水平潜流人工湿地脱氮除磷研究进展

总结了水平潜流人工湿地的脱氮除磷机理,分析了进水水质、植物、基质、温度和水力停留时间这5种影响处理效果的主要因素,从不同角度论述了提高脱氮除磷效果所采取的措施,并探讨了水平潜流人工湿地存在的局限性和发展趋势。     

抚仙湖湖滨带复合湿地氮磷去除效果分析

分析了湖滨带复合人工湿地各功能区去除氮磷的效果。沉淀池除氮效果最不明显,在该区内有机氮可能发生矿化作用而转变为氨氮。有植物系统的潜流和表面流区除氮效果较为明显,潜流区对氨氮、硝氮和总氮的平均去除率分别达18%、19.7%和22.6%;表面流区对三者的平均去除率分别达50.4%、35.9%和43.5%。磷的截留主要发生在沉淀池,平均截留率为14.9%。潜流和表面流区除磷效果欠佳。表面流区对总磷不明显,可能是因为湿地运行了近两年,土壤吸附交换达到平衡,影响去除效果。潜流区对磷的截留主要是不溶性磷的吸附和沉积,除磷效果受水力负荷影响较大。     

强化脱氮除磷人工湿地系统设计

设计了一种强化脱氮除磷一体化人工湿地系统,包括表面流人工湿地池以及垂直潜流人工湿地池。表面流人工湿地池内由下到上分别设有第一防渗层、强化脱氮介质层、第一卵石层和第一壤土层;垂直潜流人工湿地池内由下到上分别设有第二防渗层、强化除磷介质层、第二卵石层和第二壤土层。通过构建强化脱氮区与强化除磷区,对低碳氮比且氮磷污染的污水具有较为理想的同步处理效果,出水氮、磷指标可达到GB3838-2002《地表水环境质量标准》IV类标准。     

添加N、P后复合型人工湿地系统的脱氮除磷效果研究

文中介绍了采用向复合型人工湿地系统中添加氮、磷等营养物质,提升湿地系统的污染负荷,研究湿地系统4级组成湿地的脱氮除磷效果。结果表明,在湿地系统总氮、总磷进水浓度提升至4．02mg·L^-1、0．41mg·L^-1,经湿地系统运行52hr后分别下降至1．68mg·L^-1、0．16mg·L^-1,湿地系统对总氮、磷的总去除率分别为58．0％、61．0％。4级不同湿地的脱氮除磷能力不同。二级表面流湿地对总氮的去除贡献最大,一级水平流潜流湿地对总磷的去除贡献最大。湿地系统的脱氮除磷效果与湿地进水污染负荷成正相关．湿地系统进水的污染负荷是影响湿地系统脱氮除磷效率的主要因素。     

人工湿地不同水流方式对生活污水净化的比较

通过小型复合流式人工湿地实验,监测了CODcr、TN、TP、NO3--N、NH4 -N等指标,旨在通过实验,找到处理污水的最佳水流方式.结果表明,垂直流和垂直流搭配对CODCr、TN、NH4 -N去除最好;而潜流和潜流搭配对NO3--N去除最好.人工湿地基质是影响磷的处理效果的主要因素,通过合理的操作方式可以最终从污水中除磷.在复合型人工湿地中延长水力停留时间能增加污染物的去除率.     

AF——人工湿地一生态塘工艺处理养殖废水

采用厌氧生物滤池(AF)—人工湿地—生态塘工艺处理养殖废水。结果表明:AF设置在人工湿地的前端能极大地降低SS的含量,有效预防人工湿地的堵塞。人工湿地采用跌水曝气方式,节约了能源及建设维护费用;采用波式潜流的流态,为氮的去除创造了较好的条件。生态塘设置在波式潜流人工湿地后端,它能强化对氮、磷的处理;工艺对CODCr的去除率约为80.30%,SS去除率约为94.69%,NH3—N去除率约为73.39%,TP的去除率约为86.78%。     

复合潜流人工湿地对北方河流水质的净化效果研究

综合水平流人工湿地和垂直流人工湿地的优点,在山西省沁河干流建设了复合潜流人工湿地,运行及水质检测结果表明:通过合理设计基质(填料)种类及粒径,采用水平流和垂直流结合工艺的复合潜流人工湿地能够克服国内人工湿地普遍除磷能力不足的缺点,取得较好的除磷效果,在冬季运行期也具有较好的效益,适宜用于水量、水质变化不大、对管理要求不高的北方河流微污染治理。     

