| 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.
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