Experimental Study On Aquatic Organisms And Combined Purification Of Reservoir Water

Xin'an reservoir is located at the lower reaches of the Yihong river in Dongying city.After the introduction of water in the reservoir,water flow is slow,hydraulic retention time is longer,the water accumulation of nitrogen,phosphorus and other nutrients in the reservoir,the phenomenon of the rich nutrition and high content of algae,causing the water dissolved oxygen,pH,turbidity and potassium permanganate main indexes such as the surface water?class water have different degree of overweight.The safety and reliability of reservoir water supply are affected.In order to solve the water quality problem of Xin'an reservoir,this paper took Xin'an reservoir water as the research object,carried out an experimental study on the purification of water in the reservoir by aquatic organisms,and investigated the removal effect of aquatic organisms and their combinations on the main indexes of water in the reservoir.The research contents and results are as follows:?1?Investigated from 2014 to 2018 Xin'an reservoir water quality situation,with the comparison and analysis of surface water environmental quality standard,draw COD_Mn,ammonia nitrogen in?class,total phosphorus in?class,total nitrogen in?classes,the overall water quality is poorer;Xin'an reservoir eutrophication element index in 2018 high total nitrogen,total phosphorus,total nitrogen in?class,total nitrogen in?class,ammonia nitrogen and COD_Mn were?class.2018 Xin'an related water quality indexes in the eutrophication?classes to?,dominant fungi method evaluation method for evaluating eutrophication of water bodies,in 2018 concluded that the year is in is in a state-rich in nutrition and rich nutrition.Aquaticfloatingplants,Canna,calamus,bracketplantweretestedunder40%coverage,including Canna removal of each water quality index and algae in water have relatively good effect,TN in water by 0.716 mg/L fell to 0.168mg/L,TP by 0.0398 mg/L fell to 0.168mg/L,NH₃-N by 0.391 mg/L fell to 0.133 mg/L,COD_Mnn from 3.395 mg/L fell to 2.201 mg/L,the density of algae by 34.64 million/L up to 44.66million/L.Through the analysis and comparison of experimental data,Canna was selected as the optimal plant group.?2?In the experiment,shrimp,crab,river mussel and snail were selected as aquatic benthos,and the density was tested according to 30g/m³,30g/m³,4 per m² and 35 per m²respectively.Through the analysis of experimental data,the benthos had a certain effect on the removal of various water quality indexes,among which the river mussel and snail were better.In the mussel test group,TN decreased from 0.735mg/L to 0.569mg/L,TP from 0.040mg/L to0.032mg/L,NH₃-N from 0.380mg/L to 0.312mg/L,COD_Mnn from 3.354mg/L to 2.741mg/L and algae density increased from 35.26 million/L to 52.16 million/L.In the snail experiment group,TN decreased from 0.721mg/L to 0.566mg/L,TP decreased from 0.039mg/L to 0.032mg/L,NH₃-N decreased from 0.381mg/L to 0.320mg/L,and COD_Mn decreased from 3.362mg/L to2.784mg/L.?3?Floating plants canna,calamus and chlorophyta were tested under the coverage rate of40%.The results showed that canna had better removal effect on water quality indexes and algae than the other two species.In the water,TN decreased from 0.716mg/L to 0.168mg/L,TP decreased from 0.039mg/L to 0.168mg/L,NH₃-N decreased from 0.391mg/L to 0.133mg/L,and COD_Mn decreased from 3.395mg/L to 2.201mg/L.Compared with the blank test group in the same period,the density of algae was relatively low,which was 44.66 million/L.The combined experiment of aquatic plants has a good effect on the removal of various water quality indexes and the total number of algae in the water body,of which the B2 test group has the most obvious effect.In this experimental group,TN decreased from 1.004mg/L to0.183mg/L,TP decreased from0.051mg/L to 0.009mg/L,NH₃-N decreased from 0.977mg/L to 0.287mg/L,COD_Mnn decreased from 6.060mg/L to 3.525mg/L and algae density increased from 73.29 million/L to15.40million/L.?4?Submerged plant blades black algae,water,aggregates,hornwort in the density of 120g/m²,the results obtained,the blades black algae in water body of each water quality index and algae removal effect is best,TN by 0.690mg/L fell to 0.158mg/L,TP by 0.041mg/L fell to0.013mg/L,NH₃-N by 0.395mg/L fell to 0.161 mg/L,COD_Mn from 3.381mg/L fell to2.398mg/L,density is lower,compared with the blank group algae for 43.15million/L.?5?In the combined experiment of river mussel and snail,4 river mussels per m² and 35river snail per m² had the best removal effect on water quality indexes and algae.TN decreased from 1.231mg/L to 0.816mg/L,TP decrease from 0.051mg/L to 0.034mg/L,NH₃-N decrease from1.039mg/L to 0.816mg/L and COD_Mnn decrease from 5.987mg/L to 4.470mg/L.Compared with the blank test group in the same period,the density of algae was low,which was 19.97 million/L.?6?Aquatic plant cannas+blades black algae joint trial,canna coverage 40%,round leaf black algal density of 120 g/m²,the water quality indexes and algae in the water removal effect is most obvious,TN by 1.004 mg/L fell to 0.183 mg/L,TP by 0.051 mg/L fell to 0.009 mg/L,NH₃-N by 0.977 mg/L fell to 0.287 mg/L,COD_Mn from 6.060 mg/L fell to 3.525 mg/L,the density of algae from 73.29 million/L fell to 15.4 million/L.?7?Mussels+spiral lions+blades black algae and aquatic plants canna joint experiments,canna coverage rate of 40%,round leaf black algal density of 120 g/m2,mussels 4 per m²,spiral lions 35 per m²,only to the removal efficiency of each water quality index and algae in water is the most ideal,TN by 1.231 mg/L to 0.256 mg/L,TP by 0.051 mg/L fell to 0.008 mg/L,NH₃-N by1.040 mg/L fell to 0.393 mg/L,COD_Mn from 6.010 mg/L fell to 3.180 mg/L,compared with the blank test group in the same period,the algae density was low,11.05 million/L.