适合分散性农村生活污水处理的人工湿地高效能脱氮除磷填料的研究与应用

发布时间：2018-03-15 02:20

本文选题：填料改性　切入点：脱氮除磷　出处：《苏州科技学院》2015年硕士论文　论文类型：学位论文

【摘要】：分散性农村生活污水以其分散性及在农村污水排放总量中的大比例,成为太湖流域农村生活污水治理工作的重点和难点。厌氧折流板反应器(ABR)+折流湿地(BFCW)组合工艺具有有机物去除效果好、抗冲击负荷能力强、运行低耗稳定、维护简便、可美化环境等特点,适宜处理太湖流域分散性农村生活污水,但其冬季脱氮除磷效果不够理想,限制了其在太湖沿岸的推广应用。为此,本研究通过改善湿地填料对农村生活污水中磷素和氮素的吸附截留能力,提升湿地氮磷去除效果及稳定性,同时强化ABR的预处理,优化组合工艺的处理效能,以适应更为严格的排放要求。本研究主要内容和结论如下:(1)高效除磷填料的筛选及改性:综合填料对农村生活污水磷素和氮素的吸附性能及填料成本,从10种具有较高磷素饱和吸附量的填料中,筛选出钢渣、沸石和石灰石3种适宜处理分散性生活污水的人工湿地填料,并分别用酸(碱)和盐对3种优选填料进行改性,以增强其吸磷能力。结果表明,钢渣、沸石和石灰石分别经2 mol/L Al Cl3、3 mol/L Na OH及2 mol/L Al Cl3和0.5 mol/L Al Cl3溶液改性后,氮磷吸附性能最佳。填料经铝改性后,氮磷吸附效果普遍优于其他改性条件,且Al-P有利于植物直接吸收利用,含铝废水来源广泛,故推荐使用铝改液作为人工湿地填料改性试剂。(2)ABR反应器预处理效能优化研究:改进构型后,ABR截留SS的能力得到增强。ABR处理效能及氨化效果与其水力条件关系显著,一定范围内,呈现出HRT越短、有机容积负荷(OLR)越高,水力条件越好,效能越好。改进型ABR水力停留时间(HRT)为12h时,处理效能和氨化效果最佳。(3)不同运行条件下BFCW水力效率研究:研究表明,相同水力表面负荷(HLR)下,填料表面越光滑规则,粒径越大,BFCW有效体积比和水力效率越低,这种趋势随着HLR的提升而增强。植物根系导致湿地水力效率降低,湿地填料氮磷吸附能力越强,水力效率下降幅度越低。改性钢渣湿地以其碱性环境,水力条件较为稳定。(4)BFCW处理效能研究:相同HLR下,填料类型对BFCW有机物去除效果无显著影响,湿地对碳氮的去除率基本呈现出随污染物表面负荷的增大,先增加后减小的趋势,除磷呈现出随TP表面负荷的增大而增加的趋势。湿地脱氮除磷效能和抗冲击负荷能力,与填料吸附沉淀性能正相关,脱氮方面:改性沸石沸石陶粒改性钢渣;除磷方面:改性钢渣改性沸石陶粒沸石。植物的种植增强了湿地的处理效能和抗冲击负荷能力,植物湿地夏秋两季碳氮去除效果相近,秋季除磷效果优于夏季,冬季改性沸石湿地脱氮除磷效果未见明显下降,但出水浓度波动加大。当HLR≤305 L·m-2·d-1时,改性沸石湿地出水TN浓度能稳定低于5.0mg/L。改性钢渣湿地脱氮效果与水温有关,水温越高脱氮效果越好,脱氮效果不稳定,改性钢渣未实现目标效果。沸石在实际应用中除磷效果较差,经改性后,展现出良好的脱氮除磷效能及稳定性,为保证改性沸石湿地出水水质长年稳定达标,在实际应用中,推荐将改性沸石湿地的HLR设定在152L·m-2·d-1以下。(5)改性沸石湿地脱氮除磷途径初步研究及对照:研究结果表明,湿地填料对湿地脱氮除磷的影响大于植物种植的影响,植物的泌氧作用对湿地脱氮的贡献大于直接吸收的贡献。中试运行期间,改性沸石湿地氮磷去除量较沸石湿地分别增长1.8%和1倍多。填料氮素截留能力:改性沸石沸石大陶粒小陶粒;磷素截留能力:改性沸石小陶粒沸石大陶粒。流体粒子易于下向流前端形成优先流,故建议在BFCW实际应用中适当缩短下向流隔室流向方向的长度,以0.2~0.3m为宜。改性沸石湿地主要通过填料的吸附截留作用脱氮除磷,以Ca-P为主要沉淀磷素形式,植物的泌氧和吸收作用有助于稳定出水水质。湿地前端和后端分别以填料的吸附截留作用和微生物的硝化反硝化作用为主要脱氮途径。中试试验填料氮磷吸附量远高于静态试验,改性过程对沸石磷素吸附沉淀性能的大幅提升是在多重途径的协同作用下实现的,湿地构型和植物根系的影响是造成相同区域填料氮磷截留量差异的主要原因。填料种类对植物吸收的影响主要体现在植物的生物增量上,填料氮磷吸附性能越差,植物吸收作用对湿地脱氮除磷贡献越大。硝化作用强度的高低是改性沸石湿地脱氮效果及稳定性季节性波动的主因,湿地前端硝化作用强度极低与改性沸石对NH4+-N极强的吸附性能有关。
[Abstract]:A large proportion of decentralized rural sewage dispersion and in rural sewage discharge in the focus and difficulty of rural sewage treatment in Taihu basin. The anaerobic baffled reactor (ABR) + baffled wetland (BFCW) combined process has good removal effect of organic matter, strong anti impact capability and the operation of low energy consumption, convenient maintenance, can beautify the environment, suitable for the treatment of Taihu River Basin of decentralized rural domestic sewage, but the removal effect of nitrogen and phosphorus in winter is not ideal, limits its application in the Taihu coast. Therefore, this study by improving the wetland for phosphorus and nitrogen in rural sewage interception capacity of adsorption and enhance the nitrogen and phosphorus removal effect and stability of wetland, while strengthening ABR pretreatment, treatment efficiency optimization process, to meet the more stringent emission requirements. The main research contents and conclusions are as follows: (1) Screening of high phosphorus filler and filler on modified: comprehensive rural sewage phosphorus and nitrogen adsorption and packing cost, from 10 kinds of high phosphorus saturated adsorption amount of filler, screened slag, zeolite and limestone 3 suitable for the treatment of dispersed domestic wastewater the artificial wetland and filler, respectively acid (alkali) modification of 3 preferred filler and salt, in order to enhance its ability of absorbing phosphorus. The results show that the steel slag, zeolite and limestone respectively by 2 mol/L Al Cl3,3 mol/L Na OH and mol/L Al 2 Cl3 and 0.5 mol/L Al Cl3 solution after modification, adsorption of nitrogen and phosphorus can best filler by aluminum. After modification, the adsorption of nitrogen and phosphorus is better than the other modified conditions, and Al-P is conducive to the direct absorption and utilization, wastewater containing aluminum sources, so it is recommended to use modified aluminum liquid as artificial wetland filler modification reagent. (2) ABR reactor for pretreatment of performance advantages: improved structure After the ABR SS interception ability is enhanced.ABR treatment efficiency and ammoniation effect and hydraulic conditions significantly. Within a certain range, showing a HRT shorter, organic volume load (OLR) is high, the hydraulic condition is better, the better performance. The improved ABR hydraulic retention time (HRT) of 12h, and the treatment efficiency ammonization best. (3) study on the hydraulic efficiency of BFCW under different operating conditions: