碳源对反硝化聚磷菌(RC11)磷酸盐代谢的影响

反硝化聚磷微菌由于具有同时脱氮和除磷的特点,能够最大程度的减少碳源需求,为解决生物脱氮除磷工艺的碳源竞争矛盾提供了新的思路和方法。以纯培养方式探讨了外源性碳源、硝酸盐对反硝化聚磷菌(RC11)磷酸盐代谢活动的影响。结果表明,好氧培养时,菌株RC11在外源碳源存在时发生了超量吸磷现象;缺氧培养时,菌株RC11可以利用硝酸盐而非亚硝酸盐作为电子受体进行反硝化聚磷。无外加碳源时,菌株RC11经历厌氧阶段后初期可以利用硝酸盐氧化到亚硝酸盐的过程中产生的能量进行摄磷;但当亚硝酸盐的积累达到高峰时,进入以亚硝酸盐为电子受体的反硝化阶段,由于亚硝酸盐氮不能作为氧分子的替代物进行反硝化除磷,菌株RC11实际上处于一个厌氧环境,会引发释磷;在厌氧条件下菌株RC11具有利用硝酸盐作为电子受体进行反硝化除磷的功能。     

硫铁矿人工湿地对微污染水源的水质净化效果

为进一步提升人工湿地在微污染水源条件下的同步脱氮除磷能力,以硫铁矿作为湿地填料设计构建了人工湿地装置,并采用挂膜法对硫铁矿进行硫自养型反硝化细菌表面负载,在此基础上研究硫铁矿人工湿地对水体中污染物的去除规律和去除机理,并通过高通量基因测序技术分析硫铁矿表面微生物的群落结构。结果显示,从UASB活性污泥中筛选出的硫自养型反硝化菌活性最高,脱氮效果最好;在微污染水源条件下,硫铁矿潜流人工湿地具有较好的同步脱氮除磷能力,在水力停留时间为60 h条件下,其对水体中的化学需氧量(COD_Cr)、氨氮(NH₃-N)、硝态氮(NO₃-N)、总氮(TN)、总磷(TP)的平均去除率分别达到53.5%、60.9%、67.2%、49.2%、46.3%;矿石表面发现菌群群落达到13门以上,变形菌门(Proteobacteria)为矿石表面最为优势的功能微生物菌群,相对丰度比例占45%左右,硫杆菌属(Thiobacillus)为自养反硝化脱氮的主要功能菌属。研究表明,采用硫铁矿作为填料可显著提高人工湿地的脱氮除磷效果,对微污染水体有较好的水质净化效果,以硫源作为反硝化过程的电子供体可以提高低碳源条件下系统的反硝化效果。     

好氧反硝化技术处理水产养殖废水研究进展

好氧反硝化脱氮理论的出现,弥补了传统生物脱氮的不足。文章综述了好氧反硝化技术的研究进展及其在水产养殖污水处理中的应用,分别从微环境、生物化学和酶系统3个方面综述了好氧反硝化细菌作用机理方面的研究;概述了碳源、溶氧、碳氮比等环境因素对好氧反硝化效率的影响;总结了好氧反硝化反应器、固定化细菌以及外加碳源等好氧反硝化技术在水产养殖废水处理中的应用;突显了好氧反硝化在去除硝酸盐氮、从整体上调控氮的优势。好氧反硝化技术在水产养殖废水处理中优势显著,是水产养殖废水处理的有效途径。该技术在实际应用中还存在许多问题,仍需进一步研究。     

