人工湿地布水设计等与思考.doc

人工湿地“布水”设计与思考朱伟1 华国芬1 赵联芳1 （1.河海大学 环境科学与工程学院，江苏 南京 210098）摘要：人工湿地污水处理系统是一种经济高效的污水生态处理技术。然而，湿地污水处理技术在性能上仍需有待发展与完善，尤其需要对其处理工艺参数进行不断改进和系统优化。本文针对人工湿地污水处理工程中的“布水”这一技术参数，概括了人工湿地布水的原则和一般设计，探讨了几种常见人工湿地类型的布水和其优缺点.同时通过有关工程实例展示了人工湿地布水设计。关键词：人工湿地；污水处理；布水；设计Design and thinking of water distribution in constructed wetlandWei Zhu, GuoFen Hua &Lianfang ZhaoAbstract: Constructed wetland system for waste water treatment is an important technological mode of economical and high effective ecological treatment of waste water, but it is still necessary to develop and perfect in its performance, and in particular ,to make a continuous improvement and systematic optimization in its technical parameters. In this paper ,the principle and general design on water distribution were summarized ; the merits and defects of water distribution in some common constructed wetland systems were discussed. In the meantime, the relevant engineering examples on water distribution were showedKey words: Constructed wetland; Waste water treatment; water distribution ; design 1.引言人工湿地是20世纪70年代末期发展起来的一种废水生物处理技术，根据污水在湿地中的流动方式不同可将人工湿地系统分为表面流人工湿地、潜流人工湿地和垂直流人工湿地三种类型。在人工湿地中，均匀布水是至关重要的内容，布水是否均匀直接关系到湿地是否能够稳定运行。只有均匀布水，才能够保证同一级处理系统的负荷一致，防止短路流和死区的发生，从而达到理想的处理效果，这是湿地能够正常运行的基本条件之一。不同的水流方式和布水方式有着不同的处理效果，好的布水方式可以提高湿地的处理效率，不理想的布水方式使湿地的效率降低，容易发生短流和堵塞，因此对湿地进行有效布水可以改善湿地处理系统的性能，湿地布水系统的建设对增强湿地的处理能力非常重要。2.人工湿地布水的一般原则人工湿地的附属装置必须保证废水的均匀分布，控制湿地床体水位并收集出水，因此大多数人工湿地附属装置的结构应该以“简单”为原则。基金项目：江苏省自然科学基金项目(No.BK2006710)作者简介：朱伟（1962），男，博士，教授，主要从事污染水体的生态修复技术研究。E-mail：weizhu863126.com *通讯作者，E-mail：huaguofen2005163.com湿地污水传输系统一般包括管线和泵站，水控制结构如分离器、溢流堰和水槽，以及砾石收集装置等。输水系统可以建于湿地外，通过管道输入到湿地；也可以完全建于湿地内。污水向湿地处理系统的输送主要有两种：一种是通过压力管线或重力管线输送；另一种是通过明渠输送。利用水的重力自然流的方案比用泵的方案的要好。3.人工湿地进出水系统的一般设计3.1进出水系统布置人工湿地进水系统的设计应尽量保证配水的均匀性，一般采用多孔管或三角堰等。多孔管设于土壤表面上或埋于土壤表面以下，埋于土壤表面下的缺点是配水调节较为困难。多孔管设于床面上方时，应比床面高出0.5左右，以防床面淤泥和杂草积累而影响配水。同时应定期清理沉淀物和杂草等，保证系统配水的均匀性。系统的进水流量可通过阀门或闸板调节，并采取溢流、分流措施应对突发性的流量变化应有溢流、分流措施。人工湿地出水系统采用沟排、管排、井排等方式，合理的设计应考虑受纳水体的特点、湿地系统的布置及场地的原有条件等因素。为有效地控制湿地水位，一般在填料层底部设穿孔集水管，并设置旋转弯头和控制阀门。对严寒地区，进、出水管的设置须考虑防冻措施，并在系统的必要部位设置控制阀和放空阀。3.2水位控制为了保证湿地的处理效率，需要对湿地的进水水位进行控制，为有效地控制湿地水位，一般在填料层底部设穿孔集水管，并设置旋转弯头和控制阀门。通常，潜流和垂直流人工湿地对水位的控制有几点要求：在系统接纳最大设计流量时，湿地进水端不出现雍水，以防发生表面流；在系统接纳最小设计流量时，出水端不出现填料床面的淹没，以防出现表面流；为了利于植物的生长，床中水面浸没植物根系的深度应尽量均匀，并尽量使水面坡度与底坡基本一致。3.3围堰 处理湿地的围堰设计需要从水力学和地质学角度考虑。设计围堰的目的是使水流在预定的区域内沿预定的渠道布水。为了保证水的流量均匀分布，还可以通过在进水端建一个堰，将湿地分成细小单元，然后在另一个溢流口收集出水来解决问题。下面的设计（见图1）是将整体分割成10个独立的单元，这些单元被安置在10个不同点上，互相不连通。湿地单元的数量可根据实际确定。这种特别的方法在新增单元设计，或是为一个增长迅速的社区设计时非常有用，因为处理湿地单元可根据需要而扩建1。10010堰1010图1堰使水量均匀分布的示意图4.几种常见人工湿地类型的布水4.1表面流人工湿地的布水及进出水装置 表流人工湿地，与自然湿地最为接近，污水在湿地表面流动，水位较浅，多在0.1m0.9m之间。表面流人工湿地处理系统在运行过程中可能出现的最大问题是“沟流”，这会降低湿地的有效处理面积。通过控制底面平整性及植物密度可以防治布水不均，因此对原有的沟渠、道路围堰进行平整可以减少短流。同时，也可以采用类似折板的围堰或横向的深水沟进行重新布水，以达到均匀布水的目的。表面流湿地中的这些横沟可以使水流横向通畅流动，并保持恒定水头，增加停留时间，提高面积效率2。a)最不利情况（短流）b)不利情况（存在死角）c)布水较好d)布水好（布水横沟）图2 不同进水方式下的布水效果图2形象的展示了不同进水方式下的布水效果。