Removal of nitrate, nitrite from contaminated water was done by two methods. First using pseudomonas and E-coli bacteria isolated from Howaizek River in Bekaa, second using activated carbon prepared from wheat husk. The first test was by using pseudomonas aeruginosa under aerobic and anaerobic conditions, and it was found that the best removal of nitrate and nitrite was in the presence of oxygen. Also, different carbon sources such as 0.05g of glucose and 1% starch were tested and the results were more efficient by using 1% starch as a carbon source. The best result was found that the treatment of nitrate by pseudomonas bacteria with 1 % starch solution and in the presence of oxygen was 88.46%. Influence of contact time, adsorbent dose, nitrate and nitrite concentrations, pH and temperature were investigated. The experimental data were analyzed by the Langmuir, Freundlich and Temkin adsorption isotherms and the results revealed that Langmuir isotherm fitted the experimental results well. Kinetic analyses were conducted using pseudo first and second-order models and the intraparticle diffusion model. The regression results showed that the adsorption kinetics was more accurately represented by a pseudo second-order model, and the maximum capacity was calculated and it was found equal to 156.25 mg of nitrate per 1g of adsorbent. It was also found to be a spontaneous, endothermic. Removal of acid orange dye from contaminated water also done, and the adsorption process was studied and it was found to be best fit by the Langmuir isotherm model and the maximum capacity was calculated and it was found equal to 217.39 mg/g. It was also found to be a spontaneous, endothermic, pseudo second order process that proceeded with an increased randomness at the system and the mechanism of adsorption showed that it is intraparticle diffusion. Column study was also conducted and the column attained saturation after the addition of 1360 ml of acid orange for cycle 1 and the column capacity was 186.1 mg/g.