Study On Biochemical Intensified Treatment Of Acrylic Fiber Wastewater

China is the world's largest producer of acrylic fiber,its production of the world's total output of 1/3,the resulting wastewater has become an important research in the field of water treatment industry both at home and abroad. Acrylic high concentration of pollutants in wastewater, N/C high, and high levels of toxic pollutants caused by poor biodegradability. The main organic pollutants is phenols,alcohols and organic nitriles, and a large amount of polymer powder produced by polymerization unit is important source of influencing wastewater biochemical treatment.The object of this paper is the effect of polymer powder on wastewater biochemical treatment. The few study of polymer powder has not developed relatively mature technology. Polymer powder formed by many factors, its existence in wastewater, the early stage of the pretreatment can't effective settlement, along with the waste water into the subsequent biochemical treatment unit, Packaging microbial community and blocking biofilm system. In this way, the effluent of CODcr and ammonia nitrogen concentration is too high that can't discharge up to standard and virtually increase the processing cost.The thought of this paper is based on the theory of biodegradation performance study of mixed pollutants in waste water, using ultrafiltration membrane to determinate molecular weight distribution of different indicators in different processes and understand the distribution characteristics of organic matter of different molecular weight range in acrylic wastewater, then adopt different biochemical technology enhanced removal of acrylic polymer powder in the wastewater biochemical treatment. The biological intensified technology in the paper:comparing biochemical treatment effect of three different valence state of iron in the biological sponge iron system; Using additional carbon source to enhance biological treatment effect by the form of common metabolic. The conclusions provide theoretical basis for the study of the subject, to provide technical support for engineering, and provider reference for biochemical organic wastewater treatment. The research draws the following conclusion :(1) The main reasons of organic structure affecting biodegradability:The space block;Toxicity inhibition; Increasing reaction steps;The biological availability of organic matter.;The research methods of biodegradability of organic matter:Nonspecific parameters;Biodegradation kinetics constants;The removal rate of material to be tested.(2) The higher polymer powder content in the acrylic wastewater is, the greater the CODcr values. A mass of the polymer powder cause the refractory oligomer floating in the water, and the removal of CODcr and ammonia nitrogen have great influence.(3)In polymerization and recovery units,and the biochemical reaction process about the acrylic fiber wastewater.The organic matter is on the interval in the mutual transformation of the different molecular weight distribution.Each unit have different removal efficiency about the organic pollutants with different molecular weight.The CODcr of the outlet water is unstable.(4) Wastewater loads are different, the reactors effluent CODcr concentrations present the same rule, namely the CODcr effluent concentration since the childhood in water than 50% > 75% > 25%.Because water load is different, the CODcr effluent concentrations of reactors present the same rule, namely the CODcr effluent concentration developed gradually is 25%<75%<50%.Under different load conditions, wastewater treatment effect 2 # reactor is best. CODcr and ammonia effluent concentrations under various wastewater load respectively are 300.6 mg/L, 268.7 mg/L, 315.6 mg/L and 10.0 mg/L, 2.2 mg/L, 0.8 mg/L, removal rates are 55.74%, 68.53%, 63.18% and 55.74%98.05%, 99.26%.(5)The linear regression equation of first order reaction kinetics constant:-0.0436-0.1712, regression correlation coefficient: R = 0.880, which shows that under the test conditions CODcr degradation process can be well obeying the equation of first order reaction kinetics. Its reaction kinetics constant K1 = 0.0436 h-1, Ct(t=24h)= 325 mg/L.(6) During HRT cycle of 48 h,CODcr can be completed degradation within 10 h,generated during part of the ammonia nitrogen,stay CODcr degradation after the completion of the basic to degradation of ammonia nitrogen,about 28 h basic degradation of ammonia nitrogen is complete;Ammonia nitrogen degradation process, the nitrite nitrogen rise,after ammonia nitrogen degradation was basically completed, nitrite nitrogen began falling fast, nitrate nitrogen began to rise, due to the high dissolved oxygen, denitrification weaker, more accumulation of nitrate nitrogen; Total nitrogen content changed little,more difficult to remove;After 24 h of hydrolysis acidification, conducive to speed up the subsequent aerobic phase of denitrification, but no obviously improve the effect of the denitrification effect.(7)Acrylic fiber wastewater mixed with glue wastewater treatment effect is significantly better than the single effect; Premises based on two and three sewage water ratio and contrast test, can choose 3:1 mixing process, so as to save investment effect.