进水管渠是向人工湿地中输送污水的装置，布水时应尽量均匀。进水装置还可用于调控流量。进水可靠重力流，也可以靠压力流。重力流布水方式节省能量和运行维护费用，但需要大管径的进水管以减少水头损失。对于布水管，需要在一端设清洗法兰，以便周期去除积存的固体。同时在可能出现气体积累的地方设排气阀。进水方式可采用单点布水、多点布水和溢流堰布水（见图3）。如果湿地进水区较窄或湿地呈狭长形（长宽比很大），可采用单点进水。如果进水区较宽，宜采用多点进水。采用溢流堰进水就是在湿地进水前设一低地，低地出口也即湿地进口可设多个，但需处于同一标高位置，出水口设溢流堰进行均匀布水。b）多点布水a）单点布水c）溢流堰布水图3 不同进水方式示意图湿地出水口设计对均匀布水、控制水位和监控水量水质都是非常重要的。但为降低投资、运行和维护费用，出水口设计应尽可能简单。图4所示为几种常见的出水口形式。第一种为存在死区的单一出口，由于存在死区，水力停留时间缩短。第二种为多出口形式，可有效增加水力停留时间。第三种是在出水口侧设计深水沟，水收集后经出水堰流出。显示后两种出口形式效果较好。出水口大小应考虑传输最大日均流量或最大周均流量，在加上湿地面积上的降雨量。出水口的重要功能之一是控制湿地水位。水位的确定需要考虑植物生长的需要、水力停留时间和湿地单元的维护等因素。c）出水堰图4常见出水口形式b）多出口a）单一出口4.2潜流人工湿地的布水及常见设计 潜流湿地的进水布水系统设计与表面流基本相同，主要目的是均匀布水。一般进水先流经粗砾石填料区，其作用是强化在深度和宽度上的均匀布水2。出水口一般用埋在出水口端粗砾石中的穿孔管集水，然后通过管道排出。出水管口高度可调，以调通过管道排出。出水管口高度可调，以调控水体水位，见图5。可调出水口穿孔管图5潜流湿地出水口控制结构潜流湿地一般要求表面平整，避免存在坡度，即使有坡度也是非常小的坡度，因为坡度会促动水在表面的流动，破坏潜流条件。同时，表面平整对植物移植培养所需的水力淹没条件也很有利。床体底面一般也没有坡度要求，通过调整出水口高度，可形成所需的潜流水力梯度。床深视植物的根系生长深度确定，一般3060cm，但对于特定的低温和植物条件，有的床体深度可达1m。图6和图7是潜流人工湿地的常见布水方式。1的倾斜度多孔的布水管出水口图6潜流人工湿地的布水设计（一） 图6的设计是大型潜流人工湿地上面叠加一个小型的垂直流人工湿地，小型的垂直流人工湿地表面用多孔的布水管均匀布水，水直接下渗入潜流人工湿地，利用潜流的人工湿地的1%的坡度，利用重力流使处理过的水流向出水口。0%坡度进水管太阳能片上层出水管比进水管低5cm阀门出水口图7潜流人工湿地的布水设计（二） 图7的设计是进水管在植物的根部，使污水经过植物的根部进行处理，出水口设两个，上层出水口比进水管低5cm，下层的出水管设在潜流湿地的靠近底部位置，具体视情况而定，此设计的目的是尽量减少潜流人工湿地的死水区，使整个潜流人工湿地都能发挥作用。出水口安装阀门可供调节，使在系统接纳最小设计流量时，出水端不出现填料床面的淹没，以防出现表面流。出水口连接太阳能片，可以利用太阳能加热出水，到达即环保又经济的目的。4.3垂直流人工湿地的布水及常见设计 垂直流湿地的水流情况综合了表流湿地和潜流湿地的特性，水流在基质床中基本上呈由上向下的垂直流，床体处于不饱和状态，氧可通过大气扩散和植物传输进入人工湿地系统。1)简单垂直流人工湿地垂直流人工湿地，水经湿地表面下行，从底部排出3。此系统是较为简单的处理系统，表面布水，垂直向下流，然后底部排出（见图8）。图8垂直人工湿地布水示意图布水系统蓄水池水泵阀 门流量计排水给水管道2)逆向垂直流人工湿地逆向垂直流人工湿地，即水从湿地底面呈推流式上升3。此设计适合寒冷地区的人工湿地，从底部进水可以防止布水管的冻结和爆破（见图9）。图9逆向垂直流人工湿地配水示意图布水系统排水蓄水池水泵阀 门流量计给水管道进水3)复合垂直流人工湿地复合垂直流人工湿地的优点在于它的去氮的效果较好，利用上行池硝化、下行池反硝化作用可以使氮的去除效率较高4。布水设计（见图10），上行池与下行池中间利用高差使水能够均匀分布。图10复合流垂直人工湿地布水示意图（一）下行池上行池布水系统集水管蓄水池水泵阀 门流量计排水给水管道高差垂直流人工湿地处理系统的流程为：经沉淀池预处理的污水首先流入位于第一池填料表面中央的多孔布水管，使进水均匀分布在第一池整个表面上，随后污水垂直向下依次流过第一池填料层。由于整个系统底部有0.5%的倾斜度，污水自流进入第二池底部，并向上经过第二池的填料层，被位于二池表面的H型多孔集水管均匀收集，最后从二池填料底部流出系统该工艺独特的下行流一上行流水流方式有效的解决了其它类型湿地易出现的“短路”现象，而且形成了下行流池好氧、上行流池部分厌氧的复合水处理结构，促进了硝化与反硝化作用，会明显提高系统的脱氮效果5、6(见图11)。一池二池布水管H型多孔集水管二池0.5的倾斜度出水图11复合垂直流人工湿地布水示意图（二）5.工程实例5.1潜流人工湿地改善官厅水库水质工程7工程简介：官厅水库是我国20世纪50年代初期修建的一座大型水库之一，是北京市的一个重要水源地。由于水库上游地区工农业发展迅速，排污量逐年增大，库区水质不断恶化，其主要问题是有机污染和营养物质污染,本工程是利用潜流人工湿地来改善官厅水库水质。工艺流程：人工湿地系统位于河北省怀来县黑土洼村官厅水库旁，设5个面积相等的湿地单元，总面积为200m2，湿地进、出区水位差为 0.16m。芦苇和蒲草混合种植。湿地采用水平潜流结构，连续运行，系统的进水为官厅水库水。在人工湿地之前设有沉淀池，以保证湿地进水中较低的悬浮物含量。这对湿地系统长期的稳定运行很重要。图12是潜流湿地的结构示意。进水区和出水区由砾石构成，出水管的位置可调控，使系统在高、低水位交替运行，以提高去除率。底部的平均坡度为0.8%，0.5mm厚的塑料薄膜防渗，基质分为3层，厚度均为 20cm，下边是粒径为 2.0cm 左右的砾石层，中间是粒径为0.5cm 左右的砂砾层，上边是当地的沙质土壤。最上面设25cm厚的保护高度。图12 官厅水库潜流人工湿地布水示意图进水区出水区水位控制出水井优越性能：潜流人工湿地对微污染的地表水源水有较好的处理效果，对有机物和 NH4+-N 有较高的去除率，即使在冬季寒冷的条件下，对高锰酸盐指数和NH4+-N仍然有相对高的去除率。潜流人工湿地受气候影响相对较小。在寒冷的冬季，对系统的进水口和出水口采取一定的保温措施，潜流人工湿地在冰层的覆盖下可以正常运行。6.结语人工湿地是一种低能耗、高效且与自然界相和谐的污水处理工艺，正受到人们的越来越多地关注。这项技术比较适合我国国情，尤其适用于广大农村、中小城镇、居民小区及城市分散型的污水处理。