Performance of oxidation ditches in Thailand

AuthorLee, Shain-jang
Call NumberAIT Thesis no. 829
Subject(s)Water treatment plants
Oxidation
Factory and trade waste
NoteA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand.
PublisherAsian Institute of Technology
AbstractTwo full scale oxidation ditches in the field were investigated, one was designed by a local consultant company and installed to treat soft drink waste, the other was designed and supplied by another country. It is used to treat milk plant waste. The one in the milk plant, due to the incorrect design and improper operation, a foul small came out and most of time, the filtered COD removal was below 60 percent. Meanwhile, the effluent filtered COD was within a range of 260 mg/l and 850 mg/l. The amount of MLSS in the ditch was discharged into the effluent and cause a higher total COD than the influent. It means that the milk plant discharged worse waste, compared with the raw waste of the plant, to the klong. The performance of oxidation ditch in the soft drink plant was good. It was found that the range of optimum organic loading was between 0.07 and 0. 12 Kg COD/Kg MLSS/day and that effluent filtered COD was as low as 50 mg/l or below. Owing to the fish being bred in this oxidation ditch, no solid accumulation was observed throughout the study period. In order to answer the question of excess sludge and to obtain some valuable information about oxidation ditch process, a series of bench scale study of the milk and the soft drink wastes was carried out for three weeks each run. From the results, it was believed that under adequate oxygen supply condition, the dissolved oxygen did not affect the COD removal in the system. In a separate test, a laboratory study of sludge settleability was conducted. It was found that pretreated waste by anaerobic process could not improve the settleability of sludge. Whereas waste characteristics play an important role in the settling of sludge, and it was also observed that the predominance of filamentous organisms species governed the bulking sludge in carbohydrate waste treatment.
Year1975
TypeThesis
SchoolStudent Research Before 1980
DepartmentOther Field of Studies (No Department)
Academic Program/FoSThesis (Year <=1979)
Chairperson(s)Pescod, M.B. ; Yang, Yi Ping
Examination Committee(s)Samorn Muttamara
Scholarship Donor(s)Taiwan Sugar Company
DegreeThesis (M. Eng.) - Asian Institute of Technology, 1975


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