Study On Removal Of Low Ammonia Nitrogen Pollution In Groundwater Using Multi-layers Permeable Reactive Barriers At Low Temperature

The treatment of pollution of ammonia nitrogen in water at low level is difficult and complex. When the groundwater which supplied by surface water with low concentration of ammonia nitrogen used as water supply source, it is much difficulty to clear. The groundwater temperature always keeps at below about 15°C. The dissolved oxygen in groundwater is so low that it will inhibit the microbes growth as a most important factor. As is known, the anaerobic ammonium oxidation must be affected by the two reasons. So the low growth of bacteria makes the ammonia nitrogen difficult to transformation.The research of low concentration of ammonia nitrogen pollution [no higher than 15mg/l) in groundwater by situ processing technology deserves extensive concerned but the researches and applications of ammonia nitrogen treatment usually talked in the field of surface water treatment. The results of the study indicate that: multi-permeable reactive barriers in situ repair technology can create more comfortable environment for microbial growth and promote anaerobic condition ammonium oxidation bacterial growth and reproduction. As in-situ remediation technology M - PRBs can make the ammonia nitrogen in groundwater achieve water-supplied standard at low temperature [10°C - 15°C) in simulation and no secondary pollution occurs.Simulation for groundwater flow speed at about 1m/d, use different medium composite ratio three different sets of experimental columns and make them runs at the same speed with a long time it can be found by the sampling points of different pillars with the same cycle sampling that:1) In a single zeolite existence condition, in initial [posts about 6 hours), zeolite absorption function with ammonia oxidation appeared; Output of the water containing nitration nitrogen only. The process lasts about 1 mouth.2) Mixed columns with zeolite and ceramic. In Ceramic total nitrogen significantly changed before entering the zeolite column [column 2), ammonia nitrogen be consumed in four weeks or so. Outflow water standard required be satisfied at about 7mg/l totally.3 ) In the cast iron granules, zeolite and ceramic complex match columns, part of ammonia nitrogen was turn into denitration nitrogen and denitration nitrogen, part of ammonia nitrogen was adsorpted in the second column, which was fulled with iron and ziolite. The outflow had nothing left, "three nitrogen" have been completely removed. The use of iron needs to be further researched.