工艺特点 Technics Characteristic
      食品工业原料广泛，制品种类繁多，排出废水的水量、水质差异很大。废水中主要污染物有①漂浮在废水中固体物质，如碎肉、禽羽等;②悬浮在废水中的物质有油脂、蛋白质、淀粉、胶体物质等;③溶解在废水中的酸、碱、盐、糖类等;④原料夹带的泥沙及其他有机物等;⑤致病茵毒等。食品工业废水的特点是有机物质和悬浮物含量高，易腐败，一般无大的毒性。其危害主要是使水体富营养化，以致引起水生动物和鱼类死亡，促使水底沉积的有机物产生臭味，恶化水质，污染环境。
      食品工业废水处理除按水质特点进行适当预处理外，一股均宜采用生物处理。如对出水水质要求很高或因废水中有机物含量很高，可采用两级曝气池或两级生物滤池，或多级生物转盘，或联合使用两种生物处理装置，也可采用厌氧一需氧串联的生物处理系统，
      The food industry has a wide range of raw materials and many kinds of products. The quantity of waste water and water qualiyare very dfferent. The main pollutants in the wastewater are 1 floating solid substances in the wastewater, such as broken meat,poulry feathers, etc. (2) Ol, protein, starch, colloid and so on are suspended in the waste water; (3) acids, bases, salts andsugars dissolved in. wastewater; 4sediment and other organic matter contaned in raw materials; Food industry wastewater ischaracterized by high oontent of organic mater and suspended solids, easy to corrupt, and generally no toxicity, its harm ismainly to eutrophication of water body, resuting in the death of aquatic animals and fish. Organic matter that causes depositionunder the water Produce stink, worsen water quality and pollute the environment.
      In addtion to proper pretreatment according to the characteristics of water qualty, bialogical treatment is generally suitable forfood industry wastewater treatment, such as high requrement tor ffluent quaity or high content of organic matter in wastewater.Two- stage aeration tank or two-stage biofter, or multi- stage b ofilter, or combined use of two biological treatment devices, oraneerobic aerobic senes biological treatment system can be used.