JASC: Journal of Applied Science and Computations ISSN NO: 1076-5131 Modification in Rapid Sand Filter for Backwashing System Using Change in Filter Design 1 Ms.SNEHA S. TAKANKHAR, Vishwashanti Colony,Pimple Saudagar,411027, India 2 Dr.A.B.More, HOD of Civil Engineering, D.Y.Patil College of Engineering, Akurdi ,Pune,411044,India Email: [email protected], [email protected] Abstract Objectives Back washing is putting it simply; backwashing is cleaning 1. To study the conventional back washing the filter by reversing the flow of water to remove any techniques and rapid sand filter strictures. debris, build up, and contaminants. For the backwashing of 2. To study the efficiency, time and water rapid sand filter about 10 to 15 % of clean water requires requirement for the rapid sand filter and frequent backwashing (24 – 72 hr) will consume more 3. Design the model for modified rapid sand filter amount of water for the back washing purpose. To structure. minimize the amount of water require for the backwashing 4. Experimental model of rapid sand filter for system, to improve the structure of rapid sand filter for the conventional and modified rapid sand filter high efficient back washing purpose, to improve structure. backwashing technique to consume less time and efficient 5. Testing of model and comparative experimental backwashing system. analysis for the time and water requirement of backwashing system. This project deals with the modified structure and modified technique of backwashing. Here I am going to use the combine water and air filtration technique for Literature review backwashing system, this will results to minimize the required water for backwashing. In this project comparative Waleed M. K. Zahid,et al, 2002[1], the use of rapid sand- analysis has been conducted by performing the filtration for tertiary treatment of wastewater in Saudi experimental setup for the conventional and modified rapid Arabia is expected to increase dramatically with the sand filter system. implementation of the lately approved Saudi code of reclaimed wastewater and reuse. Almost all-existing tertiary wastewater-treatment plants in the Kingdom utilize Introduction imported sand for filtration. The objectives of this research project were to search for appropriate local sand, and to Filtration is one of the most important & essential process assess its performance in tertiary filtration of wastewater by of water treatment. In this process, water allows passing conducting a pilot-scale filtration study. Sand samples with through sand filter media and then collects in the storage a size range of 1.1-3.3 mm from Riyadh and Hail cities tank followed by disinfection process. This process helps to were tested for conformity to AWWA standards for remove impurities present in the water like suspended filtering materials. colloidal particles which don’t trapped in the sedimentation [2] process. At certain interval of time, sand pores may get Afshin Ebrahimi,et al, 2017 , The dataset presented in clogged due to fine colloidal particles and decreases the this article are related to the research article entitled efficiency of filter bed. And hence it is needed to remove “Hybrid coagulation-UF processes for spent filter back these fine particles from the pores of the sand. The well- wash water treatment a comparison studies for PAFC land known process for removal of these fine particles is filter FeCl3 as a pre-treatment”. This article reports the cost backwashing. Filter backwash is the process in which 4% estimation for treating produced spent filter back wash of treated water is kept aside for backwashing. This amount water (SFBW) during water treatment in Place various of treated water is then allowed to flow through the bed in methods in clouding primary sedimentation, coagulation& reverse direction i.e. upward flow. The duration required flocculation, second clarification, ultra filtration (UF) and for backwashing with treated water is 15 to 20 minutes with recirculation of settled SFBW to water treatment plant additional flow of air. (WTP) entrance. Coagulation conducted by PAFClandFeCl3 as pre-polymerized and traditional coagulants. Volume VI, Issue VI, JUNE/2019 Page No:2154 JASC: Journal of Applied Science and Computations ISSN NO: 1076-5131 have been found to determine the minimum fluidisation velocity in a three-phase system. Mokhtar Mahdavi,et al, 2017[3], During operation of most water treatment plants, spent filter back wash water (SFBW) is generated, which accounts about 2–10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a per-manent water source until the water treatment plant is Methodology working. This data article reports the practical method being used for water reuse from SFBW through different The rapid sand filter or rapid gravity filter is a type of filter method including