Without proper removal at a water treatment facility, the soluble manganese (Mn) concentration can reach and exceed the Secondary Maximum Contaminant Level (SMCL) of 0.05 mg/L in the water distribution system. At this level, soluble Mn can be oxidized to solid Mn-oxide particulates, leading to water discoloration events and resulting in numerous consumer complaints. Manganese-laden water can severely stain fixtures and laundry as well as increase turbidity and foul tastes. A major discoloration event can cause a decrease in consumer confidence in the quality of water provided to their taps. Currently, there is no other treatment alternative available that can remove soluble Mn with the high efficiency of the "natural greensand effect. Therefore, researchers are developing ways to effectively create the natural greensand effect in a post-filtration sorptive contactor for application at water treatment facilities. The process of adsorption and oxidation of Mn onto oxide-coated media grains in the contactor will be used for the removal of soluble Mn. However, small media grains, such as sand or anthracite, could produce prohibitive head loss in a sorptive contactor. The focus of this research project was to show that Mn could be effectively removed via adsorption onto larger media (2.0-6.4mm) at hydraulic loading rates of 16-24 gpm/ft², thus producing less head loss and furthering the development of soluble Mn sorptive contactors to be implemented in water treatment facilities. Research was conducted by executing laboratory- and pilot-scale experiments using columns packed with oxide-coated media. Three types of media were used: large grain "torpedo sand," pyrolucite granules, and small gravel. Before being packed into the columns, the torpedo sand and gravel media was coated with an oxide coating using a technique previously developed by Merkle (1995). Manganese uptake capacity was determined for each media type prior to use and after a number of contactor column experiments were completed. Water samples were collected during the experiments and analyzed for soluble Mn concentration. The Mn removal profile was determined by taking water samples at a certain time and at various depths in the media bed. Experiments were conducted to determine the removal profile of the media types under different operating conditions. Hydraulic loading rate, influent Mn concentration, influent free chlorine concentration, and pH were the operational parameters varied. The effect of these parameters of the Mn removal profile was evaluated. Although each media type was able to remove some percentage of soluble manganese from the applied water, pyrolucite media was the most effective media, often providing approximately 80-90% removal of initial manganese concentration. The removal performance of the large-sized media beds was affected by operational parameters as expected from knowledge of prior research. The contactor media beds also provided adequate soluble manganese removal under conditions available at the water treatment facility as determined from the pilot-scale experiments conducted at the Blacksburg-Christiansburg-VPI Water Authority Another important and complementing facet of this research was the development of a proven model that would predict soluble Mn removal performance of various oxide-coated media types and the development of recommendations that could be used for implementing and operating such post-filtration sorptive contactors. A model was developed from first principles for the prediction of soluble Mn removal and fitted to the experimental data. The predictive model showed that removal performance depended on the specific surface area of the contactor media, HLR, and the mass transfer coefficient. Recommendations for the operation of a sorptive contactor containing large oxide-coated media include an applied hydraulic loading rate of 16-24 gpm/ft² with an initial free chlorine concentration of 1.0-2.0 mg/L and a slightly alkaline pH of 7.0-8.0. Greater hydraulic loading rates are recommended to provide capital cost savings due to the decreased contactor footprint required. Alkaline pH is recommended for improved Mn removal. Facilities with a slightly acidic pH due to enhanced coagulation practices should consider adjusting the pH of the finished water for corrosion control prior to the Mn removal contactor for improved Mn adsorption performance. / Master of Science

