Efficient Solid-liquid Separation Applies To Drinking Water Treatment

Development and research of effective water treatment technologies to improve the quality of water supplies in the field of water treatment has become an important research topic due to the increasing water pollution and water shortage.In the past few years,researchers home and abroad did a lot of research about this topic,and developed a series of processing technologies.In this paper,beaker experiment was done by methods of sludge return,and carry out a highly efficient solid-liquid separation study of the dynamic test.In addition,establish the method of acrylamide detection,and detection of acrylamide in the water experiment.(1) Beaker experiment:When simulate the return sludge,dosage of PAC is no more than 5 mg / L,When more than this value,flocs can not continue to grow,even if the dosage of PAM increased.Floe size can only be maintained at about 2mm,and the minuteness flocs exis in the water,the effect of coagulation is poor.When increase the turbidity of raw water,the experimental results show that in the same dosage of PAC,PAM and the sludge return flow,the higher the turbidity of raw water,the better the treatment effect.Through by measuring the effect of post-treatment sludge back to poor waterζpotentials,the experiment found in water samples after theζpotential is lower than-10mV,the beaker floes poor continue to grow,to deal with poor results.(2) Dynamic test:When the ncreased flow rate is 30cm/min,water turbidity is between 10-20NTU,the appropriate combination of coagulation process for the two static mixer 70m plus length of the pipe reactor,the best dosage of PAM is between 0.5mg / L,the PAC is between 6 mg / L,the return sludge flow is best to be 586g/h-667g/h.,the high-performance solid-liquid separation process can only be maintained at the water turbidity 2NTU.By changing the position of PAM,as well as cessation separator of impeller Water turbidity decreased to 0.7-0.8NTU,the effect is very obvious.(3) Determination of acrylamide:First,the ultrasonic extraction of activated carbon was determined.From the amount of extraction with activated carbon,the volume of eluting agent on activated carbon,such as acrylamide extraction method optimization,and GC detection methods were optimized.The results show that activated ultrasonic extraction combined with GC detection method established to detec acrylamide has good reproducibility,precision and recovery.Although the recovery rate is lower,but the recovery rate is very stable and remained at about 65%, quantitative analysis can be done.Through the static test,select the five kinds of different PAM to test their AM monomer content,some PAM residues in AM for domestic product can not achieve national standards.Through the mixing experiment with the addition of PAC experiments,the following conclusions:dosage PAC or not has no significant impact for AM Residues,PAM generally will not grnerate AM because of Polymer bond in mixing coagulation in ordinary conditions.In the dynamic test,the PAM(molecular weight is 12million,AM is 0.022%)was chosen.When the dosage of PAM is in 1mg/L,AM wsa can not be dected because of suspend floc,which can adsorb it.When the dosage of PAM is 1.6mg/L,same big floc and low consistency apperd,some small floc fragment apperd.0.137μg/L AM was dected.As well,the mount of AM was still accord with the＜The Standard of National drinking water＞(2006).