| In this experiment,a self-made inorganic mineral material flocculant,acid-modified vermiculite flocculant was used.Based on the experimental results of the flocculant in the beaker,a complete continuous flocculation device consisting of a fast agitation tank and a slow agitation tank was designed.The effects of inorganic mineral vermiculite flocculant on the turbidity and COD removal rate,zeta potential and sedimentation velocity of organic colloidal milk simulated wastewater were investigated and compared with traditional inorganic flocculant PAC.The device is mainly composed of a vermiculite flocculant feeding device,a waste water feeding device,a quick stirring tank,a slow stirring tank and a water collecting device.The optimization operation can be realized by changing the feeding mode and the stirring speed,and the solid basic data is provided for the industrial application.At the same time,the shape and size of the quick stirring tank and the slow stirring tank are also changed for comparison.The experimental results show that:Although the effluent turbidity and COD removal rate of the continuous flocculation unit are lower than those of the intermittent beaker test supernatant,the highest can reach 95.8%and 77.6%,respectively,compared with the conventional PAC under the same operating conditions,even under the optimal conditions of PAC.The effluent turbidity and COD removal rate were only 39.3%and 33.2%.The acid neutralization effect of the acid-modified vermiculite flocculant and the settling velocity of the formed flocs are better than the traditional PAC.Under the optimal dosage,the zeta potential of the supernatant is close to 0 mV,and the flocs are easy to flocculate,while the PAC It is-6mV,which is difficult to compress and loose.The slow agitation tank is not only the location of the flocculation process but also the location of the sedimentation process.The accumulated flocs adsorb and collide the unstabilized colloids and COD contaminants.These two synergistic effects are beneficial to the removal of contaminants during continuous flocculation. |
