建设人水和谐的河道生态系统，打造水生态良好、水景观优美、水文化丰富的亲水型宜居城市已成为许多城市的发展目标。目前由于沿黄城市河道缺乏系统性整治，水质整体还不容乐观。为进一步提高和改进现有的河道生态治理技术，　本文建议根据城市河道的水文和污染特性，利用引黄水源，有针对性地构建先进、适用的生态治理模式，以实现沿黄城市河道生态良性维持。　　

图一：喷泉曝气机配合水生植物进行河湖治理

河道生态治理模式

　　河道污染程度可以分为轻度污染、中度污染和重度污染。近年来，沿黄城市对城市河道治理工作逐步重视起来，加之黄河水源的持续补给，之前城市河道存在的黑臭现象基本消失。本文将沿黄城市河道污染程度定性为轻度污染，河道生态治理模式界定为轻度污染河道生态治理模式。根据沿黄城市特别是黄河中下游沿岸城市河道的特点，将沿黄城市轻度污染河道的综合污染指数(CPI)界定为2至4。该类污染河道一般溶解氧较高，COD较低，氮磷略高于《地表水环境质量标准》规定的V类水标准，因此主要采用以水生植物为主的治理模式。该治理模式根据不同的适用环境，分为5类:

　　模式一︰浮水植物，适用于地处郊区，景观效果要求不高的河道;

　　模式二:沉水植物，适用于透明度较高，满足沉水植物种植条件的河道;

　　模式三:生态浮岛，适用于直立驳岸，景观效果要求较高的河道;

　　模式四:挺水植物带，适用于自然驳岸，滨岸带水深小于0.5米的郊区型河　　道;

　　模式五:截留+水生植物，适用于流量较小，常水位低于0.5米的山溪型河道。

　　轻度污染河道中氮的去除主要有两种途径:一是植物的生长、收割;二是依靠附着生长在根区表面上的微生物的硝化、反硝化作用。轻度污染河道中磷的去除则是依靠植物的生长、收割。　

　选择适宜的水生植物

　　选择须根发达、根系较长的水生植物，能够大大扩展水生植物净化河水的空　间，提高其净化能力。生态治理系统选择的植物应该对当地的气候条件和水环境有很好的适应能力，否则难以达到理想的效果，一般优先选用当地或本地区存在　　的植物。不同植物的耐污能力和去污效果不同，生态治理系统应根据不同的污水性质选择不同的水生植物，如果选择不当，可能导致植物死亡或者去污效果较差。另外，植物易发生病虫害，抗病虫害能力直接关系到植物自身的生长与生存，也直接影响其在生态治理系统中的净化效果，所以水生植物要具有抗冻、抗病虫害能力。不同植物种类存在相生相克现象，因此需要注意种间搭配，以避免相克效应。

　　轻度污染河道一般存在3种可能:氮偏高、磷偏高、氮磷同时偏高。　　对于氮偏高的污染河道，宜选择对氮去除能力较强的水生植物。挺水植物可选择千屈菜、再力花、美人蕉、旱伞草等;沉水植物可选择金鱼藻、伊乐藻、殖草等;浮水植物可选择黄花水龙、空心莲子草、聚草等。

　　对于磷偏高的污染河道，宜选择对磷去除能力较强的水生植物。挺水植物可选择千屈菜、水芹、旱伞草、美人蕉等;沉水植物可选择黑藻、苦草、伊乐藻等;　浮水植物可选择黄花水龙、空心莲子草、香菇草等。　对于氮磷同时偏高的污染河道，则宜选择对氮磷吸收能力均较强的水生植物。　　河道生态治理要求水质达到一定标准的同时兼具一定的景观效果，生态浮岛　和浮水植物的设计、安装过程中，在满足容易管理、不易倒伏的前提下，可考虑适当的造型。对于景观效果要求较高的河道，冬季可考虑适当换种耐低温的水生　植物，并适当种植四季常绿的水生植物。

