Sewage treatment with reference to Malta's situation

Abstract

Sewage is the waste water of the community. It consists of water and Organic and Inorganic contaminants. It also contains many bacteria, some of which are disease producing. In Malta sewage is treated at the Sant Antnin Sewage Treatment Plant in Marsascala. The main objectives of the Sant Antnin Sewage Treatment Plant are to reclaim water for re-use in agriculture and industry and to reduce the volume of sewage that has to be disposed of at sea. The present capacity of the Sant Antnin Sewage Plant is 17,000m3/day. It is important to ensure that the effluent produced from the Plant is free from disease-producing bacteria. For this reason a disinfection process is applied to the final effluent. Two contaminants in sewage interfere with the disinfection process. These are ammonia and organic matter. Before applying the disinfection process it is therefore necessary to reduce ammonia and organic contamination to very low levels. Treatment is a continuous process in which sewage is subjected to a number of treatment stages in which pollutants are separated from the water. Consequently, two products result from waste water treatment: clean water for re-use and sludge containing the pollutants originally present in the sewage in concentrated form. It is important that sewage sludge is treated and so will turn into a valuable agricultural manure. Therefore the purpose of this dissertation is to point out the importance of sewage treatment, since if sewage treatment is not carried out, the risks of having health and environmental hazards would increase considerably. The main objective is to solve all the present difficulties that are being encountered in order to arrive at a stage were all the sewage would be treated. In my introduction I have emphasized the need for sewage treatment and the after effects if this is not carried out. In my materials and methods section I have discussed the methods of sewage treatment (such as primary, secondary and tertiary treatments) and the treatment units used (such as the sedimentation tanks). I have also dedicated a section to the EEC law. The results section indicates that some kind of progress is needed and so I have inserted the Sewerage Master Plan for Malta and Gozo. My discussion section includes a site visit at the Sant Antnin Sewerage Treatment Plant at M'Scala.