Study Of SBRW Treatment By EACD Technology

As an industrial raw material,the demand of styrene butadiene rubber is increasing.And,its production wastewater contains relatively high concentration of organic matter,the complex composition,strong toxicity and is difficult to decompose.Therefore,to develop an efficient,economical and environmentally friendly technology for styrene butadiene rubber production wastewater?SBRW?treatment has become an important social demand.The SBRW used in this paper was from the division of Fushun petrochemical company.On the basis of Earthed atomizing corona discharge technique?EACD?and according to technology and principle of Fenton test for sewage,the EACD technology was used in the feasibility of SBRW treatment and improvement ideas of process for SBRW treatment was investigated by regulating the p H,adding Fe SO₄ and H₂O₂,and optimizing treatment time.The main results are as follows.1.The discharge volt-ampere characteristic curve of home-built equipment EACD was determined.According to the voltammetry curve,the corona voltage of the device is 8 k V,the optimal operating voltage is 11 k V,and the appropriate wastewater flow rate for wastewater treatment is 71 m L·min^-1.Under the conditions of the same amount of water?flow?and the same voltage,the current?I?generated by the negative electrode?i.e.negative corona?is greater than that generated by the positive electrode.The current generated by the negative electrode decreases as water flow rise.2.The EACD device has a good effect on the treatment of SBRW.After a flow of 71m L·min^-1of SBRW was treated by EACD for 21 min when negative corona discharge at 11k V,the COD value of SBRW was reduced by 66.7%from 600.8 mg·L^-1 to 200.0 mg·L^-1.While,the BOD₅ value originally increased to 70.0 mg·L^-1 from 50.0 mg·L^-1,and then stabilized at 68.0 mg·L^-1.The ratio of BOD₅ to COD increased from 0.08 to 0.34.And T_bdropped by 67.0%from 106.0 NTU to 35.0 NTU.3.Combined with the pre-treatment such as adding of H₂O₂,Fe SO₄ or adjusting p H,EACD can further improve the treatment efficiency of SBRW.With other conditions unchanged,the COD value significantly decreased after the 500 m L SBRW with 0.8g of Fe SO₄ adding was treated.The removal rate of COD increased from 66.7%to 86.7%,and BOD5/COD ratio increased from 0.35 to 0.54.Similarly,the efficiency of EACD on wastewater treatment can be significantly affected by adjusting the p H of the treated SBRW.The COD removal rate of the treated SBRW increased with increasing p H value of the treated SBRW,that is,the alkaline condition was favorable to reduce COD by EACD treatment.However,the addition of H₂O₂ had no significant effect on EACD treatment of SBRW.4.Combined with Fenton reagent,EACD can significantly improve the treatment efficiency of SBRW.Fenton reagent is a mixture of H₂O₂ and Fe SO₄ at p H=3?5,and commonly used in wastewater treatment.SBRW was treated by Fenton reagent separately.In other words,0.8 g Fe SO₄ and 3 m L H₂O₂ were added to 500m L SBRW.After 60 min,the COD value was reduced by about 80%from 600.8 mg·L^-1 to 122 mg·L^-1.The SBRW was treated by EACD With same concentration Fenton reagent added for 30 min,the COD value of the wastewater was reduced to below 100 mg·L^-1,which not only significantly improved the treatment efficiency of the wastewater,but also improved the processing speed.5.The efficiency and speed of EACD in treating SBRW can be greatly improved by optimizing the treatment process combination.Factors of treatment time,p H,H₂O₂ and Fe SO₄ affected the efficiency and speed of EACD in treating SBRW.The results of the orthogonal tests showed that adding Fe SO₄ with a concentration of 1600 mg·L^-1,adjusting the p H of the wastewater to 11,discharging time of 21 min and discharging voltage of 11.5 k V was the best EACD process for treating SBRW.The removal efficiency of COD in the wastewater was 89.1%.6.When activated carbon was used to cover the surface of tube to improve EACD device?AC-EACD?,the effect of SBRW was improved obviously.With the improved EACD device,the removal efficiency of COD increased by about 9%.The to When the SBRW was treated by AC-EACD combined with Fenton reagent for 21 minutes,the COD value of SBRW decreased to 35 mg·L^-1,reaching a stable state.In addition,if SBRW was treated by EACD combining with Fe²⁺catalysis and nanofiltration concentration membrane Fe²⁺catalysis,the removal rate of COD could be improved but the cost increased.Whie,combination of Fe²⁺catalytic EACD device with nanofiltration concentration membrane can recycle Fe²⁺and further reduce the cost of wastewater treatment.7.The mechanism of Fe²⁺catalytic EACD to treat SBRW is as follows.The air and SBRW are ionized when the discharge electrode is connected with high pressure,resulting in a lot of free electrons and active particles produced.And,the free electrons and active particles attack organic pollutants?R?to breake the chemical bond.As a result,the R are gradually decomposed into CO₂ and H₂O.However,Fe²⁺could coordinate with active particles to promote the reaction rate of active particles and R.Meanwhile,there are also electron collisions and Fe²⁺cyclic reactions(Fe²⁺?...Fe³⁺?......Fe²⁺),which as the form of electron avalanche to promote each other.So the collision probability of electrons to H₂O and O₂ were improved,resulting in producing more active particles,which could improve the oxidation ability of EACD for organic matter.Therefore,the removal efficiency of COD was improved.In conclusion,it is first time to propose the Fe²⁺catalytic EACD and nanofiltration concentration membrane-Fe²⁺catalytic EACD process for SBRW treatment in this paper.And a new efficient,economical and environmentally friendly SBRW process was formed and feasibility.Therefore,the processes has a broad application prospect and development space in the future practical production.