Viegas Rui M C, Campinas Margarida, Coelho Rosário, Lucas Helena, Rosa Maria João
Water Quality and Treatment Laboratory, Urban Water Unit, Hydraulics and Environment Department, LNEC-National Civil Engineering Laboratory, 1700-066 Lisbon, Portugal.
AdA-Águas do Algarve S.A., Rua do Repouso, 8000-302 Faro, Portugal.
Membranes (Basel). 2021 Jan 20;11(2):72. doi: 10.3390/membranes11020072.
Two pilot trials of powdered activated carbon (PAC)/(coagulation)/ceramic microfiltration were conducted to compare continuous 10-12 mg/L PAC inline dosing with 8-10 mg/L dosing to a 2 h-contact tank. Two low turbidity/low natural organic matter (NOM, total organic carbon <2 mg C/L) surface waters spiked with 7.2-10.3 µg/L total-pesticides were tested and the dosing options were compared towards operational performance, average removal of pesticides and NOM and costs. Removal differences between the two PAC dosing options depended on pesticides' amenability to adsorption and NOM characteristics (254 nm absorbance, A254). Waters containing low A254-absorbing NOM and only pesticides amenable to adsorption showed very high removals (all pesticides ≥93%) and no significant differences between the two PAC dosing options. Waters containing higher A254-absorbing NOM and high loads of pesticides less amenable to adsorption (dimethoate, bentazone) required higher inline PAC dose. Those or more severe conditions may require PAC doses higher than tested to comply with the Drinking Water Directive limits for pesticides. Cost analysis showed PAC inline dosing is more cost-effective than PAC dosing to the contact tank when identical PAC dose is sufficient or when the doses are low, even if 50% higher for inline dosing, and the plant is small.
进行了两项关于粉末活性炭（PAC）/（混凝）/陶瓷微滤的中试试验，以比较连续在线投加10 - 12毫克/升PAC与在2小时接触池中投加8 - 10毫克/升PAC的效果。对两种低浊度/低天然有机物（NOM，总有机碳<2毫克碳/升）且添加了7.2 - 10.3微克/升总农药的地表水进行了测试，并比较了这两种投加方式在运行性能、农药和NOM的平均去除率以及成本方面的差异。两种PAC投加方式的去除差异取决于农药的吸附性和NOM特性（254纳米吸光度，A254）。含有低A254吸光性NOM且只有易于吸附的农药的水体显示出很高的去除率（所有农药≥93%），两种PAC投加方式之间没有显著差异。含有较高A254吸光性NOM且高负荷的较难吸附农药（乐果、苯达松）的水体需要更高的在线PAC投加量。对于那些情况或更严峻的条件，可能需要高于测试剂量的PAC才能符合饮用水指令中农药的限值。成本分析表明，当相同的PAC剂量足够时，或者当剂量较低时，即使在线投加量高出50%，且处理厂规模较小时，在线投加PAC比在接触池中投加PAC更具成本效益。
