Study On Treatment Of Dyeing Wastewater Using Internal Electrolysis Combined With Modified Bentonite Granules Technology

In this dissertation, one typical dyestuffs, acid brilliant scarletGR, was chosen as research object. Experimental research has been done indegradation of simulative dyestuff wastewater with the adoption ofiron-carbon micro-electrolysis and modified bentonite granules in jointapplication. In this dissertation, there were four aspects studied:(1) thegranulation of bentonite and organic modification of bentonite granules werestudied, and bentonite granules were characterized by scanning electronmicroscopy.(2) the treatment effect and the adsorption mechanism of acidbrilliant scarlet GR using organically modified bentonite granules werediscussed.(3) the principle and treatment effect of dye wastewater usingiron-carbon micro-electrolysis were studied.(4) The technological conditionsof real dyestuff wastewater treatment using iron-carbon micro-electrolysisand modified bentonite granules were discussed experimentally withcombined process.Achievements via experiments and analyses are acquired as follow：(1) According to the experimental results, modified bentonite granuleshave an obvious effect on the treatment of dye wastewater. The besttreatment conditions for simulated dye wastewater are as follows: for50mLacid brilliant scarlet GR wastewater with the concentration of4g/L, thedosage of modified bentonite granules, the reaction temperature and thereaction time are5g,60℃and70min. Under the condition, the COD removalrate and color removal rate are58.5%and83.1%. The impact factors oftreating dye wastewater by modified bentonite granules were reaction time,the dosage of modified bentonite granules and the reaction temperature.(2) The thermodynamic studies of modified bentonite granules haveshown the adsorption process of acid brilliant scarlet GR, it is in accordancewith Langmuir isotherm equation, belonging to mono molecule layeradsorption. As the temperature increases, the amount of adsorption decreases.The dynamic studies of modified bentonite granules have shown theadsorption process, the fitting degree of Second-order kinetics equation is highest, and the adsorption process of organically modified bentonitegranules is physical adsorption. The activation energy of physical adsorptionwas small, so the reaction rate was fast.(3) According to the experimental results, iron-carbon method has anobvious effect on the treatment of dye wastewater. The best treatmentconditions for simulated dye wastewater are as follows: for300mL acidbrilliant scarlet GR wastewater with the concentration of4g/L, the best pH,dosage of scrap iron, ratio of Fe/C and the reaction time are2.3,11g,1:1.0and120min respectively, COD removal rate is93.5%. The impact factors oftreating dye wastewater by iron-carbon micro-electrolysis were reaction time,dosage of scrap iron, pH and ratio of Fe/C.(4) Based on researching the principle of iron-carbon micro-electrolysis,it was found that the adsorption of the activated carbon had a significantimpact, flocculation and reduction of iron had a small impact.(5) The dynamic experiments was done by dynamic test device, theCOD removal rate of wastewater was91.9%, color removal rate was97.2%after four hours treatment.