| Fatliquoring agent is a kind of important leather processing chemical. And leather fat-liquoring are in production with natural oils, and under the condition of certain technological processing of leather, the leather absorbs a certain amount of oil and gives certain physical and mechanical properties and operational performance of leather process, because it can effectively increase the mutual mobility between fiber, thus preventing hardening and splitting leather. And leather with appropriate flexibility, toughness, good physical and mechanical properties such as extensibility and flexibility, has been widely used in the field of leather processing.In the process of production, leather fatliquoring agent will discharge much effluent, and the main components of the effluent are residual oil, methanol, emulsifier, inorganic salts and some suspended solids. Leather fatliquoring agent production effluent is a kind of high organic load, whose composition is complicated, and contains organic effluent which is much difficult to completely biodegraded.This subject adopts oil separation-the anaerobic-contact oxidation-"Fenton oxidation" joint process in laboratory experiments and field engineering pilot study combined. And it is studied systematically for the effluent treatment efficiency during the leather fatliquoring agent production. COD is as the main evaluation index, and analyzes the running characteristics of the whole process, which is also as the research and promotion of leather fatliquoring agent production effluent treatment application to provide a reference basis, the results show that:(1) By the inoculation of granular sludge anaerobic reactor leather fatliquoring agent production effluent treatment, in the medium temperature (35 plus or minus 2 ?) conditions, when the reactor is in stable operation, the system can withstand the maximum volume load of 6.50 kgCOD/(m3 · d), and COD removal rate is over 65.5%, and the methane gas rate is at about 0.41 m3/kgCOD stable. Water COD concentrations remain at around 6000 mg/L, and HRT increases from 12 h to 48 h; volume load is about 3.00 kgCOD/(m3 · d); the system of COD removal rate can be raised from 28.6% to 84.7%; and effluent COD< 930 mg/L.(2) Using anaerobic reactor effluent biological contact oxidation treatment, contact oxidation reactor uses aerobic activated sludge inoculation hanging membrane, domestication, synchronized 37 days hanging membrane system to meet the design load. At room temperature, inlet COD concentration is about 920 mg/L; the pH is 7.5; dissolved oxygen is 4.0 mg/L; when HRT is in 10 h, the system to achieve the optimal treatment affects; the COD removal rate was 52.5%, and the effluent COD< 430 mg/L.(3) Using Fenton oxidation or enhanced coagulation dealing with the water which is produced by contact oxidation, and by orthogonal and single factor experiment the optimum processing conditions for Fenton oxidation are:pH is4.5; FeSO4 · 7 h20 dosing quantity is 62.5 mg/L; the dosing quantity of H2O2 (30%) is 3 ml/L; the reaction time is 90 min; under the above condition of the reaction, COD removal rate as 69.2%, and the effluent COD< 136 mg/L. Fenton oxidation water adjust pH to 8.0 or so, after adding the polyacrylamide 4.0 mg/L and after co-ordinated strengthening coagulation effluent COD< 90 mg/L.(4) The "drain-the anaerobic-aerobic-Fenton oxidation" joint process engineering pilot leather fatliquoring agent production effluent treatment field studies have shown that after two months, into the normal operation of the engineering debugging success, for the leather fatliquoring agent production effluent of total COD removal rate is over 98%; stable effluent COD< 95 mg/L; water meets the integrated effluent discharge standard GB8978-1996 the level of emissions standards.(5) Engineering pilot running on the spot shows that the oil separation-anaerobic-aerobic-"Fenton oxidation" joint technology of leather fatliquoring agent production effluent treatment reagent costing about 5.40 yuan/ton, relatively high concentration of refractory organic effluent in the other, and the joint process has higher economic feasibility. |
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