Download or read book Slow Sand Filtration Treatment of Agriculturally Impacted Water written by Weixin Chen and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agricultural runoff and influence to surface water is a widely experienced problem across the world, particularly in treating that water for potable consumption. Although many effective methods have been researched, there are few that can be considered suitable for rural regions, in-home and on-site water treatment, and extremely smallscale design without requiring significant chemical use, operator skills and sophistication, and large-scale to be economically viable. This research focuses on the use of slow sand filtration (SSF) as one of the most effective methods for potable water treatment that can meet all of the above criteria. The experiments were designed using rapid small scale column testing theory, which is a directly scalable approach to developing a robust and effective system for treating water. The SSF laboratory experiments were divided into two parts: preliminary experiments and full-scale experiments. The preliminary experiments were designed to test the removal efficiency of agriculturally-associated concentrations of orthophosphate and iron. The full-scale experiments were design simulate the realistic SSF plant which can test the removal efficiency with different concentration of additive in raw water. Raw water samples were collected from Wascana Lake as representative of complex water quality associated with both rural and urban contamination and agricultural influence. In the experiments, these raw water samples are subjected to several operational, water quality and environmental factors, including temperature, pH and filtration rate, to determine the impacts on removal efficiency and overall performance of the SSFs. The results of the preliminary experiments indicate that 25°C and alkaline conditions had the most significant impact on orthophosphate removal. Factors such as lower temperature (5°C) and acidic condition created an inhibited impact on the results, leaving higher concentration of orthophosphate in the effluent. For iron removal, the pH, temperature and filtration rate were all noted to impact removal efficiency. Higher temperature (25°C), increased alkalinity, and higher filtration rate resulted in higher effluent concentrations of iron. The results of the full-scale experiments indicate the interaction of phosphate, nitrate, iron and humic acids in SSF. The data show that increasing phosphate and nitrate in the raw water can slightly improve the performance of nitrate and phosphate removal but no obvious effect in humic acids and iron removal. The higher iron concentration can help improve humic acids removal. The experimental results clearly demonstrate that temperature and pH control in water treatment design are essential for high performance and robust and reliable production of high quality potable water.

Download or read book Slow Sand Filtration written by Nigel Jonathon Douglas Graham and published by . This book was released on 1988 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sustainable Drinking Water Treatment for Small Communities Using Multistage Slow Sand Filtration electronic Resource written by Cleary, Shawn A and published by University of Waterloo. This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Slow sand filtration is a proven and sustainable technology for drinking water treatment in small communities. The process, however, is sensitive to lower water temperatures that can lead to decreased biological treatment, and high raw water turbidity levels that can lead to premature clogging of the filter and frequent cleaning requirements, resulting in increased risk of pathogen breakthrough. Multistage filtration, consisting of roughing filtration followed by slow sand filtration, can overcome these treatment limitations and provide a robust treatment alternative for surface water sources of variable water quality in northern climates, which typically experience water temperatures ranging down to 2C̊. Prior to this study, however, multistage filtration had yet to be systematically challenged in colder climates, including testing of its performance under increased hydraulic loadings and elevated influent turbidity together with cold water conditions. The primary goal of this research was to demonstrate the reliability of multistage filtration for small communities in northern climates with reference to the Ontario Safe Drinking Water Act. In this research, testing was conducted on two different pilot multistage filtration systems and fed with water from the Grand River, a municipally and agriculturally impacted river in Southern Ontario. One system featured pre-ozonation and post-granular activated carbon (GAC) stages, and shallower bed depths in the roughing filter and slow sand filter. The other system featured deeper bed depths in the roughing filter and slow sand filter, two parallel roughing filters of different design for comparison, and a second stage of slow sand filtration for increased robustness. Removal of turbidity, total coliforms, and fecal coliforms under a range of influent turbidities (1 to>100 NTU), water temperatures (~2 to 20C̊), and hydraulic loading rates (0.2 to 0.8 m/h) were investigated. In addition, the slow sand filters in each pilot system were challenged with high concentrations (~10¡ oocyst/L) of inactivated Cryptosporidium parvum oocysts. The performance of both pilot multistage filtration systems was highly dependent on the biological maturity of the system and its hydraulic loading rate. In a less mature system operating in cold water conditions (5C̊), effluent turbidity was mostly below 0.5 NTU during periods of stable influent turbidity (no runoff events) and a hydraulic loading of 0.4 m/h, however, runoff events of high influent turbidity (50 NTU), increased hydraulic loadings (0.6 m/h), and filter cleaning occasionally resulted in effluent turbidity above 1 NTU. Furthermore, in a less mature system operating during runoff events of high turbidity, reducing the hydraulic loading rate to 0.2 m/h was important for achieving effluent turbidity below 1 NTU. However, in a more mature system operating in warm water conditions (19-22C̊), effluent turbidity was consistently below 0.3 NTU at a hydraulic loading rate of 0.4 m/h, and below 0.5 NTU at 0.8 m/h, despite numerous events of high influent turbidity (>25 NTU). It remains to be seen whether this performance could be sustained in colder water temperatures with a fully mature filter. Removal of coliform bacteria was occasionally incomplete in a less mature multistage system, whereas, in a more mature system operating in warm water conditions (>9C̊), removal was complete in all measurements. Furthermore, the average removal of Cryptosporidium was greater than 2.5 logs in both systems (with hydraulic loading rates ranging from 0.4 to 0.8 m/h) and improved with increased filter maturity. Each individual stage of the multistage system was an important treatment barrier in the overall process of turbidity and pathogen removal. The roughing filter was not only important for protecting the slow sand filter from solids loading and increasing its run length, but was also a significant contributor to coliform removal when the system was less mature. Removal of turbidity was significantly improved when the roughing filter was more mature, suggesting that biological treatment was an important treatment mechanism in the roughing filter. Although pre-ozonation was used mainly for the removal of organic carbon and colour, it achieved complete removal of coliform bacteria and was also suspected to be important for enhanced removal of turbidity. The second slow sand filter in series provided additional robustness to the process by reducing effluent turbidity to below 1 NTU during cold water runoff events of high turbidity and increased hydraulic loadings (0.6 m/h), while achieving effluent below 0.3 NTU during normal periods of operation. It also provided additional removals of coliforms under challenging operating conditions, and contributed an additional average removal of Cryptosporidium of 0.8 logs, which resulted in cumulative removal of 3.7 logs, approximately 1 log greater than all the other challenge tests. Collectively, the entire multistage system performed well with water temperatures ranging down to 2C̊, limited filter maturity, elevated raw water turbidities, and increased hydraulic loading rates. Its ability to meet the current Ontario turbidity regulations and greater than 2 log removal of Cryptosporidium over a range of operating conditions, with little or no process adjustment, is a testament to the robustness and minimal maintenance requirements of the process, which are desirable attributes for small water systems that are often located in rural areas. While this research demonstrated the performance of multistage filtration using pilot scale testing, it is important to note that full-scale plants tend to produce significantly better results than pilot facilities, due to long term biological maturation of the system. Overall, multistage filtration is a sustainable and cost-effective technology that, through this research, appears to be a safe, reliable, and robust treatment alternative for small and non-municipal water systems in North America and the developing world. Further, based on its performance with challenging influent water quality and cold water conditions, multistage filtration holds particular promise for small communities in northern climates that are required to meet safe drinking water regulations, but are dependent on surface water sources of variable water quality and temperatures.

