This study evaluated the ability of potassium ferrate(VI) and freeze-thaw to stabilise and dewater primary sludge. Potassium ferrate(VI) additions of 0.5 and 5.0 g/L were used as a pre-treatment prior to freeze-thaw. Samples were frozen at −10, −20 and −30 °C, and were kept frozen for 1, 8 and 15 days. The samples were subsequently thawed at room temperature in a setup which allowed meltwater to be separated from the sludge cake via gravity drainage. The meltwater was characterised in terms of fecal coliform, soluble chemical oxygen demand (COD), soluble proteins, soluble carbohydrates, pH and turbidity. The sludge cake was characterised in terms of fecal coliform, total solids (TS) and volatile solids (VS). Freeze-thaw with gravity meltwater drainage reduced the sludge volume by up to 79%. After being frozen for only 1 day, the concentrations of fecal coliform in many of the primary sludge samples were reduced to <1000 MPN/g dry solids (DS), representing >3-log inactivation in some cases. However, pre-treatment of the primary sludge with ≤5.0 g/L potassium ferrate(VI) resulted in significant increases in soluble proteins, soluble carbohydrates, and sCOD, and reduced the effectiveness of stand-alone freeze-thaw. Follow-up experiments using higher doses ranging from 5.1 to 24.9 g/L of potassium ferrate(VI) demonstrated that >5-log inactivation of fecal coliform in raw primary sludge can be achieved within 15 min using 15 g/L of potassium ferrate(VI), and the resulting concentration of fecal coliform in the sludge was 1023 MPN/g DS. Pre-treatment with 22.0 g/L of potassium ferrate(VI), followed by freeze-thaw, with only 3 days frozen, reduced the concentration of fecal coliform to below the detection limit in the meltwater and the sludge cake. This demonstrates that potassium ferrate(VI) and freeze-thaw offers the flexibility to adjust the ferrate(VI) dose to meet treatment requirements for land application, and can be used as a stand-alone sludge treatment technology for primary sludge that achieves both treatment and dewatering.

这项研究评估了高铁酸钾（VI）和冻融稳定和脱水初级污泥的能力。冻融前添加0.5和5.0 g / L的高铁酸钾（VI）作为预处理。将样品冷冻在-10，-20和-30°C下，并冷冻1、8和15天。随后将样品在室温下解冻，其设置允许融水通过重力排水从污泥饼中分离出来。根据粪便大肠菌，可溶性化学需氧量（COD），可溶性蛋白，可溶性碳水化合物，pH和浊度来表征融水。根据粪便大肠菌，总固体（TS）和挥发性固体（VS）对污泥饼进行了表征。重力融水排水的冻融功能可将污泥量减少多达79％。冻了一天之后 许多初级污泥样品中粪大肠菌群的浓度降低至<1000 MPN / g干固体（DS），在某些情况下代表> 3 log失活。但是，用≤5.0g / L高铁酸钾（VI）预处理主要污泥会导致可溶性蛋白质，可溶性碳水化合物和sCOD显着增加，并降低了独立的冻融效果。使用5.1至24.9 g / L高铁酸钾（VI）的更高剂量的后续实验表明，使用15 g / L高铁酸钾（15 g / L）可以在15分钟内实现粪便大肠菌群> 5对数灭活（ VI），污泥中粪便大肠菌的最终浓度为1023 MPN / g DS。用22.0 g / L高铁酸钾（VI）预处理，然后冻融，仅冷冻3天，将粪便中大肠菌群的浓度降低到熔融水和污泥饼中的检测极限以下。这表明高铁酸钾（VI）和冻融可灵活调节高铁酸根（VI）的剂量以满足土地应用的处理要求，并可作为实现两种处理方式的一次污泥的独立污泥处理技术。和脱水。