a case study in Thailand Baig, Mirza Laeeque creator Samorn Muttamara Chairperson Mora, J. C. Examination committee Verink, Johan Examination committee Visvanathan, C. Examination Committee The King's Scholarship, Thailand Scholarship donor text series technical report th Bangkok Asian Institute of Technology 1992 continuing eng 106 p. The research was conducte d on Bang Pa-In Paper Mill Industry Co ., Ltd., Auyutthaya Provi nce , Thai land. This study was carried out in order to determine t he wastewater flows and characteristics of pulp and paper mi 11 , to find the effi ciency of ex isting pond t reatment syst em, and to treat the pulp and paper wastewater by conventional and modified activated s ludge . In add ition to these, tertiary treatabi l ity by granular activated carbon was a lso checked for reuse purpose and/or to meet effluent standard enacted by the Ministry of Industry. Information about different processes, operation time and production were obtained, wastewater flow variations were meas ured , and samp l es were taken and analysed . Tests were carried out with composite sampl es made from grab samples and with representative sampl es from composi te sampl es. The quantity of wastewater from pulp mill was about 275 m3/t of pulp produced. There are seven types of wastewater streams from different processes. Black 1 iquor wastewater was found to be most signifi cantly, repres ents a lmost two thirds of t he pollution load gene r ated by the pulp mi 11 . The quantity of wastewater from paper mi 11 was about 178 m3/t of paper produced. The wastewat e r generated f rom different paper mi 11 processes is being treated in OAF unit , which amounts to 4000 m3/d. The unit capacity is 8000 m3/d and is operating wel l and i ts e ffluent is reused. The f i bers a nd talc recovered (about 4 t /d) ar e recyc l ed to the process. About 40 3 of wastewater produced from paper mi 11 is be ing treated with OAF unit and remaining is being discharged to Chao Phraya river. The existing anaerobic pond s ystem cons isted of four ponds i n s eries. The pond perf ormance in t erms of physical, chemical and microbiological characteristics of the influent and effluent was eva luated . The sampl es on every month for 4 mont hs were co llected and analysed. No s ignificant co lor removal was found . Total col i form and faecal co liform concentration was highest in pond 3. The organi c loading in pond 1 is 10800 kg COD/( ha .d ) . The overal 1 detention time is about 188 days . The bio logical treatabi l ity of pulp and paper wastewater by act i vated s ludge gives 74 % COD removal at 0 . 4 kg COD/(kg MLSS.d) and modifi ed activated sludge a lso gives the same resu l t. SS removal effi c i ency found to about 90 % i n both the cases . No s ludge bulking occurred in both the cases. Resul ts from GAC t reatabil ity s tudy indicated that at a dose of 25 g/ l GAC can r emove 53 . 6 % of COD from t he origina l concentration of about 220 mg/ 1 and 80 % of co l or from the original 500 col or unit within 50 minutes , which conformed to the effluent standards establ is hed by the Ministry of Industry of Thailand . Furthermore, t his tert i ary treated wastewater can be reused. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering Thesis (M.Eng.) - Asian Institute of Technology, 1992 Sewage Purification Factory and trade waste Thailand Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B16848 http://203.159.5.9/ait-thesis/detail.php?q=B16848 170399 20260817163735.0