environmental assessments in the drinking water sector. In this study, this approach has been used to present a comparative evaluation of the potential environmental impacts associated with nine different process alternatives for future drinking water production at Norrvatten. This study is a pioneering one that explores the potential of LCA as a decision support tool to prioritize and optimize environmental impacts during the operational phase in Swedish drinking water production. The nine alternatives are designed for the year 2050 to meet the average daily demand of 208 MLD for the 14 municipalities in the northern Stockholm region that Norrvatten supplies with drinking water. Out of the nine alternatives, the alternative based on direct filtration of raw water on nanofiltration membranes came out as the most environmentally friendly solution due to the use of renewable electricity from hydro and wind power. The results indicate that the potential environmental impacts are dominated by the use of chemicals in all alternatives, which in turn depends on the energy sources used for chemical production that are mostly dominated by fossil-based non-renewable sources. The impacts due to transportation and energy consumption are relatively less in Swedish drinking water production. Moreover, filtration through granulated activated carbon (GAC) is the most environmentally damaging treatment step, but regeneration of saturated GAC induces positive impacts in all alternatives. Among environmental impact categories, categories related to fine particulate matter formation; global warming, human carcinogenic toxicity, and human non-carcinogenic toxicity are the most significant in all alternatives. Several of the treatment technologies included in the nine alternatives, such as Nanofiltration, have only been tested on a pilot scale and have not been used for drinking water production at Norrvatten. So this study should be followed up and supplemented with better representative inventory data relevant to the Swedish context in order to contribute more effectively in making the future Swedish drinking water production more sustainable and environmentally friendly. Also, this study is based on the most recently available data that may not be valid in 2050 and the latest trends to substitute non-renewable energy sources with renewable sources may reduce the impacts due to chemical production and transportation in the future. Moreover, this LCA study does not include any aspects of water quality and treatment costs. Hence, while comparing different alternatives, the quality of the treated water and its production cost must also be taken into account. / Klimatförändringar är en global utmaning som kräver proaktivt agerande från kommuner, företag och andra organisationer för att prioritera hållbarhet i sin dagliga verksamhet. Under de senaste decennierna har livscykelanalys (LCA) använts för miljöbedömningar inom VA-sektorn. I denna studie har detta tillvägagångssätt använts för att presentera en jämförande utvärdering av den potentiella miljöpåverkan som är förknippad med den framtida dricksvattenproduktionen vid Norrvatten. Med hjälp av LCA så jämförs nio olika processalternativ för den framtida produktionen och kan på så sätt bidra till att prioritera och optimera processval utifrån miljösynpunkt. De nio alternativen är utformade för år 2050 för att tillgodose den genomsnittliga dagliga efterfrågan på 208 MLD för de 14 kommuner i norra Stockholmsregionen som Norrvatten försörjer med dricksvatten. Av nio alternativ kom alternativet baserat på direkt filtrering av råvatten på nanofiltreringsmembran som den mest miljövänliga lösningen på grund av användningen av förnybar el från vatten- och vindkraft. Resultaten indikerar att de potentiella miljöeffekterna domineras av användning av kemikalier i samtliga alternativ, vilket i i sin tur beror på de energikällor som används för kemikalieproduktion domineras av fossilbaserade energibärare. Effekterna på grund av transport och energiförbrukning är relativt låg i svensk dricksvattenproduktion. Filtrering genom granulerat aktivt kol (GAC) det mest miljöbelastande behandlingssteget, men regenerering av mättad GAC ger positiva effekter i alla alternativ. Bland kategorier för miljöpåverkan så är kategorier relaterade till bildning av fina partiklar; global uppvärmning, mänsklig cancerframkallande toxicitet och mänsklig icke-cancerogen toxicitet de viktigaste i alla alternativ. Flera av de behandlingstekniker som ingår i de nio alternativen, såsom Nanofiltration, har enbarts testats i pilotskala och inte använts för dricksvattenproduktion vid Norrvatten. Så denna studie bör följas upp och kompletteras med data som är relevanta för förhållanden vid Vättern Denna studie baseras också på tillgängliga data som kanske inte är giltiga 2050 och de senaste trenderna för att ersätta icke förnybara energikällor med förnybara källor som kan minska effekterna på grund av kemisk produktion och transport i framtiden. Dessutom innehåller denna LCA-studie inga aspekter av vattenkvalitet och behandlingskostnader.. Vid jämförelse av olika alternativ måste även kvaliteten på det behandlade vattnet och dess produktionskostnad beaktas.