但是国内对这项技术的研究和应用尚处于起步阶段，有关工艺设计的资料及应用的实例还不多见，尤其是在布水的设计方面更为少见，有待结合我国不同地区的具体情况，深入地开展研究工作，取得适合于不同地区、不同环境气候条件及不同污水特性的实用数据，以促进其在我国适当地区的推广应用。参考文献：1 美克雷格·S·坎贝尔，迈克尔·H·奥格登著 吴晓芙译 湿地与景观 M。中国林业出版设2005(第1版) P1032 尹君，崔玉波编著，人工湿地污水处理技术 M 化学工业出版设 环境能源出版中心 出版发行 2006（第1版）P1743 董婵，崔玉波，余丹，等. 垂直潜流人工湿地污水处理特性J. 工业用水与废水2006,37(5)4 吴振斌，詹德昊，张晟，等.复合垂直流构建湿地的设计方法及净化效果J.武汉大学学报(工学版)，2003,36(1).5 付贵萍，吴振斌，任明迅，等. 垂直流人工湿地系统中水流规律的研究J.环境科学学报2001,21(6).6 贺锋，吴振斌，陶菁，等. 复合垂直流人工湿地污水处理系统硝化与反硝化作用J.环境科学2005,26(1).7 刘红，代明利，欧阳威，等. 潜流人工湿地改善官厅水库水质试验研究 J.中国环境科学 2003,23(5):462466.115（英文版 ） easily blame, to prevent the broken window effect. Supervise the leading cadres to play an exemplary role, take the lead in the strict implementation of the < code > and < rule >, lead to safeguard the solemnity and authority of the party discipline, ensure that the party discipline and the laws and regulations for implementation in place. Throughout the discipline in the daily supervision and management, strengthen supervision and inspection, from the thorough investigation of violations of discipline behavior. Strengthen to key areas, key departments and key projects as well as the masses reflect the concentration of the units and departments for supervision. - strengthening supervision, discipline inspection and supervision of cadres to set an example for compliance with the < code > and < rule > is a man must be hexyl, blacksmith needs its own hardware. Discipline inspection organs as the executor of the party discipline, and supervisor of the defenders, for its supervision must be more strictly, discipline inspection and supervision of cadres to firmly establish the awareness of Party Constitution, sense of discipline and rules consciousness, politics loyalty, sense obey. Action speak Ji Ordinance to set an example of the regulations of the rule of law, strengthen supervision and accept the supervision of the firmness and consciousness, do comply with < > and < >. To firmly establish the discipline must first be disciplined, the supervisor will be subject to the supervision of "concept, and consciously safeguard and implement party compasses party, take the lead in practicing" three strict real strict, so loyal, clean, play. To be good at learning, the Constitution and the < code > as morality, politics and brought to fruition; to implement < >, do not want to, dare not, not with disciplinary ruler to supervision; to discipline a ruler, often the control inspection, and consciously in the ideological red line to draw the row Ming Good accumulation is indeed the bottom line, so that the heart has fear, said to have quit, the line has ended. Attached: indifferent to heart, calmly to the table in our life, there are many unpredictable things will happen, some good, some bad things, we cannot control is powerless to stop, but with time, you will find in life sometimes turns out to be not good, some bad things finally turned out to be a good thing, but then we muddy however did not know, this is the life teach us things. 