Tackling the Coexisting Challenges of Fluorine, Phosphorus, Copper, and High Ammonia-Nitrogen: SINOKLE's Customized Process-Chain Recommendations
Aiming at the pain point of semiconductor-industry wastewater—where 'fluorine, phosphorus, copper, and high ammonia-nitrogen' coexist and complexed pollutants are difficult to treat—SINOKLE's CDFU, CDOF and KFMequipment, although focused on physical separation and advanced oxidation, has a high degree of applicability in breaking pretreatment bottlenecks and strengthening resource recovery thanks to its technical mechanism, and can serve as the core unit of 'pretreatment+deep oxidation', seamlessly connecting with subsequent precipitation and biochemical systems.
1.Fluorine- and Phosphorus-Containing Wastewater
High concentrations of fluoride ions and phosphate radicals in semiconductor wastewater are usually removed by adding calcium salts or aluminum salts to form calcium fluoride or calcium phosphate precipitates, but in actual operation the generated fine precipitates (particle size often smaller than 10μm) settle slowly, leading to excessive suspended solids in the effluent.
SINOKLE's CDFUcyclonic dissolved-air flotation device can play a key role in this step. Using the microbubbles it generates (μm), it can efficiently 'float' these hard-to-settle fluorine- and phosphorus-containing flocs to the water surface, replacing the traditional, time-consuming gravity sedimentation tank.
KFMThe active-filter media filter can then serve as a polishing unit, further intercepting any tiny particles that escape. This combination can shorten the retention time of the conventional sedimentation process from several hours to a few tens of minutes, directly solving the common 'turbidity breakthrough' problem in fluorine-containing wastewater treatment and ensuring stable compliance of the effluent fluoride ions.
2.Copper- and Heavy-Metal-Containing Wastewater
In semiconductor chemical-mechanical polishing or electroplating wastewater, copper ions often form extremely stable soluble complexes with EDTAcitric acid, or ammonia water. The traditional alkaline-precipitation method cannot directly remove complexed copper, which is the main technical difficulty in the industry.
SINOKLE's CDOFequipment (integrated ozone-cyclone-flotation unit) generates high-oxidation-potential hydroxyl radicals (·OH) that can directionally attack and break the molecular chains of EDTAand other organic complexing agents.CDOFIt has a unique advantage in removing chemically complexed copper, nickel, and other heavy metals, converting the hard-to-treat complexed heavy metals into easily precipitated free-state ions.
CDOFPerforming advanced oxidation in a purely physical manner, compared with dosing sodium sulfide and other agents, avoids secondary pollution and the generation of toxic gases, and the ozone utilization rate is as high as 99%or above, with a low operating cost.
3.High Ammonia-Nitrogen Wastewater
High ammonia-nitrogen wastewater mainly comes from lithography and developing processes (containing tetramethylammonium hydroxide, TMAH) and etching and cleaning processes.
CDOFSINOKLE's ozone catalytic oxidation process, although it cannot directly convert large amounts of ammonia nitrogen into nitrogen gas, can oxidize and decompose TMAHand other organic amines, releasing ammonia nitrogen, thereby significantly improving the treatment efficiency of the subsequent biochemical system. For wastewater that still contains a small amount of ammonia nitrogen after biochemical treatment, CDOFcan also serve as a final safeguard process, using the selective oxidation of hydroxyl radicals to directly oxidize ammonia nitrogen into nitrogen gas, achieving deep nitrogen removal.
This technology has significant advantages in the transformation of high-difficulty organic nitrogen, and has a strong resistance to shock loads.
4.Recommended Synergistic Process Chain
It is recommended to adopt a combined process of 'equalization and regulation → CDOF(breaking complexes chain scission) → chemical precipitation (fluorine removal phosphorus removal heavy-metal removal) → CDFU+KFM(high-efficiency solid-liquid separation and fine filtration) → biochemical system (nitrogen removal)'. Using CDOFto solve the organic-complex problem in the first step, creating conditions for subsequent chemical precipitation; using the CDFUhigh-efficiency separation capability to guarantee the precipitated effluent quality; and finally letting the biochemical system specialized for ammonia nitrogen operate in an optimal environment.
5.Summary
SINOKLE's equipment is not a 'panacea' in semiconductor wastewater treatment, but it is a key link in opening up the complex wastewater-treatment flow. For fluorine-, phosphorus-, and copper-containing wastewater, CDFUandKFMSINOKLE solves the problem of 'difficult separation'; for wastewater containing heavy-metal complexes and high ammonia-nitrogen, CDOFSINOKLE solves the problems of 'difficult degradation' and 'difficult transformation'. Its characteristics of 'no chemicals, high efficiency, and small footprint' align with the long-term trend of clean production and resource recovery in the semiconductor industry.
