Study On Reverse Osmosis Concertrated Water In Papermaking With Different Treatment Processes

At present,the use of reverse osmosis technology can make papermaking wastewater meet the requirements of recycling,but it will concentrate high concentration of impurities,such as colloid,organic matter and inorganic salt in the water,to produce hard to be degraded reverse osmosis water.Therefore,the research on the treatment technology of RO refractory organic wastewater is of great significance for the treatment of pulp and paper wastewater.The object of this paper is to study the reverse osmosis water in a paper paper in Dongguan.The research is carried out by the method of powdered activated carbon adsorption,Fenton oxidation,coagulation and the combination of Fenton coagulation.COD and UV254 are used to characterize the content of refractory organic matter and the removal efficiency of aromatic organic compounds,such as benzene ring.The main research results are as follows:(1)In the single factor test of powdered activated carbon for adsorption of concentrated reverse osmosis water in papermaking,the test results showed that the removal rates of UV254 is 91%,the removal rates of CODCr is 75%respectively,when the powder activated carbon dosage of 2 g/L,pH = 3,time for 30 min,at 30 ?.In fitting of isothermal adsorption model,the isothermal adsorption process of powdered activated carbon for CODCr and UV254 is more in accordance with the Freundlich adsorption isotherm model,and the adsorption process follows the pseudo second-order kinetics adsorption model.(2)In the experiments of the single factor of Fenton oxidation and response surface theory analysis,The experimental results showed when FeSO4.7H2O dosage of 2.59 g/L,the pH si 3.24,H2O2 dosage of 1.55 mL/L(m(FeSO4.7H2O):V(30%H2O2)=1:0.6),time for 26.12 min that the removal rates of CODCr is 63%,the removal rates of UV254 is 82.7%.It is close to the predicted value,showing that the response surface method is suitable for process optimization of CODCr removal rate and UV254 removal rate,and has practical value.The influence factors of CODCr removal rate and UV254 removal rate are as follows:the CODCr removal,the pH>reaction time>FeS04.7H20 dosage;the UV254 removal,the pH>reaction time>FeSO4.7H20 dosage.(3)In the experiment of the coagulant,The experimental results showed when pH is 7,PFS of 2 g/L,PAM dosage of 2 mg/L and settling time for 20 min that the removal rate of UV254 and CODCr is 47.27%and 32.14%respectively.the waste water were treated under their respective preferred conditions by Fenton and coagulation,the removal rates of the CODCr and UV254 respectively are 75.6%and 90.8%.(4)The analysis of concentrated osmosis water and different effluent in papermaking by GC-MS,the results showed that the powdered activated carbon adsorption method and Fenton oxidation method had good removal effect on alkanes.In particular,the Fenton oxidation method had better removal effect than powder active adsorption method on alkanes.But the removal effect of organic compounds containing benzene rings or heterocycles is not good,activated carbon adsorption method is better than Fenton oxidation method;The coagulation has little effect on the removal of a small amount of alkanes and organic matter,and Fenton coagulation has far better than its single effect on organic matter.