【作者】 徐昌伟；

【导师】 李晔；

【作者基本信息】 武汉理工大学 ， 环境工程， 2005， 硕士

【摘要】 经济的发展离不开矿产资源的开发和利用,据统计,2001年矿业的总产值达5295. 43×108元,占全国工业总产值的5. 31%。与此同时,矿业产生的废水总排放量占了工业废水总量的6. 69%以上,矿业的发展为国民经济的腾飞作出巨大贡献的同时,带来了严重的环保问题。我国的磷矿资源极其丰富,居世界第三位,其贮存量能保证约2000年的需要。近年来,随着国家农业政策的调整及磷肥价格的上涨,磷矿资源的开发和利用进入了一个飞速发展的时期,以P2P5计,年产量己达九百多万吨。我国的磷矿资源多属于贫质胶磷矿,选矿过程中不仅要求磨矿细度高,而且浮选药耗大,废水中溶有残留的多种浮选药剂和固体颗粒悬浮物,是具有稳定性的多相分散体系,其COD、总磷及固体颗粒物等污染物严重超出国家规定的排放标准。许多企业在找不到合适的处理途径时,只好将大量废水直接排入水体之中,导致了附近水域的严重污染。由于矿山企业一般建在郊区,周边农田较多,经常发生由于水污染而引发的一系列健康问题和经济问题。为解决这一矛盾,实现废水的循环利用,本论文着手研究混凝沉淀联合生物膜法处理选磷废水的可行性。首先通过小型混凝沉淀实验寻找最佳的混凝剂并确定其最佳用量,然后在扩大实验中进行曝气生物滤池的深度处理。在此之前,对曝气生物滤池的挂膜条件、污水处理效果的影响因素及其降解基质的动力学模型进行了比较系统的研究。预处理后的废水在最佳工况条件下进入曝气生物滤池进行深度处理,出水不设沉淀池而直接排放,及时监测废水中各污染物的去除效果。通过本文的实验研究可以得出如下结论:FeSO4对高碱性的选磷废水具有非常显著的沉淀效果,在去除废水中CODCr、TP、TSS等污染物方面与Al2(SP4) 3、 Ca(OH)2效果相当,但其用量最少,处理后的废水接近中性,可直接进入曝气生物滤池进行深度处理;以酶促生物填料作为微生物的载体,武钢焦化厂二沉池回流污泥作为接种污泥,采用上流式的运行方式及“闷曝法”可在13天内挂膜成功;废水的pH值、水温、气水比、水力停留时间及废水水质等是影响曝气生物滤池污水处理效果的重要因素,其较佳运行参数为:pH值7. 8,气水比10:1,水力停留时间12h,一定的水温和滤床高度;当水力停留时间在15h以内时,COD的降解速度对COD浓度为一级反应,并建立了BAF的基质降解动力学模型;混凝法与曝气生物滤池联合处理工艺完全可以实现选磷废水的达标排放,出水水质中CODCr、BOD5、 TP、SS浓度分别从375. 6mg/L、69. 0mg/L、986. 4mg/L、11247. 8mg/L降至10. 8mg/L、3. 0mg/L、0. 11mg/L、10. 2mg/L,各项指标均优于国家一级排放标准,为企业创造经济效益的同时,也创造了社会效益。更多还原

【Abstract】 It is necessary that the development and utilization of mineral resources to society economy. An investigation showed that the total production value of mining industries in 2001 was 529.543 billion, which took up 5.31 percentage of the industries’. At the same time, the wastewater came from mining industries took up 6.69 percentage of the total industries’. Mining industry made great contribution to country’ economy on the one hand and brought very serious environmental problem on the other hand.Phosphorite resources are abundant in our country and hold the third place in the world, the reserve is enough to supply for 2000 years’ demand. In recent years, the agriculture policy is regulated and the price of phosphorous ores is rising quickly, which lead to more and more phosphorite resources being exploited, as far as P₂O₅ is concerned, the production has reached 9Mt.Because of the low grade and complicated structure of collophane, the process of floatation needs not only fine degree particles but also quantity of reagent, so the wastewater includes high concentration of SS and chemical reagents, which makes the whole water body a steady collide system. For these reasons, the concentration of COD, TP and SS etc is much higher than the nation discharge standard. Many enterprises has to discharge the wastewater before it was well treated for less of technological resort, which causes serious pollution to the water in the vicinity, therefore, a series of trouble concerning health and economy happens.To solve these problems and recycle the wastewater, feasibility of chemical sedimentation connected biofilm to treat the phosphorite flotation wastewater in the paper is discussed. First we found the optimum coagulant and make sure the optimal dosage in small experiment. And then, A large amount of wastewater is precipitated with chemical coagulant before they are secondarily treated by biological aerated filter, before this, the condition of development of biofilm, the influencing factors to the treatment efficiency and the dynamic model of biological aerated filter have been studied. In these experimental processes, the concentration of contaminants are inspected in time.From the research of this experiment, some conclusions are drew: FeSO₄ is a high efficient coagulant to the alkaline phosphorite flotation wastewater, the effect can compare with the Al₂ （SO₄） 3 and Ca （OH） 2 in removing the COD_cr, TP and SS et though it needs less quantity of dosage, what’s more, the effluent is neutral in pH and can bedirectly treated by biological aerated filter. When the enzymatic carrier is used as the filter bed, the backsludge from the secondary sedimentation tank of coke-oven plant is used as the inoculating sludge together with the way of upflow and closed aeration are used, the biofilm can be developed in 13 days. The experimental results showed that the wastewater quality, temperature, pH, HRT and the ratio of air to water and etc are the very important factors to the efficiency of BAF, the optimum parameters are these: the pH is 7.8, the ratio of air to water is 10 and the HRT is 12h, Besides, a given water temperature and filter height are necessary. When the HRT is less than 15h, the biodegradable velocity of COD is linear relationship to the residual COD concentration, and then, the dynamic model is established. At the last of the experiment, the feasibility of sedimentation and BAF connected to treat the real phosphorite flotation wastewater is testified, the concentration of C0D_cr, BOD₅, TP and SS is reduced from 375.6mg/L, 69.0mg/L, 986.4mg/L, 11247.8mg/L to 10.8mg/L, 3.0mg/L, 0.11mg/L and 10.2mg/L respectively, the effluent quality is superior to the nation discharge standard, so the good economic and social performance are created.更多还原