الفهرس 
INTRODUCTION AND AIM OF THE WORKOnly 14 pages are availabe for public view
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Abstract
Under conditions of alarming water scarcity, treating wastewater is becoming indispensable for meeting the staggering water demand in Kuwait in addition to its environmental and financial benefits. Treating wastewater will help in reducing the pressure on expensive desalinated water production in Kuwait. In Kuwait there are five main wastewater treatment plants using suspended growth treatment method. Four of them Jahra, Riqqa, Kabed and the Sulaibiya treatment plants use activated sludge treatment technology and one, Um Alhayman, uses oxidation ditch technology. Um Alhayman wastewater treatment plant (site 1) is located 61 km south Kuwait city. It started in 2001 with a design capacity of 30000 m3/day. The main objective of this plant is to treat the sewage received from the township at Ali Sabah al-Salem and adjoining areas, through an intermediate pumping station. Alriqqa plant started in 1982 with a capacity of 85,000 m3/day then it has expanded in 1999 to a capacity of 180,000 m3/day. It receives an overflow of 240,000 m3/day.
This study is a cross sectional comparative study between Um Alhayman and Alriqqa Wastewater Treatment Plants, having the following specific objectives: calculation of the capacity of different treatment units of the two plants, evaluation of the efficiency of wastewater treatment, calculation of the land use and energy use for the two selected plants, and doing a cost effectiveness analysis for the two selected plants. For this comparative study, the design documents of both wastewater treatment plants were consulted. Laboratory records for wastewater characterization, operational records, operation contracts and wastewater treatment plant operators, in the two selected wastewater treatment plants, were investigated. Also, the design codes for wastewater treatment plant and the relevant books were consulted.
Site 1 treatment plant can receive up to (39312 m3/day) of wastewater, which is almost 1.33 times the value of design flow (30000 m3/day). Also, site 2 treatment plant, can receive up to (243121 m3/day), which was only 1.35 times the value of design flow (180000 m3/day).
The COD, TN, TC, FC and EC effluent values for site1 and site2 were complying to The Environment Public Authority (2001)in Kuwait. Also, for site1 BOD and TSS were within the range of The Environment Public Authority (2001). However, for site 2, they were violating the range specified in Kuwait EPA standards. Total Phosphorus concentration in effluents from the two sites under study, was violating the range specified in Kuwait EPA standards.
Land requirement for site1 that uses oxidation ditch technology was 4 m2 for each m3 of treated wastewater; it was more than the area needed for site2 that uses extended aeration technology which needs only 2.8 m2 for one m3 of treated wastewater. In addition, the electricity consumption for site2 was 0.3(kwh/m3), more than that of site 1 (0.19kwh/m3). Finally, as a reason of equal operational and maintenance annual cost for the two plants, the total annual cost per unit discharge for site 1 (oxidation ditch plant) was eight times higher than that of site 2 (extended aeration plant).
This study concluded that the wastewater treatment plant of site 1 and site 2, were found to have different capacities for the different units. The operation of each treatment plant was based upon the unit having the maximum capacity: oxidation ditch capacity for site 1 and extended aerated for site 2. The removal efficiency of site1 was more than that of site 2. Land requirement for site 1 was more than that of site 2, however the electric energy consumption for site 2 was more than that for site 1.The annual cost per discharge for site 1 was more than that of site 2.
It is recommended to checking the operating and maintenance contracts should be done to avoid spending equal operating and maintenance costs on different plant technologies or different plant sizes. Re-tendering contracts and the details of the design capacities of WWTP units for the future plants should be carefully taking place to avoid confusion during construction, operating and monitoring, and to avoid wasting money. It is also recommended choosing an oxidation ditch better than an extended aeration technology for any future wastewater treatment plant planning in Kuwait, since it has better efficiency.