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Comparative life cycles assessment on a drinking water treatment plant / Jämförande livscykelanalys av ett reningsverk för dricksvattenSimsek, Muhammed-Enes January 2024 (has links)
Climate change and increasing population demands expansion of infrastructures in urban areas. Drinking water treatment plants are part of the critical infrastructure and must upgrade in the future. However, expansions and technological advancements often come with impacts on the environment. Therefore, this thesis compares two drinking water treatment technologies regarding its environmental impacts through a life cycle assessment. In specific, the thesis elaborates the impacts of membrane precipitation and conventional precipitation in the suspended solids removal stage at a treatment plant in Piteå, Sweden. The research addresses the environmental challenges posed by traditional and modern water treatment methods, providing insights and knowledge to more sustainable water practices. The research involves an attributional, comparative life cycle assessment. The findings from this thesis intend to guide decision-making for future drinking water treatment plant designs. The research was conducted through an attributional and comparative LCA using SimaPro software based on ISO 14040-series standards. This approach allowed for a detailed analysis of both the operational and construction phases of the treatment technologies, considering various environmental impact categories. The results indicate that membrane system presents for most impact categories, a lower environmental impact in the combined configuration scenario. The combined configuration scenario includes for the membrane system calcium carbonate, aluminium sulfate and 95% reduced hypochlorite consumption. The conventional system considers in the combined configuration scenario aluminum sulfate and calcium carbonate This is primarily due to its efficiency in reducing chemical usage such as coagulants. However, if both systems use the same chemical composition (same coagulant, pH-controlling chemicals as in the base scenario), the conventional system becomes more environmentally friendly than the membrane system in most impact categories. This is mainly due to the additional CEB chemical consumption of the membrane system, which nullifies the advantage of lower consumed coagulants. Compared to the operational phase in both systems, the construction phase is insignificant over the lifetime of the treatment plants. The major hotspots are identified as operational chemicals and chemical enhanced backwash chemicals, which are used for the membrane system only. Scenario analysis shows that chlorine/aluminum-based chemicals such as polyaluminum chloride and hypochlorite have a high environmental impact and with reducing or even changing these chemicals major improvements can be achieved. Especially changing aluminum-based chemicals to iron-based chemicals show a significant decrease of impacts in all categories. Further, the scenario analysis shows that by changing lime to calcium carbonate, the environmental impacts can be reduced significantly. Therefore, the future focus should rely on reducing and changing chemicals, especially switching aluminum/chlorine based to iron-based chemicals. / Klimatförändringarna och den ökande befolkningen kräver utbyggnad av infrastrukturen i stadsområden. Reningsverk för dricksvatten är en del av den kritiska infrastrukturen och måste uppgraderas i framtiden. Expansioner och tekniska framsteg medför dock ofta påverkan på miljön. Detta examensarbete jämförs därför två tekniker för dricksvattenberedning med avseende på miljöpåverkan genom en grundlig livscykelanalys. Mer specifikt behandlar avhandlingen effekterna av membranfiltrering och konventionell fällning i steget för avlägsnande av suspenderade ämnen vid ett reningsverk i Piteå, Sverige. Forskningen tar upp de miljömässiga utmaningar som traditionella och moderna vattenbehandlingsmetoder innebär och ger insikter och kunskap om mer hållbara vattenmetoder. Resultaten från denna avhandling är avsedda att vägleda beslutsfattandet för framtida utformningar av