A series of sand filters in the shape of a “U” are an inexpensive option to to the treatment of nitrogen pollution. This filter system was contained three compartments. Each compartment was contained two columns, a filter column and a settling one. The size of filter media decreased successively in the direction of water flow. This disposition of layering increases solids absorption et adsorption. However, the filter sand depth and media grain size can impact their treatment efficiency. Thus, the effect of sand filter depth and media grain size upon treatment kinetic was studied. To do this, three (3) sand depth (60, 70 et 90 cm) was studied. The results show that the filter bed depth of 90 cm was the most efficient for nitrogen removal. However, the coarse shales provide a good reduction of ammonium and Total Kjeldahl nitrogen in the filtrates compared to the other media grain size. Shale medium and lagoon sand are efficient in the nitrate removal and chemical oxygen demand. The results obtained show that the filter of 90 cm of mean shale and with lagoon sand is an efficient technology for treating nitrogen urban wastewater.