Research And Engineering Applicationon Of Rigid Microbial Stereoscopic Biological Bed Technology For Malodorous River

Due to the wide water area and direct contact with the biosphere,the basic require-ment for the treatment technology of black and odorous water in rivers and lakes is that no secondary pollutants shall be produced with a low cost,so the bio-film method has obvious advantages.However,there are some problems in bio-film process,such as slow start-up,high cost of large-scale deployment in wide waters and being easy to cause blockage by bio-film,which greatly affect its advantages and practical applica-tion.In view of the aforementioned problems in bio-film process,based on the in-depth study of the basic characteristics of bio-film and the engineering characteristics of bio-film process,this paper explores the rigid three-dimensional bio-bed and its engineering technology model of manual mobile sub-regional purification and direct use and recycle of Off-site transportation in vast waters,studies its characteristics and carries out engi-neering practice,showing low cost,fast start-up and high efficiency in purification,which provides an efficient treatment technology and device for the realization of low cost and rapid treatment of black and odorous water.Firstly,a rigid three-dimensional biological bed with good contact,anti-clogging and good transportability between organisms and water was developed.By fixing the upper end of the carrier fiber and the structure of the lower free end of the bio-film,the lower free end can oscillate under the impact force of water flow,resulting in the swing angle force to break the blocked bio-film,which effectively prevents the blockage caused by the adhesion of the bio-film in the adjacent section.The bio-fillers are ar-ranged in a regular triangular cross arrangement,thus realizing the good contact be-tween the low resistance of water flow and the bio-film.Comparing the impact re-sistance of steel,PVC and bamboo rigid frameworks,the most rigid steel frameworks were selected,whose impact resistance was 10.2 times higher than that of traditional soft bed frameworks;the load-bearing capacity of nylon wire rope stereo bio-film frameworks was over 2 times higher than that of traditional ones;the film-hanging ca-pacity of the bed was 768 mg/L within 20 days,which was 2 times higher than that of the traditional floating bed.The service life of the bed is 7 years long,which is 3.5 times as long as that of the commonly used bed in engineering.It lays the foundation and equipment guarantee for the wide water area and the different use of the black and odorous water body in rivers and lakes.Second,the engineering application features of rigid three-dimensional bio-bed in water with different flow velocities were studied,and the zonal purification mode of rigid three-dimensional bio-bed was studied by using the integral movable features of rigid three-dimensional bio-bed.The results showed that in the 1100 m³static flow wa-ter area（Yuhuangshan South Fundation Town）,the paving rate was 0.6%.After 30 days operation,COD_Cr,TN and TP are reduced by 33%,20%and 10%respectively com-pared with the original water.Compared with the in-situ purification without moving,it saved at least 9.4 days and 2/3 of the cost.The anti-blockage ability of the bed and the feasibility of engineering application wer studied in the high-speed water body（Daxi river in Wenling city as an example）.The results showed that the change of water flow could produce 5.6-8.5 N peeling force on the bio-film,and the anti-blockage effect was remarkable.After 15 days of operation,when the coverage rate was only 2.8%,COD_Cr,TN and TP were reduced by 9%,9%and 8%respectively compared with the original water,and the annual cost of the project was only 0.38 times of the traditional artificial floating island technology.When the rigid three-dimensional bio-bed was transported to other areas of polluted water,the bio-film could directly be used to purify the water and the quick start was realized.The start-up time was shortened from 20days to 1 day,which not only realized the repetition of the rigid three-dimensional bio-bed but also reduced cost,construction and governance time.The rapid start-up of trans-porting in different places,the application of rigid three-dimensional bio-bed in the re-gional treatment of wide static water area and the anti-blockage application in high-speed water provide technical support and reference for the efficient and low-cost treat-ment of black and odorous water body.Finally,in view of the problem of high pollution load and limited use of traditional bio-ecological technology in unmanaged areas,this paper developed the coupling treat-ment technologies of anaerobic hydrolysis,ferrous sulfate electro-catalytic pretreat-ment and rigid bio-bed,respectively.The results showed that the anaerobic hydrolysis module was applied to the domestic sewage outlet of Yuhuangshan Foundation Town as a pretreatment technology.After 55 days of operation,COD_Cr,TN and TP reached the"Surface Water Environmental Quality Standard"（GB3838-2002）type-V water standard.Ferrous sulfate electro-catalytic module was applied to the industrial sewage outlet of Daxi river in Wenling city as a pretreatment technology.After 8 months of operation,the removal rates of COD_Cr,TP and TN are 69%,65%,86%and 73%re-spectively.The rconcentrations of COD_Cr,TP and TN are promoted to the water of type-IV,and the purification effect was obvious,which provided technical guidance and case reference for the popularization and application of large-scale projects.