Ecological Remediation Technology of Urban Landscape Water Body

Urban landscape water body is not only an important part of urban landscape construction,but also an important way to maintain landscape diversity and biodiversity,carrying the beautiful yearning of urban residents for natural life.A good state of urban landscape water body is crucial to the ecological environment of the city.However,due to the poor kinetic energy of urban landscape water body and the influence of various human factors,the quality of urban landscape water body often declines,and urban population is threatened by water security problems.Through the study of several water body ecological remediation technologies,relevant suggestions are put forward,in order to provide a reference for water pollution restoration and treatment in urban human settlement environment.

Research on Ecological Water Cycle and Purification in Rural Landscape——Take Zhangjia Village Ecological Wastewater Treatment Project in Henan Province as an Example

Rural landscape is not only a natural landscape,but also a cultural landscape.The improvement of rural environment in Lushi County is carried out under the background of“Building Beautiful Villages”.Through the plan of environmental improvement,the appearance of villages in rural areas will be significantly improved,and the gap between urban and rural areas will be shortened.This research addresses the problems of scarce water resources,imperfect rainwater collection facilities,and increased environmental pollution in rural areas,and explores a flexible,effective,and integrated landscape ecological water treatment system that integrates with natural ecosystems.The practice has shown that the flexible combination of different technical measures according to local conditions and the construction of ecological water self-circulation and self-purification systems can reduce maintenance costs and achieve sustainable landscape.The virtuous cycle of the revetment’s micro-ecology greatly improves the environmental carrying capacity of the landscape.Reasonable water management system is more flexible in dealing with unexpected problems.The thesis proposes landscape design strategies for water circulation and water purification in rural areas,and applies them to actual design cases.It attempts to introduce a combined treatment system to achieve a more diverse landscape concept and further explore the healthy and sustainable development of rural water environment.

A Study on Chinese Waterfront Landscape Based on CiteSpace V Visualization Analysis

Taking 457 papers in core journals of Chinese waterfront landscape included in CNKI database from 2000 to the fi rst half of 2020 as samples,visualization analysis of the number of papers,research institutions,research authors,key words and spatial and temporal distribution of domestic research papers on waterfront landscape in the past 20 years were performed to grasp the dynamic process of the development of domestic waterfront landscape research and clarify the development context,so as to provide academic information with scientific basis and valuable theoretical reference for waterfront landscape related research in China.The results showed that the researches on domestic waterfront landscape presented a downward trend from prosperity to decline;research forces were mainly concentrated in colleges and universities,and most research institutions did not form cooperative relations with authors,and were still in a relatively isolated situation.At present,the research hotspots and frontiers of waterfront landscape in China mainly focus on urban waterfront,urban historical landscape,ecology,cultural landscape and plants landscape.

Effects of main factors on remedying northern landscaping water by hybrid ecological filter

Natural zeolite and coal cinder were layered as main packing medium of the ecological filter instead of traditional filling to remedy the static lake water in Northern China.The ecological filter was running in a combined upward and downward flow mode.Dynamic experiments were carried out to study the effects of retention time and ambient temperature on pollutants' removal efficiency of the hybrid ecological filter.The function of plant was also studied by contrast test.It is showed that the removal efficiencies of NH4+-N and TP are increased when the retention time is changed from 1 h to 2 h and 4 h,but the removal efficiency of TN is decreased,the removal efficiency of NH4+-N is increased from 91.5% to 98% and that of TP is increased from 31.8% to 52.5%.When the temperature declines,the temporal removal efficiency of NH4+-N is reduced,but the removal efficiency of 24 h and 48 h is remained.The removal efficiency of TP after 24 h and 48 h is decreased when the temperature declines evidently.The retention time plays an important role in NH4+-N and TP removal,and the ambient temperature is significant for TP removal.The plant favors for TP and organic matter removal but has little effect on TN removal.

Analysis on Aquatic Environment of an Artificial Lake and Control Measures to Its Pollution

[Objective] This study aimed to find out effective measures to solve land- scape water eutrophication. [Method] Based on an overview of the urban landscape water characteristics and pollution control situation, taking an example of the artificial lakes in a campus in Xi＇an, we comparatively analyzed the present pollution situation of Xiuyuan Lake and Mingyuan Lake, and provided controlling measures against eutrophication pollution, as well as restoration measures. [Result] All the indicators （TN, TP, Chl-a, NH3-N, CODMn） of the landscape water quality in both Xiuyuan Lake and Mingyuan Lake went severely beyond the Grade IV standards, presenting a state of heavy eutrophication. Nitrogen, phosphorus and other nutrient salts carried by atmospheric precipitation and its runoff, as well as domestic garbage generated by human activities were primary exogenous pollutants of the artificial lakes. And the release of sediment pollutants was endogenous substances causing deterioration of water quality. [Conclusion] This paper presents some measures to control the pollution of artificial lakes, and provides scientific references for the construction, operation and management of artificial lakes, as well as maintenance of aquatic environment.

Modelling the thresholds of nitrogen/phosphorus concentration and hydraulic retention time for bloom control in reclaimed water landscape

The risks posed by algal blooms caused by nitrogen and phosphorus in reclaimed water used in urban water landscapes need to be carefully controlled.In this study,the combined effects of the nitrogen and phosphorus concentrations and the light intensity and temperature on the specific growth rates of algae were determined using Monod,Steele,and Arrhenius models,then an integrated algal growth model was developed.The algae biomass,nitrogen concentration,and phosphorus concentration mass balance equations were used to establish a new control model describing the nitrogen and phosphorus concentration and hydraulic retention time thresholds for algal blooms.The model parameters were determined by fitting the models to data acquired experimentally.Finally,the control model and numerical simulations for six typical algae and mixed algae under standard conditions were used to determine nitrogen/phosphorus concentration and hydraulic retention time thresholds for landscape water to which reclaimed water is supplied(i.e.,for a reclaimed water landscape).

Treatment and hydraulic performances of the NiiMi process for landscape water

This paper describes the NiiMi process designed to treat landscape water. The main aim of the research was to investigate the feasibility of NiiMi for removing organic and nutriment materials from landscape water. During the batch-scale NiiMi operation, the removal rates of color ranged from 66.7%o-80% , of turbidity from 31.7%-89.3%o, of chemical oxygen demand （COD） from 7%-36.5%, of total phosphor （TP） from 43%-84.2%, of soluble phosphate from 42.9%-100%, of total nitrogen （TN） from 4.2%-46.7%, and of NH4^＋-N from 39.3%-100% at the hydraulic loading of 0.2 m^3/（m^2·d）. Results showed that the removal efficiencies of COD, TP, soluble phosphate and TN decreased with the decline in the temperature. The NiiMi process had a strong shock loading ability for the removal of the organics, turbidity, TP, soluble phosphate, TN and NH4^＋-N. Three sodium chloride tracer studies were conducted, labeled as TS 1, TS2, and TS3, respectively. The mean hydraulic retention times （mean HRTs） were 31 h and 28 h for TSI and TS2, respectively, indicating the occurrence of a dead zone volume of 12% and 20% for TS 1 and TS2, respectively. TS 1 and TS2 displayed the occurrence of short-circuiting in the NiiMi system. The comparison results between TS1 and TS2 were further confirmed in the values obtained for some indicators, such as volumetric efficiency （e）, short-circuiting （S）, hydraulic efficiency （2） and number of continuously stirred tank reactors （N）.