Download or read book Slow Sand Filtration written by American Society of Civil Engineers. Task Committee on Slow Sand Filtration and published by American Society of Civil Engineers. This book was released on 1991 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarises current practice regarding slow sand filtration in the US. It examines topics such as the biological and physical mechanisms, appropriate water quality, micro-organisms removal, filter design, construction, operation, maintenance, costs and pilot studies.

Download or read book Recent Progress in Slow Sand and Alternative Biofiltration Processes written by Rolf Gimbel and published by IWA Publishing. This book was released on 2006-03-31 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Slow sand filtration is typically cited as being the first "engineered" process in drinking-water treatment. Proven modifications to the conventional slow sand filtration process, the awareness of induced biological activity in riverbank filtration systems, and the growth of oxidant-induced biological removals in more rapid-rate filters (e.g. biological activated carbon) demonstrate the renaissance of biofiltration as a treatment process that remains viable for both small, rural communities and major cities. Biofiltration is expected to become even more common in the future as efforts intensify to decrease the presence of disease-causing microorganisms and disinfection by-products in drinking water, to minimize microbial regrowth potential in distribution systems, and where operator skill levels are emphasized. Recent Progress in Slow Sand and Alternative Biofiltration Processes provides a state-of-the-art assessment on a variety of biofiltration systems from studies conducted around the world. The authors collectively represent a perspective from 23 countries and include academics, biofiltration system users, designers, and manufacturers. It provides an up-to-date perspective on the physical, chemical, biological, and operational factors affecting the performance of slow sand filtration (SSF), riverbank filtration (RBF), soil-aquifer treatment (SAT), and biological activated carbon (BAC) processes. The main themes are: comparable overviews of biofiltration systems; slow sand filtration process behavior, treatment performance and process developments; and alternative biofiltration process behaviors, treatment performances, and process developments.

Download or read book Water Filtration Practices written by Gary S. Logsdon and published by American Water Works Association. This book was released on 2011-01-12 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water operators will find a wealth of hands-on information on the operation and maintenance of pretreatment, rapid-rate granular media filtration, slow-sand filtration, and diatomaceous-earth filtration systems in this book. This practical guide provides recommended procedures for operating, monitoring, and maintaining all types of filters used for conventional water treatment. These procedures are tested and time-proven by hundreds of water utilities and filtration experts to provide high filter efficiency, excellent water quality, long filter runs and minimum downtime. The book also gives advice on what not to do-and why-so you can avoid water quality problems, filter damage, and treatment problems in the future.

