| Fenhe is regarded as "the mother river" in Shanxi province. In recent years, with the rapid development of economy, the industrial productivity boosted, industrial enterprises have produced large quantities of waste water. Although it was after the processing of wastewater treatment at all levels, there was still much not discharged standard. As a result, Fenhe river was polluted in different degree, especially chemical oxygen demand (COD) and ammonia nitrogen. It not only affected the health of the residents around, but also restricted the sustainable development of society and economy in Fenhe river basin. Therefore, solving the pollution problem of the Fenhe river is urgent.The study was projecting to use permeable reactive barriers and undercurrents wetland of the coupling of new technology to treat the Fenhe sewage, which combined with local characteristics and the treatment of the cavalcade of demand. This technology was very good to make up for the lack of a single technology with defects and promoted the processing power of the whole system. It was a high-performance, innovative and practical new wastewater treatment technology.In this paper, the material selection of active response which was the key link of the technology was researched firstly. According to the characteristic of industrial waste in Shanxi province, using the steel slag and the fly ash which had good adsorption performance as the mixed materials to treat the sewage in stead of traditional reaction materials. It can achieve the purpose that using waste to treat waste. The steel slag was good at treating heavy metal ions wastewater and inorganic non-metallic wastewater, and the treatment effect was remarkable. However, it was not significant in treating the organic and ammonia nitrogen pollution of fenhe sewage. Therefore, it must be modified in order to promoting the adsorption ability on organic and ammonia nitrogen. Because of the small particle size of the fly ash, it can not produce tolerability and easy to be water washed away. So it not suitable for using as the water treatment materials directly. If discuss a modeling method of fly ash, it can not only meet the practical application request, but also can have certain process performance. To solve the above problems, the permeable reactive barriers and undercurrents wetland of the coupling of new technology was simulated applied in the laboratory secondly, which using the modified steel slag in Taiyuan Iron and Steel Co. and the formed fly ash in Taiyuan the first thermal power plant as the mixed materials, PolygonumorientaleL. as the wetland plants. Finally, the study evaluated the processing efficiency of system, and provided the reference for the practical application. The main researches were that:(1) The studies on the modification of the steel slag. For COD and ammonia nitrogen pollution respectively, using four kinds of modified method:CTMBA surface modification, acid modification, basic modification and high temperature activation modification.5factors4levels orthogonal experiment was designed. To analyze the importance of the influential factors and select the best modification methods. To research the single influence factor experiment of adsorbing COD and ammonia nitrogen in order to obtaining the best experimental conditions and the saturated adsorption capacity. Results showed that:the importance sequence of affecting factors on COD adsorbed by modified steel slag were:COD initial quality concentration、pH value、adsorption time、steel slag granularity、the modification methods. CTMBA surface modification was the best method which the removal efficiency increased from27%to46%. With the initial quality concentration increased, the COD removal rate was reduced.7was the best pH value for adsorbing, the adsorption rate was slower, and10-15mm was the best particle size range. The adsorption processes met the Longmuir equation, the correlation coefficient was0.9779, and the theory quantity of adsorption was2.5664mg/g. The importance sequence of affecting factors on NH/4+-N adsorbed by modified steel slag were:NH4+-N initial quality concentration steel slag granularity、the modification methods、 pH value、adsorption time. High temperature activation was the best modification method, and the removal efficiency increased from12%to30%. With the initial quality concentration and the steel slag granularity increase, the pH value decreased, the NH4+-N removal rate was reduced. The adsorption rate was faster. The adsorption processes met the Longmuir equation, the correlation coefficient was0.9993, and the theory quantity of adsorption was2.8491mg/g.(2) The researches on the preparation of porous fly ash water treatment materials. Using fly ash, quick lime, cement and gypsum as the main raw materials, aluminums as the gas agent, prepared the light porous water treatment materials which through adding water, mixing, pouring, gassing, inflating, cutting and high-pressure steaming. To research the factors in the process of forming in order to obtaining the best molding conditions through investigating the performance indexes. Results showed that:The quality ratio of fly ash、lime、gypsum、cement、aluminums、water and sodium dodecylbenzenesulfonate was34.5:10.5:2:4:0.056:35:0.15, the granularity was0.075mm, the stirring speed was400r/min, each index of the porous specimens all reached a superior level. The dry density was540-590kg/m3, compressive strength was0.7-0.9Mpa, bibulous rate was70-80%, COD removal rate was22%, NH4+-N removal rate was38%,quality loss after freeze-thaw was2.5%and compressive strength after freeze was0.5Mpa.(3) The studies on simulated application of the coupling of permeable reactive barriers and undercurrents wetland new technology. The new technology was simulated applied in the laboratory, which using the CTMBA surface modified steel slag, high temperature activation modified steel slag and formed light porous fly ash block as the mixed materials, PolygonumorientaleL. as the wetland plants. Monitoring the concentration of the pollutants in and out of the water, observing and recording the growth conditions of the PolygonumorientaleL., evaluating the processing efficiency of system. Results showed that:The COD removal rate was slower, which achieved to the highest on the eighth day,61%.8to10days later basically stabilized at50%-60%, and then reduced slightly; the NH4+-N removal rate was faster, which achieved to the highest on the fourth day,55%. Then slowed down, dropped to20days of31%.The growth of the plant was good and designed to be used as wetland plants. In a word, the effect of short-term operation system was remarkable. Moreover, it realized the economic use value of the solid waste as a new type of water material in stead of the traditional media and achieved the purpose that using waste to treat waste. |
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