由于工业的迅速发展，工业废水的水量及水质污染量很大，它是最重要的污染源，具有以下几个特点：

Because of the rapid development of industry, the amount of water and water pollution of industrial wastewater is very large. It is the most important pollution source, and has the following characteristics:

(1) 排放量大，污染范围广，排放方式复杂 工业生产用水量大，相当一部分生产用水中都携带原料、中间产物、副产物及终产物等排出厂外。工业企业遍布全国各地，污染范围广，不少产品在使用中又会产生新的污染。如全世界化肥施用量约5亿t，农药200多万吨，使遍及全世界广大地区的地表水和地下水都受到不同程度的污染。工业废水的排放方式复杂，有间歇排放，有连续排放，有规律排放和无规律排放等，给污染的防治造成很大困难。

(1) large amount of emission, wide pollution range, complex discharge mode, large amount of water used for industrial production, a considerable portion of production water carries raw materials, intermediate products, by-products and end products. Industrial enterprises all over the country, the pollution range is wide, many products in use will produce new pollution. Such as the world's fertilizer application of about 500 million T, about 2000000 tons of pesticides, so that all over the world in vast areas of surface water and underground water are subject to varying degrees of pollution. Industrial wastewater has a complicated discharge mode, with intermittent emissions, continuous emissions, regular emissions and irregular emissions, which poses great difficulties for the prevention and control of pollution.

(2) 污染物种类繁多，浓度波动幅度大 由于工业产品品种繁多，生产工艺也各不相同，因此，工业生产过程中排出的污染物也数不胜数，不同污染物性质有很大差异，浓度也相差甚远。

(2) many kinds of pollutants, the concentration fluctuation due to industrial product variety, production process is also different, therefore, the pollutants discharged in the industrial production process is beyond count of different pollutants have very different properties, the concentration, but also far away.

(3) 污染物质毒性强，危害大 被酸碱类污染的废水有刺激性、腐蚀性，而有机含氧化合物如醛、酮、醚等则有还原性，能消耗水中的溶解氧，使水缺氧而导致水生生物死亡。工业废水中含有大量的氮、磷、钾等营养物，可促使藻类大量生长耗去水中溶解氧，造成水体富营养化污染。工业废水中悬浮物含量很高，可达3000mg/L，为生活废水的10倍。

(3) pollution toxicity is strong, serious pollution of wastewater by acid-base irritating, corrosive, and oxygen-containing organic compounds such as aldehydes, ketones, ethers are reducing energy consumption, the dissolved oxygen in water, the water hypoxia caused death of aquatic organisms. Industrial wastewater contains large amounts of nitrogen, phosphorus, potassium and other nutrients, which can cause algae to grow in large quantities, consume dissolved oxygen in water, and cause eutrophication pollution of water bodies. The content of suspended solids in industrial wastewater is very high, up to 3000mg/L, 10 times as much as that of domestic wastewater.

(4) 污染物排放后迁移变化规律差异大 工业废水中所含各种污染物的性质差别很大，有些还有较强毒性，较大的蓄积性及较高的稳定性。一旦排放，迁移变化规律很不相同，有的沉积水底，有的挥发转入大气，有的富集于生物体内，有的则分解转化为其他物质，甚至造成二次污染，使污染物具有更大的危险性。

(4) the law of migration and variation of pollutants after discharge is different; the nature of pollutants contained in industrial wastewater varies greatly, and some of them are more toxic, larger accumulation and higher stability. Once the discharge change laws are not the same, some sedimentary water, some volatile into the atmosphere, some enrichment in living organisms, some are transformed into other substances, or even cause two pollution, the pollution is more dangerous.