【作者】 张运华；

【导师】 甘复兴；

【作者基本信息】 武汉大学 ， 环境工程， 2011， 博士

【摘要】 钢铁工业生产过程中会产生各种工业废水,虽然企业在各工序生产过程中建立了废水回用或污水达标排放处理设施,但为满足生产要求,降低浓缩倍数,回用循环水处理过程中必须定期排污,这些未经处理的回用循环过程中的排污水和少量工序事故水、经处理后达标排放污水与少部分生活污水、雨排水等汇合到一起,形成的混合废水,称之为钢铁工业综合废水。钢铁工业循环用水量占总用水量的比例往往在95%以上,其综合废水也主要来源于浊循环水系统的排污水(敞开式净循环水系统的排污水一般作为浊循环水系统的补充水)和冷轧、硅钢等经单独处理后达标排放的特种工业废水以及少部分生活污水、雨排水等。其中,冷轧含油/乳化液、平整液废水和热轧含油循环废水是两种重要而难处理的工业污水,也是造成综合废水处理难度大和影响回用的主要原因；目前,大流量的综合废水有效处理方法报道甚少,处理后的综合废水由于电导率的偏高等因素影响了回用范围；综合废水处理产生的综合污泥必须用汽车送去填埋、既增加运输和处置费用、又会造成二次环境污染,其有效利用研究目前尚无报道；而热轧和冷轧含油废水常规方法存在运行费用高、药剂消耗量大、出水不稳定等缺点,特别是前者用传统的石英砂、无烟煤深度除油除浊,易出现跑料、板结、寿命短等现象。有鉴于此,论文课题在充分的文献调研基础上,选择具有代表性的钢铁工业综合废水及其处理产生的综合污泥和前者主要来源组成的热轧、冷轧含油废水作为研究对象,进行先进水处理技术和污泥资源化技术研究,对于减少水污染和固体废弃物污染,实现钢铁工业清洁生产,具有重要实际意义,同时对于发展工业污染控制的技术和方法,具有一定的理论和学术价值。本论文共分七张,即：第一章绪论,第二章钢铁工业综合废水处理技术工艺设计与优化研究；第三章新型电吸附技术深度处理钢铁工业再生水技术研究；第四章钢铁工业综合废水处理污泥资源化利用研究；第五章亲油性改性滤料深度处理钢铁工业热轧高线含油废水的研究与应用；第六章含油／乳化液、平整液废水处理的技术研究；第七章总结与展望。本论文得到的主要研究成果如下：1.提出并确定了利用国外高密度沉淀技术和V型滤池过滤技术处理大流量的钢铁工业综合废水的技术工艺路线,实践证明是可行的,具有应用推广前景；对该技术工艺的核心即化学药剂处理单元进行了优化研究,结果表明：在武钢A综合废水处理厂水质条件下,在前混凝处理工艺中,Ca(OH)2加入量是去除硬度的关键因子,pH和电导率可以反映硬度去除的效果,pH值控制在9.6左右可取得硬度去除的最佳效果,随着石灰投加量增加,CODCr去除效果更好,与之相匹配的聚合硫酸铁(PFS)和聚丙烯酰胺(PAM)最优投加量分别为40ppm和0.3ppm,但是,总铁含量与PFS投加量正相关,因此,PFS投加量不宜偏高；污泥循环对强化系统去除浊度、CODCr和进一步降低电导率是非常有效的,并可以改善系统结垢的性能,污泥回流比控制在5%-20%为最佳；Ca(OH)2、PFS、PAM和回流污泥的投加次序对浊度、CODCr、硬度的去除和电导率的降低有影响：Ca(OH)2先于PFS投加、PAM同时分别向回流污泥和絮凝反应池投加是较佳的投加方式；在后混凝处理工艺中,混凝剂采用PAC替代PFS,可降低总铁,PAC投加量3 ppm为佳；出水pH调节用的H2SO4投加量约12ppm为佳；在出水消毒工艺中,采用紫外消毒、二氧化氯消毒或紫外与次氯酸钠联合消毒取代次氯酸钠消毒,这样对降低Cl-和电导率均有明显效果。出水水质分析结果显示：优化后出水水质指标均优于优化前出水水质指标,且出水水质较为稳定；优化后出水水质指标都能达到武钢直接循环冷却水系统补充水水质要求,同时,为离子交换软化／脱盐系统等特殊生产用水的深度预处理创造了条件。2.开展了将新型电吸附技术应用于处理后的综合废水(以下称为工业再生水)深度净化脱盐处理的研究,使之达到特殊用途标准。中试试验结果表明,当原水电导率在700μS/cm左右,工作流量从500L/h逐步增大至1000L/h时,电吸附技术处理的出水水质稳定,完全能够满足武钢离子交换软化／脱盐系统等特殊生产用水的水质要求,对电导率、Cl-、Ca2+的平均去除率分别达到70%、75%和68%左右,对COD也有较好的去除效果。同时,产水率可达到75.3%,明显优于传统技术。电吸附技术对前期预处理要求较低,整套处理系统的产水和再生不需要添加任何酸、碱和盐溶液等化学药剂,不会引入污染。因为无需使用膜或者高压泵,电吸附技术比电渗析和反渗透等传统方法运行成本更低、操作更为简便、更为节能,具有广阔的推广应用前景。3.对综合废水处理过程中产生的综合污泥进行了资源化利用研究,主要是利用综合污泥制备改性综合污泥质多孔陶瓷滤料,首先,针对成孔剂添加工艺,研究了不同的成孔剂、不同的成孔剂添加量、骨料颗粒级配对Pa、Wa、D的影响以及成孔剂颗粒、烧成温度对Pa、D的影响,研究结果表明,煤粉为最佳成孔剂,成孔剂和骨料的颗粒级配对滤料的显气孔率影响不大,煤粉添加量在一定范围内与综合污泥质多孔陶瓷滤料的Pa、D成线性正相关关系,可通过控制煤粉添加量实现对Pa、D的调控；烧成温度控制在1130℃～1160℃范围内为佳,此范围内研制滤料的理化性能良好,气孔率较大；陶瓷滤料显气孔率与抗压碎强度之间的关系可用二次曲线拟合,可通过调控煤粉添加量来平衡多孔陶瓷滤料的P与抗压碎强度之间的矛盾,从而使滤料显气孔率高且抗压碎强度也大,得到适合需要的多孔陶瓷滤料。在此基础上,对综合污泥质多孔陶瓷滤料进行了亲油改性研究,通过对照试验和多参数的测试结果分析,确定武钢综合污泥质陶瓷滤料亲油性涂层表面最优改性条件为：改性剂为202含氢硅油,固化时间为25min.,固化温度为200℃,涂层次数为1次,体积浓度为10%。4.研究了用改性综合污泥质多孔陶瓷滤料对热轧高线含油废水进行深度处理,探讨了影响处理效果的因素,优化了相关操作工艺参数,并用FTIR、SEM、XRD等测试手段对相关性能进行了表征。同时,研究了油等污染物去除的机理,并与传统石英砂滤料进行了对照实验研究,实验结果显示,相对传统的石英砂滤料,改性滤料具有出水水质好,除浊率高,周期长,水头损失小的优点；设计的串级连续流的压力过滤工艺,采用“反粒度过滤”的运行方式,每段滤层仍保持均质滤料结构,使得截污量在整个滤层中分布趋于均匀,并有效避免了混层的发生,确定了最佳运行参数；经过连续反洗再生实验和性能测试,证明改性滤料能够在长期运行过程中保持稳定的除油、除浊、耐磨和耐腐蚀的性能；现场中试和生产性动态试验研究结果进一步证明：采用以武钢综合污泥质改性滤料为核心的过滤工艺,除油和悬浮物效果明显,在进水水质条件波动较大的情况下,处理后的出水悬浮物始终保持在30mg/L以下,油在4mg/L以下,满足武钢热轧高线生产的需要,避免了传统石英砂易板结、跑料、使用寿命短等弊端,为钢铁工业综合污泥资源化利用提供了典范。5.对冷轧含油/乳化液、平整液废水这一综合废水主要来源,进行了处理研究,采用气能絮凝(GEF)、超滤(UF)、电化学催化氧化(ECO)、膜生物反应器(MBR)组合工艺,通过不同组合、调试研究、逐步完善,最终确定了以电催化氧化为主体的新型组合工艺处理冷轧含油/乳化液、平整液废水。研究结果表明：采用‘’GEF+ECO+MBR"和"UF+ECO+MBR"两种新型组合工艺,均能有效处理冷轧乳化液废水,最终出水CODCr≤30mg/L,满足《钢铁工业水污染物排放标准》(征求意见稿)要求,但前者出水水质更稳定一些,"GEF+ECO +MBR"新型组合工艺处理冷轧乳化液、平整液废水为最佳工艺。该工艺达到了生产回用水水质要求,为冷轧乳化液废水深度处理和资源化提供了新的工艺路线[11。更多还原

【Abstract】 A variety of industrial wastewater has been produced in iron-steel enterprises during production process. Effective treatment facilities for reuse or discharging meeting the national standard have been established in every production of enterprises. However regular discharging is needed in the process of reuse water circulation in order to meet the requirement of production and reduce the enrichment multiples. The comprehensive wastewater is composed of the untreated wastewater during reuse circulation process, a few process accident water, treated wastewater meeting the discharging standard and a little sewage, rain storm water. Recycling water consumption in the proportion of total water consumption often exceeds 95%. The comprehensive wastewater mainly comes from turbid