图二：沉水风机配合水生植物进行河湖治理

　　对于流量较小、常水位低于0.5米的河道，可采用模式五进行治理，截留的形式有生态石笼、透水坝等。生态石笼或透水坝具有调蓄上游来水、对下游均衡配水、提高河水溶解氧和透明度、拦截大颗粒的砂粒或悬浮物等功能。下游水生植物宜在平整河床的基础上进行种植，水生植物可采用沉水、浮水或挺水的单一水生植物种植模式，也可采用沉水+浮水、沉水+挺水、浮水+挺水、沉水+浮水+挺水等多种植物组合模式。上游来水经生态石笼或透水坝拦截后均流过水生植物,在水生植物及其根系负载生物膜的吸附吸收作用下，使污染河水得以净化。对于透明度较高的轻度污染河道，优先采用沉水植物恢复水体生态环境;对于自然型河道，优先考虑在滨岸带适当种植挺水植物;对于景观效果要求较高的河道，可优先选用以生态浮岛为主、浮水植物为辅的治理形式;配水型河道选用浮水植物时，浮水植物必须框养，以防被河水冲走。　　

生态治理实施要点

　　覆盖面积:模式一、模式二和模式三中，水生植物种植面积宜为治理河道水域面积的25%至30%。模式四挺水植物带种植面积根据河道具体水深而定。

　　材料要求:浮水植物宜采用竹木或PVC网框，并在网框下部覆盖渔网种植;　生态浮岛材质要求透气性好、耐老化、使用寿命长、机械强度高。

　　宽度要求:浮水植物种植网框总宽度不高于治理河道宽度的1/3;生态浮岛

　　拼装单元宽度不大于1.5米。

　　植物种类要求:浮水植物要求根系泌氧能力强;耐寒、耐热沉水植物混种，

　　各占50%的面积;挺水植物要求生物量大、须根发达、分孽能力强、植株较矮、不易倒伏。

　　植物搭配要求:浮水植物要求四季常绿;挺水植物以常绿水生植物为主，搭

　　配春、夏、秋季开花的种类。

　　模式二中可适当搭配生态浮岛以满足治理河道的景观需求;也可采用物理、化学、生物的手段提高河水透明度后种植沉水植物。

　　模式三可以生态浮岛为主、浮水植物为辅，也可全部采用生态浮岛。

　　模式四可适当搭配浮水植物。

　　模式五中的截留方式可采用生态石笼、透水坝，但必须能耐受洪水冲击;水生植物可采用浮水、挺水或浮水+挺水植物模式，植物覆盖面积为治理水域面积的75%至80%。

河湖生态治理不仅要种植相应的水生植物

　　如果河湖生态治理仅仅种植一些水生植物，放养一些水生动物，效果肯定不太理想!瑞柘环保认为，水生动植物虽然可以帮助我们修复河湖生态，但其生存环境也需要一定的改善!众所周知，水生动植物以溶解氧进行呼吸，若水体溶解氧含量过低，会危及刚种植或放生的水生植物、动物、鱼虾的存活!因此，我们建议各位在治理河湖生态时，不仅要选对水生植物的种类，还要适当的增氧水体增氧设备!以保证水生动植物的生存环境!

图四：河湖治理选用罗茨风机增氧

　　关于水体增氧设备，瑞柘环保推荐大家选用我厂生产销售的喷泉曝气机，或使用罗茨风机与沉水风机配合微纳米曝气盘进行水体增氧!在这三种不同的增氧方式中，喷泉曝气机可选用太阳能等新型能源作为动力!该设备不仅可以增氧，同时在开启时也具有一定景观性!效果如上文图一所示!而沉水风机与罗茨风机需要假设供电系统!**区别是罗茨风机常安装在岸边，需要设置独立的风机房!以保证罗茨风机的正常运转!而沉水风机不需要设置独立的风机房!该设备常常安装在水中!客户可根据自己河湖的周边环境与需求进行选择!

友情提示：在这三种不同的增氧方式中，喷泉曝气机的增氧效果低于罗茨风机与沉水风机!

　　It has become the development goal of many cities to build a river ecosystem with harmonious human and water, and to build a hydrophilic livable city with good water ecology, beautiful water landscape and rich water culture. At present, due to the lack of systematic regulation of urban rivers along the Yellow River, the overall water quality is not optimistic. In order to further improve and improve the existing river ecological treatment technology, this paper suggests that according to the hydrological and pollution characteristics of the urban river, using the water source from the Yellow River, we should build an advanced and applicable ecological treatment mode, so as to realize the benign maintenance of the river ecology along the yellow river.

