The pulp industry is characterized by high water consumption and high environmental pollution potential. The waste water produced mainly depends on the type of raw materials used, the type of process technology used, the amount of internal waste water recycling, and other management methods such as operating conditions and the presence of additives.www.chinactivecarbon.com
Especially for kraft pulping, the use of chemical processes for pulping is currently a common technology in this industry, where high-concentration organic waste water is produced, lignin derivatives and other substances produce color and toxic compounds, and the chemicals used in the process substance. As a result, it is more difficult to treat with traditional treatment methods. This time we tested the use of activated carbon combined with activated sludge system to adsorb and treat kraft paper wastewater.
The system used is activated sludge, which consists of an aerobic reactor with an effective volume of 1L, a sedimentation tank and an airlift return system. Feed the reactor through a peristaltic pump, and through an air-to-air compressor to promote aeration. To prepare the side stream, before processing, add a solution containing NH4 CI and K2 HPO4 to obtain a ratio of N: P to COD: 100: 5:1. In addition, the pH value of the side stream is adjusted to 7.0+0.1. In Figure 1, you can observe the experimental flow chart and the sludge reactor system activated with activated carbon as a carrier.
Control the inlet flow and hydraulic residence time according to the expected VOC. In the future, the sludge from the Kraft Wastewater Treatment Plant will be added to the reactor to concentrate the volatile suspended solids with a concentration of 2.5g L-1. coal based activated carbon manufacturer After the system was assembled and stabilized, the treatment effect was evaluated in four stages for a total of 110 days, in which stage|only activated sludge was used, and the concentrations of stages I, III and IV were 2.4 and 6g L-1 during the treatment period. Accumulatively increase the activated carbon by 5%, that is, once every 30 days, add 2g L-1 of activated carbon until a total of 6g L-1 of activated carbon is obtained. It is worth noting that the system runs continuously, and during the entire operation, industrial raw material wastewater is injected into the reactor.