AF—人工湿地—生态塘工艺处理养殖废水

采用厌氧生物滤池(AF)—人工湿地—生态塘工艺处理养殖废水。结果表明:AF设置在人工湿地的前端能极大地降低SS的含量,有效预防人工湿地的堵塞。人工湿地采用跌水曝气方式,节约了能源及建设维护费用;采用波式潜流的流态,为氮的去除创造了较好的条件。生态塘设置在波式潜流人工湿地后端,它能强化对氮、磷的处理;工艺对CODCr的去除率约为80.30%,SS去除率约为94.69%,NH3—N去除率约为73.39%,TP的去除率约为86.78%。     

基于铁碳物化-生物耦合法的新型湿地填料研究

针对北方人工湿地运行过程中出现的植物生长萎靡、微生物活性低下、脱氮除磷效率不能满足设计要求等问题,研究新型铁碳湿地材料,利用其微电解产生的[Fe2+]和[H]给硝化细菌做电子供体,将硝酸盐氮还原为N2,实现物化-生物耦合脱氮,并在实验室构建不同介质、不同类型的人工湿地,试验中对比了传统填料人工湿地与新型铁碳人工湿地的运行状况。结果表明:进行间歇曝气情况下,采用脱氮除磷功能材料的人工湿地在水力停留时间24 h的情况下对氨氮、总磷、COD的去除效率分别达到89%、76%、67%,均高于传统填料去除效率,尤其是对氨氮;采用脱氮除磷功能材料的人工湿地植物生长良好,表明脱氮除磷功能材料作为新型湿地填料发挥了良好的效果。     

北方多级复合人工湿地水质净化效果分析——以官厅水库黑土洼湿地为例

为系统探究北方低温地区多级复合人工湿地水质净化效果,以官厅水库黑土洼湿地系统示范工程为例,选取2008—2021年共14年水质监测数据,分析了湿地系统整体净化效果,对比分析了稳定塘与人工湿地、表流湿地与潜流湿地净化效果。研究表明：黑土洼湿地对TN、NH₃-N、NO₃-N、TP、溶解性正磷酸盐磷、BOD₅和COD_Mn去除率分别为53%、59%、52%、41%、39%、49%和21%;稳定塘与人工湿地净化效果差别较明显,稳定塘对TP、溶解性正磷酸盐磷去除效果较好,人工湿地对BOD₅、COD_Mn及TN去除效果较好;潜流湿地和表流湿地的净化效果略有差别,相比较,潜流湿地对BOD₅、COD_Mn及TN去除效果较好,对TP去除效果较差。研究结果可为北方低温地区湿地系统建设与运维提供参考。     

太阳能曝气人工垂直潜流湿地去除生活污水氮磷的试验研究

利用芦苇和砾石构建太阳能曝气人工垂直潜流湿地处理生活污水。设定水力负荷400 mm/d,气水比10∶1,当进水氨氮(NH₄-N)、总氮(TN)、溶解性反应磷(SRP)和总磷(TP)平均浓度为5.14,7.56,0.40,0.53 mg/L时,引入太阳能曝气后,各自的平均去除率分别提高24.8%,9.4%,15.7%和11.5%。随着气温下降和进水浓度降低,湿地微生物脱氮除磷能力下降,曝气对改善生活污水氮磷去除作用不显著。对试验系统而言,太阳能曝气湿地基本建设费用是无曝气湿地的2.85倍;但以20 a运行为基础折算出的污水处理费比无曝气湿地仅高0.02元/m³。综上,从污染去除性能和污水长期处理费用来看,太阳能曝气湿地在生活污水处理方面具有较好的技术经济优势。     