　　Figure 1: Fountain aerator cooperates with aquatic plants to treat rivers and lakes

　　Figure 1: Fountain aerator cooperates with aquatic plants to treat rivers and lakes

　　River ecological governance mode

　　The degree of river pollution can be divided into mild pollution, moderate pollution and heavy pollution. In recent years, cities along the Yellow River have gradually attached importance to urban river regulation, and the continuous replenishment of the water source of the Yellow River has basically eliminated the black and smelly phenomenon that existed in the urban river before. In this paper, the degree of river pollution along Huangcheng city is characterized as mild pollution, and the river ecological governance model is defined as the ecological governance model of slightly polluted river. According to the characteristics of the rivers in cities along the Yellow River, especially the cities along the middle and lower reaches of the Yellow River, the comprehensive pollution index (CPI) of the slightly polluted rivers in cities along the Yellow River is defined as 2 to 4. Generally, this kind of polluted river has high dissolved oxygen, low COD, and nitrogen and phosphorus slightly higher than the class V water standard specified in the environmental quality standard for surface water. Therefore, the treatment mode based on aquatic plants is mainly adopted. The governance model is divided into five categories according to different applicable environments:

　　Mode 1: floating plants, suitable for rivers located in suburbs with low requirements for landscape effect;

　　Mode 2: submerged plants, suitable for rivers with high transparency and meeting the planting conditions of submerged plants;

　　Mode 3: ecological floating island, which is suitable for rivers with vertical revetments and high requirements for landscape effect;

　　Mode 4: emergent plant zone, suitable for natural revetment, and suburban river channels with water depth less than 0.5m in the coastal zone;

　　Mode 5: interception + aquatic plants, applicable to mountain stream channels with small flow and normal water level lower than 0.5m.

　　There are two main ways to remove nitrogen in slightly polluted rivers: one is plant growth and harvesting; The second is to rely on the nitrification and denitrification of microorganisms attached to the surface of the root zone. The removal of phosphorus in slightly polluted rivers depends on the growth and harvesting of plants.

　　Choose suitable aquatic plants

　　Choosing aquatic plants with developed fibrous roots and long roots can greatly expand the space for aquatic plants to purify river water and improve their purification capacity. The plants selected for the ecological management system should have a good adaptability to the local climatic conditions and water environment, otherwise it is difficult to achieve the desired effect. Generally, local or local plants are preferred. Different plants have different pollution resistance and decontamination effects. The ecological treatment system should select different aquatic plants according to different sewage properties. If the selection is improper, it may lead to plant death or poor decontamination effect. In addition, plants are prone to diseases and pests, and their ability to resist diseases and pests is directly related to their own growth and survival, and also directly affects their purification effect in the ecological management system. Therefore, aquatic plants should have the ability to resist freezing and diseases and pests. Different plant species are mutually exclusive, so it is necessary to pay attention to interspecific collocation to avoid the mutually exclusive effect.

　　There are generally three possibilities for slightly polluted rivers: high nitrogen, high phosphorus, and high nitrogen and phosphorus at the same time. For polluted rivers with high nitrogen, aquatic plants with strong nitrogen removal ability should be selected. The emergent plants can be selected as Lysimachia chelonifera, Zaili flower, Canna, parachute, etc; Submerged plants can choose ceratophyta, Elodea, Agropyron, etc; Floating plants can choose yellow water dragon, hollow lotus seed grass, Jucao, etc.

　　For polluted rivers with high phosphorus, aquatic plants with strong phosphorus removal ability should be selected. For emergent plants, you can choose Lysimachia, cress, parachute, Canna, etc; Submerged plants can choose black algae, bitter grass, Elodea, etc; Floating plants can choose yellow flower water dragon, hollow lotus seed grass, shiitake grass, etc. For polluted rivers with high nitrogen and phosphorus, aquatic plants with strong absorption capacity of nitrogen and phosphorus should be selected. River ecological treatment requires that water quality meet certain standards and have certain landscape effects at the same time. During the design and installation of ecological floating islands and floating plants, on the premise that it is easy to manage and not easy to collapse, appropriate modeling can be considered. For rivers with high requirements for landscape effect, it can be considered to appropriately replace low-temperature tolerant aquatic plants in winter, and appropriately plant perennial aquatic plants.