dricksvattenreningsverk och erbjuder ett första verktyg för mer hållbara vattenbehandlingsmetoder. Forskningen genomfördes genom en bokförande och jämförande LCA med hjälp av programvaran SimaPro baserat på ISO 14040-seriens standarder. Detta tillvägagångssätt möjliggjorde en detaljerad analys av både drifts- och konstruktionsfaserna för behandlingsteknikerna, med beaktande av olika miljöpåverkanskategorier. Resultaten tydar på att membranfiltrering ger en lägre total miljöpåverkan vid vanliga förhållanden. Detta beror främst på dess effektivitet när det gäller att minska kemikalieanvändningen, t.ex. koaguleringsmedel. Men om båda systemen använder samma kemiska sammansättning (samma koaguleringsmedel) är det konventionella systemet mer miljövänligt än det konventionella systemet. Detta beror främst på den extra kemikalieförbrukningen för CEB i membransystemet, vilket upphäver fördelen med lägre förbrukning av koaguleringsmedel. Jämfört med driftsfasen i båda systemen är byggfasen obetydlig under reningsverkens livstid. De viktigaste aspekterna identifieras som driftskemikalier och kemikalier för kemiskt förstärkt backspolning, som endast används för membransystemet. Scenarioanalysen visar att klor-/aluminiumbaserade kemikalier som polyaluminiumklorid och hypoklorit har en hög miljöpåverkan och att stora förbättringar kan uppnås genom att minska eller till och med byta ut dessa kemikalier. Särskilt om aluminiumbaserade kemikalier byts ut mot järnbaserade kemikalier minskar påverkan betydligt i alla kategorier. Vidare visar scenarioanalysen att miljöpåverkan kan minskas betydligt genom att byta ut kalk mot kalciumkarbonat. Därför bör fokus i framtiden ligga på att minska och byta ut kemikalier, särskilt att byta ut aluminium/klorbaserade kemikalier mot järnbaserade kemikalier.
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The Effect of Selected Coagulants on Chloride-to-Sulfate Mass Ratio for Lead Control and on Organics Removal in Two Source WatersEl Henawy, Walid January 2009 (has links)
Lead is a known toxin, with the ability to accumulate in the human body from as early as fetal development. Lead exposure is known to cause a myriad of health effects which are more prominent among children. Health effects upon exposure can range from renal and heart disease or potentially cancer in adults to neurotoxicity in children.
The continued presence of old lead service lines and plumbing in distribution systems as well as lead-containing solders and brass fixtures in homes may contribute lead to drinking water. Recent studies have highlighted the importance of a predictor known as the chloride-to-sulfate mass ratio (CSMR) in controlling lead release. A ratio above 0.5 – 0.6 theoretically increases the aggressiveness of lead leaching in galvanic settings, while a lower ratio controls lead corrosion. A switch in coagulant type could significantly alter the ratio. However, a coagulant switch could also trigger changes in finished water turbidity and organics, including disinfection by-product (DBP) precursors, as well as impact sludge production.
Anecdotal evidence from an Ontario water treatment utility suggested the potential applicability of a newly formulated polymer, cationic activated silica (CAS), in improving DBP precursor removal when used in concurrence with a primary coagulant. No previous scientific research had been dedicated to testing of the polymer.
The present research had three primary objectives: The first was to investigate the effect of conventional coagulation with six different coagulants on the chloride-to-sulfate mass ratio as it pertains to lead corrosion in two Ontario source waters of differing quality. Additionally, the effect of coagulant choice on pH, turbidity, and organics removal was investigated. The second objective was aimed at testing potential reductions in CSMR and organics that could be brought about by the use of two polymers, cationic and anionic activated silica (CAS and AAS, respectively), as flocculant aids. Finally, the performance of a high-rate sand-ballasted clarification process was simulated at bench-scale to gauge its performance in comparison with conventional coagulation simulation techniques.