Using a simulated lake water containing humic acid, various combinations of water treatment processes were utilized to determine their effect on precursor removal and haloform removal subsequent to their formation. Laboratory tests t including temperature, pH, alkalinity, absorbance, and chlorine residual, were performed throughout the treatment process. Samples were collected and shipped to California Analytical Laboratory for volatile organic analysis. The results of this study supported those from past studies in that it showed humic .acid to be a precursor to volatile organics. The data indicated that effective precursor removal could be achieved by coagulation, flocculation, and sedimentation, especially when followed by doses of activated carbon in the range of 30-50 mg/l. It was also observed that the chlorine concentration had more effect on the production of volatile organics than the humic acid concentration. The reaction between humic acid and chlorine was not instantaneous as haloform concentrations continued to increase for up to eight or more hours after chlorination. The data appear to show that the most effective treatment to insure minimum concentrations of haloforms in finished waters is precursor removal prior to chlorination. If the raw water is a surface water, then coagulation, flocculation, and sedimentation, and possible powdered activated carbon treatment, should proceed chlorination. However, if prechlorination is necessary, chlorination should be rapidly succeeded by the routine water treatment processes which would insure reasonably low haloform levels in finished water. / Master of Science

Water utilities can experience problems from bubble formation during conventional treatment, including impaired particle settling, filter air binding, and measurement as false turbidity in filter effluent. Coagulation processes can cause supersaturation and bubble formation by converting bicarbonate alkalinity to carbon dioxide by acidification. A model was developed to predict the extent of bubble formation during coagulation which proved accurate, using an apparatus designed to physically measure the actual volume of bubble formation. Alum acted similar to hydrochloric acid for initializing bubble formation, and higher initial alkalinity, lower final solution pH, and increased mixing rate tended to increase bubble formation. Lastly, the protocol outlined in Standard Methods for predicting the degree of supersaturation was examined, and when compared to this work, the Standard Methods approach produces an error up to 16% for conditions found in water treatment. Air entrainment and ozonation are the key causes of dissolved gas supersaturation and eventual bubble formation in water treatment plants. Total dissolved gas probes (TDGP) are now available to directly measure supersaturation and have many advantages compared to conventional techniques. Bubble formation during coagulation-flocculation hindered particle sedimentation, producing settled turbidities double that of solutions without dissolved gases. In a filtration study, run time to one half of initial flow was decreased by 54% when the source water was increased from 0.1 to 0.2 atm supersaturation. Indeed, even at 0.05 atm supersaturation, run length was only 21 hours in solutions without added particulate matter. A case study confirmed that bubble formation can interfere with coagulation and filtration processes at conventional treatment plants. / Master of Science

The purpose of this study is to study the effect of water quality and quantity of raw water on advanced and conventional treatment processes. We are using data of water quality and quantity to investigate difference of quality of treated water in water treatment plant. Finally we compared items of ware quality ( turbidity, free residual chlorine, total hardness, conductivity, pH, NH3-N) whether passed the Taiwan¡¦s national standard of drinking water or not. We are hoping the treated drinking water will all fit the goal of high quality. Results show that high variation of turbidity was found from May to October in every year. The high turbidity was frequently occurred from 9.9% (2008) to 39.5% (2010). It indicated the worsen trend of water quality of raw water is increased yearly. In all monitoring items of water quality, turbidity, conductivity, NH3-N was greatly influenced in seasons from June to September. The rest items had no significant affect by season¡¦s variation. The removal efficiency in items of water quality of advanced and conventional WTP we found there were high value at hardness and TDS with 49.3% and 43.3% respectively. These items, water quality of treated water (such as turbidity, free residual chlorine, total hardness, conductivity, pH, NH3-N), were all pass the current drinking standard in Taiwan ( i.e., turbidity¡Õ2NTU¡BTDS¡Õ500mg/L¡B6.0¡ÕpH¡Õ8.5¡B0.2mg/L¡Õfree residual chlorine¡Õ1.0mg/L¡BNH3-N¡Õ0.1mg/L ).

