Guangzhou Zhonghang Recycling Aquaculture Project Case - Zhao'an Qiandao Lake


Qian’an Qiandao Lake enjoys a beautiful environment, clear lake water, and always maintains the highest quality of the ecological environment. The water quality of the outbound section continues to be Class I and was rated as a Grade 5A tourist attraction by the country in April 2010. However, the lake water in Qiandao Lake is transformed from eutrophication to eutrophication. The feeding of cages increases the organic matter in the water and increases the solubility of nitrogen and phosphorus, which has a great impact on the growth of water bodies and fishes. The local government needs to vigorously develop the tourism industry and begin to rectify the environment of the Qiandao Lake. Since 2014, the Jiande waters of the Qiandao Lake have all been withdrawn from the cages for a complete ban.

Due to the government’s difficulty in breeding the environment and natural conditions, aquaculture farmers have turned to indoor recycling. A client of Qiandao Lake ordered a set of circulating aquaculture equipment from the company. The full set of equipment includes: automatic microfiltration machine, floating bed biofilter, ultraviolet sterilizer, constant temperature system, and aeration system. It is mainly used for breeding freshwater grouper. Because many farmers have chosen indoor breeding, the artificial breeding industry in Qiandao Lake has been gradually developed and the annual fish production is nearly 90 tons. Factory farming has brought huge benefits to Qiandao Lake.

1, device description

1.1 Automatic Microfiltration Machine

The automatic box type drum microfiltration machine is mainly composed of four components: a box assembly, a roller assembly, an anti-cleaning system, and an electric control box system, and is made of a non-toxic, corrosion-resistant and environment-friendly material. The imported stainless steel 316L filter was used to separate the suspended solids from the water. The stainless steel filter was used as the medium for removing suspended solids. When water containing particles of suspended matter enters the drum, the suspended matter is trapped by the stainless steel mesh and the filtered water that does not contain suspended matter enters the reservoir. When the suspended solids in the drum accumulate to a certain amount, the permeation of the filter will decrease, causing the water level in the drum to rise. When the water level rises to the set high level, the liquid level automatic control system works. At this time, the anti-cleaning water pump and The drum motor is automatically turned on at the same time. The high-pressure water output from the anti-cleaning water pump is subjected to high-pressure cleaning of the rotating drum filter by the anti-cleaning system of the micro-filter, and the suspended matter remaining on the filter is washed into the dirt collection tank by the high-pressure water. Sewage pipe discharge. When the filter is cleaned, the permeation of the roller filter increases, and the water level in the drum drops. When the water level drops to the set low level, the anti-cleaning water pump and drum motor will automatically stop working, and the micro filter will enter the new one. Wheel work cycle

1.2 Floating Bed Biofilter

The floating bed biofilter utilizes the solid fluidization technology and the principle and characteristics of the large surface area of the micro-particles, concentrating the advantages of the trickling filter and the activated sludge method. The bio-film has a high concentration, a high concentration, a high purification efficiency, and an ammonia nitrogen conversion rate. Can increase 2 to 4 times. Compared with conventional biofilters, bio-drums, bio-rotary disks, activated sludge, and other methods used in the past, it has the advantages of small footprint, less obstruction, or good biological membrane activity. As the purification efficiency of water is increased, the construction cost and the floor area can be reduced, and the management is easy.

1.3 UV sterilizer

The principle of sterilization of ultraviolet sterilizers is to use the energy of ultraviolet photons to break the DNA structure of various viruses, bacteria and other pathogenic bodies in water bodies. It is mainly to break various structural bonds in DNA or photochemical polymerization reaction, for example, to dimerize THYMINE in DNA, so that various viruses, bacteria, and other pathogenic bodies lose the ability of reproduction and reproduction to achieve sterilization effect.

1.4 Constant temperature system and aerobic system

The constant temperature system regulates and controls the water temperature of the fish pond, effectively controls the water temperature within +5°C to +35°C, and the display accuracy is 0.1°C. It can control the water temperature all year round to grow in a better environment.

Oxygen-increasing system - dissolved oxygen cone, can quickly increase the amount of dissolved oxygen in water in a short time, and is to dissolve oxygen into water, all come out of high-oxygen water, oxygen utilization rate of up to 95%.

2. Workflow of industrial circulating aquaculture system

The recirculating aquaculture system will input aquaculture water into an automatic microfiltration machine, purify and filter it through the equipment, and then undergo a bioreactor treatment of the floating bed biofilter. At the same time, it will be oxygenated, and then it will be sterilized by the ultraviolet sterilizer and the temperature will be adjusted. The water flows back to the farm.

3, output

Freshwater grouper fish breeding can reach an average weight of two kilograms, the largest up to more than 3 kilograms, and the density per cubic meter can be as high as 80KG or more. It is one of the fish with high economic value.

4. Characteristics of Recirculating Aquaculture System

  1. Low energy consumption: The system uses a circulating pump to lift water once to fully utilize the potential energy generated by the water level difference to complete the work cycle of the entire system.

  2. Reduced floor space, system technology, reasonable operation, easy maintenance, low failure rate, low investment.

  3. It is not affected by natural environments such as climate and water quality.

  4. Easy to culture and manage, effectively isolate diseases and control the invasion of pathogens, reduce bacteria and morbidity.