Research On Efficacy Of Enhanced Ecological Floating Wetland In Purifying Contaminated Water

As a special form of constructed wetland,artificial floating island has many advantages such as providing habitat for fish and birds,inhibiting algae growth and eliminating waves.However,the traditional foaming floating islands can only rely on plant absorption to transfer nutrients such as nitrogen and phosphorus in water,which means the treatment is inefficient.In this study,a new type of artificial floating island with energy self-sustaining electrochemical enhancement was constructed for the surface Inferior V water body.The selection of plant species,plant amount,matrix material and floating material used in the system was optimized.Compared with the conventional foaming floating island system on the market,the performance of the new artificial floating wetland system was investigated for the purification of pollutants.The effects of different hydraulic retention time,intermittent flow and continuous flow operation mode,and different inorganic nitrogen concentration ratios on the removal of TOC,TN,TP,NH₄⁺-N,and NO₃^--N were discussed.According to the plant's oxygen production capacity and freezing resistance and carbon and nitrogen removal ability,and calamus was selected for subsequent experiments from the iris,cattail,Alisma,Citrus,Scallion,and calamus.Set plants in amounts of 0,4,6,8,12.when the amount of calamus was 8,the treatment effect on TN and ammonia nitrogen was the best,and the treatment efficiency was 64.73%and65.84%,respectively.According to the hardness,structure and microbiological friendliness of the matrix material,polyamide fiber is selected as the upper layer collective material and rattan cotton as the underlying matrix material.PVC pipes and PVC expansion sheet with relatively stable and inexpensive properties have been selected for several common floating material materials.The combination formed a framed ecological floating island and a frameless ecological floating island.It was found two new floating islands had a better treatment effect on nitrogen and phosphorus after15 days of trial operation.A carbon fiber cloth was set as the anode and a carbon brush was used as the cathode,and a microbial electrochemically enhanced framed floating wetland and microbial electrochemically enhanced frameless floating wetland were constructed.In order to ensure the successful functioning of functional microbes,the HRT was set to 3days and the intermittent flow was run for 30 days to start the floating wetland and coupling system.It was found that after the operation,the two floating wetlands were better than the traditional ones for the treatment of nitrogen and phosphorus.Floating islands,floating wetlands with electrochemical systems are the best.The effects of intermittent and continuous flow,different loads,and framed and frameless structures on contaminant removal efficiency are clarified.Under the intermittent high-nitrogen nitrogen load,the electrochemically enhanced effluent TOC,TN and NH₄⁺-N of the frame-type floating wetland have reached the three standards of surface water,and TP reaches the four types of surface;under continuous flow of high-nitrogen nitrogen,the effluent concentration of carbon,nitrogen and phosphorus reached three categories of surface water.During operation,the microbial electrochemically enhanced framed floating wetland had a maximum voltage of 427 mV,while the electrochemically enhanced frameless 258 mV.After the operation,the plants of each floating island system were tested,and the fresh weight of the plant in the traditional floating island,the frameless floating island,the framed floating island,the electrochemically enhanced frameless floating island,and the electrochemically enhanced framed floating island were compared.It was reduced by more than 15%before operation,while catalase increased by more than 10%.In addition to the frameless floating island series,the leaves of the floating islands contained more than 5%chlorophyll content.fibers.The total number of cathodes,anode species,community abundance and community diversity of electrochemically enhanced frameless systems are higher than those of electrochemically enhanced framed floating island systems.The amount of microorganisms supported by the plant roots,polyamide fibers,rattan cotton,cathode and anode of the electrochemical and framed floating island coupling system is basically higher than other systems.Moreover,the addition of electrochemical systems increases the abundance and diversity of microbes on plant roots,rattan cotton,sand,and the abundance of microbes on polyamide...