4种木本植物在潜流人工湿地环境下的适应性与去污效果

为解决冬季植物问题,将4种木本植物引入潜流人工湿地环境,进行植物适应性和去污效果研究,结果表明:(1)4种木本植物在潜流人工湿地环境下的净光合速率日变化规律为夹竹桃、栀子、女贞变化规律是"双峰"型,木槿则是"单峰"型;叶片气孔导度日变化规律为木槿是"单峰"型,其他3个品种没有明显规律;植物胞间CO2浓度的日变化规律与净光合速率日变化规律相反对应关系;蒸腾速率日变化规律为4种植物都呈现"单峰"型规律,且高峰出现在11:00—13:00之间。(2)除女贞外较低外,其余3种植物叶绿素含量较高但差异不大;丙二醛含量较高的是木槿与栀子,女真最低;氮磷积累量最高是夹竹桃,最低的是木槿;基质脲酶活性夹竹桃、木槿高于栀子、女贞,基质磷酸酶活性在4种植物中比较接近。(3)4种木本植物引入湿地后长出了白色的水生根系,且数量多于陆地土壤栽培条件的土培根系;在内部结构上也有较大差异,土培根系的组织非常致密,水生根系则有发达的通气组织。(4)试验期间系统TN平均去除率为40.2%,TP平均去除率为80.8%。COD Cr的平均去除率较低为15.4%,NH+4-N的平均去除率为61.8%,各月份间的差异随着季节温度的变化基本一致。

The adaptability and decontamination effect of four kinds of woody plants in constructed wetland environment

To solve the problem of plant dieback over winter, four kinds of woody plants have been applied to constructed wetland and a series of physiological and biochemical indicators have been measured to analyze the adaptability and decontamination capability of the plants. The results showed that: (1) The diurnal variation of the net photosynthetic rate of oleander, gardenia and privet was of a "Twin Peaks" type, while the hibiscus was "unimodal" type; the diurnal variation of the leaves stomatal conductance of hibiscus was of "unimodal" type while the other three varieties showed no obvious trend. The highest peak time of the four plants was inconsistent and the diurnal variation of CO₂ concentration in the plant cells was contrary to the diurnal variation of the net photosynthetic rate. The diurnal variation of the transpiration rate of the four woody plants was of "unimodal" type with the peak time appearing at 11:00-13:00. (2) The Chlorophyll content of privet is low compared to that of the other three kinds of plants, which are all similarly high. The hibiscus and gardenia had the highest accumulation of malondialdehyde while the ligustrumlucidum contained the lowest accumulation. The nerium oleander had the highest nitrogen and phosphorus content and the hibiscus syriacus had the lowest, related to the biomass. The total phosphorus accumulation of the gardenia was low. The urease activity of the matrix was higher in the oleander and hibiscus than in the gardenia and privet and the activity of matrix phosphatase was approaching in four plants. (3) The change of external morphology and internal structure. External morphology is introduced into wetlands on four kinds of woody plants growing out of the aquatic root system of significantly increased white fibrous root, root number and significantly more land soil cultivation conditions, suggesting that the four kinds of plant root system can adapt to an artificial wetland environment. On the internal structure of four kinds of bacon with a hydroponic plant soil root system have bigger differences in the internal structure. The soil bacon system organization is very dense, but after the introduction of wetland plants, root systems have developed aerenchyma. (4) The research into the decontamination effect of four woody plants in constructed wetland showed that over the whole test, TN removal rate was on average 40.2%. TP removal rate was on average up to 80.8%. The lower average removal rate of COD_Cr was 15.4%, the average removal rate of NH₄⁺-N was 61.8%, and the change between each month usually appears as a change of seasonal temperature change rule. The higher the temperature, the greater the processing efficiency and at low temperatures the treatment effect is poor. Therefore, this research into the four kinds of woody plants can be well applied to the undercurrent of artificial wetland systems.