Research On Biochemical Clogging Of GWHP Prevent And Control In Shenyang Shengjing Hosipital

Groundwater source heat pump in the domestic is developing very rapidly in recent years,a nd its use area has more than 5 500 square meters in Shenyang city.However,due to the current domestic groundwater recharge technology is not mature,recharge-clogging problem becomes th e bottleneck of the development of it.Currently,researches on the physical,biological and other single factor clogging are already quite mature;however,the study on complex biochemical clog ging is rarely involved.This study opened up a new direction for the research of clogging by studying the biochemical complex clogging mechanism.At the same time,the research on prevention and control technology of it can make sure the efficiency of the recharge operation and safety management of the project.It has important theoretical and practical significance for promoting the development of groundwater source heat pump.This paper took groundwater source heat pump project of Shenyang Shengjing Hospital as an example.The arrangement of monitoring points and monitoring,introducing the spatial variability theory,analyzed the spatial variation characteristics of underground water level,water temperature and ion concentration in Shenyang city and the research project location.Setting up the flow of water,water temperature and water quality mathematical model,simulated the operation of subway line 9 impact to the project,in view of the existing safety problems put forward the corresponding security technical measures.the problems existing in the operation of the project injection test,analyzed the problems existing in the recharging of the operation project,concluded that the blockage of main impact factors,Through indoor recharging test,analyzed the biochemical compound plugging mechanism and the impact of the content of iron bacteria,iron and manganese ion on the biochemical complex clogging.Put forward the prevention and control technology and measures of the biochemical complex clogging.Through the above theoretical and experimental study,obtained the following conclusions.(1)Two-thirds of the area of iron ion concentration exceeds 0.3mg/L,a quarter of the area of manganese ion concentration exceeds 0.1 mg/L in Shenyang City.Among them,the Tiexi District and Heping District are high iron and high manganese areas;the project site area belongs to a high manganese and low iron area,which exceeded more than 10 times.(2)After put the subway line 9 after into production,there were seven recharge wells beyond the ground elevation on the water level,posing a safety hazard.The water and the solute were relatively stable and within the standard limitation.Recharge well position in carrying out a research project to decorate,was lower than the safety limit water level simulation results,which can to ensure the safety of recharge.(3)Water samples on the project and fouling substances were detected.It proves the presence of iron,manganese ions or precipitates and iron bacteria in both of them.Moreover,iron bacteria can promote divalent iron ions oxidation which also be proved through the test.(4)The results of lab recharge tests show that iron and manganese oxidation rate increased by 5 times or more than the pure chemical reaction rate under the action of iron bacteria.The obvious clogging occurred ahead of time.There are a small number of iron bacteria in the recharge water trapping inside the porous medium,growing and reproducing.However,there is no certain regularity for rest of them in the effluent.In recharge wells surrounding porous media,the increase of iron ion content will increase the number of iron bacteria around the recharge wells.The increase of manganese ion content has less impact on the iron bacteria.Iron,manganese ion concentration and the logarithm of iron bacteria count have positive correlation.And they have good correlation.This can imply that iron bacteria are a key factor in complex biochemical clogging.The increase of iron ion content and iron bacteria will cause aggravated degree clogging and making clogging ahead of time.(5)According to the biochemical complex clogging of the research project,setting device for removing iron and manganese ions at water outlet and impressed current cathodic protection technology can be used to control clogging for it.At same time,cooperating with rotary high-pressure water jet washing wells and regular moderate back pumping to reduce congestion degree,can ensure the purpose of the injection efficiency.And they can also be extended to other clogging control which are occurred by complex biochemical factors.Selecting the appropriate filter material,coating the inside of recharge filter with anti-corrosion materials,optimization project site and rational design recharge process can be used to prevent biochemical clogging.This study explore the biochemical complex clogging mechanism at the first time,analyzed the iron bacteria and iron and manganese ions effects on this kind of clogging.At the basis of completing recharge clogging mechanism research of the national natural science fund project,combining with the actual research project——the characteristics of ground water source heat pump project of Shenyang Shengjing Hospital.Put forward the effective prevention and control measures.