潜流湿地对微污染水体中氮磷去除效果的中试研究

以南京水利科学研究院铁心桥试验基地内象目湖微污染水体为对象,研究总氮大于1.0 m3/(m2·d)的高水力负荷条件下,鹅卵石、陶粒、砾石、钢渣、蛭石、碎石和砂子等多种基质和再力花、芦苇、美人蕉及菖蒲等水生植物组合条件下的垂直流湿地和水平潜流湿地对氮磷的去除效果。试验结果表明:进水总氮浓度在0.793~2.662 mg/L时,种植菖蒲,填料从上到下分别为鹅卵石、碎石、粗砂和细砂的垂直潜流湿地单元(20单元)出水总氮平均浓度最低,为0.905 mg/L;总氮、氨氮和硝态氮平均去除率最高,达80.89%,43.06%和46.32%;总氮浓度从Ⅳ类水体提升至Ⅲ类。进水TP浓度在0.035~1.003 mg/L时,20单元总磷平均去除率最高,为30.59%,价格相对便宜的碎石对磷素的去除效果较好。种植菖蒲及填料组合为鹅卵石、碎石、粗砂和细砂的人工湿地处理单元可以应用于饮用水源地原水等微污染水强化处理。     

城市湖泊污水处理的实验分析

以西安市兴庆湖为研究对象,对湖泊的水质进行了水平潜流和自由表面流净化的实验研究,比较了两种湿地的净化效果。在相同的水力负荷、水力停留时间、水深等条件下,分析了两种人工湿地对城市湖泊中的有机物、氮、磷等主要污染物的净化效果,及不同影响因素对系统处理效果的影响,比较了两种人工湿地的优缺点。     

人工湿地生态系统脱氮除磷机理及研究进展

介绍了人工湿地生态系统去除污水中氮磷的机理,并从工艺优化、湿地植物、基质和微生物四个方面系统地阐述了目前人工湿地系统提高氮磷去除率的研究进展情况;通过优化湿地系统设计、湿地植物的筛选、基质的选择和复合、微生物种群的调控等可以有效提高人工湿地的氮磷去除率,提出了当前人工湿地研究中存在的问题和研究方向.     

Analysis of pollutant removal effect usinginnovative ridge-shaped constructed wetland

In this paper,a new type of ridge-shaped constructed wetland which combines surface flow and horizontal subsurface flow was proposed.The proposed wetland had simple structure,low construction and operating cost,less human interference and good pollution removal effect.The combination of surface flow and subsurface flow provided an aerobic and anaerobic alternating environment for the entire wetland.The performance of the proposed wetland was compared with a traditional horizontal subsurface flow wetland.The comparison results showed that the removal rates of BOD(biochemical oxygen demand),TN(total nitrogen),and TP(total phosphorus)in the ridge-shaped wetland increased up to 20.3%,17.0%,and 9.1%,respectively.The proposed wetland structure could be widely applied for treatment of rural and urban domestic sewage pollution or agricultural point and nonpoint source water pollution.     

Enhanced P, N and C removal from domestic wastewater using constructed wetland employing construction solid waste (CSW) as main substrate

Construction solid waste (CSW), an inescapable by-product of the construction and demolition process, was used as main substrate in a four-stage vertical subsurface flow constructed wetland system to improve phosphorus P removal from domestic wastewater. A 'tidal flow' operation was also employed in the treatment system. Under a hydraulic loading rate (HLR) of 0.76 m3/m2 d for 1st and 3rd stage and HLR of 0.04 m3/m2 d for 2nd and 4th stage of the constructed wetland system respectively and tidal flow operation strategy, average removal efficiencies of 99.4% for P, 95.4% for ammoniacal-nitrogen, 56.5% for total nitrogen and 84.5% for total chemical oxygen demand were achieved during the operation period. The CSW-based constructed wetland system presents excellent P removal performance. The adoption of tidal flow strategy creates the aerobic/anoxic condition intermittently in the treatment system. This can achieve better oxygen transfer and hence lead to more complete nitrification and organic matter removal and enhanced denitrification. Overall, the CSW-based tidal flow constructed wetland system holds great promise for enabling high rate removal of P, ammoniacal-nitrogen and organic matter from domestic wastewater, and transforms CSW from a waste into a useful material.     

The role of plant uptake on the removal of organic matter and nutrients in subsurface flow constructed wetlands: a simulation study.