1, life can be complex, can also be simple. Want simple life of precipitation, to have enough time to reflect, to make Become more perfect. Life is the most important thing is not to win, but the struggle; not to have conquered, but to have fought well. 2, the plain is the background of life. Live a plain life, give up on themselves is not a coward, but the wise answers; not disillusioned after the heart, such as ashes, but experience the storm after the enlightenment; not unrewarding perfunctorily, but calm attitude of life of unrestrained self-confidence. Plain living, there is no noise noisy, no earthly troubles, more did not fill in the discontent of desire, some just a calm, a calm. 3, memory of heart will not good things to erase the, life is a When no movie, pain is a beginning, the struggle is a kind of process, death is a kind of ending. Give up this giving up is the helpless, do not give up the abandoned, do not give up this giving up is ignorance, do not give up should not give up is persistent. 4, a thing figured is heaven, think impassability is hell. Since the living, to live better. Sometimes we because of too narrow-minded, too care around the chores and penny wise and pound foolish, not worth the candle. Some things to attract trouble and worry, completely depends on how we look at and deal with it. Don't always take everything back to things, and don't get into a blind alley, don't want to face, don't be narrow-minded. Poke to care, is a kind of open-minded, a free and easy. 5, I am not afraid of others behind me a knife, I afraid to look back and see stab me, is my intention to treat people; I am not afraid of the truth to tell the best friend, I'm afraid he turned to it as a joke to tell don't 6, when we are in a positive frame of mind, you will find many good things; and when we are in a negative state of mind, you will find many depressed things; life happy and worry, all is you of life attitude, optimistic, good luck; loss of sink, Eritrea company. When you are in adversity, may wish to change a point of view to think everything over to the good Think, because good mentality decided the fate of the! 7, people are tired, rest; heart tired, calm. Grow up, mature, this society read. Tired and sad, squat down, to their a hug. Because the world no one can sympathize with you, have mercy on you. You cry, tears is your own; you pain, no one can understand. Then you only tears to smile. 