Ecological Behavior Characteristics And Control-Removal Technology Of Fouling Organisms Limnoperna Fortunei In Hydraulic Engineering

The environmental problems such as biological invasion, environmental destruction and biofouling are accompanied with the development of hydropower resources. The biofouling is one of the major problems endangering the safe and efficient operation of water conservancy project. The main biological fouling in water conservancy project is limnoperna fortunei. Limnoperna fortunei is a kind of intrusive fouling organisms. At present, it has caused serious harm to the hydropower project in the southern region of China, including the blockage of the water pipeline, the reduction of the water conveyance capacity, the corrosion structure surface, the pollution of the water quality and so on.Based on the Limnoperna fortunei's to hazard profile of water conservancy project,This article researched the ecological behavior characteristics and control-removal technology of Limnoperna fortunei. Through the fouling investigation, the harm characteristics and adhesion properties on different substrates of Limnoperna fortunei were explored. Through the indoor control experiment, the influence of different environmental conditions such as temperature, pH value, dissolved oxygen, water quality and phytoplankton concentration on the Limnoperna fortunei's behavior characteristics were also researched. Through the experiment, the article studied the attachment characteristics of Limnoperna fortunei under different roughness and different sizes of sandy substrates,and the chemical killing technique such as sodium hypochlorite, chlorine dioxide, potassium permanganate and chloramine, hydrogen peroxide, plant extracts etc,and also studied the physical culling technology such as separated from the water to death,death of high water immersion,ultrasonic killing method,electric shock killing method.Through indoor and outdoor experiments, this paper obtained the fouling prevention coatings for Limnoperna fortunei.The results showed that: Limnoperna fortunei has obvious negative phototaxis and water-surface attachment characteristics. They tended to be attached on the attachment surface of larger roughness and multi surface structure, which most easily attached to the matrix when attachment matrix particle size has little difference with the body length of Limnoperna fortunei.Through study the ecological behavior characteristics of Limnoperna fortunei, its suitable environment temperature for the survival is 16? ~28?. when the temperature was below 16?,its reproduction is restrained, and it will quickly die when the temperature was higher than 28 degrees. Limnoperna fortunei is sensitive to water pH value, and its most suitable pH value is 6~8. Dissolved oxygen in water is a key factor affecting the conduct of Limnoperna fortunei. They began to show the anoxic characteristics when the concentration of dissolved oxygen in water is less than 3 mg/L. And when the dissolved oxygen concentration is less than 1 mg/L they will die quickly. They also has strong absorption ability to filter feeding phytoplankton. The experiment concluded that the killing rate of Limnoperna fortunei with sodium hypochlorite can reach more than 90%. The killing rate of Limnoperna fortunei with separated from the water to death?death of high water immersion is more than 60%. When the pipe flow velocity is greater than 2 m/s,it can remove more than 90% of Limnoperna fortunei. Polyurethane rubber base coating and fouling prevention coatings of Limnoperna fortunei developped by plant extracts additives showed good prevention and control effect both in indoor experiment and field experiment, which has engineering feasibility.The core of fouling prevention is to prevent the intrusion and mass-production blooms of Limnoperna fortunei. At this time the focus of prevention is to control the Limnoperna fortunei's harm on water conservancy facilities. The paper presents comprehensive prevention and control measures of Limnoperna fortunei,which is On the basis of studying on the characteristics of ecological behavior of Limnoperna fortunei and on the principle of " preventing invasion-rapid killing- long-term control".