Application of Ultrafiltration Membrane in Sewage Treatment

1, drinking water treatment

Ultrafiltration generally removes microorganisms such as leeches, algae, protozoa, bacteria and even viruses from the water, and combines with the second-generation treatment process to give full play to the advantages of various processes, pathogenic microorganisms in the water, turbidity, and natural organic substances. , Trace organic contaminants, ammonia nitrogen, etc. have better outgoing effects, so as to meet the increasing water quality requirements of people.

2. Wastewater treatment

According to the characteristics of ultrafiltration membranes, whether it is widely used in domestic sewage or industrial wastewater, the domestic wastewater is treated with ultrafiltration to make the water quality better and reused, while the industrial wastewater can meet the standards and the ultrafiltration technology can be used. Can fully handle wastewater.

1) Domestic sewage treatment

Wastewater from urban sewage treatment plants can be treated with ultrafiltration membrane technology. The treated water quality is good. It can be used for the reuse of recycled water, and the reactor has a small footprint and low investment in equipment. It can be widely used in residential water reuse. .

2) Oily wastewater treatment

The state of oily wastewater is divided into three types: oil slick, dispersed oil, emulsified oil, and money are easier to handle. Mechanical separation, flocculation and sedimentation, activated carbon adsorption can be used to reduce the fraction to very low, but the emulsified oil contains surface activity. Organic substances with the same function as gas and gas, oils exist in water with micron-sized ions, gravity separation and coarse granulation methods are more difficult, ultrafiltration membrane can achieve the purpose, he makes water and low-molecular organic substances penetrate the membrane, thus achieving oil-water separation. For example, the oil content of the oil-bearing oil in the oil field is usually 100-1000 mg/l, so the hollow fiber ultrafiltration membrane technology must be applied to the oil-removal treatment before discharge to make the waste water reach 100 mg/l.

3) Wastewater Treatment in Food Industry

In the food industry, waste water formed during the processing of milk, beverages, starch, yeast, tofu, and meat contains a large amount of protein, starch, yeast, lactose, and fat, all of which have a certain recovery value. BOD and COD are relatively high and cause environmental pollution. They are difficult to deal with by general biochemical methods and are useful for recovering the useful substances. Ultrafiltration can be used to achieve purification.

4) Electroplating wastewater treatment

Electroplating wastewater has high water consumption, and the heavy metal ions such as cyanide, hexavalent chromium, nickel, copper, zinc, iron, and septum are very toxic and cause serious impact on humans and animals and crops. Electroplating wastewater is characterized by biodegradability, and the metal ions inside are difficult to be absorbed by microorganisms. Using ultrafiltration membrane and reverse osmosis can make the outflow of nickel, nitrate, and total organic carbon in nickel-plating wastewater at 97%, 99.8%, 95%, and 87%, respectively, through the ultrafiltration membrane as a pretreatment. The contamination of reverse osmosis membranes is significantly reduced, and the flux of reverse osmosis membranes can be increased by 30-50%.

5) Treatment of papermaking wastewater

UF is used in papermaking wastewater, mainly for the concentration and recovery of certain components, and the returned water is returned to the process for use. The main material recovered is sulphonated lignin, which can be returned to the pulp for reuse. This will create greater environmental and economic benefits.

6) Desalination

The research of the small-scale desalination device shows very clearly that the ultrafiltration system can effectively control the quality of seawater and provide high-quality water for the reverse osmosis system. Long-term tests have shown that the SDI value of the effluent of the ultrafiltration system can be very good. Below, these tests do not have to be any pretreatment before the ultrafiltration system and apply to various seawater quality.