牛聪, 陈浩天, 李鑫, 王乐宜, 王勇, 张宝莉. 基于磷去除效果的人工湿地中含活性氧化铝复合基质配比优化[J]. 农业工程学报, 2019, 35(17): 240-247. DOI: 10.11975/j.issn.1002-6819.2019.17.029
    引用本文: 牛聪, 陈浩天, 李鑫, 王乐宜, 王勇, 张宝莉. 基于磷去除效果的人工湿地中含活性氧化铝复合基质配比优化[J]. 农业工程学报, 2019, 35(17): 240-247. DOI: 10.11975/j.issn.1002-6819.2019.17.029
    Niu Cong, Chen Haotian, Li Xin, Wang Leyi, Wang Yong, Zhang Baoli. Effect of phosphorus removal from sewage using substrates of activated alumina in constructed wetlands[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(17): 240-247. DOI: 10.11975/j.issn.1002-6819.2019.17.029
    Citation: Niu Cong, Chen Haotian, Li Xin, Wang Leyi, Wang Yong, Zhang Baoli. Effect of phosphorus removal from sewage using substrates of activated alumina in constructed wetlands[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(17): 240-247. DOI: 10.11975/j.issn.1002-6819.2019.17.029

    基于磷去除效果的人工湿地中含活性氧化铝复合基质配比优化

    Effect of phosphorus removal from sewage using substrates of activated alumina in constructed wetlands

    • 摘要: 为探究北方寒冷地区人工湿地中含活性氧化铝基质的除磷效果,研究选用活性氧化铝与常用的钢渣、石灰石和沸石作为基质材料,在同等条件下通过等温吸附和吸附动力学试验选择吸附能力最强的活性氧化铝。考虑基质的孔隙度及对水力停留时间的影响,将活性氧化铝与砂和石灰石按不同粒径及不同体积比例混合构建9种组合基质,以生活污水(平均磷浓度为2.89 mg/L)为处理对象,模拟单级垂直流人工湿地系统进行小试试验,并选取除磷效果较好的同粒径且含活性氧化铝组合基质以探索其在高浓度磷(15.96、38.13和68.22 mg/L)下出水水质达标情况。最后筛选出磷吸附效果最优的含活性氧化铝的组合基质,在多级垂直流人工湿地系统进行中试试验以评价其对污水中高浓度磷(20 mg/L)的去除效果。研究结果表明:1)活性氧化铝对磷的吸附能力最佳,依次为钢渣、石灰石、沸石;2)9种组合基质中75%的活性氧化铝和25%的石灰石组合基质对磷的去除率最高,达93.48%,粒径为3~5 mm且含不同比例活性氧化铝的4种组合基质对磷去除效果较好,将其应用于高浓度磷的污水处理后,出水磷浓度可以达到《北京市水污染物综合排放标准》(DB11/307-2013)中总磷A标准排放限值(0.2 mg/L);3)以75%的活性氧化铝和25%的石灰石构建的组合基质在多级垂直流人工湿地中出水磷浓度均达到A标准排放限值,去除率在94%以上。因此,研究建议以75%的活性氧化铝和25%的石灰石构建组合基质,该含活性氧化铝的基质组合在人工湿地中具有良好的除磷效果和应用价值。

       

      Abstract: Abstract: The eutrophication caused by excess phosphorus (P) in sewage is drawing public attention increasingly. Constructed wetland (CW) is one of the most particularly useful and common ways to recover P from sewage, especially in countryside. The aim of this study was to determine the P adsorption capability of different substrates in CW in cold areas of Northern China. The paper studied four different kinds of substrates including activated alumina, steel slag, limestone and zeolite. The P adsorption kinetics and adsorption isotherms of different substrates were tested on same condition to analyze the adsorption properties of P of different substrates, and made a comparison; Then, we selected the substrate with best adsorption effect and also considered the effect of substrates' porosity on hydraulic residence time to design nine groups with different particle sizes and different volume ratios with other substrates, and carried out small-scale experiments by simulating single-stage vertical-flow constructed wetland (VFCW) to study the P removing effect in domestic sewage of low concentration (1.18-4.39 mg/L) of different combined substrates. And four kinds of combined substrates with better P removal effect were adopted to explore whether the effluent quality met the standard under high concentration of P (15.96, 38.13 and 68.22 mg/L). Finally, the optimal combined substrates for P removal effect was filtrated to evaluate the removal effect of high concentration P about 20 mg/L by the pilot-scale test of multistage VFCW system. Adsorption isotherm and adsorption kinetics tests of four substrates were carried out in the laboratory of China Agricultural University. Small-scale and pilot-scale experiments were conducted in Fangshan district, Beijing, and domestic sewage used in all experiments was collected from a factory, and the designed hydraulic load was 0.3 m3/(m2?d). The results showed that P adsorption characteristics of the four kinds of substrates could be described by the Freundlich model, Langmuir model and adsorption kinetics model commendably. The materials of activated alumina had the strongest adsorption capacity for P, followed by steel slag, limestone, zeolite. After that, nine groups of different combined substrates were applied to vertical-flow test, the removal rate of P of mixed substrates which contained activated alumina was 83.54%-93.48%, and that four substrates with different proportions of active alumina with particle size of 3-5 mm were combined with sand and limestone whose removal efficiency were good for P was 87.36%-93.48%, and their average removal rate was 89.63%, among which the removal rate of P in the combined substrates contained 75% activated alumina and 25% limestone was the highest, up to 93.48%. When the concentration of P in sewage increased to a high level, the P concentration of effluent could meet the A grade in sewage effluent discharge standard, which was 0.2 mg/L in the comprehensive discharge standard for water pollutants of Beijing (DB11/307-2013). Besides, different mixed ratios of substrates could also affect the P removal rate in sewage. No matter what the P concentration in sewage was low or high, the P removal rate of 75% aluminum and 25% limestone was about 94%-99% in pilot-scale VFCW test and the P concentration of effluent sewage was less than 0.2 mg/L, meeting the A grade in sewage effluent discharge standard. Therefore, activated alumina as a kind of substrate had commendable removal effect of P and high application value in CW.

       

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