Plants in constructed wetlands have several functions related to the treatment processes. It is generally agreed that nutrient uptake is a minor factor in constructed wetlands treating wastewater compared to the loadings applied. For low loaded systems plant uptake can contribute a significant amount to nutrient removal. The contribution of plant uptake is simulated for different qualities of water to be treated using the multi-component reactive transport module CW2D. CW2D is able to describe the biochemical elimination and transformation processes for organic matter, nitrogen and phosphorus in subsurface flow constructed wetlands. The model for plant uptake implemented describes nutrient uptake coupled to water uptake. Literature values are used to calculate potential water and nutrient uptake rates. For a constructed wetland treating municipal wastewater a potential nutrient uptake of about 1.9% of the influent nitrogen and phosphorus load can be expected. For lower loaded systems the potential uptake is significantly higher, e.g. 46% of the nitrogen load for treatment of greywater. The potential uptake rates could only be simulated for high loaded systems i.e. constructed wetlands treating wastewater. For low loaded systems the nutrient concentrations in the liquid phase were too low to simulate the potential uptake rates using the implemented model for plant uptake.     

表面流人工湿地不同植物及其组合净化污水处理厂尾水研究

为提高表面流人工湿地对低污染水的生态净化效率,对人工湿地中湿生植物的组成进行比选研究,设置8个由不同湿生植物(包括挺水、沉水和浮叶植物)组成的表面流人工湿地,比较其净化尾水氮磷效果。结果表明:挺水植物圆币草(Hydrocotyle verticillata)和大聚藻(Myriophyllum aquaticum)组合的表面流人工湿地净化尾水氮磷效果最好,其人工湿地对TN、NO-3-N和NH3-N的平均去除率分别为68.6%、62.6%和78.2%,对TP和溶解性无机磷(DIP)的平均去除率分别为64.5%和80%。浮叶植物睡莲(Nymphaea L.)人工湿地去除氮磷能力次之,TN、NO-3-N、NH3-N、TP和DIP平均去除率分别为55%、55.2%、63.3%、56.1%和64.7%,体现一定的污染物去除潜力。沉水植物苦草[Vallisneria natans(Lour.)Hara]在与圆币草等共存净化尾水过程中逐渐失去优势种地位。而由黄菖蒲(Iris pseudacorus L.)和再力花(Thalia dealbata)等挺水植物构建的表面流人工湿地,虽然生物量高,但其氮磷去除效果较差,尤其是再力花人工湿地对TN、NO-3-N和NH3-N平均去除率仅在18%~36.2%之间,对TP和DIP平均去除率也分别只有41.5%和38.7%。因此,采用圆币草和大聚藻组合构建的表面流人工湿地能更有效净化污水处理厂尾水中氮磷,对TN的去除尤为高效,能有效提升尾水水质。     

Effect of polyaluminium chloride on phosphorus removal in constructed wetlands treated with swine wastewater

Total phosphorus (TP) removal in aged constructed wetlands poses a challenge, especially when treated with swine wastewater with high concentrations of phosphorus (P). Our earlier studies with anaerobic lagoon swine wastewater treatment in constructed wetlands showed a decline in P removal (45-22%) with increased years of operation. These particular wetlands have been treated with swine wastewater every year since the first application in 1997. Preliminary lab-scale studies were conducted to evaluate the efficiency of polyaluminium chloride (PAC) in the removal of phosphate-P (PO4-P) from swine wastewater. The experimental objective was to increase the phosphorus treatment efficiency in constructed wetland by adding PAC as a precipitating agent. PAC was added by continuous injection to each wetland system at a rate of 3 L day(-1) (1:5 dilution of concentrated PAC). Swine wastewater was added from an anaerobic lagoon to four constructed wetland cells (11m wide x 40m long) at TP loads of 5.4-6.1 kg ha(-1) day(-1) in two experimental periods, September to November of 2008 and 2009. Treatment efficiency of two wetland systems: marsh-pond-marsh (M-P-M) and continuous marsh (CM) was compared. The wetlands were planted with cattails (Typha latifolia L.) and bulrushes (Scirpus americanus). In 2008, PAC treatment showed an increase of 27.5 and 40.8% of TP removal over control in M-P-M and CM respectively. Similar trend was also observed in the following year. PAC as a flocculant and precipitating agent showed potential to enhance TP removal in constructed wetlands treated with swine wastewater.