工藝特點 Technics Characteristic
食品工業(yè)原料廣泛，制品種類繁多，排出廢水的水量、水質(zhì)差異很大。廢水中主要污染物有①漂浮在廢水中固體物質(zhì)，如碎肉、禽羽等;②懸浮在廢水中的物質(zhì)有油脂、蛋白質(zhì)、淀粉、膠體物質(zhì)等;③溶解在廢水中的酸、堿、鹽、糖類等;④原料夾帶的泥沙及其他有機物等;⑤致病茵毒等。食品工業(yè)廢水的特點是有機物質(zhì)和懸浮物含量高，易腐敗，一般無大的毒性。其危害主要是使水體富營養(yǎng)化，以致引起水生動物和魚類死亡，促使水底沉積的有機物產(chǎn)生臭味，惡化水質(zhì)，污染環(huán)境。
食品工業(yè)廢水處理除按水質(zhì)特點進行適當預處理外，一股均宜采用生物處理。如對出水水質(zhì)要求很高或因廢水中有機物含量很高，可采用兩級曝氣池或兩級生物濾池，或多級生物轉(zhuǎn)盤，或聯(lián)合使用兩種生物處理裝置，也可采用厭氧一需氧串聯(lián)的生物處理系統(tǒng)，
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.