复合垂直流人工湿地基质理化性质对nirS和nirK型反硝化菌多样性的影响

采用Illumina高通测序技术,探讨喀斯特地区复合垂直流人工湿地基质理化性质对nirS和nirK型反硝化菌多样性的影响。结果表明,复合垂直流人工湿地中4个池子（即一级垂直流下行池、一级垂直流上行池、二级垂直流下行池、二级垂直流上行池）的基质理化性质存在显著差异。其中,pH在中4个池子中均呈中性,DO呈先下降后升高趋势,下行池的基质电导率EC均比上行池要高;TN、TP含量随着人工湿地梯级呈显著下降趋势,未出现厌氧现象;NO3--N和NH4+-N含量在二级垂直流下行池中大量积累并达到峰值。在AlpHa和Beta多样性分析中,nirS、nirK型两类反硝化细菌丰度随着人工湿地梯级呈先降低后升高的趋势,多样性随人工湿地级数逐渐降低,且下行池丰度多样性显著高于上行池。基质中nirS型反硝化细菌鉴定为5门9属,nirK型为6门14属,变形菌门是nirS、nirK型反硝化菌群的共同优势菌门,相对丰度为55.36%~65.72%、30.06%~45.66%。其中,优势菌属为红杆菌属（Rhodobacter）、脱氯单胞菌属（Dechloromonas）、红假单胞菌属（Rhodopseudomonas）、慢生根瘤菌属（Bradyrhizobium）和氏菌属（Bosea）。红杆菌属和脱氯单胞菌属相对丰度在空间上随着人工湿地级数升高总体呈上升趋势,红假单胞菌属、慢生根瘤菌属和氏菌属在空间上随人工湿地级数升高总体呈下降趋势,此2类优势菌属在空间上存在显著差异（P<0.01）。韦恩图表明nirS型反硝化菌群丰度明显高于nirK型,且各级池中反硝化菌群相似度较高。冗余分析表明基质中nirS和nirK反硝化菌群的构建主要受pH、NH4+-N、DO、TP、TN影响,且nirS型对pH,以及nirK型对NH4+-N的响应更为强烈。综上,本文研究了人工湿地nirS、nirK型反硝化菌多样性特征及其与环境因子的关系,为复合垂直流人工湿地高效脱氮提供理论依据。     

循环水养殖用水中反硝化碳源研究现状

通过硝化作用和反硝化作用可以有效控制循环水养殖系统水中的氧氮、亚硝酸盐和硝酸盐.进行水产养殖用水硝化作用的生物过滤器的研究已经系统而深入,而关于养殖用水反硝化作用的脱氮反应器的研究则并未引起相应的关注.水产养殖用水进行异养反硝化必需添加碳源.在已有的研究中,经常使用的甲醇等有机液体碳源存在添加量不易控制、出水有残留等弊端;可生物降解聚合物被证明是比较理想的水产养殖用水异养反硝化碳源的选择之一;近年来对以养殖活动中产生的残饵和粪便作为异养反硝化内供碳源的研究也引起了广泛的关注.总结了近年来循环水养殖系统异养反硝化不同种类碳源的效率、在实际生产中的可操作性的相关研究进展.     

不同进水硝酸盐浓度和温度下聚己内酯/玉米芯复合固体碳源的反硝化性能探究

以人工高分子聚合物+农业废弃物为复合碳源的反硝化系统兼具高效脱氮和低脱氮成本的优势。进水硝酸盐浓度(INC)和温度(T)是生物反硝化过程的重要影响因素，本研究以质量比为1∶1的聚己内酯(PCL)和玉米芯(CC)为复合碳源构建反硝化系统，设置3种INC和温度，测定了脱氮能效、有机物利用情况、微生物群落结构和功能基因丰度来判定这2个因素对反硝化的影响。实验结果显示，反应器最佳的INC为30 mg/L，60~90 d的平均硝酸盐去除率(NRE)达到99.12%，且无明显亚硝酸盐氮积累；在不同INC下，优势菌门均为变形菌门(Proteobacteria)，其丰度随INC升高而下降，分别为54.46%、39.96%和24.77%；T=25 ℃为最佳温度条件，其功能基因表达量除napA外均最高，后30 d的NRE为99.21%；T=30 ℃和T=25 ℃优势菌门均为变形菌门，丰度分别为55.86%和38.85%，而T=20 ℃的系统中丰度最高的为拟杆菌门(Bacteroidota)(28.87%)；各系统的优势菌属都为红细菌属(Rhodobacter)。各系统产生的短链脂肪酸中，乙酸占比最高且其与丙酸的比值均>1，同时未检出丁酸，有利于反硝化进行。本研究认为，人工高分子聚合物+农业废弃物形式的复合碳源可为海水养殖尾水固相反硝化的工艺优化提供理论依据。     

好氧反硝化细菌YX-6特性及鉴定分析

从对虾池塘筛选得到1株高效的好氧反硝化细菌,命名为YX-6。对该菌生长及反硝化性能间的关系进行研究;同时研究了不同温度、pH、盐度及碳源对该菌生长及反硝化性能的影响。结果表明,该菌反硝化作用主要发生在对数生长期,可将亚硝酸盐氮由10mg/L降至0;该菌最适生长及反硝化温度为30℃;pH值范围为7～9时最适于该菌生长及反硝化性能的发挥。该菌最适盐度范围为0～15;丁二酸钠、乙酸钠为该菌生长及反硝化的最适碳源。通过对YX-6菌株生理生化及16SrRNA分子鉴定,初步鉴定为凝结芽孢杆菌(Bacillus coagulans)。对该菌株亚硝酸还原酶基因进行序列分析,结果表明,该菌含有亚硝酸还原酶nirS基因。     