circulating water system (the discharged wastewater from open-style indirectly-touched circulating water system is often used as the supplementary water of the directly-touched circulating system) and special industrial wastewater from the process of cold rolling and coking which have been treated separately and met with the discharge standard. In addition, they also come from a small number of domestic wastewater, rain drainage and so on. Among them, cold rolling oil/emulsion, wastewater from cold-rolled strip temper mill and hot-rolling oily wastewater are two kinds of important and hard-to-degraded industrial wastewater, which are the main composition sources of comprehensive wastewater and the main reason making the comprehensive wastewater difficult to be degraded. There is no report about the effective treatment method of high-flow comprehensive wastewater up to now. The scope of reuse of treated comprehensive wastewater is limited by certain factor such as relatively high conductivity. The comprehensive sludge must be sent to landfill by cars, which can increase the transportation and treatment costs, and cause potential environmental pollution. At present there is no report about the effective use of research on its effective utilization. However the regular treatment methods of hot-rolling and cold-rolling oily wastewater have some shortcomings such as high cost of running and chemicals consumption, unstable effluent quality. Especially there exist filter media losing, easy to compaction and short life using traditional quartz sand, anthracite to remove oil and turbidity. In view of these problems, based on full literature investigation, representative iron-steel industrial comprehensive wastewater and comprehensive sewage sludge during its treatment processes and hot and cold rolling oily wastewater as the former’s main source are selected as the object in this thesis. Research on technologies of advanced water treatment and sludge resourcelization are conducted. It is of great significance of reducing water and solid wastes pollution and realizing clean production in the iron-steel industry. Meanwhile, it has certain theoretical and academic value to developing the techniques and methods for industrial pollution control. The thesis is divided into seven chapters:The first chapter is introduction, the second is concerned about process design and optimal application of iron-steel industrial comprehensive wastewater treatment, the third is about technological research on electrosorption technique enhanced treatment of reused comprehensive iron-steel industrial wastewater, the fourth is about research on iron-steel industrial comprehensive wastewater treatment sludge resourcelization, the fifth is about research and application of oleophylic modified filter meida enhanced treating hot-rolling high speed wire oily wastewater in WISCO, the sixth is about the technical research and application of treatment for oil/emulsion and the wastewater from cold-rolled strip temper mill. The last chapter is conclusion and outlook. On this basis, main results in this thesis are as follows:1. High-density precipitation technology and V-filter processing have been proposed and determined. It has been proved to be practicable and have wide application prospects. The optimal study on the chemical salts process as the core of this technique is conducted. The research results show that under the water quality condition of A comprehensive steel industrial recycling wastewater treatment project in WISCO, in the pre-coagulation process, the amounts of Ca(OH)2 is the key factor to the hardness removal, pH and electrical conductivity can reflect the effect of hardness removal, the optimal effect of hardness removal is achieved when pH value is controlled around 9.6, with the increase of amount of lime, the higher CODcr removal efficiency can be achieved, the optimal dosage of matching PFS and PAM was 40ppm and 0.3ppm respectively. However, total iron content was positively related to the dosage of PFS, so