| 摘要 |
PROBLEM TO BE SOLVED: To obtain an improvement agent for recycled soil which can solve an environmental problem arising from a polymer flocculant by using various natural polysaccharides as a flocculant for dehydrated sludge from sewage disposal plants and waste water treatment plants of an agricultural villages. SOLUTION: A flocculant for dehydrated sewage comprises a viscosity improver and stabilizer (8 kinds including sodium alginate, etc.), and various natural polysaccharides (polysaccharides made from seeds, resins, saps and seaweeds, fermented products, extracts from plants, an extract from the crustacea, etc.). Materials suitable for dehydration of sludge are chosen from among the compounds and may be employed alone or as a mixture thereof. Since the materials to be employed have been used as an additive for jam, ketchup, ice cream, mayonnaise, etc., it is possible to solve a problem of influence of a toxic acrylamide monomer slightly included in polyacrylamide-based polymer flocculants on soil and plants. |