1株好氧反硝化芽孢杆菌的脱氮特性研究

以具有较强反硝化能力的芽孢杆菌D5为出发菌株,研究了其牛长及好氧脱氮特性.研究结果表明,在高浓度的亚硝酸盐环境下其仍具有相当强的反硝化能力,且碳源为乙酸钠时脱氮能力最强.当碳源浓度0.2 mol/L、温度36℃、初始pH 7.0、溶氧5～7 mg/L时具有最佳的反硝化活性.和已报道的反硝化细菌相比,其具有更强的耐氧能力,同时也具有较高的反硝化速率.     

低C/N驯化生物絮团的自养和异养硝化性能研究

为减少生物絮团培养过程中的碳源添加和溶氧消耗,节约成本,逐步将C/N比值从15降至7.9,进行低C/N驯化培养。在此基础上,对低碳条件下培育的生物絮团在无外加碳源和碳源充足时的氮去除、NO_2~--N积累、碱度消耗等情况进行了研究,综合评价其自养硝化(autotrophic nitrification,AN)和异养硝化-好氧反硝化(heterotrophic nitrification-aerobic denitrification,HN-AD)效能。结果表明,低C/N驯化的生物絮团具有较高的AN活性和HN-AD活性,对NH_4~+-N去除率分别达97.10%和100.00%。氨氧化过程为AN的限速步骤,比氨氧化速率为13.17 mg·(g VSS·d)~(-1),小于比亚硝酸盐氧化速率[29.20 mg·(g VSS·d)~(-1)],HN-AD的比氨氧化速率达40.28 mg·(g VSS·d)~(-1),约为AN过程的3倍。由于同步硝化反硝化的存在,HN-AD的碱度消耗(3.34 g碱度·g~(-1)NH_4~+-N,以Ca CO_3计)小于AN(4.30 g碱度·g~(-1)NH_4~+-N),且HN-AD的TIN去除率达53.69%。HN-AD的NO_2~--N积累较多,最多达2.62 mg·L~(-1),积累率为46.37%,AN的NO_2~--N最高仅0.47 mg·L~(-1),积累率为3.31%。研究结果可为生物絮团定向驯化及其在水产养殖水处理中的应用提供理论参考。     

玉米芯强化生物反应器对罗非鱼循环养殖废水脱氮效果研究

研究了以玉米芯同时作为反硝化碳源和生物膜载体的人工强化生物反应器对罗非鱼(Oreochromis spp.)循环养殖废水的脱氮效果,并对新型反应器脱氮微生物多样性进行了分析。结果表明,实验室条件下,人工强化挂膜方式可明显缩短装置的启动时间,新型脱氮装置具有良好的脱氮效果,氨氮可从(8.00±2.22)mg·L~(-1)降至3.50 mg·L~(-1),硝酸盐可从(31.50±1.57)mg·L~(-1)降至0.5 mg·L~(-1),较好地实现了高溶氧养殖废水的同步硝化反硝化作用,总氮去除率达85%以上。微生物群落结构分析表明,人工富集培养的硝化菌和反硝化菌均较为成功,随着装置运行时间的延长,玉米芯表面生物膜菌群也随之发生变化,参与脱氮的硝化细菌菌属主要由亚硝酸螺菌属(Nitrosospira)、亚硝酸单胞菌属(Nitrosomonas)、亚硝酸球菌属(Nitrosococcus)3个属组成;丰度最大的反硝化菌属为产碱菌属(Alcaligenes)、副球菌属(Paracoccus)、假单胞菌属(Pseudomonas)和脱氮硫杆菌(Thiobacillus denitrificans)。     

