采用传统折板絮凝池处理低浊水时面临絮体沉降性差、“跑矾”等现象。为解决上述问题,宁夏某水厂采用微涡旋絮凝工艺对折板絮凝池进行升级改造,但改造完成后的运行效果仍不理想。通过分析对比微涡旋絮凝池和折板絮凝池中的颗粒数、浊度、絮体沉降体积、分形维数、分子荧光光谱等,讨论现有微涡旋改造的不足,并建立一套评价体系,以指导水厂的升级改造。试验结果表明:经过微涡旋改造后除第二絮凝段外,其他各段对浊度的去除率分别提高了8.7%、6.7%、6.5%、56.1%,絮体颗粒数分别降低了20.8%、14.7%、25.2%、48.4%;第二絮凝段由于布水方式和填加微涡旋球过多(水力扰动过大、短流)等问题,使得絮体的形成受到影响,对浊度和颗粒数的去除率相比折板絮凝池无明显提高。所采用的评价指标能够评价水厂微涡旋改造,具有广泛的应用性,为今后水厂的升级改造提供了良好的评价体系。
Poor settleability of flocs and alum loss took place in the treatment of low turbidity water using traditional folded plate flocculator. To solve these problems, micro-eddy floeculation was used to upgrade the folded plate flocculator in a water treatment plant. However, the operation efficiency after the upgrade was low. The particles content, turbidity, settling volume of flocs, fractal dimension and EEM were used to estimate the deficiencies of micro-eddy flocculation. The experimental results showed that except for the second floeculation section, the removal rates of turbidity in the other four sections in- creased by 8.7%, 6.7%, 6.5% and 56.1%, and the amounts of particles decreased by 20.8%, 14.7% , 25.2% and 48.4% , respectively. The formation of floes in the second floeeulation section wasaffected by water distribution pattern and adding excessive micro-eddy balls (excessive hydraulic disturb- ance and short circuiting). The estimation method can assess the upgrade of water treatment plants, and has broad applicability,