Studies On Water Consumption Characteristics And Renovating Wastewater Of Landscape Species In City

North cities are plagued by a serious shortage of water resources, but green spaces in city consume a large amount of water resources each year. Due to low awareness of the water consumption law for plants, irrigation management of green spaces is blind which causes huge waste of water resources. The paper analysed the water consumption characteristics of the three greening shrubs and the three aqua-cultured plants on the basis of the summary of water consumption characteristics of the vegetation. The purification effect on experimental wastewater by three plants was also studied. The research method and contents include following aspects:(1)Based on the classical weighing method and using Ligustrum vicaryi, Berberis thunbergii and Euonymus japonicus Thunb as experimental material,a detailed calculation and comparison of records about water requirement throughout the trial period had been done in this paper. Setting 75%-100%,75%-55%,55%-35% and 35%-15% of soil moisture content for the four water gradients. Meanwhile, the real-time of main meteorological factors was observed, and established a correlation model between the result and water consumption.with SPSS ( version18.0).(2) Three aqua-cultured plants Philodenron selloum Koch, Scindapsus aureun and Cenetlla asiatica were chosen for water consumption experiment. Classical weighing method was chosen too.Settting two water level based on the beaker which was used for cultivating plants. The change process of the plants under two water level were discussed along with the water distribution features, also investigated was how the transpiration responsed to dominant environment variables, contributing to the formation of transpiration-environment response model.(3) This paper chose three aqua-cultured plants Philodenron selloum Koch, Scindapsus aureun and Cenetlla asiatica for this experiment. The aqua-cultured technologies of these plants were discussed. The results showed that the three ornamental plants had good purification capacity and adaptability in wastewaterThis paper comes to the following conclusions:(1)The water consumption experiment of Ligustrum vicaryi, Berberis thunber -gii and Euonymus japonicus Thunb show that:Each gradient of water consumption went through a overall law was unimodalities. Meanwhile, from the start of the trial in July to the end of the trial in November, water consumption had also experienced a downward trend after rising. As the trial processed, the result about water consumption of three species under the same soil water content was Ligustrum vicaryi>Euonymus japonicus Thunb>Berberis thunbergii. Water consumption of seedlings and different moisture gradients were positively correlated. There was significant difference between the water consumption of 35%～15% and the other different gradients, while the other different gradients of seedlings was no significant difference. Meanwhile, the real-time of main meteorological factors was observed, and established a correlation model between the result and water consumption. Air temperature and intensity of illumination are the main factors for these 3 shrubs(2)The water consumption experiment of three aqua-cultured plants Philodenron selloum Koch, Scindapsus aureun and Hydrocotyle vulgaris show that: The rules of three kinds of aqua-cultured plants take on"single peak style"in normal water supply in a day, and the peak value appears between ten o'clock and fourteen o'clock. Under the same environment the water consumption of Hydrocotyle vulgaris was the maximum, and then Philodenron selloum Koch, Scindapsus aureun. Through variance analysis,it showed that the water consumption of Philodenron selloum Koch carried out in the 2 water level was significant difference(P<0. 01), but Scindapsus aureun and Hydrocotyle vulgaris were no significant difference(P>0. 01). According to the correlation and regression analysis among the leading meteorological factors that influence water consumption of the aqua-cultured plants, temperature is the key one, intensity of illumination is the second one, and then the relative humidity. Using stepwise regression analysis build the optimization model of the meteorological parameter can predict water consumption of the plants.(3)The experiment of three ornamental plants purifying wastewater showed that the three ornamental plants had good purification capacity and adaptability in wastewater. The removal rates of TP,TN,NH₃^-N,NO₃^--N and CODcr by Philodenron selloum Koch,Scindapsus aureun and Hydrocotyle vulgaris were all higher than the control treatment. Furthermore, the length, the fresh weight and the number of leaves of the three plants were measured during the experimental process. The plant fresh weight can preferably indicate the growth condition and purification effect on aqua-cultured ornamental plants in wastewater. It could be the guide for ecological restoration project in a lake or other water bodies with aqua-cultured ornamental plants.