海水养殖尾水人工湿地处理系统及其脱氮过程研究进展和展望

利用人工湿地处理海水养殖尾水具有很大的应用前景，其中，脱氮是人工湿地的主要任务之一。基质上栽培的植物和附着的微生物参与的氮循环是人工湿地生物脱氮的主要路径，植物和多种氮代谢菌群在人工湿地内部相互协同与制约，构成了一个复杂的氮代谢网络。海水养殖尾水的高盐度和低碳氮比(C/N)又决定了此类人工湿地独特的处理环境和生物脱氮机制。同时，人工湿地的供氧模式、水力负荷(HRT)、水力停留时间(HLR)等水力条件参数对脱氮效能也有很大影响，对这些指标进行调控和优化，可以提高湿地的整体脱氮性能。本文从海水人工湿地的构建、基质的选取、耐盐植物的筛选、氮循环相关微生物以及运行参数调控四个方面，对近年来海水养殖尾水人工湿地生物脱氮方面的研究进展进行了综述和展望，以期为深入理解海水人工湿地脱氮机制和优化运行方式提供参考。     

Denitrification in recirculating systems: Theory and applications

Profitability of recirculating systems depends in part on the ability to manage nutrient wastes. Nitrogenous wastes in these systems can be eliminated through nitrifying and denitrifying biofilters. While nitrifying filters are incorporated in most recirculating systems according to well-established protocols, denitrifying filters are still under development. By means of denitrification, oxidized inorganic nitrogen compounds, such as nitrite and nitrate are reduced to elemental nitrogen (N₂). The process is conducted by facultative anaerobic microorganisms with electron donors derived from either organic (heterotrophic denitrification) or inorganic sources (autotrophic denitrification). In recirculating systems and traditional wastewater treatment plants, heterotrophic denitrification often is applied using external electron and carbon donors (e.g. carbohydrates, organic alcohols) or endogenous organic donors originating from the waste. In addition to nitrate removal, denitrifying organisms are associated with other processes relevant to water quality control in aquaculture systems. Denitrification raises the alkalinity and, hence, replenishes some of the inorganic carbon lost through nitrification. Organic carbon discharge from recirculating systems is reduced when endogenous carbon sources originating from the fish waste are used to fuel denitrification. In addition to the carbon cycle, denitrifiers also are associated with sulfur and phosphorus cycles in recirculating systems. Orthophosphate uptake by some denitrifiers takes place in excess of their metabolic requirements and may result in a considerable reduction of orthophosphate from the culture water. Finally, autotrophic denitrifiers may prevent the accumulation of toxic sulfide resulting from sulfate reduction in marine recirculating systems. Information on nitrate removal in recirculating systems is limited to studies with small-scale experimental systems. Packed bed reactors supplemented with external carbon sources are used most widely for nitrate removal in these systems. Although studies on the application of denitrification in freshwater and marine recirculating systems were initiated some thirty years ago, a unifying concept for the design and operation of denitrifying biofilters in recirculating systems is lacking.     

Activated sludge denitrification in marine recirculating aquaculture system effluent using external and internal carbon sources

Stringent environmental legislation in Europe, especially in the Baltic Sea area, limits the discharge of nutrients to natural water bodies, limiting the aquaculture production in the region. Therefore, cost-efficient end-of-pipe treatment technologies to reduce nitrogen (N) discharge are required for the sustainable growth of marine land-based RAS. The following study examined the potential of fed batch reactors (FBR) in treating saline RAS effluents, aiming to define optimal operational conditions and evaluate the activated sludge denitrification capacity using external (acetate, propionate and ethanol) and internal carbon sources (RAS fish organic waste (FOW) and RAS fermented fish organic waste (FFOW)). The results show that between the evaluated operation cycle times (2, 4, and 6 h), the highest nitrate/nitrite removal rate was achieved at an operation cycle time of 2 h (corresponding to a hydraulic retention time of 2.5 h) when acetate was used as a carbon source. The specific denitrification rates were 98.7 ± 3.4 mg NO₃⁻-N/(h g biomass) and 93.2 ± 13.6 mg NO_x⁻-N/(h g biomass), with a resulting volumetric denitrification capacity of 1.20 kg NO₃⁻-N/(m³ reactor d). The usage of external and internal carbon sources at an operation cycle time of 4 h demonstrated that acetate had the highest nitrate removal rate (57.6 ± 6.6 mg N/(h g biomass)), followed by propionate (37.5 ± 6.3 mg NO₃⁻-N/(h g biomass)), ethanol (25.5 ± 6.0 mg NO₃⁻-N/(h g biomass)) and internal carbon sources (7.7 ± 1.6–14.1 ± 2.2 mg NO₃⁻-N/(h g biomass)). No TAN (Total Ammonia Nitrogen) or PO₄^3- accumulation was observed in the effluent when using the external carbon sources, while 0.9 ± 0.5 mg TAN/L and 3.9 ± 1.5 mg PO₄^3--P/L was found in the effluent when using the FOW, and 8.1±0.7 mg TAN/L and 7.3 ± 0.9 mg PO₄^3--P/L when using FFOW. Average sulfide concentrations varied between 0.002 and 0.008 mg S^2-/L when using the acetate, propionate and FOW, while using ethanol resulted in the accumulation of sulfide (0.26 ± 0.17 mg S^2-/L). Altogether, it was demonstrated that FBR has a great potential for end-of-pipe denitrification in marine land-based RAS, with a reliable operation and a reduced reactor volume as compared to the other available technologies. Using acetate, the required reactor volume is less than half of what is needed for other evaluated carbon sources, due to the higher denitrification rate achieved. Additionally, combined use of both internal and external carbon sources would further reduce the operational carbon cost.     

