Mikrokum uygulamalı içmesuyu arıtımının değerlendirilmesi

Abstract

Bu çalışma mikrokum uygulamalı içmesuyu arıtımının değerlendirilmesi amacıyla yapılmıştır. Bu kapsamda, öncelikle Ömerli Hamsuyu kalitesini gösteren 1 yıllık içmesuyu parametreleri incelenmiş olup Ömerli Muradiye İçmesuyu Arıtma Tesisinin çalışması detaylı bir şekilde gözlemlenmiştir ve mikrokum uygulamalı içmesuyu arıtımı için laboratuvar çalışması yapılmıştır. Yapılan bu çalışma altı ana bölümden oluşmaktadır. Birinci bölümde, çalışmanın anlam ve önemi ile amaç ve kapsamı belirtilmiştir. îkinci bölümde, Ömerli Muradiye İçmesuyu Arıtma Tesisinin işletilmesinde sürekli takip edilmesi gereken Ömerli Hamsuyu, her gün Ömerli İçmesuyu Arıtma Tesisleri laboratuvarında analizi yapılan içmesuyu parametrelerine bağlı olarak incelenmiştir. Ömerli Muradiye İçmesuyu Arıtma Tesisi de bu bölüm içerisinde tanıtılmıştır. Bu yapılırken arıtma kademelerine ait hem teorik bilgiler hem işletme bilgileri verilmiştir. Üçüncü bölümde, mikrokum uygulamalı Ömerli Muradiye İçmesuyu Arıtma Tesisi performansı sürekli izlenen arıtma ve içmesuyu parametrelerine göre incelenmiştir. Dördüncü bölümde, mikrokum uygulamalı içmesuyu arıtımının değerlendirilmesini sağlayacak deneysel çalışma ve elde edilen sonuçlar yer almıştır. Beşinci bölümde, mikrokum uygulamalı içmesuyu arıtımına ait deney sonuçlan ve performans verilerinin değerlendirilmesi yapılmıştır. Son bölümde, sonuçlar ve öneriler sunulmaya çalışılmıştır.

