食品工廠之廢水所產生的污泥，含豐富的有機成分，可考慮製成飼料或有機肥料回收再利用，傳統混凝劑會殘留於污泥，須以焚化或掩埋丟棄處理；從海產殼上分離出的幾丁聚醣(chitosan)，具多價正電荷及營養成分，可當污泥調理劑，又不污染污泥，適合於處理欲回收之污泥。本文即利用幾丁聚醣作為污泥調理劑，探討其效果。結果指出，從啤酒廠取回之濃縮污泥雖然非常黏稠，無添加幾丁聚醣不易僅靠重力成餅；污泥餅成型與否，受pH影響很大，Ph值為4及5時，只加少量幾丁聚醣即可固液分離，極易成形，而構形紮實與否則隨添加量增加而增強，但pH值大於6時，縱然加幾丁聚醣近20,000 ppm，亦不能成形，所得過濾液亦明顯比前兩者少，甚或不滴落;此乃幾丁聚醣當調理劑，低pH值之污泥液可使-NH2形成帶正電荷之-NH3+，發揮電價中和之混凝效果。隨幾丁聚醣添加，成形之餅乾燥後的直徑及高度收縮率會下降，即乾污泥餅之體積增大、密度變小，此說明幾丁聚醣添加量增加所形成之凝聚顆粒較大，顆粒間孔隙也愈大。 The sludge generated from food processing factories contains large amopunt of organic materials. Hence producing animal feed or organic fertilizer is a feasible way for reusing this type of sludge. Traditional coagulants used for sludge dewatering would remain In sludge then can be only treated by incineration or buried. Chitosan extracted from shells of seafood obtains multiple charges and nutrients., meanwhile, it can also be used as conditioner for sludge dewatering.Because sludge would not be contaminated by chitosan, hence, the treated sludge can be reused and recycled. This paper is study of the effect on using chitosan as conditioner for sludge dewatering.The results show that although the sludge from a brewery factory was very thick, it still could not form sludge cake simply dewatered gravitationally without adding chitosan. The formation of sludge cake was highly affected by pH. Within pH ranged from 4 to 5, small amount of chitosan could easily achieve solid/liquid separation and from sludge cake. The stiffness of sludge cake increased with increasing amount of chitosan added. However, when pH was higher than 6, sludge cake could not form ever condltioned with 20,000 ppm of chitosan and filtrate was also signficantly reduced or even stopped dropping. Along with increasing addition of chitosan, the ratios of diameter and height of the dried to wet sludge cake would increase, i.e., the volume of dried sludge cake increased and density decreased. This means that the higher amount of chitosan added would form larger coagulated particles.
