Fluidised Bed Heterogeneous Catalytic Oxidation Treatment Of Industrial Wastewater Thiocyanate

Fluidized bed apparatus with heterogeneous catalytic oxidation process simulation gold leaching wastewater of thiocyanate. Experiments by spectrophotometry measuring the concentration of SCN- waste water, and then compared the coconut shell charcoal, coal char, orange shell charcoal, molecular sieve effect of the four load carriers, and characterized by XRD, BET. Found that coconut shell charcoal, whether or pore surface area is higher than the other three carriers,loading the best optimal effect. Followed by impregnation method Cu, Fe, Ni three catalysts supported on the carrier, investigated the effect of differences in their catalytic oxidation. Catalytic effect of Cu was found superior to Fe and Ni.After choosed the carrier and heterogeneously catalyzed oxidation catalyst, then we investigated the effect of immersion time, immersion temperature, dipping concentration, calcination temperature, different Cu salts and other liquid impregnating the catalyst produced. It was found that the concentration of impregnating 025 mol / L, the immersion time is 24 h, calcination temperature of 300 ℃, the produced catalyst’s catalytic effect are the best.After making sucess catalyst, then we investigateing the influence: the dosage of catalyst, initial concentration, flow rate, aeration, pH and temperature on the catalytic oxidation effects. It found that when the initial concentration is certain, choosing the dosage of catalyst is 3 g/L, the initial concentration of aeration rate 21 L / min, pH 6-7, temperature 30-40 ℃,the catalyst removaltion can reach up to 90%.At the experiments of Catalyst regeneration,we choosing acid treatment, alkali treatment, and water soaking method which were commonly used in the chemical treatment methods. First, we compared the speed of 0, 100, 200, 300 r / min and ultrasonic cleaning conditions’ s regeneration effect. Secondly, the effects of the concentration of acid and alkali, the effects of regeneration temperature and regeneration time on the regeneration of catalyst were studied. The study showed that ultrasonic treatment was superior to other techniques, and the regeneration rate of acid treatment was higher than that of alkali treatment, and it was found that the concentration of acid, regeneration temperature and regeneration time were proportional to the efficiency of catalyst regeneration. When using ultrasound with acid treatment and control the acid regeneration concentration 2 mol / L, the regeneration temperature is 100 ℃,the regeneration time was 24 h.After repeatedly recycled the Cu / AC catalyst regeneration efficiency can still be reached more than 80 %. The effect of acid treatment on catalyst regeneration is obvious, and has good prospects for development.