【作者】 吕建波；

【导师】 赵新华；

【作者基本信息】 天津大学 ， 环境工程， 2010， 博士

【摘要】 以天然石英砂和无烟煤等环境友好型滤料作为研究对象,针对城市污水处理厂二级处理出水中的浊度、COD、磷酸盐等污染物质,提出并验证了污水回用高速过滤技术(滤速≥30m/h)的可行性,并制备开发了以除磷为目标的新型改性滤料——改性石英砂。研究了微絮凝-高速过滤和KMnO4预氧化强化微絮凝-高速过滤处理二级出水的效果。结果表明,高速过滤工艺出水均符合《城市污水再生利用城市杂用水水质》(GB/T 18920-2002)要求。并且确定了高速过滤的反冲洗方式和主要参数。经过对不同滤料级配和厚度(石英砂-无烟煤双层滤料)的11种工况的周期实验确定出,双层滤料的粒径范围、滤床深度、有效粒径及滤料层ΣL/d10,高速过滤技术应该以过滤开始的自然滤速,也即最大滤速进行,对高速过滤的流态通过两种Re公式进行了计算,认为高速过滤的流态为紊流。将微电解工艺产生的铁泥应用于滤料改性,以废治废。该思想同时为高浓度金属(铁、铝、锰等)废液的处理提供了一条有益的思路。研究了铁泥砂、铁铝砂和铁砂直接过滤处理再生水的效果。分别在低温(200℃)和高温(550℃)条件下制备出以除磷为目标的两种铁改性砂滤料——IOCS-1和IOCS-2,对其进行了表面特征分析(SEM、XRD、FTIR、EDAX),研究了铁改性砂静态吸附除磷影响因素、吸附等温线、热力学和动力学。结果发现,IOCS-1的PO43-吸附去除效果明显优于IOCS-2。共存阴离子SO42-、Cl-、HCO3-对IOCS-1吸附PO43-影响的大小顺序为:HCO3->SO42->Cl-,但影响不大。IOCS-1动态过滤实验表明,溶液初始pH值、滤速、床深等均会影响过滤除磷效果。IOCS-1连续三个周期的滤柱再生循环利用实验表明,吸附PO43-后IOCS-1可以使用0.1MNaOH溶液解吸再生,并且保持较稳定的PO43-去除率。与国内外相关研究相比,低温制备铁改性砂滤料对水中PO43-具有良好的吸附性,材料成本低,经实验表明可再生重复利用,具有环境友好性,因而有利于对现有水和废水处理中过滤除磷工艺的升级改造。更多还原

【Abstract】 In order to remove turbidity, COD and phosphate from municipal secondary effluent for wastewater reuse, high-rate filtration technology (filtration rate≥30m/h) using granular media (natural quartz sand and anthracite) is put forward and investigated. Several new types of modified filter media—metal-oxides-coated sands were prepared for enhancing filtration.Treatment efficiency of reclaimed wastewater with or without preoxidation (KMnO4) enhanced microflocculation high-rate filtration was investigated. The results show that effluent quality by high-rate filtration can meet <Municipal wastewater reuse——miscellaneous water quality> (GB/T 18920-2002). Moreover, hydraulic flow pattern of high-rate filtration were investigated. Meanwhile, backwash method and main operation parameters of high-rate filtration were determined.By experiments in 11 cycles of different operation conditions (gradation and bed depth of double-layer media), the results indicate that, the particle size of sand ranges from 0.6~1.2mm, bed depth=50cm, effective particle size=0.7mm, L/d100=714; the particle size of anthracite ranges from 1.2~1.6mm, bed depth=60cm, effective particle size=1.2mm, L/d10=500,ΣL/d10=1214. The initial filtration rate of high-rate filtration should be controlled at naturally largest filtration rate. Hydraulic flow pattern of high-rate filtration was calculated by two different Reynolds number formulas, and hydraulic flow pattern was thought to be turbulent flow.Reclaimed iron oxide was used to prepare iron-oxide-coated sand (RIOCS) in order to solve waste sludge deriving from micro-electrolysis process. The experimental results also can provide a beneficial idea which waste solutions containing high concentrations of metal (iron, aluminum or manganese) ions can be used for coating sand filter media in view of solving waste disposal problem. The effects of different MOCS (RIOCS, IAOCS, IOCS) and natural quartz sand (QS) on the removal of pollutants were researched for wastewater reuse.Two new types of iron-oxide-coated sand filter media IOCS-1 and IOCS-2 (prepared at low coating temperature and high coating temperature, respectively) were investigated for phosphate removal. SEM, XRD, FTIR and EDAX analysis were conducted for the characterization of IOCS-1 and IOCS-2. In batch experiments, the effects of initial solution pH, contact time and dose of IOCS on phosphate removal were investigated. The adsorption isotherms of phosphate by IOCS were fitted using Langmuir, Freundlich and Temkin equations at various temperatures (15℃,25℃, 35℃). The phosphate adsorption kinetics and thermodynamics of IOCS-1 and IOCS-2 were researched. The results indicate that the removal efficiency of PO43- by IOCS-1 was greater than IOCS-2. The sequence of anions studied competing with phosphate on IOCS-1 was HCO3->SO42->Cl-, but the effect of competitive adsorption was not great.The results of column filtration incate that phosphate removal depends on initial pH, flow rate and bed depth. Moreover, Phosphorus adsorbed IOCS-1 can be effectively regenerated by 0.1 M NaOH solution and column kept almost constant phosphate removal consecutively during three cycles.Results of this study showed that IOCS can be used as a new type of filter media through reforming filtration unit for removal of low concentration phosphate in water and wastewater treatment.更多还原