Separation treatment and disposal of screenings from water pollution control works.

Little development in screening practice at sewage treatment works has taken place since the basic design was originated some 100 years ago. This thesis details a comprehensive investigation and assessment of screening practice in the United Kingdom. A review has been undertaken of previous work carried out both in this country and abroad and the findings summarised.The results from questionnaires concerning screening practice sent to over one hundred sewage treatment works in this country are summarised and the major problems outlined. During the course of this project visits were made to the main manufacturers of screening equipment and several sewage treatment works and installations to inspect plant and discuss screening practice. The conclusions from these visits are also presented and discussed.Data relating to screenings quantities and sewage flows has been collected from a number of sewage treatment works, collated and the results analysed.The various items of equipment available for the separation and treatment of screenings have been evaluated, their advantages and disadvantages discussed and recommendations made on their operation and application. The various methods of disposal have been evaluated and recommendations made.The feasibility of constructing a pilot plant to test screenings equipment has been investigated and recommendations are presented.Finally, recommendations have been made concerning screen design and screening practice, and the necessity for further work in some particular areas.