Piazza G J, Garcia R A
US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Fats, Oils and Animal Coproducts Research Unit, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
Bioresour Technol. 2010 Jan;101(2):781-7. doi: 10.1016/j.biortech.2009.03.078. Epub 2009 Sep 5.
Readily available proteins were tested as renewable flocculants, and their actions were compared to that of anionic PAM, a common, commercial flocculant that requires the coaddition of a calcium ion source. Two soy proteins, a whey fraction, a porcine gelatin, and a meat & bone meal (MBM) extract were used in the flocculation test. It was found that MBM extract and porcine gelatin promoted clay flocculation, and flocculation was complete by 24h with or without the addition of calcium chloride. The other tested proteins did not promote clay flocculation, but all of the proteins were found to be adsorbed to clay. The protein adsorptions were well described by the Langmuir model, and gelatin and MBM extract had higher maximum adsorption capacities than the other proteins. Zwitterionic buffer solutions at pH 5.5, 7.0, and 10.0 were tested in the flocculation experiments. Addition of the pH 5.5 buffer caused the two soy proteins to become clay flocculants and lowered the concentration of gelatin and MBM extract necessary to promote complete flocculation by 24h. Calcium chloride was not required for flocculation. Under optimal testing conditions, the dried weight of gelatin or MBM extract was 2.6 and 17 times higher, respectively, than the weight of anionic PAM required for complete flocculation at 24h.
对易于获取的蛋白质作为可再生絮凝剂进行了测试，并将它们的作用与阴离子聚丙烯酰胺（一种常见的商业絮凝剂，需要添加钙离子源）的作用进行了比较。在絮凝试验中使用了两种大豆蛋白、一种乳清组分、一种猪明胶和一种肉骨粉（MBM）提取物。结果发现，MBM提取物和猪明胶促进了粘土絮凝，无论是否添加氯化钙，絮凝在24小时内完成。其他测试的蛋白质没有促进粘土絮凝，但发现所有蛋白质都被吸附到粘土上。蛋白质吸附可用朗缪尔模型很好地描述，明胶和MBM提取物的最大吸附容量高于其他蛋白质。在絮凝实验中测试了pH值为5.5、7.0和10.0的两性离子缓冲溶液。添加pH值为5.5的缓冲溶液使两种大豆蛋白成为粘土絮凝剂，并降低了在24小时内促进完全絮凝所需的明胶和MBM提取物的浓度。絮凝不需要氯化钙。在最佳测试条件下，明胶或MBM提取物的干重分别比24小时内完全絮凝所需的阴离子聚丙烯酰胺重量高2.6倍和17倍。