Comparing denitrification rates and carbon sources in commercial scale upflow denitrification biological filters in aquaculture

Aerobic biological filtration systems employing nitrifying bacteria to remediate excess ammonia and nitrite concentrations are common components of recirculating aquaculture systems (RAS). However, significant water exchange may still be necessary to reduce nitrate concentrations to acceptable levels unless denitrification systems are included in the RAS design. This study evaluated the design of a full scale denitrification reactor in a commercial culture RAS application. Four carbon sources were evaluated including methanol, acetic acid, molasses and Cerelose™, a hydrolyzed starch, to determine their applicability under commercial culture conditions and to determine if any of these carbon sources encouraged the production of two common “off-flavor” compounds, 2-methyisoborneol (MIB) or geosmin. The denitrification design consisted of a 1.89 m³ covered conical bottom polyethylene tank containing 1.0 m³ media through which water up-flowed at a rate of 10 lpm. A commercial aquaculture system housing 6 metric tonnes of Siberian sturgeon was used to generate nitrate through nitrification in a moving bed biological filter. All four carbon sources were able to effectively reduce nitrate to near zero concentrations from influent concentrations ranging from 11 to 57 mg/l NO₃–N, and the maximum daily denitrification rate was 670–680 g nitrogen removed/m³ media/day, regardless of the carbon source. Although nitrite production was not a problem once the reactors achieved a constant effluent nitrate, ammonia production was a significant problem for units fed molasses and to a less extent Cerelose™. Maximum measured ammonia concentrations in the reactor effluents for methanol, vinegar, Cerelose™ and molasses were 1.62 ± 0.10, 2.83 ± 0.17, 4.55 ± 0.45 and 5.25 ± 1.26 mg/l NH₃–N, respectively. Turbidity production was significantly increased in reactors fed molasses and to a less extent Cerelose™. Concentrations of geosmin and MIB were not significantly increased in any of the denitrification reactors, regardless of carbon source. Because of its very low cost compared to the other sources tested, molasses may be an attractive carbon source for denitrification if issues of ammonia production, turbidity and foaming can be resolved.     

A novel approach to denitrification processes in a zero-discharge recirculating system for small-scale urban aquaculture

This paper presents an innovative process to solve the nitrate build-up problem in recirculating aquaculture systems (RAS). The novel aspects of the process lie in a denitrification bioreactor system that uses solid cotton wool as the primary carbon source and a unique degassing chamber. In the latter, the water is physically stripped of dissolved gaseous O₂ (by means of a Venturi vacuum tube), and the subsequent denitrification becomes more efficient due to elimination of the problems of oxygen inhibition of denitrification and aerobic consumption of cotton wool. The cotton wool medium also serves as a physical barrier that traps organic particles, which, in turn, act as an additional carbon source for denitrification. Operation in the proposed system gives an extremely low C/N ratio of 0.82 g of cotton wool/g of nitrate N, which contributes to a significant reduction of biofilter volume. The additional advantage of using solid cotton wool as the carbon source is that it does not release organic residuals into the liquid to be recycled. Operation of the system over a long period consistently produced effluents with low nitrate levels (below 10 mg N/l), and there was only a very small need to replace system water. The overall treatment scheme, also incorporating an aerobic nitrification biofilter and a granular filtration device, produced water of excellent quality, i.e., with near-zero levels of nitrite and ammonia, a sufficiently high pH for aquaculture, and low turbidity. The proposed system thus provides a solution for sustainable small-scale, urban aquaculture operation with a very high recovery of water (over 99%) and minimal waste disposal.     