8, each people have youth,Each youth are a story, the life of the world never gets easier, I want what, wish the world all know, as has been the same; now want anything, for fear that others know, or like to lose the same. 9, the heart move, everything in the world is followed by birth, Rangrang, important thing is often the most difficult to open one's mouth, because words will reduce its importance; to let strangers people care about your life in the good things, the original is not easy 10, do not blame, do not laugh at who, also don't envy who. Like a person is a kind of feeling, not like a person is true. The truth is easy to explain, I feel Is unspeakable. The best travel life is that you in a strange place found a long lost touched. 11, happy life not in the bustling in, and in the peace of mind; no matter how many grievances, how uncomfortable, and ultimately to heal themselves or their own, others may got you to comfort, but never know your heart is how wanjianchuanxin. 12, ma'am, like a movie, learn to appreciate, learn to be grateful, learn tolerance, and goodness, helping others. Instead of accusing the society, as into one; and an exception is better to give than to what 13, don't envy him A sum of, don't lose your life and the life, respectively is: the former is a we experienced cannot escape in a day finally will last minute, while the latter is our persistent, we want to cherish the memory of those people and things. 14, learn to smile, learn to strong, the world you know so many people, so many people and you are, you cannot change also can't let everyone like you, so also do not want to do. Life is too short to go crazy to love to go to waste, to chase the dream to regret. 15, when temper, a blessing to go. A wounding elegant people, the key is to control their own emotions. With the mouth is the most stupid behavior. A control negative emotions than a can take a city more powerful water flow slow, language is expensive. People spent two years of time to learn to speak, but to spend a few years time to shut up. That is a kind of ability, that is a kind of wisdom. 16, life is not perfect, sometimes, growth is not a cry, not an eyeful of tears, there is no trace of emotion, there is no gleam of hope, no desire, no action, no static, there is only one kind of downward sinking feeling, sink A murky? 6? 7? 6? 7 sink? 6? 7? 6? 7 toward the bottom of the sink. 17, in some way, do not go, you will not know the other side scenery is beautiful. To you is not good, you do not mind too much, no one has an obligation to you; you learn knowledge, is you have weapons, you can start from scratch, but not unarmed; how do you treat people, does not represent how others treat you, if cannot see through this point, only inviting worry. 18, time is like a sponge in the water, as long as you are willing to squeeze, the total water is still there. Every life, after the ups and downs The best test of live, to life, survival and continuation, do not stop the struggle in the joys and sorrows of life on the road, so that different soul to bear life beat, acceptance of suffering. 19, indifferent to heart, calmly in table, elegant and comfortable life, do not take what is so important. The pursuit wil