the study shows that the same hydraulic surface loading (HLR), the surface more smooth, larger particle size, BFCW effective volume ratio and the hydraulic efficiency is lower, this trend increased with the increase of HLR. The roots of plants leads to reduced hydraulic efficiency wetland, nitrogen and phosphorus adsorption ability of wetland fillers is stronger, the hydraulic efficiency decreased. The modified steel slag in the alkaline environment of wetland, the hydraulic condition is relatively stable. (4) study on the effectiveness of BFCW treatment: the same HLR, filler type on BFCW organic matter removal effect Significant effects of wetland on carbon and nitrogen removal rate basically showed increases with the surface load of pollutants, first increased and then decreased, phosphorus removal showed increases of TP surface load trend. Wetland nitrogen and phosphorus removal efficiency and the ability to resist impact load and adsorbted performance is positively related to nitrogen removal. Modified zeolite ceramsite modified steel slag; phosphorus modified steel slag modified zeolite ceramsite zeolite. Plants enhance the treatment efficiency of wetland and wetland plant resistance to impact load, the summer two Ji Tandan removal effect is similar to that of phosphorus removal effect is better than that of summer autumn winter, modified zeolite wetland removal effect of nitrogen and phosphorus were decreased significantly. But the effluent concentration fluctuations increase. When HLR is less than or equal to 305 L - m-2 - D-1, the modified zeolite wetland effluent TN concentration lower than 5.0mg/L. can stabilize the modified steel slag wetland nitrogen removal effect is related to water temperature, water temperature is high nitrogen The better nitrogen removal effect is not stable, the modified steel slag does not achieve the goal and effect. The poor zeolite results in practical application, after modification, show the efficiency and stability of nitrogen and phosphorus removal is good, in order to ensure the modified zeolite wetland effluent quality standard for many years, in the practical application, recommended the modified zeolite wetland HLR set in 152L m-2 D-1. (5) wetland preliminary study on nitrogen and phosphorus removal and control of modified zeolite: the results show that the effects of nitrogen and phosphorus in wetland wetland than plants, plants for direct absorption of oxygen exudation on wetland nitrogen removal contribution is greater than the contribution. During the test run, the modified zeolite wetland nitrogen and phosphorus removal amount of zeolite increased 1.8% and 1 times more wetlands respectively. Nitrogen filler retention capacity: Zeolite modified zeolite ceramsite with little ceramsite; phosphorus retention capacity of modified zeolite ceramsite: small zeolite ceramsite. The fluid particles tend to down flow front formation of preferential flow, it is suggested that appropriate shortened in the practical application of BFCW to the current flow direction of the compartment length should be 0.2~0.3m. The modified zeolite wetland mainly through the adsorption and retention of nitrogen and phosphorus removal, with Ca-P as the main form of phosphorus precipitation, urinary oxygen plant and the absorption contributes to stable water quality. Wetland front and back respectively to the adsorption and interception of nitrification and denitrification and microbial denitrification pathways. As the main test filler of nitrogen and phosphorus adsorption capacity is far higher than the static test, the modified zeolite on phosphorus adsorption sedimentation performance significantly improved is realized synergistic effect of multiple pathways under the influence of wetland configuration and plant roots are mainly caused by the same area filling nitrogen and phosphorus interception differences. Influence of filler type on plant uptake is mainly reflected in the growth of plants Object increment, nitrogen and phosphorus adsorption properties of filler is worse, plants absorb greater effect on wetland with nitrogen and phosphorus removal. The nitrification rate is the main reason of modified zeolite wetland nitrogen removal effect and stability of seasonal fluctuations, the adsorption properties of wetland nitrification intensity is very low and the front end of the modified zeolite to NH4+-N strong.

【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X799.3

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