The first series of jar-tests investigated the effectiveness of CAS as a primary coagulant on Lake Ontario water. In comparison with the conventional coagulants aluminum sulfate and polyaluminum chloride, CAS did not offer any apparent advantage with respect to turbidity and organics removal.
Testing of CAS and AAS as flocculant aids was also conducted. Results from a full factorial experiment focused on CAS testing on Lake Ontario water showed that coagulant dose is the most significant contributor to CSMR, turbidity, DOC removal, and THM control. Generally, improvements resulting from CAS addition were of small magnitude (<15%). Reductions in CSMR were attributed to the presence of the sulfate-containing chemicals alum and sulfuric acid in the CAS formulation. Testing of sulfuric acid-activated AAS on Grand River water showed that pairing of AAS with polyaluminum chloride provides better results than with alum with respect to DOC removal (39% and 27% respectively at 60 mg/L coagulant dose). Highest turbidity removals (>90%) with both coagulants were achieved at the tested coagulant and AAS doses of 10 mg/L and 4 mg/L respectively. CSMR reductions in the presence of AAS were also attributable to sulfate contribution from sulfuric acid. Bench-scale simulation of a high-rate sand-ballasted clarification process on Grand River water showed comparable removal efficiencies for turbidity (80 – 90% at 10 mg/L), and DOC (30 – 40% at 50 mg/L).
Finally, six different coagulants were tested on the two source waters for potential applicability in CSMR adjustment in the context of lead corrosion. The two chloride-containing coagulants polyaluminum chloride and aluminum chlorohydrate increased CSMR in proportion to the coagulant dose added, as would be expected. Average chloride contribution per 10 mg/L coagulant dose was 2.7 mg/L and 2.0 mg/L for polyaluminum chloride and aluminum chlorohydrate, respectively. Sulfate-contributing coagulants aluminum sulfate, ferric sulfate, pre-hydroxylated aluminum sulfate, and polyaluminum silicate sulfate reduced CSMR as coagulant dose increased, also as would be expected. The highest sulfate contributors per 10 mg/L dose were pre-hydroxylated aluminum sulfate (6.2 mg/L) and ferric sulfate (6.0 mg/L). The lowest CSMR achieved was 0.6 in Lake Ontario water at a 30 mg/L dose and 0.8 in Grand River water at a 60 mg/L dose. Highest DOC removals were achieved with the chloride-containing coagulants in both waters (35 – 50%) with aluminum chlorohydrate showing superiority in that respect. DOC removals with sulfate-containing coagulants were less, generally in the range of 22 – 41%.
Specificity of critical CSMR values to source water needs to be investigated. Additionally, long term effects of sustained high or low CSMR values in distribution systems need to be further looked into. Finally, the effect of interventions to alter CSMR on other water quality parameters influencing lead corrosion such as pH and alkalinity still represent a research deficit.
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The Effect of Selected Coagulants on Chloride-to-Sulfate Mass Ratio for Lead Control and on Organics Removal in Two Source WatersEl Henawy, Walid January 2009 (has links)
Lead is a known toxin, with the ability to accumulate in the human body from as early as fetal development. Lead exposure is known to cause a myriad of health effects which are more prominent among children. Health effects upon exposure can range from renal and heart disease or potentially cancer in adults to neurotoxicity in children.
The continued presence of old lead service lines and plumbing in distribution systems as well as lead-containing solders and brass fixtures in homes may contribute lead to drinking water. Recent studies have highlighted the importance of a predictor known as the chloride-to-sulfate mass ratio (CSMR) in controlling lead release. A ratio above 0.5 – 0.6 theoretically increases the aggressiveness of lead leaching in galvanic settings, while a lower ratio controls lead corrosion. A switch in coagulant type could significantly alter the ratio. However, a coagulant switch could also trigger changes in finished water turbidity and organics, including disinfection by-product (DBP) precursors, as well as impact sludge production.