聚己内酯添加量对淡水养殖水体硝酸盐氮处理效果的影响

以可生物降解聚合物(Biological degradable polymers,BDPs)为有机碳源进行异养反硝化可以避免多次添加碳源、碳源不足或过量等问题。聚己内酯(Polycaprolactone,PCL)已被证明能够作为水产养殖用水异养反硝化的有机碳源。研究了聚己内酯添加量对水产养殖用水硝酸盐氮去除效率的影响。在进水硝酸盐氮(NO_3~--N)负荷为0.1 g/(L·d)条件下,200 m L水体中分别加入5 g、10 g、15 g、20 g、25 g和30 g的PCL颗粒进行反硝化,各组的NO_3~--N去除效率没有明显差异;出水中溶解有机碳的质量浓度随着PCL添加量的增加而增加;5 g组的PCL利用率明显高于其他组。结果显示:试验条件下,PCL添加量的增加并不会必然增加NO_3~--N的去除效率,反而会造成出水中溶解有机碳的增加;添加5 g PCL为最适添加量。     

基于CNKI数据库的人工湿地文献计量分析

人工湿地是污水处理过程中重要的生态技术之一。了解人工湿地的发展过程和研究热点对于今后人工湿地的研究工作具有重要意义。本文使用文献计量学方法,自CNKI数据库采集数据,通过Citespace软件,从刊文数量、机构、主要作者、研究热点等方面对人工湿地研究进行可视化分析。结果表明：1987-2019年我国人工湿地的研究可以分为三个阶段,分别为起步阶段1987-2000年、快速发展阶段2001-2010年、稳定发展阶段2011-2019年。国家自然科学基金委是人工湿地研究的主要基金提供者,同济大学、东南大学和中国科学院水生生物研究所是发文量最多的学术机构,吴振斌等10名学者发表文章数占总发文量的5.5%,国内各机构及学者之间均有较为紧密的联系,研究热点体现在处理河流和污水处理厂尾水、工艺组合、植物耐寒和根系研究、发掘新兴基质等。本文提出了今后的研究方向为人工湿地生物膜理论的丰富、堵塞和冬季高效运行技术的工程化应用、人工湿地设计和运行管理维护的标准化等。     

The composition of readily available carbon sources produced by fermentation of fish faeces is affected by dietary protein:energy ratios

Fish solid waste (faeces) produced in recirculated aquaculture systems (RAS) might be used for on-farm, single-sludge denitrification if transformed into soluble organic carbon substances. The current study investigated the effect of feeding diets with increasing protein to energy ratios (P:E_15, 17, 19, 21 and 23 g/MJ) to rainbow trout (Oncorhynchus mykiss) on the production of volatile fatty acids (VFAs) and ethanol during 7 days fermentation of the produced fish faeces. The total yields of VFAs and ethanol obtained (expressed as chemical oxygen demand (COD)) ranged between 0.21–0.24 gCOD/gTCOD, showing no differences between treatments. However, the type and quantities of individual VFAs and ethanol changed according to the dietary treatment. Lower P:E ratio diets resulted in higher production of butyric acid and ethanol, whereas higher P:E ratio diets resulted in an increased production of acetic and valeric acid. Changing the diet composition thus affects the composition of readily available carbon that can be derived from the faeces. This can be applied to enhance on-farm single sludge denitrification and reduce the need for adding external carbon sources such as e.g. methanol.     

复合池塘养殖系统湿地水质净化功能研究

由潜流和表面流湿地组成复合人工湿地,与池塘有机结合构成鱼塘-湿地水循环系统应用于草鱼苗种培育,研究了该系统对池塘水质的改善效果。结果显示:在760 mm/d的水力负荷率条件下,复合湿地系统对NH4+-N、NO2--N、NO3--N、TN、TP、COD和TSS的平均去除率分别为(33.56±3.71)%、(50.73±3.95)%、(46.33±4.95)%、(27.99±2.78)%、(58.15±3.38)%、(29.60±2.24)%和(84.49±1.77)%;湿地出水水质符合渔业水质标准(GB11607-89)要求。结果表明鱼塘-湿地水循环系统对养殖用水具有较好的净化效果。