pre-sedimentation, coagulation and used in purification and is commonly used in flocculation, second clarification, ultra filtration (UF) and municipal drinking water facilities as part of a multiple- returned settled SFBW to the beginning of water treatment stage treatment system. plant(WTP). J.C.J. Gude,,et al, 2018[4], Current groundwater treatment facilities, mostly relying on aeration-filtration configurations, aim at the removal of iron (Fe), ammonia (NH4 8 +) and manganese (Mn). However, recently water companies expressed the ambition to also reduce arsenic (As) concentrations in these rapid sand filters. The aim of this study was to investigate the effect of the Fe oxidation state entering a biological filter bed on As removal. By varying supernatant water level, either Fe(II) or Fe(III) in the form of hydrous ferric oxides (HFO) could be stimulated to enter the filter bed at alkaline groundwater pH. Case study, science direct,et al, 2016 [5], the required secure retention of microbiological parameters cannot cost Fig. Block diagram of project effectively be guaranteed by conventional technologist e Rapid sand filters are typically designed discussion of reusing the backwash water today oft en as part of multi-stage treatment systems used by large results in consider ring the use of membrane technology. A municipalities. These systems are complex and expensive safe re tension of microorganism s in combined ion with to operate and maintain, and therefore less suitable for high fluxes arc essential for a successful application of UF small communities and developing nations. The filtration in the treatment of filter backwash water, In the reported system requires a relatively small land area in proportion to case it has been proved that high fluxes can be maintained the population served, and the design is less sensitive to for long time per time by tailoring the module flushing changes in raw water quality, e.g. turbidity, than slow sand procedure to the individual application . It has been filters. demonstrated, that the combination of fee ds ide air. R Addicks, science direct,et al, 2015 [6], Simultaneous use of water and air has been proved to be the superior method of backwashing granular media filters in waste water treatment. In this paper it will be shown that it is possible to determine the water and air flow rates which enhance optimal simultaneous backwash, and that the mixing of media can be avoided or enforced depending upon the choice of rates. Our own studies with artificial coated glass beads indicate that the optimum scour coincides with the maximum contraction of the filter bed and the beginning of three phase fluidisation. In that case the applied velocities of water are much lower than with water-fluidisation. The theory of three-phase fluidisation explains the phenomena of simultaneous backwash. In the literature four methods Volume VI, Issue VI, JUNE/2019 Page No:2155 JASC: Journal of Applied Science and Computations ISSN NO: 1076-5131 Fig. Rapid Sand Filter that water in to the conventional filter tank and modified filter tank. Then, took the 10 litre water and send it into the sand filter to find the turbidity. We take the five turbidity readings by sending 3 times 10 litre water in the sand filter. Construction of conventional rapid sand filter Then we collect this filter water and take 3 turbidity readings on both conventional and modified model and then Drawing: compare them with each other. The process of find the turbidity in both filtration and backwashing is same but their results are different as given below in table. The turbidity of the sample input water after mixing dust (suspended solids), the turbidity of the water has been tested and the turbidity of the water is as follows, RESULT The turbidity results are as follows, TURBIDITY READINGS OF CONVENTIONAL Fig Conventional Model MODEL Sr. No. Sample no. Turbidity readings Construction of modified rapid sand filter (NTU) 1. Trial 1 5.8 2. Trial 2 5.2 3. Trial 3 4.9 4. Trial 4 4.1 5. Trial 5 3.6 6. Trial 6 3.2 Turbidity readings (NTU) 8 6 4 2 Turbidity 0 readings (NTU) Trial Trial Trial Trial Trial Trial 1 2 3 4 5 6 Fig. Modified RSF TURBIDITY READINGS OF MODIFIED MODEL Experimental Testing for filtration Sr. No. Sample no. Turbidity readings First we take 15 litters of water in a bucket and add equal (NTU) amount of dirt and dust in both the water buckets and pour 1. Trial 1 5.6 Volume VI, Issue VI, JUNE/2019 Page No:2156 JASC: Journal of Applied Science and Computations ISSN NO: 1076-5131 2. Trial 2 4.5 5. Reuse Of Filtration Of Back Water Using 3. Trial 3 3.8 Ultra Filtration Technology, Case Study: 4. Trial 4 3.5 Science Direct Paper. 5. Trial 5 (10 litter of water ) 3.1 6. R Addicks, Examining The Backwashing Of Rapid Granular Media Filters, Procledinqs Of Tne Filtration Society, January/February 1991 7.