The treatment of industrial liquid wastes is placed in a wide context of technologies and is related to the high variability of the influent physical–chemical characteristics. In this condition, the achievement of satisfactory biological unit efficiency could be complicated. An alternate process (AC) with aerobic and anoxic phases fed in a continuous way was evaluated as an operative solution to optimize the performance of the biological reactor in a platform for the treatment of industrial liquid wastes. The process application has determined a stable quality effluent with an average concentration of 25 mg TN L−1, according to the law limits. The use of discharged wastewaters as rapid carbon sources to support the anoxic phase of the alternate cycle, realizes a reduction of TN of 95% without impact on the total operative costs. The evaluation of the micro-pollutants behaviour has highlighted a bio-adsorption phenomenon in the first reactor. The implementation of the process defined 31% of energy saving during period 1 and 19% for the periods 2, 3 and 4.
Keywords: energy savings, industrial liquid wastes, micro-pollutants bio-adsorption, nutrient removal, operating configurations, plant upgrading