The Technology Research Of Aquatic Oorganisms On Xin’ An Reservoir Water In Situ Remediation

Xin’an reservoir is located in Dongying City, Shandong Province, is a typical plain shallow reservoirs, as located in the Yellow River which is enriched with nitrogen, phosphorus and other nutrients from the accumulation of the Yellow River, combined with reservoir water slowly and compared with HRT long, so that the eutrophication reservoir run for a long time and have a serious impact on the role of Xin’an reservoir. Eutrophication is a direct manifestation of the explosive growth of algae, currently ways to control algae include physical, chemical and ecological method, because of low cost, environmentally friendly, long duration of action, etc,ecological method is a currently hotspot to control algae.Xin’an reservoir were carried out separately aquatic ecological pond trials and aquatic plants joint aquatic ecological pond trials, so that study silver carp, bighead carp, submerged plant control effect of Xin’an phytoplankton densities of phytoplankton species and improve water quality indicators repair effect for Xin’an eutrophication control to provide technical support. The main contents and results are as follows.(1) In Silver carp, bighead 3:1 ratio test, fish density of control algae significant effect is≥35 g/m3, this density, algae density can be reduced from 31,380,000 a/L to 9,630,000a/ L; TN by 0.857mg/L down to 0.710 mg/L; NH3-N from 0.43mg/L reduced to 0.35mg/L; TP by 0.044mg/L down to 0.035mg/L, CODMn from 3.18mg/L reduced to 2.54mg/L. Silver carp, bighead total density at≥35 g/m3 of water quality indicators can achieve significant improvements.(2)In Silver carp, bighead carp 1:3 ratio test, fish density of control algae significant effect is≥45 g/m3, this density, algae density can be reduced by 104,150,000 a/L to 80,390,000 a/L; TN by 0.649mg/L to 0.564 mg/L, NH3-N by 0.33mg/L reduced to 0.28mg/L; TP from 0.027mg/L reduced to 0.025mg/L, CODMn from 4.63mg/L reduced to 4.41mg/L. The proportion of total Carp stocking density is≥150g/m3, water quality indicators can achieve significant improvements.(3) In Silver carp, bighead carp 1:1 ratio test, fish density of control algae significant effect is>90 g/m3, this density, algae density can be reduced from 86,230,000a/L to 47,890,000 a/L; TN by 0.578mg/L down to 0.348 mg/L; NH3-N from 0.37mg/L reduced to 0.23mg/L; TP reduced from 0.032mg/L to 0.019mg/L, CODMn from 4.53mg/L reduced to 3.65mg/L. Stocking this ratio of silver carp and the bighead,under the total density at>60 g/m3 water quality indicators can be achieved significant improvement.(4) Silver carp, bighead 3:1 ratio and joint P.crispus trials most appropriate silver carp, bighead carp total density is 50g/m3 for control algae, this density of algae density can be reduced from 3,500,000 a/L to 1,170,000 a/L; TN by 0.817mg/L down to 0.549 mg/L, NH3-N from 0.32mg/L reduced to 0.19mg/L; TP by 0.031mg/L down to 0.019mg/L, CODMn from 2.69mg/L decreased to 1.83mg/L.(5) Silver carp, bighead carp 1:3 ratio malaianus joint test, the control algae significant effect of fish density is>45g/m3,this density is lower algae density can be reduced from 61,900,000a/L to 47,500,000 a/L; TN decreased from 0.714mg/L to 0.664mg/L; NH3-N by 0.44mg/L reduced to 0.36mg/L; TP from 0.039 mg/L reduced to 0.032 mg/L, CODMn from 4.03mg/L is reduced to 3.62mg/L. Silver carp, bighead total density at≥105 g/m3 of water quality indicators can achieve significant improvements.The results showed that the silver carp, bighead carp joint submerged plants have a significant role on water quality restoration and algae density control for the eutrophication in Xin’an reservoir, but the test was found the problem of advance decline in submerged plant. Under no circumstances aquatic plants, only silver carp and bighead carp also have a significant role on water quality purification and algae density control affect. In Silver carp, bighead 3:1 ratio test, fish density of control algae significant effect is≥35 g/m3,which removal rete of algae is up to 69.3 percent and the amount of fry put to practical use is the lowest of 490 tons, far less than other programs in volume.Combined program operability and fish density of economic rationality, made suitable for the most appropriate control eutrophication for Xin’an silver carp, bighead carp ratio is 3:1, more appropriate density is 35 g/m3.