Research On The Effect Of Vegetables On Water Purification In Aquaponics

With the development of fish farming,the problem of water pollution has become more and more serious.The Aquaponics system can solve the problems of water pollution and soil pollution in the process of traditional fish breeding and vegetable growth to a certain extent,realize the purification and reuse of water resources,and obtain vegetables and fish products.There are many factors that affect the water purification effect in the Aquaponics system.This paper studied the effects of different vegetable types,cultivation substrates and vegetable planting densities on the water purification effect in the fish and vegetable symbiosis system,in order to establish an efficient Aquaponics system for water purification.The main findings are as follows:1.The experiment selected four vegetable: cucumber,tomato,water spinach,and celery to study the purification effect of water quality.The test results showed that the removal rate of water spinach on nitrogen and phosphorus was as high as 72.63%,and the removal rate of total phosphorus was 55.62%;the removal rate of cucumber,tomato,and celery was 40% ~ 48%.At the same time,the biomass of water spinach increased the most after 30 days of experiment,and the absorption of mineral elements was also the highest.As far as these four vegetables are concerned,water spinach has a better purifying effect on water quality.2.The research on using ceramics,sand,flower mud and non-woven fabrics as cultivation substrates and water spinach as cultivated vegetables shows that when ceramics and sand are used as cultivation substrates,the removal rate of nitrogen and phosphorus in the cultivation water is high,and the purification effect is overall.It is better,and the water spinach grows well and absorbs more mineral elements.However,when sand is used as the cultivation substrate,the chlorophyll content of the leaves of water spinach is low,and the leaves have some yellowing.Although non-woven fabrics play a role in improving water quality,plant growth is not as good as pottery and sand,and flower mud has little effect on the removal of total phosphorus in water bodies.Therefore,when pottery is used as the cultivation substrate,the water purification effect is better.3.Using lettuce as a cultivated vegetable,the influence of vegetable planting density on water purification effect was explored.Three planting densities of 15,24 and 33 plants/m2 were set in the experiment.The results showed that lettuce had a certain purification effect on the aquaculture water,and the ammonia nitrogen content of the water body decreased by 36.34% at the end of the experiment.When the planting density is 33 plants/m2,the mineral element content of lettuce is the highest from the perspective of the mineral element content of the raw menu plant and the total mineral element content of the plot(1.5 m2)lettuce plant.On the whole,an appropriate increase in vegetable planting density has a better purification effect on water quality.In summary,under the experimental conditions,the aquaponics system used ceramic gravel as the cultivation substrate,planting water spinach,and appropriately increasing the planting density,which had a better purification effect on water quality.At the same time,a certain amount of nutrient solution could be added to the leaf surface to promote the growth and development of vegetables and further enhance the purification effect of water quality.