Orientador: Ricardo de Lima Isaac / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-24T14:00:51Z (GMT). No. of bitstreams: 1 Campos_MarlonCaianeloDias_M.pdf: 3410126 bytes, checksum: bb9db3577d3074777f6ae59b1de2ad29 (MD5) Previous issue date: 2014 / Resumo: A recirculação de água de lavagem de filtro em estação de tratamento de água do tipo convencional (ETA) pode representar economia significativa tanto do recurso hídrico quanto de energia, aspecto fundamental do ponto de vista da sustentabilidade. Contudo, se praticada sem critério, tal prática operacional pode representar risco à saúde do consumidor. O objetivo geral desta pesquisa foi avaliar o impacto da recirculação da água de lavagem de filtros (ALAF) na qualidade da água tratada. O trabalho desenvolveu-se na ETA-3 de Campinas-SP que capta do manancial superficial (rio Atibaia), utiliza pré-cloração e policloreto de alumínio como coagulante no processo de tratamento. Investigou-se em escala de bancada (Jar-test) o impacto da aplicação de taxas de recirculação equivalentes a 2, 4, 6, 8 e 10 % em volume de ALAF em relação ao volume total de água tratada na formação de subprodutos de desinfecção (trihalomeanos e ácidos haloacéticos). Os parâmetros carbono orgânico total (COT), carbono orgânico dissolvido (COD), UV254, turbidez, cor (aparente e verdadeira) e metais (alumínio, bário, cádmio, chumbo, cobre, cromo, manganês, zinco e níquel) foram também avaliados. Em geral, as diferentes taxas de recirculação de ALAF não provocaram inadequações quanto ao padrão de potabilidade para os parâmetros: cor, turbidez, metais (bário, cádmio, chumbo, cobre, cromo, manganês, zinco e níquel) e trihalometanos. Quanto aos ácidos haloáceticos, porém, notou-se que não se atendeu ao valor limite estabelecido na legislação e que o aumento da taxa de recirculação provocou a elevação da concentração deste subproduto da desinfecção na água tratada / Abstract: Filter backwash water recycling at conventional water treatment plants (WTP) certainly contributes to water and energy resources rational use, essential for sustainability. However, if practiced without criteria, such operational practice may pose a risk to users¿ health. The overall objective of this research was to evaluate the impact of recirculating filter backwash water on filtered water quality. The work was carried out at Campinas WTP, Sao Paulo State, Brazil. The plant treats surface raw water from Rio Atibaia (pre-chlorination, polyaluminum chloride as main coagulant). It was investigated in lab scale (jar-test) the effect of applying recirculation flowrate corresponding to 2, 4, 6, 8 and 10 % volume of backwash water ratio to total volume of treated water on the formation of disinfection byproducts (trihalomethane, THM and haloacetic acids, HAA). Metals content (aluminum , barium, cadmium, lead, copper, chromium , manganese, zinc and nickel), total organic carbon (TOC), dissolved organic carbon (DOC) , UV254 , turbidity, apparent and true color were also evaluated . In general, tested recirculation rates did not cause filtered water quality mismatches to drinking water standards for the parameters: color, turbidity, metals (barium, cadmium, lead, copper, chromium, manganese, zinc and nickel) and THM. However, for HAA it was found that recycling led to concentration values upper than the maximum contaminant level in Brazilian drinking water standards. Increasing the rate, higher was the concentration of this disinfection by-product in treated water / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

The use of particle counters in potable water treatment is achieving higher levels of acceptance on an ongoing basis. This is due to its superior sensitivity in terms of water clarity determination in comparison to turbidity meters. However, the ability of the particle counter to distinguish between various particle sizes, arguably its biggest advantage over turbidity measurement, is not being utilised fully, due to the large volumes of data generated and the amount of post-measurement data processing required to unlock some of the information. In many cases it is being used purely as a substitute or parallel measurement for turbidity. Furthermore, in the South African context, where data is being generated, the particle count data holds little value as it cannot be compared to generally available data sets to reveal the entire message contained in the count. No record of counts is available to rate new measurements against. / Prof. J. Haarhoff

Ozonation is used as an alternative disinfection process to chlorination but unfortunately has a potential of oxidizing bromide, a natural component of water sources, to bromate. Bromate is a possible carcinogen with a maximum contaminant level of 10 ppb. To understand bromate formation in full-scale systems, a comprehensive study was conducted at the Moorhead Water Treatment Plant (WTP). Bromide concentrations in source waters were monitored. Water samples from locations in the ozonation chambers were collected and analyzed for bromate and other parameters. Results showed that bromate formation was increased through increases in pH, bromide, and ozone dose during high temperatures and was decreased by increases in organics. The impact of the bromate influential parameters was minimized at low temperatures. To assist Moorhead WTP on developing bromate control strategies, a modeling approach was adopted to predict bromate formation at various operational conditions using temperature, pH, ozone dose, bromide, and TOC. / MWH Global, AWWA Scholarship / American Water Works Association (AWWA), Minnesota and North Dakota sections / North Dakota Water Resources Research Institute / Department of Civil Engineering, North Dakota State University