　　Figure 2: submerged fans cooperate with aquatic plants to harness rivers and lakes

　　Figure 2: submerged fans cooperate with aquatic plants to harness rivers and lakes

　　For rivers with small flow and normal water level lower than 0.5m, mode 5 can be adopted for treatment, and the forms of interception include ecological gabions, permeable dams, etc. The ecological gabion or permeable dam has the functions of regulating and storing the water from the upstream, distributing water evenly to the downstream, improving the dissolved oxygen and transparency of the river water, and intercepting large particles of sand or suspended solids. Downstream aquatic plants should be planted on the basis of leveling the riverbed. Aquatic plants can be planted in a single mode of submerged, floating or emergent water, or in a combination mode of submerged + floating, submerged + emergent, floating + emergent, submerged + floating + emergent and other plants. The water from the upstream flows through aquatic plants after being intercepted by ecological gabions or permeable dams. Under the adsorption and absorption of the biofilm loaded by aquatic plants and their roots, the polluted river water can be purified. For slightly polluted rivers with high transparency, submerged plants are preferred to restore the ecological environment of the water body; For natural rivers, priority should be given to the appropriate planting of emergent plants in the coastal zone; For rivers with high requirements for landscape effect, priority can be given to the treatment form of ecological floating islands, supplemented by floating plants; When floating plants are selected for water distribution rivers, floating plants must be framed to prevent being washed away by the river.

　　Key points of ecological governance implementation

　　Coverage area: in mode 1, mode 2 and mode 3, the planting area of aquatic plants should be 25% to 30% of the water area of the river. The planting area of the emergent plant zone in mode 4 depends on the specific water depth of the river.

　　Material requirements: floating plants should be planted with bamboo or PVC net frames, and the lower part of the net frame should be covered with fishing nets; The material of ecological floating island requires good permeability, aging resistance, long service life and high mechanical strength.

　　Width requirements: the total width of floating plant planting net frame shall not be higher than 1/3 of the width of the river channel; Ecological floating island

　　The width of the assembled unit shall not be greater than 1.5m.

　　Plant species requirements: floating plants require strong oxygen secretion capacity of roots; A mixture of cold and heat-resistant submerged plants,

　　Each accounting for 50% of the area; Emergent plants require large biomass, developed fibrous roots, strong ability to divide iniquity, short plants, and are not easy to collapse.

　　Requirements for plant collocation: floating plants are required to be evergreen all year round; Emergent plants are mainly evergreen aquatic plants, with

　　Species with spring, summer and autumn flowering.

　　In mode 2, ecological floating islands can be appropriately matched to meet the landscape needs of river regulation; Submerged plants can also be planted after physical, chemical and biological means are used to improve the transparency of the river water.

　　Mode 3 can be mainly ecological floating islands, supplemented by floating plants, or all ecological floating islands.

　　Mode 4 can be appropriately matched with floating plants.

　　The interception method in mode 5 can adopt ecological Gabions and permeable dams, but it must be able to withstand the impact of floods; Aquatic plants can adopt the floating, emergent or floating + emergent plant mode, and the plant coverage area is 75% to 80% of the treated water area.

　　Ecological management of rivers and lakes

　　The ecological management of rivers and lakes should not only plant corresponding aquatic plants

　　If the ecological management of rivers and lakes only grows some aquatic plants and raises some aquatic animals, the effect is certainly not ideal! Ruizhe environmental protection believes that although aquatic animals and plants can help us repair the river and lake ecology, their living environment also needs to be improved! As we all know, aquatic animals and plants breathe with dissolved oxygen. If the content of dissolved oxygen in water is too low, it will endanger the survival of newly planted or released aquatic plants, animals, fish and shrimp! Therefore, we suggest that you not only choose the right species of aquatic plants, but also appropriate oxygenation water body oxygenation equipment when managing River and lake ecosystems! To ensure the living environment of aquatic animals and plants!

　　Roots blower is selected to increase oxygen for river and lake treatment

　　Figure 4: Roots blower is selected for oxygenation in river and lake treatment

　　As for the water oxygenation equipment, Ruizhe environmental protection recommends that you choose the fountain aerator produced and sold by our factory, or use Roots fan and submerged fan with micro nano aeration disk to oxygenate the water! In these three different ways of increasing oxygen, the fountain aerator can use new energy such as solar energy as its power! The device can not only increase oxygen, but also have a certain landscape when it is turned on! The effect is shown in Figure 1 above! The submerged fan and Roots fan need a hypothetical power supply system! The only difference is that roots fans are often installed on the bank, and an independent fan room is required! To ensure the normal operation of Roots blower! The submerged fan does not need an independent fan room! This equipment is often installed in water! Customers can choose according to their surrounding environment and needs!

　　Tips: in these three different ways of increasing oxygen, the effect of fountain aerator is lower than that of Roots fan and submerged fan!