Development of Resource Recovery System for Phosphate and Fluoride Using Waste form Marine Industries

(1)磷酸盐的回收：研究了在铜(II)存在下，磷酸溶液与氧气氧化的动力学。在373K、3atm、pH 3、[Cu(II)]1.0moldm~(-3)Χ~(-3)的条件下，在200分钟的停留时间内，氧化率可达90%以上。认为自氧化反应可用于回收化学镀废液中的磷酸盐。(2)工业废水除氟：发现大气中的CO_2干扰除氟效率，并通过生成碳酸钙产生大量污泥。为了证实这些现象，利用实际废水在正常和脱气条件下进行了实验，不仅通过测量废水中的氟浓度，而且通过表征形成的污泥的性质。因此，从最小排放的角度来看，脱气条件下的氟化钙法是一种很有前途的含氟废水处理方法。(3)氟回收系统的开发：从“生态技术”的角度对一种新的废水除氟系统进行了评价。该设备在柱中加入活性氧化铝，可在不增加处理后水中任何化学成分的情况下除氟。然而，该系统必须在活性氧化铝饱和后再生，以最大限度地减少由此产生的排放。在此基础上，提出了吸附共沉淀与氢氧化铝相结合的生态化氟处理系统，以氟化钙的形式去除水中的氟。结果表明，该系统具有节能、节约资源的特点，具有很好的应用前景。

(1) Recovery of phosphate : The kinetics of the oxidation of phosphorous acid solution with oxygen in the presence of Cu (II) was studied. The achievement of oxidation above 90% is readily done at 373K, 3 atm, pH 3, [Cu (II)] 1.0Χ10^<-3>moldm^<-3> during the retention time of 200 minutes. It was considered that autoxidation reaction may be applicable to the recovery of phosphate in spent electroless plating liquors.(2) Fluoride removal from industrial wastewater : It is found that CO_2 in the atmosphere interferes with fluoride removal efficiency and produces a large amount of sludge by forming calcium carbonate. In order to confirm these phenomena, experiments using real wastewater under normal and degassed conditions were carried out not only by measuring the fluoride concentration in the wastewater, but also by characterizing the properties of the formed sludge. As a result, the calcium fluoride method under degassed conditions is suggested to be a very promising method for treatment of wastewater containing fluoride from the viewpoint of minimum emission.(3) Development of fluoride recovery system : A novel system of fluoride removal from wastewater was assessed from the viewpoint of "Ecotechnology". The equipment with activated alumina in a column can remove fluoride without increment of any chemical components in treated water. However, this system must be regenerated after activated alumina saturating, in order to minimize the emission derived from it. Then, we proposed an ecotechnological fluoride treatment system, which is composed to combine the adsorption and co-precipitation with aluminum hydroxide, and fluoride was removed as calcium fluoride from the system. As a result, the system is suggested to be very promising because of it's possibility of energy saving and resources saving.