Pollution-free microbes paper mill sewage treatment

The treatment of papermaking wastewater is mainly to reduce COD, which is composed of non-dissolved COD and dissolved COD. Usually, non-dissolved COD accounts for most of the total amount of COD. When SS is removed from wastewater, most of non-dissolved COD is removed at the same time.  Therefore, the main problem to be solved in papermaking wastewater treatment is to remove SS and COD.  

At present, the main methods to treat papermaking wastewater are:  

1, air floating or precipitation method.  By means of air floatation or precipitation and adding coagulant, most of SS, most of non-dissolved COD and part of dissolved COD and BOD5 can be removed.  

2. Combination of physicochemical and biochemical treatment.  For large and medium-sized papermaking enterprises with low discharge of papermaking wastewater and high COD content, it is more difficult to achieve the national first-level discharge standard by means of single stage air floatation or precipitation, because soluble COD and BOD5 can only be effectively removed by biochemical methods.  

The treatment method of physicochemical plus biochemical is generally adopted.  Sludge disposal and comprehensive utilization.  The loss of pulp is inevitable in the process of papermaking. There are two advantages to recycling the waste pulp into the wastewater: first, the recycled pulp can be used for papermaking or sold as raw materials of low-grade paper, resulting in direct economic benefits;  The second is to reduce the waste water treatment load, reduce the consumption of pharmaceutical.