建設人水和諧的河道生態系統，打造水生態良好、水景觀優美、水文化豐富的親水型宜居城市已成為許多城市的發展目標。目前由于沿黃城市河道缺乏系統性整治，水質整體還不容樂觀。為進一步提高和改進現有的河道生態治理技術，　本文建議根據城市河道的水文和污染特性，利用引黃水源，有針對性地構建先進、適用的生態治理模式，以實現沿黃城市河道生態良性維持。　　

圖一：噴泉曝氣機配合水生植物進行河湖治理

河道生態治理模式

　　河道污染程度可以分為輕度污染、中度污染和重度污染。近年來，沿黃城市對城市河道治理工作逐步重視起來，加之黃河水源的持續補給，之前城市河道存在的黑臭現象基本消失。本文將沿黃城市河道污染程度定性為輕度污染，河道生態治理模式界定為輕度污染河道生態治理模式。根據沿黃城市特別是黃河中下游沿岸城市河道的特點，將沿黃城市輕度污染河道的綜合污染指數(CPI)界定為2至4。該類污染河道一般溶解氧較高，COD較低，氮磷略高于《地表水環境質量標準》規定的V類水標準，因此主要采用以水生植物為主的治理模式。該治理模式根據不同的適用環境，分為5類:

　　模式一︰浮水植物，適用于地處郊區，景觀效果要求不高的河道;

　　模式二:沉水植物，適用于透明度較高，滿足沉水植物種植條件的河道;

　　模式三:生態浮島，適用于直立駁岸，景觀效果要求較高的河道;

　　模式四:挺水植物帶，適用于自然駁岸，濱岸帶水深小于0.5米的郊區型河　　道;

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

　　輕度污染河道中氮的去除主要有兩種途徑:一是植物的生長、收割;二是依靠附著生長在根區表面上的微生物的硝化、反硝化作用。輕度污染河道中磷的去除則是依靠植物的生長、收割。　

　選擇適宜的水生植物

　　選擇須根發達、根系較長的水生植物，能夠大大擴展水生植物凈化河水的空　間，提高其凈化能力。生態治理系統選擇的植物應該對當地的氣候條件和水環境有很好的適應能力，否則難以達到理想的效果，一般優先選用當地或本地區存在　　的植物。不同植物的耐污能力和去污效果不同，生態治理系統應根據不同的污水性質選擇不同的水生植物，如果選擇不當，可能導致植物死亡或者去污效果較差。另外，植物易發生病蟲害，抗病蟲害能力直接關系到植物自身的生長與生存，也直接影響其在生態治理系統中的凈化效果，所以水生植物要具有抗凍、抗病蟲害能力。不同植物種類存在相生相克現象，因此需要注意種間搭配，以避免相克效應。

　　輕度污染河道一般存在3種可能:氮偏高、磷偏高、氮磷同時偏高。　　對于氮偏高的污染河道，宜選擇對氮去除能力較強的水生植物。挺水植物可選擇千屈菜、再力花、美人蕉、旱傘草等;沉水植物可選擇金魚藻、伊樂藻、殖草等;浮水植物可選擇黃花水龍、空心蓮子草、聚草等。

　　對于磷偏高的污染河道，宜選擇對磷去除能力較強的水生植物。挺水植物可選擇千屈菜、水芹、旱傘草、美人蕉等;沉水植物可選擇黑藻、苦草、伊樂藻等;　浮水植物可選擇黃花水龍、空心蓮子草、香菇草等。　對于氮磷同時偏高的污染河道，則宜選擇對氮磷吸收能力均較強的水生植物。　　河道生態治理要求水質達到一定標準的同時兼具一定的景觀效果，生態浮島　和浮水植物的設計、安裝過程中，在滿足容易管理、不易倒伏的前提下，可考慮適當的造型。對于景觀效果要求較高的河道，冬季可考慮適當換種耐低溫的水生　植物，并適當種植四季常綠的水生植物。

