Research On The Biological-Conventional-Membrane Water Treatment Technology

On the basis of the conventional water treatment processes, the experiment combined with the biological and the membrane water treatment processes. After reasonable combination of the three processes above, the experiment put forward three kinds of processes,"Biological-Conventional-Membrane water treatment process","Conventional-Membrane water treatment processes"and"Biological-Conventional water treatment processes". The experiment made a research on the water treatment ability of all the three processes above, and the experiment also made a study on the submerged and pressurized ultra filtration.The experimental results show that:(1) In the wet season, the effluent quality of the three processes all achieved the"drinking water health standards"(GB5749-2006) and"Drinking Water Quality Standards"(CJ94-2005). The final effluent of"Conventional-Membrane treatment"nitrogen﹥0.5mg/L, CODMn﹥2.0mg/L in a few days around the flood peak, the effluent quality unable to achieve the"drinking water health standards"(GB5749-2006) and"Drinking Water Quality Standards"(CJ94-2005). The effluent quality of"Biological-Conventional treatment"and"Biological-Conventional-Membrane treatment"achieved the the double standard.(2) Compared with"Biological-Conventional treatment", although the ammonia nitrogen and CODMn removal efficiency of"Biological-Conventional-Membrane treatment"decreased slightly, the turbidity, particles and micro-organisms removal efficiency of"Biological-Conventional-Membrane treatment"were improved a lot. The final turbidity effluent of"Biological-Conventional-Membrane treatment"was about 0.1NTU all the same, the total of particles between 2μm and 25μm was 48cells/mL, and micro-organisms were not detected in the effluent.(3) In the raw water artificial add ammonium experiment, when the raw water ammonia was between 2.030mg/L and 2.280mg/L,"Biological-Conventional-Membrane treatment"effluent ammonia nitrogen was under 0.5mg/L after 14 hours. When the raw water ammonia was between 2.0 mg/L and 3.0mg/L, the average of"Biological-Conventional-Membrane treatment"effluent ammonia nitrogen was 0.144mg/L, and the average removal rate was 94.2%; When the raw water ammonia nitrogen was between 3.0mg/L and 4.0mg/L, the average of"Biological-Conventional-Membrane treatment"effluent ammonia nitrogen was 0.246mg/L, and the average removal rate was 92.9%.(4) The pressurized ultra filtration membrane flux was 80L/(m~2·h), and the submerged ultra filtration membrane flux was 35L/(m~2·h). The pressurized ultra filtration and the submerged ultra filtration have the similar capacity in turbidity and ammonia nitrogen removal, but in the CODMn removal ability, the pressurized ultra filtration was better than the submerged ultra filtration. During operation, the transmembrane pressure (TMP) of pressurized ultra filtration was higher than submerged ultra filtration.(5) During operation, the TMP of the pressurized ultra filtration was 41.6KPa in the beginning. After the third chemical cleaning the transmembrane pressure was 52.7KPa, and the transmembrane pressure increased 11.1KPa comparing with the original. The TMP of the submerged ultra filtration fluctuated in the scope of 6.8 to 14.8KPa, and changed a little before and after chemical cleaning.