新型中置式高密度沉淀池优化投药试验研究

通过小试和生产性试验对新型中置式高密度沉淀池的投药系统(包括回流污泥、混凝剂及助凝剂PAM的投加)进行了详细研究.小试研究表明回流污泥和混凝剂投加量的增大降低了上清液浊度,PAM的投加略微降低了上清液出水浊度,但影响不大.生产性试验研究结果表明,实际生产运行中可灵活利用回流污泥来提高絮凝效果,在合理的范围内回流污泥投加量越大,絮凝效果越好;沉淀池随着混凝剂投加量的增大,出水浊度逐渐降低,同时,不同的回流污泥投加量条件下混凝剂投加对沉淀池出水浊度的影响表现出不同特性;增大PAM投加量对直接提高沉淀池的絮凝效果以及降低出水浊度的贡献不明显,PAM投加量的增大间接引起回流污泥投加量变大是导致出水浊度变小的原因.

Optimization of agents addition processes for high efficiency mid-flocculation-sedimentation tank

Agents (coagulants and coagulant aids PAM) addition and activated sludge recycle processes for high efficiency mid-flocculation-sedimentation tank were investigated in this study by employing experiments of both laboratory and full-scale. Laboratory experiments results showed that increasing dosages of activated sludge and coagulants decreased the turbidity in supernatant fluid. Addition of PAM slightly decreased the turbidity of supernatant fluid. In further, full-scale experiments based on laboratory experiments were carried out to eliminate limits of laboratory experiments. It was found that activated sludge could be used to improve coagulation efficiency in practical operation. Within a certain range, increasing the dosage of activated sludge could lead to higher coagulation efficiency. Turbidity of outflow apparently decreased with increasing of coagulates dosage in sedimentation tank. In the meanwhile, under the condition of various sludge dosages, different effects of coagulants on outflow turbidity were observed. Compared to coagulation efficiency contributed by PAM directly, that it was the increasing sludge dosage indirectly caused by PAM dosage increasing that resulted in decreasing of outflow turbidity.