application of barley straw to remove nitrate from drainage water

Nowadays farmers often use nfertilizers to increase crop yield, but they lost quickly by leaching causes environmental contaminations that reported as most important source of pollutant. although biofilters are useful for removing nitrate from drainage water, but many researches show that they need an external carbon source to sustain denitrification. many researchers study on different method, but most of them need equipment or material that becoming use in laboratory experiment. so this study describes laboratory experiments that investigated nitrate removal with barley straw in different percentages layered or mixed with soil. results showed that layering method was more effective for removing nitrate. the percentage of optimum volume mixture of barley straw in layering and mixing methods was 20% and 30% respectively, both removing approximately 80% of the influent nitrate. so barley straw can be used in a layered form as an effective, prompt, feasible and inexpensive method to remove nitrate.