Application Of MNB Technology In Water Ecological Restoration And Its Engineering Design

Under the impetus of rapid social development,the construction of landscape water has become a new scenery under the city’s reinforced concrete jungle.However,the landscape water is subject to its own defects,such as serious closedness,poor mobility,and low self-repair ability,and is easily subject to human activities.As a result,water quality deteriorated,destroying the new scenery gradually.In view of this phenomenon,this project takes a college landscape water quality improvement project as an example,and combining with MNB（micro-nano-Bubble）technology,we construct a new project of water quality restoration and guarantee,which is mainly based on ecological rehabilitation and supplemented by artificial intensification.The landscape water of the university is hardened by concrete as a whole.The water body is less transparent,most of the lake is covered with a single species of water grass,and the water body is blackish green and fetid.Calculating the water environment capacity of the river,it was found that the actual capacity of COD_cr（Dichromate index）and TP（Total phosphorus）in the water exceeds the theoretical environmental capacity.The actual amount of COD_cr detected in water is 179.25%of the theoretical environment capacity,and there is a serious over-standard phenomenon.The COD_cr exceeding the standard is the most serious one.The MNB activation system is based on the micro-nano bubble technology and is based on the environment-friendly high-efficiency water ecological restoration technology.This program uses the MNB activation system as the core artificial auxiliary system of the project.Through（1）laboratory static simulation experiments to assist the engineering program to rationally design the distribution of aquatic plants in the contaminated areas;（2）field simulation test to simulate the feasibility of the project program.（1）Using the MNB activation system to help purify water quality of aquatic plants In the static simulation test conditions,each plant combination achieved good results in reducing the total amount of TN（Total nitrogen）,TP,and COD_cr in the experimental water samples.Taking the four species,such as Iris pseudacorus L、Lythrum salicaria L、Vallisneria natans、Hydrilla verticillata（ILVH）as research objects,any three plants were selected randomly to simulate the average removal rate of TN.Among them,the combination of Iris pseudacorus L,Vallisneria natans and Hydrilla verticillata（IVH）showed the best removal efficiency of TN,which was 91.62%.The combination of Lysimachia,Vallisneria and Hydrilla verticillata（LVH）was the worst,which was only 86.99%.The simulation results of the combination of yellow iris,Vallisneria and Vallisneria natans（ILV）showed that the removal effect of TP was the highest,which was 91.33%;and the worst removal was the combination of Iris pseudacorus L,Vallisneria natans and Hydrilla verticillata（IVH）,which was 85.33%.The effect of the four kinds of plants was the best,and the reduction effects on TP and TN were 92.67%and 92.77%,respectively.In COD_cr removal tests,there was a slight recovery in the COD_cr content at the end of the experiment.By looking up similar literatures and observing the experimental environment,it was speculated that the reasons of this rebound might be the metabolism of plants in the growth process and the degradation of the stems and leaves in the water.Therefore,in the plant’s physiological cycle,planting plants should be considered for harvesting and pruning,so as to avoid secondary pollution of the remediation waters that have been treated.At the same time,in the planting distribution design of plants,the degree of pollution and the type of pollution should be taken into account,and to form a reasonable mix of aquatic plant species and planting density（2）Through field simulation experiments,in the experimental group of the MNB activation system,the average plant height of the emerged plants was 9.43%higher than that of the control group,and the average plant height of the submerged plants in the experimental group was 20.33%higher than that of the control group.The engineering design laying area of aquatic weeds is 35%of the total water area.With the help of the MNB activation system,the absorption of TN reduction by aquatic plants is503.53kg/a⁹06.35kg/a,and that of TP is 56.12kg/a.¹01.02kg/a.The annual intake of TN in the East River is 172.5kg and the TP amount is 52.5kg.This project scheme will enable the eastern river water quality meet to the desired goal.With the help of engineering programs,through the analysis of the pollution of landscape water, the calculation of the water environment capacity,and the amount of supplementary water and the study of the key parameters,our engineering is designed by combining with the MNB activation system.By combining with ecological restoration system,aquatic animal and plant restoration system,MNB water reoxygenation activation system,we made the simulation study in water quality restoration.In order to provide certain theoretical support,data support and engineering plan reference for the water quality improvement of urban landscape water body,we established an water quality restoration and protection project scheme,operation mechanism and management measure that is mainly based on ecological rehabilitation and supplemented by artificial technology,such as MNB activation system,cloud platform monitoring module.