02268nam a2200253   450000500170000000800410001703500150005810000270007324500600010026000520016030000110021249000220022350001630024550200580040852011870046665000360165370000370168970000350172670000440176170000460180571000440185181000540189585600650194920260818133715.0110398         th                  eng    a.b103355601 aSivakumar, Muttucumara10aHorizontal flow prefiltration of tropical surface water  aBangkok :bAsian Institute of Technology,c1976  a114 p.1 aThesis ;vno. 993  aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering at the Asian Institute of Technology, Bangkok, Thailand.  aThesis (M.Eng.) - Asian Institute of Technology, 1976  aA horizontal flow prefiltration system was developed using crushed stone as a filter medium for treating tropical surface waters. The main objective of the study was focussed on the reduction in turbidity and the factors affecting it. The multiple regression technique has been used to find the regression coefficients of the variable parameters. The influent turbidity, the depth of media, the length of media and the flow rate have been found to be the factors affecting the turbidity re duction in the horizontal flow filter. For raw water sources of low turbidity, about 35 JTU, the optimum flow rate was found to be 0.34 m3 /m2-h, and of high turbidity level about 150 JTU, it was 0.19 m3 /m2-h. There is no appreciable head loss noted in the laboratory scale study and thus this type of filter could  function for longer duration without cleaning. A cost model has been developed for a pilot plant size horizontal flow prefilter unit and solved by Lagrange's function. It is concluded from this study that the horizontal flow filtration  system using coarse media such as crushed stone is found to be very effective in removing suspended solids from tropical surface waters.   0aWaterxPurificationxFiltration1 aNguyen Cong Thanh, eChairperson1 aPescod, M.B., eCo-Chairperson1 aEdwards, Peter, eExamination Committee0 aSamorn Muttamara, eExamination Committee2 aBritish Government, eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. 993  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B23864