high dosage of PFS is inadvisable; it is very effective for sludge recycling to remove the turbidity, CODCr and to reduce electrical conductivity further in the improved system, and can also improve system performance of fouling. The optimal controlled return sludge ratio is between 5%～20%. The dosing turn of Ca(OH)2, PFS, PAM and returning sludge has impact on the removal of turbidity, CODcr, hardness and reduction of electrical conductivity:it is a better way of dosing to dose Ca(OH)2 slightly before PFS, PAM is put to the return sludge and flocculation reaction tank respectively at the same time. In the post-coagulation process, using PAC as coagulant instead of PFS can reduce the total iron. The optimal dosage of PAC is 0.3ppm.The optimal H2SO4 dosage of effluent pH adjustment is about 12ppm; In the effluent disinfection process, the use of UV disinfection, chlorine dioxide disinfection or ultraviolet disinfection combined with sodium hypochlorite can replace sodium hypochlorite disinfection, that will reduce Cl- and electricity conductivity significantly. The results of optimized effluent show that the water quality indexes in the effluent are better than those in the influent and keep stable. The optimized effluent water quality indexes can meet the requirements of supplement water quality of direct recycling cooling water systems in WISCO and create favorable condition for enhanced pre-treatment of ion exchange softening/desalination system for special production water.2. Carrying out research on the novel electric adsorption technology which is applied to the comprehensive wastewater (it is called industrial regenerated water in the following content) enhanced desalination and purification treatment, make it achieve special use standard. Pilot test results show that when the raw water electricity conductivity is about 700μS/cm, the work flow is from 500L/h and gradually increases to 1000L/h, the quality of water treated with electric adsorption treatment is stable, can meet the special production water standard of WISCO’s ion-exchange softening/desalination system, the average removal rate of electricity conductivity,Cl-,Ca2+ is up to about 70%、75% and 68% respectively, it also has a good removal effect of COD. At the same time, water production rate can reach 75.3%, significantly better than traditional technology. Electrosorption technology has a low requirement in the prophase preprocessing, the water’s production and regeneration of the whole treatment system need no any chemical agents such as acid, alkali and saline solution and so on, will not introduce pollution. Electrosorption technology has a lower operating cost and easier operation, more energy saving than traditional methods such as electrodialysis and reverse osmosis without the use of film or high-pressure pump, it has broad application prospects.3. Research on resourcelization of comprehensive sludge during the comprehensive wastewater treatment mainly using comprehensive sludge to produce modified porous ceramic filter media made form comprehensive sludge is conducted. Firstly, Aiming to pore-formation addition process, effects of pore-forming agent kinds, pore-forming agent addition, graded aggregate size, graded pore-forming agent size, firing temperature on apparent porosity, volume density and crush strength of filter media are studied. The results show that coal powder is chosen as optimal pore-forming agent and the size distribution of pore-forming agent and graded aggregate have little effect on apparent porosity of filter media. The relation between coal addition with apparent porosity and volume density of filter media in certain scope is linear. So regulation to apparent porosity and volume density of filter media can be realized by coal addition, firing temperature should be controlled between 1130℃～1160℃. The physical-chemical properties of meida produced in this temperature range are sound and porosity is relatively large. The relation between the apparent porosity and crush strength of filter