New-Generation Fully Closed-Loop Advanced-Treatment Package for Landfill Leachate
Landfill leachate has complex composition, high pollutant concentration, heavy color, and enrichment of ammonia nitrogen and refractory organics, making it a recognized difficult point in water treatment in the solid-waste disposal industry. Traditional processes suffer from pain points such as lengthy flow, large chemical dosing, low nitrogen-removal efficiency, unstable effluent, and high O&M costs. Our company has developedCDFU CDFU + multi-stageCDOF CDOF ozone advanced oxidation + high-efficiency denitrification + MBR membrane biotreatment combined package, which specifically breaks the bottleneck of landfill leachate treatment and combines core advantages such as high treatment efficiency, small footprint, high automation, and stable operation, providing a one-stop solution for leachate treatment at landfills and incineration plants.
The entire process forms a complete closed-loop treatment chain, with each unit dividing labor and cooperating to degrade pollutants layer by layer. Raw landfill leachate first enters theCDFU CDFU cyclonic dissolved-air flotation device, with ozone and a dedicated flocculant dosed simultaneously. The cyclonic structure enhances flocculation, demulsification, and solid-liquid separation, rapidly removing suspended sludge, oil, colloids, and macromolecular humus from the leachate; the separated waste residue is discharged to the sludge tank for unified dewatering; the system backwash waste liquid is refluxed to the front end for retreatment, preventing secondary sewage discharge. The front-end ozone pre-oxidation can prematurely cleave some refractory organic molecular chains, greatly reducing the load on downstream oxidation units, and the suspended-solids removal rate is improved by more than 40% compared with traditional flotation.
The pretreated wastewater enters the first-stageCDOF CDOF ozone advanced-oxidation flotation integrated device, with ozone and a water-quality modifier dosed.CDOFIntegrating multiple functions of ozone catalytic oxidation, microbubble flotation, and flocculation-sedimentation, ozone generates strongly oxidizing hydroxyl radicals under the action of a dedicated catalyst, efficiently decomposing biochemically refractory COD such as humic acid and aromatic compounds, and simultaneously separating the floc impurities generated by oxidation via flotation. The ozone tail gas produced by the device is uniformly collected and decomposed in a tail-gas destructor before being discharged up to standard, with no odor escaping and a clean plant operating environment. The first-stageCDOF CDOF effluent is divided into two streams: one enters the high-efficiency denitrification reactor, and the other refluxes to buffer and equalize water quality, ensuring the system's impact-load resistance.
The high-efficiency denitrification reactor is the core nitrogen-removal unit of this process. An external carbon source is dosed as needed to build a complete nitrification-denitrification system, deeply reducing total nitrogen and ammonia nitrogen. The reactor is equipped with a dedicated backwash system, and the backwash water is sent to the second-stageCDOF CDOF device for advanced treatment, avoiding accumulation of nitrogen pollutants. The denitrified effluent enters the second-stageCDOF CDOF advanced-oxidation unit, where ozone and a water-quality modifier are dosed again to further decolorize and degrade residual trace refractory organics, ensuring stable compliance of effluent color and COD; the second-stageCDOF CDOF's generated backwash waste liquid is refluxed to the front endCDFU CDFU, realizing whole-process cyclic reduction of sewage.
The second-stageCDOF CDOF effluent enters the MBR membrane bioreactor, where a carbon source is supplemented to maintain microbial activity; the membrane modules efficiently retain activated sludge, greatly increasing the sludge concentration of the biochemical system and strengthening the deep removal of residual COD and total nitrogen. The MBR is equipped with an internal sludge-reflux pipeline; the sludge refluxes to the front-end sludge tank for unified disposal, preventing sludge loss; the MBR product water finally flows into the clean-water tank, and the clean water stably meets standards for reuse or discharge. The whole process is equipped with closed-loop disposal units for sludge, backwash wastewater, and ozone tail gas, truly realizing simultaneous treatment of sewage, solid waste, and waste gas with no secondary-pollution risk.
Compared with traditional leachate treatment processes, this package technology has prominent advantages. First, multi-stage ozone catalytic oxidation combined with cyclonic flotation has extremely strong adaptability to high-color and highly refractory pollutants and is unaffected by leachate age fluctuations; second, the coupling design of the high-efficiency denitrification reactor + MBR eliminates the need for complex multi-stage A/O tanks and reduces equipment footprint by 50%; third, the highly integrated all-in-one equipment, modular layout, and automated online dosing, backwashing, and tail-gas treatment greatly reduce manual O&M workload; fourth, the whole-process waste-liquid reflux closed-loop design achieves significant sewage reduction, with chemical and water-electricity unit consumption lower than conventional processes, giving obvious long-term operating-cost advantages; fifth, centralized tail-gas decomposition and separate sludge disposal thoroughly solve the environmental pain points of leachate treatment stations such as odor nuisance to residents and random sludge discharge.
As environmental discharge standards become increasingly stringent, stable compliant disposal of landfill leachate has become the key to compliant operation of solid-waste enterprises. ThisCDFU+CDOF CDFU multi-stage oxidation denitrification MBR integrated process covers the whole chain of pretreatment, advanced oxidation, biological denitrification, deep filtration, and by-product disposal, and is suited to new and old landfill and incineration-plant leachate upgrading and new construction projects. With efficient, stable, economical, and environmental technical strength, it safeguards water-environment governance in the solid-waste industry.
