Advances in Clogging Research of Artificial Recharge

The generation of clogging problem during artificial recharge of groundwater has something to do with the quality of recharge water source,mineral and grain characteristics of aquifer.According to the formation reason,clogging is generally divided into physical,chemical and biological types.Physical clogging generated by large particles was understood very well,but the clogging mechanism of intermediate and colloidal particles were not very clear.The mechanism of chemical clogging,which has lots of influence factors,is very complicated.The geochemistry modeling method will be a powerful tool to study the chemical clogging process.The biological clogging was induced by growth and metabolizable products of microbiology bodies in recharge water sources.Most of researches focus on the bacteria clogging,but much less on the algae clogging problems.During actual artificial recharge process,several clogging types usually take place together,but the predominant type is different in different time and space.Therefore,the interaction process and its mechanism is one of the difficult problems.There are three methods to predict clogging process: the first one is specific indexes,such as MFI,concentration of suspended solid,turbidity,AOC and BFR,etc.This kind of method is much easier to use,but it can not describe or quantify the evolution process.The second method is experiential way,which is limited by specific field sites,and hard to use directly.The third method is analytic model,which is more scientific and reasonable than above methods,but it is hard to set and solve the analytical model.With appropriate pre-treatment of recharge water quality and recharge technologies,the taking place time of clogging can be delayed and the clogging degree can be lighten.Developing the rapid,efficient and simple technologies is very useful to prolong the longevity of recharge facilities and to reduce the economic cost.