Improvement in Sedimentation by Installation of Conventional and Modified Tube Settlers - A Review

摘要

The change is a law of nature and hence the forms of impurities in water are getting change day by day. The most occurring impurity in surface water flow is turbidity. Turbidity is a serious problem especially in rainy season which is a great challenge for the local municipal operated water treatment plants faces ever. Permissible limit for the potable water is 5-10 NTU wherein in rainy season it goes above 1000NTU. The removal of turbidity from raw water is usually done by the sedimentation tank. The sedimentation process removes the turbidity of water, when it is kept in still position for prescribed time period (detention time). Sedimentation can be done by two methods viz. conventional settling and high rate settling. It is a practice from last few decades of using conventional settling process for sedimentation and high rate sedimentation has been accepted technology in water treatment process in many countries after strong hesitation. However in view of performance efficiency and importance of this technology, still few are not satisfied with the achievements so far. This article describes a simple point of view of the known conventional settling process and high rate sedimentation methods (emphasize on tube settlers) by investigating the reviews of various scholars from an originally accepted methods.