Download or read book Progress in Slow Sand and Alternative Biofiltration Processes written by Nobutada Nakamoto and published by IWA Publishing. This book was released on 2014-05-14 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a state-of-the-art assessment on a variety of biofiltration water treatment systems from studies conducted around the world. The authors collectively represent a perspective from 23 countries and include academics/researchers, biofiltration system users, designers, and manufacturers. Progress in Slow Sand and Alternative Biofiltration Processes - Further Developments and Applications offers technical information and discussion to provide perspective on the biological and physical factors affecting the performance of slow sand filtration and biological filtration processes. Chapters were submitted from the 5th International Slow Sand and Alternative Biological Filtration Conference, Nagoya, Japan in June 2014. Authors: Nobutada Nakamoto, Shinshu University, Japan, Nigel Graham, Imperial College London, UK, M. Robin Collins, University of New Hampshire, Durham, NH, USA and Rolf Gimbel,Universität Duisburg, Essen, Germany.

Download or read book Slow Sand Filtration written by American Water Works Association and published by . This book was released on 1994 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Manual of Design for Slow Sand Filtration written by and published by . This book was released on 1991 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Implementation of Household Level Intermittent Slow Sand Filters for Rural Areas to Mitigate Water related Diseases written by Sangya-Sangam Kumari Tiwari and published by . This book was released on 2008 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Slow Sand Filtration in the United States written by Gary S. Logsdon and published by . This book was released on 1988 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in slow sand filtration has increased dramatically in the United States in the past ten years. Research conducted to evaluate removal of Giardia cysts and bacteria, showed that slow sand filtration is very effective in removal of these contaminants. Slow sand filters are much simpler and easier to operate than plants that employ coagulation. Thus they are very well suited for treatment of previously unfiltered surface waters and would be well suited for small utilities serving from 25 to 3000 persons. The U.S. EPA estimates that about 1000 slow sand filters may be built as a result of proposed EPA regulations on surface water treatment.

Download or read book Advances in Slow Sand and Alternative Biological Filtration written by Nigel Graham and published by Wiley. This book was released on 1996-07-10 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Slow sand filtration is credited with being the first drinking water treatment process utilised to improve the quality of water in both modern Europe and the USA. Within the last 10 years, there has been a renaissance of interest in the potential use of enhanced processes of slow sand filtration throughout the world, especially for small and rural communities, and it continues to be the primary treatment process for many major European cities. The book deals with the latest research developments in slow sand and alternative biological filtration processes for drinking water treatment, including advances in the understanding of the fundamental mechanisms of the processes. In addition, progress in the techniques of operation and upgrading of the processes are described, with case studies from around the world. The principal themes of the book are: General overview; Removal of Natural Organic Matter (NOM), Biodegradable Organic Carbon (BOC) and Ozonation by-products; Biofilter media characteristics; Influence of process design variables and modifications; Modelling process performance; Pre-treatment applications; Operational experience and cleaning; and Upgrading treatment processes. The book also has an international perspective with case-studies from around the world.

Download or read book Slow Sand Filter Maintenance written by Raymond D. Letterman and published by . This book was released on 1985 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimization of Slow Sand Filtration to Remove Plant Pathogens from Irrigation Runoff Water written by Michael Alan Harris and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: California is tremendously dependent on water for a highly productive agricultural industry, growing commercial and industrial sectors, and the human population. In the next 15 years, the population is expected to grow dramatically, which will only put more pressure on an already tight water supply. Effective, low cost, simple, and reliable water treatment methods need be developed to alleviate this pressure. Two experiments were conducted to determine the efficacy of slow sand filters (SSFs) to remove plant pathogens from water to be reused for irrigation. The first experiment evaluated three increasing loading rates to determine if SSFs maintain efficacy. The second experiment was a field study in which SSFs that were initially exposed to Phytophthora capsici were then used to treat stream water known to contain numerous Phytophthora spp. A third experiment examined the effect of chilling and agitation on the recovery rate of P. capsici. Very low numbers of colony forming units were recovered below the sand surface during the fall trial of the slow sand filtration optimization experiment. Chilling and agitation of P. capsici propagules reduced the recovery of colony forming units. Slow sand filters are very effective at removing more than 99% of plant pathogen propagules from water and there was little difference in the removal rate between the slowest loading rate (0.15 m/hr) and the fastest (0.50 m/hr). In colder temperatures, the medium (0.25 m/hr) and fast loading rates caused the filters to foul. Slow sand filters established in the presence of P. capsici can remove other Phytophthora spp., however frequent fouling occurred due to turbidity of the creek water. Slow sand filtration is a simple, low cost, low maintenance, effective and reliable technology that can be used by nurseries to reduce water consumption.

Download or read book Drinking Water Treatment Using Slow Sand Filtration written by Kim Ray Fox and published by . This book was released on 1987 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Slow rate Sand Filtration written by Ann Elizabeth Scarritt and published by . This book was released on 1991 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Slow Sand Filtration written by L. Huisman and published by . This book was released on 1974 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: