Dissolved Air Flotation Machine for Gelatin Wastewater Treatment Process

Recently Jorsun?built a new dissolved air flotation system installation for our customers. The system is applied as pretreatment process in the gelatin production wastewater process. Gelatin is produced by processing animal skin, bone, sarcolemma and other tissues. Gelatin products are usually made through more than a dozen processes such as classification, washing, degreasing, neutralization, hydrolysis, filtration, concentration, gelation, drying, and pulverization. In the production process, a large amount of waste water will be produced. The waste water contains a large amount of oil, suspended solids, high concentration of COD and other pollution factors. It must be treated to meet the discharging standard.

In the customer's original wastewater process, there is a 5mm mechanical bar screen the inflow ditch, which has a limited oil removal rate from the wastewater. And also there are two-stage dissolved air flotation process in operation, but no micro-bubbles are generated, the removal efficiency of oil and suspended solids is not obvious, and a lot of chemicals and energy consumption are wasted. The poor performance of the existing pretreatment facilities resulted in high load of the secondary biological treatment system, unstable operation, and large fluctuations in the effluent index. Another problem is that the wastewater has strong acidity or alkalinity, and the incoming water has not been homogeneously adjusted, so the primary treatment equipment is seriously corroded; the wastewater contains relatively high concentrations of Cl-, SO42-, and the steel structure equipment in the pretreatment stage Severe corrosion.

The previously existing design process is as below:

Jorsun?has rich experience, and the key point of this project is to improve the oil removal efficiency of the pretreatment section. Considering the high concentration of oil and fat in the incoming water and the limited site area, this time we chose the high-efficiency sedimentation air flotation machine SDAF as the core equipment of the pretreatment section. The hydraulic load of the air flotation device can reach 9m3/m2*h. The air flotation optimizes the flow state of the separation zone, increases the wetted peripheral area of?the separation zone, greatly reduces the Reynolds number, and effectively improves the conditions of the separation zone. Make the water flow in the separation zone laminar. This sewage facility is specially designed for the treatment of concentrated acid water and concentrated alkaline water. This type of wastewater has the characteristics of high concentration of grease and SS, strong corrosion, and large fluctuation of water volume. The design of the dissolved air flotation system has a maximum processing capacity of 200m3/h. The dissolved air flotation system has also been optimally designed. Due to the high solid content of the incoming water, the dissolved air?reflux ratio needs to be appropriately enlarged and designed, which should not be lower than 45%. In order to reduce the frequency of blockage of the releaser, the releaser should be designed with anti-clogging and non-disassembly and cleaning capabilities. At the same time, the influence of the waste water medium on the corrosion and failure of the instrument in the later stage is considered. The air flotation area is equipped with a sludge hopper for easy sludge discharge. During the air flotation process, there are a lot of floating grease and suspended matter, and the sludge?scraper covers the entire area, and there is no dead angle to scrape the sludge.?

After this pretreatment process upgrade, the removal rate of oil and grease?in wastewater is greater than 95%, and the effluent from the system can be directly discharged into the wastewater station for biochemical treatment.

At the same time, the oil separated by this system can be recycled and refined into industrial oil, which has high economic value, and the annual income of tens of millions of dollars?depends on oil recovery.