含高浓度有机物及重金属的废水处理方法研究

采用铁屑综合处理含高浓度有机物及重金属的废水。经处理后的废水，重金属和ＣＯＤ均达到国家排放标准，研究了铁屑用量，作用时间等的最佳值，并对作用机理作了解释。

STUDY ON TREATMENT OF WASTE WATER WITH HIGH CONCENTRATION OF ORGANIC COMPOUNDS AND HEAVY METALS

This paper gives a feasible treatment for waste water with high concentration of organic matter and heavy metals.

It is possible to remove heavy metals and organic compounds at the same time when they are in high concentration and treated with cast iron chippings. The waste water was made to react with the iron chippings and then its pH adjusted to 9.5±0.4, the precipitation would occur by coagulation. Let the supernatant flow through an iron chippings bed and then adsorbed by cinder. After this treatment, all the indexes of heavy metals and COD could reach the national discharge standard (i. e. COD < 10mg/L, total chromium < 0.05mg/L, copper < 0.5mg/L, lead < 0.5mg/L and tin < 0.5mg/L).

The waste water was treated twice with iron chippings. At first time the reaction time of waste water with iron chippings was controlled within 60- 90min; the consumption amount of iron chippings was controlled within 0.6 - 0.8g/L and pH was adjusted to 9.5±0.4 with lime. Then all the Cr³⁺, Cu²⁺, Pb²⁺ and Sn²⁺ were precipitated in hydroxides, so that the concentration of heavy metals was lower than the national discharge standard. Besides, the organic compounds in waste water were also absorbed on the particles of hydroxides of Fe²⁺ and heavy metals and removed. The removing extent of COD could come to 81.08% - 84.80%. The waste water which had passed the first processing was again passed through an iron chippings bed, and allowed to stay there for 30 - 60min, After that the content of organic compounds was reduced further; the removing extent of COD could reach 78.5% - 85.31%.

The characteristics of this treatment are simple technology, reasonable combination, convenient operation, low material cost, less investment for engineering, and good disposal effect. Iron chippings and cinder are all waste of industry, so according to this method to control waste by waste is achieved.

The optimum amount of iron chippings to be used and the reaction time were studied. The mechanism was also explained.