Performance Of Surface Industrial Comprehensive Wastewater Treatment By Biofilm Enhanced Hydrolysis-MBR Process

All industrial enterprises discharging industrial wastewater of surface treatment industry in in water treatment center for centralized treatment, industrial waste water was produced in electroplating production process and conventional biochemical treatment alone is difficult to stabilize reach the discharge standard. Therefore, it is necessary to intensive treatment can reach the standard.In this paper, we mainly study the treatment efficiency of surface industry comprehensive wastewater treatment by biofilm enhanced hydrolysis acidificationMBR combination process, and the matched group was treated with conventional hydrolysis acidification-MBR combination process. By starting the reactor and optimization of operating parameters so that the combination of the two groups of stable operation of process, then according to the gradient increase of three heavy metals Cu2+, Ni2+ and Cr(VI) concentration experiments were carried out on the impact of system, to explore the impact before and after changes in the water system and the accumulation of heavy metals on the activated sludge in the system.The HRT of hydrolysis reactor is 8h, MBR is 10 h, the aeration rate 20 m L/min, the reflux ratio is the 150%. When the operation is stable, conventional process effluent COD concentration was 52mg/L, removal rate was 83%, average concentration of NH4+-N was 8.23mg/L, removal rate was 73%, the average TN concentration was 15.85mg/L, removal rate was 59.3%; biofilm enhanced system process average effluent COD concentration was 28mg/L, and the removal rate was 90.6%, average concentration of NH4+-N was 6.01mg/L, removal rate was 80.5%, average TN concentration was 9.28mg/L, removal rate was 75.6%. Each index meet the comprehensive wastewater discharge standard, and the running time of the water fluctuation is not big, the water quality is stable.After the operation of combined process stable going on the impact test, keep the inflow concentration of sodium saccharin in 20mg/L, sodium dodecyl sulfonate concentration is 50 mg/L, and polyethylene glycol concentration is 70mg/L. The impact stage is divided into four stages, the control of Cu2+, Ni2+, Cr(VI) concentration gradient is 5mg/L, 10mg/L, 20mg/L and 30mg/L, under different concentration gradient conditions, to study the effectiveness of integrated wastewater treatment of the two groups processes. When the impact of low concentration of heavy metals, COD, NH4+-N and TN removal rate of the two processes is not different, the higher the impact concentration of heavy metals, the greater the difference. When the concentration of heavy metal ion in 20mg/L, combination of conventional process effluent COD and NH4+-N barely reached electroplating wastewater discharge standard, TN is not up to standard; when the heavy metal ion concentration was increased to 30mg/L, combination of conventional process effluent indicators are not up to the discharge standards, system deterioration rate accelerated. The biofilm process in the concentration of heavy metal ions in the 20mg/L system effluent discharge standards, when the concentration of heavy metal ions to COD system effluent 30mg/L emission standards, but the effluent TN and NH4+-N is not standard. Biofilm process with higher concentration of sludge, biomass than the conventional process is more abundant, recovery ability and stronger shock resistance and biofilm strengthening hydrolysis reactor can absorb more heavy metals, greatly reduce the impact of the MBR system enhancement of subsequent biological membrane. The hydrolysis reaction preferentially degrades the biological filter, and the biodegradability of the other substances is difficult to be degraded, and is easy to accumulate in the system. After the hydrolysis reaction, the fluorescence intensity of the microbial strain decreased, and the fluorescence peak intensity of the aromatic protein, the rich acid and humic acid were stronger. MBR of aromatic protein degradation effect is better, MBR effluent aromatic protein fluorescence peak of the extremely weak, microbial filter out matter distribution is much more in the TPI, hpo-a hpo-n, this part of the microbial leaching material are difficult to be degraded by microorganisms is the main component of the system effluent COD.The concentration of Ni in the combined process was weak, and the content of Cr, Ni and Cu in sludge was significantly increased, and the content of Cu, Ni and Cr in the biofilm system was higher than that of the conventional system. Before the impact of heavy metals hydrolyzed sludge and MBR sludge biological rich phase, the sludge contains a large number of bacteria, spirochetes and coccus; greatly reduces the impact of sludge biomass, including pureed conventional hydrolysis and MBR appeared filamentous bacteria system began to deteriorate. Under the action of impact biofilm system in mud EPS concentration is generally higher than the conventional system, microbial leaching out and aromatic protein fluorescence peak intensity is stronger, wider range, biofilm system mud can secretion more extracellular polymers to reduce the toxicity of heavy metal ions. Impact of arbuscular mycorrhizal fungi in bio logical membrane mud system number is greater than that of the conventional mud system number, significantly increased the number of fungi, eukaryotic organisms, and anaerobic microbial number has dropped, and conventional system put actinomycetes number is greater than that of the biological membrane systems, appeared the sludge bulking.