Activated carbon modified by HNO_3 was used as an adsorbent for orange G wastewater treatment. The effects of activated carbon dosage,reaction time and salt concentration on orange G adsorption were studied. The adsorption isotherm and adsorption kinetics were also investigated. The results showed that orange G was adsorbed quickly in 0 ~ 10 min,when the activated carbon dosage was 2. 5 g / L,the removal rate of orange G reaches 95. 5% in 40 min. The presence of NaCl with high concentration has little impac...