The Study On Artificial Water Eutrophication In Xi’an

To illustrate the reasons of major pollution factors that cause Xi’an artificial watereutrophication, develop integrated control measures for artificial water eutrophication. in thisstudy，the water quality of five individuals are monitored and analyzed. On the one hand, theuse of literature and field surveys, explores the relationship between the factor of waterquality and phytoplankton growth factors, analyze and get which factors leading thephenomenon of water eutrophication. On the another hand, the use of physical and chemicalindicators of water quality, integrating index evaluation method,5artificial water bodies areevaluated, develop the key indicators of affecting the water quality. On this basis, the use ofpublic participation, propose the comprehensive control measures of eutrophication inartificial water bodies. Provide theoretical and technical basis for the control of artificialeutrophication of water bodies.1. During the investigation,55species (including varieties) belonging to29genera of6phyla including bacillariophyta, Chlorophyta:9phyla and25genera, representing45.45%ofthe total; diatoms:7genera and12species, accounting for21.82%of the total; Cyanophyta:7genera and11species, accounting for20%of the total; Euglenophyta:4genera and5species, accounting for9.09%of the total; Cryptophyta1genera and1species, accounting for1.82%of the total; Chrysophyta1genera and1species, accounting for1.82%of the total.2. The algae of Fengqing Lake outbreak in August, the majority of algae are Cyanophyta,dominant species of algae is Ankistrodesmus falcatus; the algae of Xingqing Lake outbreak inOctober, the majority of algae are Chlorophyta, dominant species of algae is Right-angled Cross algae; The algae of South Lake outbreak in October, the majority of algae arediatoms, dominant species of algae is synedra acus; the algae of moat outbreak in September,the majority of algae are Chlorophyta, dominant species of algae are Ulva and C.venus; Thealgae of Expo outbreak in August, the majority of algae are diatoms, dominant species ofalgae is Cyclotella.3. During the investigation, found that the minimum of nitrogen-phosphorusratio is10:1,a maximum of nitrogen-phosphorus ratio is1050:1, Limiting nutrient whether changes overtime or location, Nitrogen and phosphorus ratio is greater than10:1, the initial determination is phosphorus restrictions. Effects of high levels of algae peak is phosphorus in the water, butnitrogen factors also play a promoting in the water, even the interaction of nitrogen andphosphorus，and pH is a more impotant factor.4. Integrated pollution index of Xi’an artificial water bodies P>12.0, belonging worsethan Grade Ⅴ, the water quality is poor. The main pollution indicators of Fengqing Lake、Xingqing Lake、moat or Expo are mostly COD、TN、TP; the main pollution indicators ofSouth Lake are COD、TN、and Permanganate index；The main reason why the quality ofartificial water bodies is poor are high chemical oxygen demand and total nitrogen.