| Always the concentration of the inlet wastewater which loads the wastewater treatment plants(WTP) in South China is much lower than the expected level in the design stage,which not only makes the operation and management of plants become very difficult,but also leads to the vast waste of funds and energy.In fact,the low or medium concentration wastewater after primary or enhanced primary treatment can also meet the discharge requirements.Hence the technology of enhanced primary treatment of municipal wastewater has much significance to most cities in South China. In this dissertation, experiment and mechanism of essential activate diatomite as adsorbent for the treatment of low strength municipal wastewater was studied. The main parameters, which affect the absorbing process, including diatomite dosage, the ratio of acid equivalent to diatomite, concentration of sulfide acid,activation time and so on. Experimental results showed the following regular patterns: under the hydrodynamics condition ofGTreact=0.430×104,GTmix=2.750×104,and 15min's sedimentation.the best static adsorption parameters are as following: diatomite dosage was 5mg/L, the ratio of acid equivalent to diatomite was 1.1, concentration of sulfide acid was 12.3%, activation time was 3 days.At last,an elementary analysis was given to discuss the flocculation mechanism of the activate diatomite. Experimental results showed that, under the best parameters, the adsorb ratios of turbidity, COD, ammonia-nitrogen are 98%, 62.2% and 16.3%. From the characteristic of diatomite adsorbing low strength municipal wastewater, we can conclude that when it used in pretreatment process it can remove SS efficiently which will create a better condition for later treatment.It's a very wonderful technology in enhanced primary treatment to municipal wastewater. |
