Development of dewatering system for activated sludge by using novel thermosensitive porous hydrogels

研究了利用丙烯酰胺衍生物聚合物独特的温敏特性制备新型温敏多孔凝胶的方法，以及利用这种温敏凝胶开发脱水体系.以N，N-二乙基丙烯酰胺（DEAA）和N-异丙基丙烯酰胺（NIPAM）为主要单体合成温敏多孔凝胶。这些单体溶于水，而它们的聚合物的转变温度分别约为32 ℃和31 ℃。换句话说，这些聚合物在低于这些温度时溶解在水中，而在高于这些温度时具有疏水性。这些主要单体与交联剂通过自由基共聚合可以很容易地合成多孔凝胶。通过控制合成温度、交联剂浓度等条件可以控制F结构的形成，在合成过程中形成了由几个微米的微凝胶颗粒和大孔组成的多孔结构 ...更多信息 温度高于40 ℃时，凝胶颗粒的尺寸随交联剂浓度的增加而减小.溶胀和收缩行为在40 ℃以上合成的多孔凝胶溶胀或收缩非常快，而不变形，因为水的渗透阻力小。这些多孔凝胶的溶胀速率比无孔凝胶大几百倍，并且与凝胶特征长度的平方成反比。收缩率与传热率相当.洗米机有机废水的脱水试验400 mL废水中有机物含量约为70000 ppm通过使用在50 ℃下合成的100片的多孔凝胶（初始水含量约为93%）进行脱水。凝胶的尺寸为3.5mm。凝胶在50 ℃下收缩，浸入10 ℃的废水中15- 20分钟。30分钟。通过重复这些步骤5次，可以容易地将含水量降低到70%以下。结论通过对温敏性多孔凝胶合成条件的选择，可以实现温敏性多孔凝胶对有机废水的脱水。实际应用还需进一步研究。少

Preparation method of novel thermosensitive porous gels utilizing unique thermosensitive properties of acrylamide derivative polymers and development of dewatering system by using such thermosensitive hydrogels were investigated.1. Novel synthesis of thermosensitive porous gels N,N-diethylacrylamide (DEAA) and N-isopropylacrylamide (NIPAM) were used as primary monomers. These monomers dissolve in water, while their polymers have the transition temperature of about 32ﾟC and 31ﾟC, respectively. In other words, these polymers dissolve in water below these temperatures, while they have hydrophobic properties above these temperatures. The porous gels could be synthesized easily by a radical copolymerization of one of these primary monomers and cross-linker. The structures F could be controlled by the synthesis temperature, the concentration of cross-linker and so on. The porous structures composed of microgel particles of several microns and macro pores were formed clearly at the synthesis … More temperature above 40ﾟC, and the size of gel particles decreased with increasing the cross-linker concentration.2. Swelling and shrinking behaviors The porous gels synthesized above 40ﾟC swelled or shrank very fast without deformation because of the small resistance for permeation of water. The swelling rate of these porous gels was larger several hundred times compared with non-porous gels, and was inversely proportional to the square of the characteristic length of gel. The shrinking rate was comparable to the heat transfer rate.3. Dewatering tests of organic wastewater discharged from a rice washing machine The wastewater of 400mL containing organic materials of about 70000 ppm (the initial water content was about 93%) was dewatered by using the porous gels of 100 pieces which were synthesized at 50ﾟC.The size of gel was 3.5 mm. The gels shrank at 50ﾟC immersed into the waste water at 10ﾟC for 15-30min. The water content could be decreased easily to less than 70% by repeating these procedures 5 times.4. Conclusion By selecting the synthesis condition of thermosensitive porous gels, the dewatering of the organic wastewater by using these porous gels proposed in this research could be attained. The further study for practical application will be needed. Less