Anecdotal evidence from an Ontario water treatment utility suggested the potential applicability of a newly formulated polymer, cationic activated silica (CAS), in improving DBP precursor removal when used in concurrence with a primary coagulant. No previous scientific research had been dedicated to testing of the polymer.
The present research had three primary objectives: The first was to investigate the effect of conventional coagulation with six different coagulants on the chloride-to-sulfate mass ratio as it pertains to lead corrosion in two Ontario source waters of differing quality. Additionally, the effect of coagulant choice on pH, turbidity, and organics removal was investigated. The second objective was aimed at testing potential reductions in CSMR and organics that could be brought about by the use of two polymers, cationic and anionic activated silica (CAS and AAS, respectively), as flocculant aids. Finally, the performance of a high-rate sand-ballasted clarification process was simulated at bench-scale to gauge its performance in comparison with conventional coagulation simulation techniques.
The first series of jar-tests investigated the effectiveness of CAS as a primary coagulant on Lake Ontario water. In comparison with the conventional coagulants aluminum sulfate and polyaluminum chloride, CAS did not offer any apparent advantage with respect to turbidity and organics removal.
Testing of CAS and AAS as flocculant aids was also conducted. Results from a full factorial experiment focused on CAS testing on Lake Ontario water showed that coagulant dose is the most significant contributor to CSMR, turbidity, DOC removal, and THM control. Generally, improvements resulting from CAS addition were of small magnitude (<15%). Reductions in CSMR were attributed to the presence of the sulfate-containing chemicals alum and sulfuric acid in the CAS formulation. Testing of sulfuric acid-activated AAS on Grand River water showed that pairing of AAS with polyaluminum chloride provides better results than with alum with respect to DOC removal (39% and 27% respectively at 60 mg/L coagulant dose). Highest turbidity removals (>90%) with both coagulants were achieved at the tested coagulant and AAS doses of 10 mg/L and 4 mg/L respectively. CSMR reductions in the presence of AAS were also attributable to sulfate contribution from sulfuric acid. Bench-scale simulation of a high-rate sand-ballasted clarification process on Grand River water showed comparable removal efficiencies for turbidity (80 – 90% at 10 mg/L), and DOC (30 – 40% at 50 mg/L).
Finally, six different coagulants were tested on the two source waters for potential applicability in CSMR adjustment in the context of lead corrosion. The two chloride-containing coagulants polyaluminum chloride and aluminum chlorohydrate increased CSMR in proportion to the coagulant dose added, as would be expected. Average chloride contribution per 10 mg/L coagulant dose was 2.7 mg/L and 2.0 mg/L for polyaluminum chloride and aluminum chlorohydrate, respectively. Sulfate-contributing coagulants aluminum sulfate, ferric sulfate, pre-hydroxylated aluminum sulfate, and polyaluminum silicate sulfate reduced CSMR as coagulant dose increased, also as would be expected. The highest sulfate contributors per 10 mg/L dose were pre-hydroxylated aluminum sulfate (6.2 mg/L) and ferric sulfate (6.0 mg/L). The lowest CSMR achieved was 0.6 in Lake Ontario water at a 30 mg/L dose and 0.8 in Grand River water at a 60 mg/L dose. Highest DOC removals were achieved with the chloride-containing coagulants in both waters (35 – 50%) with aluminum chlorohydrate showing superiority in that respect. DOC removals with sulfate-containing coagulants were less, generally in the range of 22 – 41%.
Specificity of critical CSMR values to source water needs to be investigated. Additionally, long term effects of sustained high or low CSMR values in distribution systems need to be further looked into. Finally, the effect of interventions to alter CSMR on other water quality parameters influencing lead corrosion such as pH and alkalinity still represent a research deficit.
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