圖二：沉水風機配合水生植物進行河湖治理

　　對于流量較小、常水位低于0.5米的河道，可采用模式五進行治理，截留的形式有生態石籠、透水壩等。生態石籠或透水壩具有調蓄上游來水、對下游均衡配水、提高河水溶解氧和透明度、攔截大顆粒的砂粒或懸浮物等功能。下游水生植物宜在平整河床的基礎上進行種植，水生植物可采用沉水、浮水或挺水的單一水生植物種植模式，也可采用沉水+浮水、沉水+挺水、浮水+挺水、沉水+浮水+挺水等多種植物組合模式。上游來水經生態石籠或透水壩攔截后均流過水生植物,在水生植物及其根系負載生物膜的吸附吸收作用下，使污染河水得以凈化。對于透明度較高的輕度污染河道，優先采用沉水植物恢復水體生態環境;對于自然型河道，優先考慮在濱岸帶適當種植挺水植物;對于景觀效果要求較高的河道，可優先選用以生態浮島為主、浮水植物為輔的治理形式;配水型河道選用浮水植物時，浮水植物必須框養，以防被河水沖走。　　

生態治理實施要點

　　覆蓋面積:模式一、模式二和模式三中，水生植物種植面積宜為治理河道水域面積的25%至30%。模式四挺水植物帶種植面積根據河道具體水深而定。

　　材料要求:浮水植物宜采用竹木或PVC網框，并在網框下部覆蓋漁網種植;　生態浮島材質要求透氣性好、耐老化、使用壽命長、機械強度高。

　　寬度要求:浮水植物種植網框總寬度不高于治理河道寬度的1/3;生態浮島

　　拼裝單元寬度不大于1.5米。

　　植物種類要求:浮水植物要求根系泌氧能力強;耐寒、耐熱沉水植物混種，

　　各占50%的面積;挺水植物要求生物量大、須根發達、分孽能力強、植株較矮、不易倒伏。

　　植物搭配要求:浮水植物要求四季常綠;挺水植物以常綠水生植物為主，搭

　　配春、夏、秋季開花的種類。

　　模式二中可適當搭配生態浮島以滿足治理河道的景觀需求;也可采用物理、化學、生物的手段提高河水透明度后種植沉水植物。

　　模式三可以生態浮島為主、浮水植物為輔，也可全部采用生態浮島。

　　模式四可適當搭配浮水植物。

　　模式五中的截留方式可采用生態石籠、透水壩，但必須能耐受洪水沖擊;水生植物可采用浮水、挺水或浮水+挺水植物模式，植物覆蓋面積為治理水域面積的75%至80%。

河湖生態治理不僅要種植相應的水生植物

　　如果河湖生態治理僅僅種植一些水生植物，放養一些水生動物，效果肯定不太理想!瑞柘環保認為，水生動植物雖然可以幫助我們修復河湖生態，但其生存環境也需要一定的改善!眾所周知，水生動植物以溶解氧進行呼吸，若水體溶解氧含量過低，會危及剛種植或放生的水生植物、動物、魚蝦的存活!因此，我們建議各位在治理河湖生態時，不僅要選對水生植物的種類，還要適當的增氧水體增氧設備!以保證水生動植物的生存環境!

圖四：河湖治理選用羅茨風機增氧

　　關于水體增氧設備，瑞柘環保推薦大家選用我廠生產銷售的噴泉曝氣機，或使用羅茨風機與沉水風機配合微納米曝氣盤進行水體增氧!在這三種不同的增氧方式中，噴泉曝氣機可選用太陽能等新型能源作為動力!該設備不僅可以增氧，同時在開啟時也具有一定景觀性!效果如上文圖一所示!而沉水風機與羅茨風機需要假設供電系統!**區別是羅茨風機常安裝在岸邊，需要設置獨立的風機房!以保證羅茨風機的正常運轉!而沉水風機不需要設置獨立的風機房!該設備常常安裝在水中!客戶可根據自己河湖的周邊環境與需求進行選擇!

友情提示：在這三種不同的增氧方式中，噴泉曝氣機的增氧效果低于羅茨風機與沉水風機!

　　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!