A recent study at the Moorhead water treatment plant (MWTP) determined that bromate formed during ozone disinfection and, at times, exceeded the maximum contaminant level (MCL) of 10 parts per billion (ppb) in the summer months. Operational data showed that bromate formation was directly related to raw water bromide concentration and control of the ozone system. This study was conducted with the purpose of developing and implementing operational strategies to minimize bromate formation in the MWTP. Several operational changes, including selection of source water based on bromide concentration and controlling ozone addition in a manner that reduces the ozone dose used to achieve disinfection, were implemented and were effective at minimizing bromate formation in the ozone chambers. The bromate concentration in the finished drinking water was significantly reduced and only a few samples contained greater than 10 ppb bromate. / Moorhead Public Service / American Water Works Association

Avloppsreningsverket i Hallsberg kommun är beläget i direkt anslutning till Hallsberg, med Ralaån som recipient. Tekniken på reningsverket bygger på principerna för en klassisk aktivslamanläggning med mekanisk rening, kemisk rening, biologisk rening och en slambehandling där rötning av primär- och sekundärslam används för utvinning av biogas. Hallsberg ARV har under en längre tid haft problem med kvävereningen. Under senaste åren har man överskridit riktvärdet för kväveutsläpp vid ett flertal tillfällen och under 2009 överskreds även gränsvärdet. Riktvärdet för Hallsberg ARV är i dagsläget satt till 10mg NH4-N/l som medelvärde per månad, gränsvärdet är satt till 10 mg NH4-N/l som medelvärde per kalenderår. Då Hallsberg ARV inte drivs vid full kapacitet antas en minskning av kväveutsläppen vara möjlig att genomföra genom trimning av befintligutrustning och processer på verket. Detta antagande låg till grund för det här examensarbetet som syftar till att optimera kvävereningen på Hallsberg ARV. I optimeringen ingick en teknisk, ekonomisk och miljömässig utvärdering av olika alternativa lösningarna för att förbättra funktionen hos anläggningen. Extra hänsyn togs till energi- och kemikalieåtgång i syfte att få en så effektiv drift av verket som möjligt. Arbetet genomfördes genom en initial litteraturstudie på området, vartefter en provtagningsserie om fyra veckor realiserades på verket. Data som ligger till grund för slutsatserna i projektet har också inhämtats från onlinemätare på verket samt från äldre externt analyserade prover. Efter analys av insamlad data antas orsakerna till Hallsberg ARV:s höga utsläpp av kväve bero på en kombination av flera faktorer: -Vid vår och höst kan brunnsslamintaget vara så stort att bräddning sker ut till verket. Detta leder till att kvävebelastningen höjs så kraftigt att nitrifierarna inte hinner acklimatisera sig och får förhöjda kväveutsläpp till följd. -Mycket kväve följer med slammet från simultanfällningen till rötningen. Detta kan påverka halten kväve i rejektet från rötkamrarna som i sin tur kan leda till störningar i kvävereningen. -Centrifugens rejekt innehåller mycket kväve och körs idag endast under ett par dagar i veckan vilket leder till stora variationer i inkommande kvävehalt. -En hög förfällning av fosfor och organiskt material har bidragit till en låg halt av organiskt material i denitrifikationen. Sammantaget föreslås att vidare studier bör genomföras av ovan nämnda områden för att driften på Hallsberg ARV ska kunna drivas med så låga miljömässiga och ekonomiska kostnader som möjligt. / The waste water treatment plant in Hallsberg municipal is situated adjacent to Hallsberg, with Ralaån as a recipient. The technique at the waste water treatment plant is based on the principles for a classical activated sludge treatment plant and includes mechanical treatment, chemical treatment, biological treatment, and a sludge treatment where the digestion of primary and secondary sludge is used for extraction of biogas. Hallsberg waste water treatment plant has during some time had problems with the nitrogen removal with high nitrogen emissions as a consequence. The target value has been exceeded a couple of times during the last years and in 2009 the limit value was exceeded as well. The target value for Hallsberg waste water treatment plant is 10 mgNH4-N/l as an average value per month, the limit value is set to 10 mg NH4-N/l, as an average value per year. Since the waste water treatment plant in Hallsberg not is operating at full capacity, a lowering of the nitrogen emissions is assumed to be possible though a trimming of the existing equipment and of the processes on the site. This assumption formed the basis for this thesis, designed to optimize the nitrogen removal at the waste water treatment plant in Hallsberg. A technical, economical and environmental evaluation was included in the optimization to improve the function of the plant. Extra evaluations were made in the energy- and chemical consumption in order to streamline the operations at the plant as much as possible. The project was carried out through an initial literature-investigation followed by a four week period of sampling and analyzing at the site. The data that form the conclusion in this project has also been collected through online measurements at the plant as well as through analyses of older samples. After analyzing the collected data, the reasons for the high emissions of nitrogen is thought to be due to a combination of reasons: -During the spring and the autumn the external intake of well sludge can lead to a direct release of sludge in to the plant. The change of nitrogen content will not give enough time for the nitrifying bacteria to acclimatize, with elevated emissions of nitrogen as a consequence. -The usage of simultaneous precipitation could lead to an irregular concentration of nitrogen released to the treatment plant from the digesters. This in turn could contribute to higher nitrogen emissions. -The irregularities of the usage of the centrifuge contribute to nitrogen irregularities and contribute to the difficulties of acclimatization of the nitrifying bacteria. -A high pre-precipitation of phosphorus and organic matter has contributed to a level of organic material in the denitrifikation below what is recommended. To sum up, further investigations are suggested in the above mentioned areas to make the operations at the plant carried trough at the lowest possible environmental and economically cost.

