Alum and ferric chloride were used individually as coagulants to remove P25 TiO₂ nanoparticles (NPs) from a simulated wastewater. Previous studies have addressed the use of alum, polyaluminum chloride, chitosan, and polyaluminum chloride with chitosan for coagulation of NPs. A goal of this study was to reduce chemical usage associated with wastewater treatment by examining the coagulation effectiveness of chitosan in conjunction with alum. To further reduce chemical consumption during coagulation, the initial solution pH was limited to 6 or 8. A range of alum doses removed NPs from pH 8 wastewater to achieve residual turbidity <1 NTU. NP removal from pH 6 solutions produced water with residual turbidity <2 NTU only at lower initial NP concentrations. For pH 8 solutions, ferric chloride produced treated water with residual turbidity <1 NTU but at higher doses than required for alum. While chitosan alone did not significantly reduce turbidity, the use of alum and chitosan together reduced the optimal alum dose by 10% and also reduced alum treatment acidification. Therefore, the use of chitosan in coagulation can potentially reduce chemical usage during water treatment and the energy and water consumption associated with chemical production. Use of alum with low chitosan concentrations produces faster settling floc, which can potentially reduce settling tank volume and produce an effluent containing lower aluminum concentrations.

中文翻译：

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使用传统化学混凝剂和壳聚糖去除废水中的二氧化钛纳米颗粒

分别使用明矾和氯化铁作为凝结剂去除P25 TiO ₂模拟废水中的纳米颗粒（NPs）。先前的研究已经解决了使用明矾，聚氯化铝，壳聚糖和聚氯化铝与壳聚糖一起用于NP凝结的问题。这项研究的目的是通过检查壳聚糖与明矾的混凝效果来减少与废水处理相关的化学物质的使用。为了进一步减少凝结过程中的化学消耗，将初始溶液的pH值限制为6或8。使用明矾剂量范围从pH 8废水中去除了NP，以实现残留浊度<1 NTU。仅在较低的初始NP浓度下，从pH 6溶液中除去NP的水残留浊度<2 NTU。对于pH 8的溶液，氯化铁产生的处理水残留浊度<1 NTU，但剂量要比明矾高。虽然单独使用壳聚糖并不能显着降低浊度，但同时使用明矾和壳聚糖可以将最佳明矾剂量降低10％，并且还可以降低明矾处理的酸化程度。因此，在凝结中使用壳聚糖可潜在地减少水处理过程中的化学用量以及与化学生产相关的能量和水消耗。使用壳聚糖浓度低的明矾会产生更快的沉降絮凝物，这有可能减少沉降池的体积并产生含铝量较低的废水。在凝结过程中使用壳聚糖可以潜在地减少水处理过程中的化学用量以及与化学生产相关的能源和水的消耗。使用壳聚糖浓度低的明矾会产生更快的沉降絮凝物，这有可能减少沉降池的体积并产生含铝量较低的废水。在凝结过程中使用壳聚糖可以潜在地减少水处理过程中的化学用量以及与化学生产相关的能源和水的消耗。使用壳聚糖浓度低的明矾会产生更快的沉降絮凝物，这有可能减少沉降池的体积并产生含铝量较低的废水。