Landfill leachate advanced treatment equipment, including pipeline mixers, security filters, high-pressure pumps, one-stage circulating pumps, one-stage nanofiltration membrane filters, two-stage circulating pumps, two-stage nanofiltration membrane filters and The concentrated liquid storage tank, the section of the nanofiltration membrane filter water outlet and the section of the nanofiltration membrane filter water inlet also include a section of concentrated water returning to a section of filtration water inlet pipeline, and the section of the nanofiltration membrane filter water Between the water inlet of the water pump and the second-stage circulating pump, the second-stage concentrated water return to the second-stage filtering water inlet pipe is also included. The equipment of the utility model makes the treated effluent water stable and reliable through the reflux and circulating filtering treatment of concentrated water, convenient management, economical and reasonable, and strong self-control.
Landfill leachate treatment methods generally include physical and chemical methods and biological methods.
When the BOD / COD value of the leachate is greater than 0.3, it indicates that the biodegradability of the leachate is good, and biochemical treatment can be adopted. The biochemical treatment has the advantages of good treatment effect and low cost. It is currently the most widely used treatment method. However, as the landfill leachate increases, the BOD / COD ratio becomes lower and the biodegradability becomes worse. The removal rate of COD by the biological treatment of landfill leachate is only about 70%. When the COD of the influent is high, the biological method alone cannot reach the national discharge standard.
In the physical and chemical method, the liquid separation membrane process can be generally divided into four categories: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO). Their filtration accuracy is getting higher and higher according to the above order. . Microfiltration (MF): Capable of retaining particles between 0.1-10 microns, suspended matter, bacteria, some viruses, and large-sized colloids. The advantages are large water flux and good filtration effect. The disadvantage is that macromolecular organics and soluble solids (inorganic salts) cannot be removed.
Ultrafiltration (UF): Capable of trapping particles and impurities between 0.002 and 0.1 micron, such as colloids, proteins, microorganisms and macromolecular organic matter. The advantages are large water flux and good filtration effect. The disadvantage is that it cannot remove small molecules and soluble solids (inorganic salts).
Reverse osmosis (RO): It can block all soluble salts and organic matter with a molecular weight greater than 100 and allow water molecules to pass through. The advantage is that it can remove more than 98% of soluble salts and organic matter with a molecular weight greater than 100. The disadvantage is that while removing pollutants, the minerals and trace elements that are beneficial to human health are also removed.
Nanofiltration (NF): It is a special and promising type of separation membrane. It is named for its ability to retain substances with a size of about 1 nanometer or 0.001 micrometer. The operating range of nanofiltration is between ultrafiltration and reverse osmosis. Among them, it retains the molecular weight of organic matter is about 200-400, and its ability to retain soluble salts is between 20-98%. Organic matter and chroma, remove the hardness and radioactive material of well water, and partially remove soluble salts.
Reverse osmosis has high filtration accuracy and is suitable for the application of leachate treatment. However, because the reverse osmosis desalination rate is generally higher than 98% and its operating pressure is also high, the recovery rate should not be too high, generally 70 to 75%. And the investment is high, the equipment is complex, and the energy consumption is high; the nanofiltration desalination rate is relatively low, generally 50 to 60%, and the operating pressure is also low. Through special design, the recovery rate can reach 90%, which can greatly reduce concentrated liquid. Production, but the prior art usually uses first-stage high-pressure filtration, and the concentrated water produced is low in recovery efficiency.
400T / D Landfill Leachate Treatment Project
Landfill leachate treatment equipment
(400 tons per day) Landfill leachate treatment equipment