The removal of 34 per- and polyfluoroalkyl substances (PFAS) were compared in a 1 stagegranular activated carbon (GAC) filtration to a 2 stage GAC filtration in a pilot study at adrinking water treatment plant (DWTP). The PFASs that were present in the water wereperfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluoropentanoic acid(PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorobutanesulfonic acid (PFBS), perfluoropentane sulfonic acid (PFPeS) and perfluorohexane sulfonic acid(PFHxS). A cost comparison for the operation of a one stage GAC to a two stage GAC wascompared for PFAS4 (sum of PFOA, PFNA, PFHxS and PFOS) at treatment goals ranging from2 - 10 ng/L. The pilot was operated at three different flows and the three different bed volumes(BV)s resulting in three different empty bed contact times (EBCTs) at three different times.Therefore, the Lin & Huang adsorption model (1999) was used to model the concentrations ateach EBCT. It was found that the model worked good for PFBS, PFPeS, PFHxS, PFOS andPFOA but not for PFPeA, PFHxA and PFHpA (except for PFPeA and PFHxA during EBCT 5min) and did not work for desorbing PFASs. The removal comparison of PFASs was made,partly by comparing removal efficiencies between the first stage and the second stage GAC filterand by comparing the removal per weight of GAC per BV 1 stage and 2 stages. It was found thatthe removal efficiency decreases with decreasing chain length and increasing treated BVs forboth the first stage and the second stage. The short chain PFCAs were also desorbing after anumber of BVs. The removal per weight of GAC showed that the removal does not increasewhen comparing a one stage GAC to a two stage GAC for any the PFAS. The cost comparisonwas made using the adsorption model. It showed that it was cheaper to operate a 2 stage GAC forthe EBCT of 5 minutes and 8 minutes for the whole range of treatment goals. However, for theEBCT of 15 minutes the costs for the second stage was decreasing with decreasing treatmentgoal which is unrealistic result. This was caused by too few data points available for the model topredict reliable results.