The aim of this study is the evaluation of Potable Water Treatment using Microsand. In the first part of this study, drinking water parameters of one year indicating the quality of Ömerli raw water have been examined. Then, the operation of Ömerli Muradiye Water Treatment Plant has been carefully observed and the laboratory works have been carried out to evaluate the use of microsand in potable water treatment. This study consists of six main chapters. In the first chapter, meaning, importance, aim and consistence of this study have been indicated. In the second chapter, Ömerli raw water has been evaluated by laboratory analysis in accordance with potable water parameter. In addition, Ömerli Muradiye Water Treatment Plant has been introduced by the way both theoretical and operational information. In the third chapter, Ömerli Muradiye Water Treatment Plant has been shown as an example for potable water treatment using microsand. The performance of this plant has been observed during the last one and half year and data of December 1996 has been used as water parameters. In the fourth chapter, laboratory studies and their results have been given to indicate the evaluation of potable water treatment using microsand. In the fifth chapter, the laboratory studies and the performance of potable water treatment using microsand have been evaluated. Finally, lime quantity has been calculated by using Rothberg, Tamburini & Winsor Model to increase the value of Langelier Index. In the final chapter, results of the evaluation and suggestions have been presented. Drinking water supply is the basic human's need. The water treatment plants which give the best water quality have to be built and operated in water supply works. Some water treatment processes in the world have been developed to increase the treated water quality. Potable water treatment using microsand is one of this water treatment process that has been improved in France. This process is a compact unit with three phases which consists in coagulation-flocculation-sedimentation. The following steps happen in these processes: - The cyclofioc process where microsand is used in the flocculation, - The multifio process where tube (lamella) elements in the sedimentation zone is applied to increase the contact surface. XI The aim of this process is to reduce fiocculation times and increase rates of settling. Potable water treatment with microsand is a new water treatment process in Turkey. Therefore, this process has to be examined with all aspects. Firstly, in this study, raw water treated in Ömerli Muradiye Water Treatment Plant has been evaluated with using drinking water quality parameters. Both raw and treated waters have been analysed every day in the laboratory of Ömerli Water Treatment Management. In order to evaluate these results from the laboratory, the drinking water quality parameters of Ömerli raw and treated water are compared with Turkish Standards (TS-266) concerning drinking water. Both the turbidities of raw and treated water are not higher than 25 NTU which is maximum value in TS-266. Ömerli raw water's turbidity has changed between 2.81 NTU and 10.6 NTU. Meanwhile, Ömerli treated water's turbidity has changed between 0.56 NTU and 1.64 NTU. The turbidity removal efficiency in 1996 is approximately 80%. There is no odour in raw and treated water of Ömerli Plant. The iron value is not higher than 1 mg/1 and the iron removal efficiency is approximately 75%. The sulphate and chlorine values are more less in Ömerli raw and treated water. pH values are between minimum and maximum standard values of TS-266. The chlorine value is higher than standard value, since chlorination is not done in drinking water storage tanks in Istanbul. The total organic substance of Ömerli raw and treated water is less than the standard total organic substance (3.5 mg/1) and the total organic substance removal efficiency is approximately 30%. Moreover in this study, Ömerli Muradiye Water Treatment Plant has been introduced and examined. The capacity of Ömerli Muradiye Water Treatment Plant is 300.000 m3/day. The flow is equally divided in five Actiflos. There are ten rapid and slow mixing tanks, five settling tanks in this plant. The contact time in a rapid mixing tank is 2 minutes and the velocity gradient is 219sn \ Aluminium sulphate, polymer and microsand are injected in the rapid mixing tanks. These chemical substances are pumped from the machine room. Aluminium sulphate prepared in Ömerli Chemical Building is carried in the transfer tank. Polymer is diluted in preparation tanks. Microsand is prepared in the microsand tank. Chlorine prepared in chlorine room is carried for pre and post chlorinating in Ömerli Water Treatment Plant. Lime prepared in two tanks is used at the end of the filtration. In addition, sludge is pumped by microsand-sludge transfer xii pumps from the settling tanks to hydrocyclones. The hydrocyclones separate microsand from sludge. Microsand is injected again in the rapid mixing tanks. Sludge is discharged by channel into the lake. The contact time in a slow mixing tank is 6 minutes and the velocity gradient is 176 sn"1. The settling time is 6 minutes, the surface load is 40 m3/m2 hour and Hazen velocity is 2.3 m3/m2 hour in the settling tanks. Ömerli Muradiye Water Treatment Plant has twelve rapid sand filters that their available surface is 140 m2. There is a contact tank to make chlorination and inject lime. The volume of the contact tank is 15.000 m3. Microsand use in Ömerli Muradiye Water Treatment Plant has been followed during two years. Potable water in the laboratory and operation parameters in the plant have been clearly established. Data has been collected during two years and the data of December 1996 has been taken, due to some errors observed in other months. Inlet and outlet flow in Ömerli Muradiye Water Treatment Plant are approximately 319419 -302548 m3 /day. The flow of each Actiflo is 2700 m3 / hour. Inlet and outlet turbidity are approximately 3.40 - 0.99 NTU. Raw and treated water pH is approximately 7.70 - 8.73. There are approximately injected 5348 kg/day aluminium sulphate, 1326 kg/day lime, 2962 kg/day chlorine, 3077 kg/day microsand in the plant. Backwashing number of each filter is two or three by day. The outlet turbidity of Ömerli Actiflo Process has been followed to determine the removal efficiency of Ömerli Actiflo Process. Turbidity shows removal efficiency which is the most important parameter to drinking water treatment. The outlet turbidity values are between 2 NTU and 6 NTU. In scientific source concerning microsand use for Potable Water Treatment, this values should not be higher than 2.5 NTU to supply the best treated water quality at the end of the treatment process. In order to determine the main principals and the operation performance of potable water treatment with microsand, jar test analysis has been done by Ömerli raw water in the Ömerli Laboratory. All potable water treatment process can be applied in the jar test analysis. The effects of microsand above the water treatment processes can be found by the jar test analysis, because microsand is injected in the rapid mixing tanks and is passed trough all processes. The mixing time - velocity of coagulation-flocculation, the floe size, the settling time, the optimum dosages of coagulant and coagulants aids can be easily xni determined in this test. Therefore the optimum operation condition and the optimum chemical substance dosages can be decided before real applications. Firstly in the making jar analyses, aluminium sulphate and polymer were diluted in the laboratory. Then 1 litres raw water was taken from the raw water tap in jars. All potable water treatment processes - coagulation, flocculation, settling - were applied for Ömerli raw water. The jar test analyses were made both classical water treatment and potable water treatment with microsand. The results found in the jar test analyses are given below. When aluminium sulphate concentration is below 20 mg/1 and polymer concentration is 0.15-0.20-.25 mg/1, the turbidity in classical treatment process is lower than the turbidity in potable water treatment with microsand. However the turbidity in classical treatment process is approximately the same as turbidity in potable water treatment with microsand when aluminium sulphate concentration is above 20 mg/1 and polymer concentration is 0. 15-0.20-.25 mg/1. Another point in the jar test, the aluminium sulphate dosage in potable water treatment with microsand is lower than the aluminium sulphate dosage in classical water treatment process. The polymer dosage in potable water treatment with microsand is higher than the polymer dosage in classical water treatment process. The floe size in potable water treatment with microsand is smaller than the floe size in classical water treatment process at all aluminium sulphate and polymer dosage. The settling time in potable water treatment with microsand is lower than the settling time in classical water treatment process.. After the evaluation of examination results, the differences have been determined between treatment with microsand and classical water treatment processes. The contact time in the coagulation tank for potable water treatment with microsand is longer than the contact time in the coagulation tank for classical water treatment process. The velocity gradient in the coagulation tank for potable water treatment with microsand is lower than the velocity gradient in the coagulation tank for classical water treatment process. The contact time in the flocculation tank for potable water treatment with microsand is shorter than the contact time in the flocculation tank for classical water treatment process. The velocity gradient in the flocculation tank for potable water treatment with microsand is higher than the velocity gradient in the flocculation tank for classical water treatment process. xiv The settling time in potable water treatment with microsand is lower than the settling time in classical water treatment process. In order to be high Langelier index from zero, minimum lime quantity was found 13.50 mg/1 by using of Rothbergs, Tamburini & Winsor Model in accordance with the potable water parameters of one year. Potable water treatment using microsand area in Turkey has need much more interesting and new studies. xv