media accords with quadratic curve. Thus, contradiction between apparent porosity and crush strength of filter media is conciliated by controlling coal addition, which can produce porous ceramic filter media with a higher apparent porosity and crush strength. On this basis, the pro-oil modification of comprehensive sludge porous ceramic filter media is conducted through the analysis of controlled trials and multi-parameter test results, the optimal modification condition of WISCO comprehensive sludge porous ceramic filter media pro-oil surface is confirmed:modifier is 202 hydrogen silicone oil, curing time is 25 min, curing temperature is 200℃, coating one time, the volume concentration of 10%.4. Enhanced treatment of hot rolling speed wire oily wastewater with modified comprehensive sludge porous ceramic filter media is studied, the factors that influence the treatment result are discussed, related operation process parameters are optimized, related performance is characterized by FTIR, SEM, XRD and other relevant testing methods. Meanwhile, the removal mechanism of oil and other pollutants is studied, comparison experiments of traditional quartz sand filter was conducted, the research results turn out:compared with traditional quartz sand filter media, modified filter media have the advantage of high water quality, high turbidity removal efficiency, long filtration run, minor loss of water; the designed pressure filtration devices of cascade continuous flow using "anti-granularity filtering" operation mode. Each filter layer remains uniform media structure, making the distribution of interception amount in the entire filter layer to uniform and avoiding the occurrence of the mixing layer effectively, the optimum operating parameters were confirmed. Through the continuous reverse-wash regeneration experiment and performance testing, it is confirmed that modified filters can maintain the stable performance like oil removal, turbidity and corrosion resistance; On-site pilot scale test and productive dynamic test results further prove that using filtering technology centered on WISCO sludge quality modified filter media will have obvious effect on oil and suspended solids removal, on the condition of higher fluctuation of influent, the effluent suspended solids remain below 30mg/L, oil remains below 4mg/L, can satisfy the WISCO hot rolling speed wire production need and achieve the expected goal of the study, comparing with the traditional quartz sand,modified filter media has better performance on oil and turbidity removal, the effluent is more stable, run longer and avoid the disadvantages of traditional quartz sand such as easy to compaction and lose, short life, and so on; Meanwhile, it can provide typical examples for resourclization of the iron-steel industrial comprehensive sludge.5. Research on the treatment of cold rolling oily/emulsion, flat liquid wastewater, which is the main source of comprehensive wastewater is carried out. Four modules GEF (Gas Energy Flotation),UF(Ultra filtration), ECO(Electrical Chemical Oxidation), MBR(Membrane Biological Reactor) are under debugging combined study and improved gradually through different combination. Eventually it is determined that the novel combined processes with electro-catalytic oxidation as the focus technique to treat cold rolling oily/emulsion, flat liquid wastewater. The results show that two kinds of novel integrated processes--GEF+ECO+MBR and UF+ECO+MBR, can treat cold rolling emulsion wastewater effectively, the ultimate treated water’s CODcr content is less than 30mg/L,can meet the requirement for "Iron and steel industrial water pollutant discharge standards" (opinion draft). The former’s water quality is more stable. Therefore the integrated process "GEF+ECO+MBR" is determined to be the optimal process to treat cold rolling oily/emulsion, flat liquid wastewater, which can meet the water quality requirement of production recycled water, providing a new technology route for the enhanced treatment and resourcelization.更多还原