| As the foundation of humans' life,water is the essential natural resources in people's life and the support for the sustainable development of any kind of societies.However,with the industrial and agricultural development as well as the population growth in China,large amounts of wastes generated from various industries are discharged into the water,resulting in serious pollution to our water environment.As China Environmental Status Bulletin issued in 2015 shows,water quality monitoring results from 967 surface water control section nationwide has indicated that from Class ? to poor-quality ? Class water quality sections respectively account for 35.5%.Furthermore,public security incidents have frequently occurred in recent years,where the breakout of water environmental pollution has influenced the urban water supply,seriously affecting people's lives and economic production and causing baneful social influence.According to statistics,there were 271 public health events of water pollution breakout in China from 1996 to 2006,affecting an accumulative total of 7 million people.Among these events,there were respectively 171 cases of biological pollution,92 cases of chemical pollution and 8 cases of mixed pollution,respectively accounting for 63.1%,33.9% and 3.0%.To effectively control the pollution on the water environment,the state has successively formulated the relevant laws,regulations and standards,and meanwhile vigorously implemented the research on the water pollution control technology.The current water pollution control methods mainly include the physical method,the chemical method,the physical-chemical method and the biological method.Adsorption technology has been widely used in water pollution control due to its advantages of easy operation,renewable,easy to control &management as well as the strong impact load capacities for the water quality,water temperature and water volume change.Although the adsorption technology has been widely used in the treatment of physical pollutants,chemical contaminants and biological contaminants in the body of water,it cannot meet the actual demand for water pollution control due to the weakness in the limited adsorption capacities of many adsorbent materials,the difficult regeneration and high requirements on the water quality.Mainly targeting on issues of the organic matter,heavy metals and virus contamination in the water environment,this research takes advantage of the feature of the adsorption technology that various pollutants could be adsorbed and investigates adsorption efficiency of Activated Carbon Fiber(ACF)for organic contaminants in water.The research utilizes nitric acid to oxidize the activated carbon fiber to change its nature,thus to observe the adsorption effect of heavy metal pollutants.The research also applies the method of coating column-layer chromatographic silica gel with positive charge gel to prepare the cation-loaded adsorbent materials for the virus adsorption in the water and establishes a set of device and the method to gather the virus in large water samples.1.Used the activated carbon fiber to adsorb the aniline in the water: ACF is a kind of ideal high efficient adsorption material based on carbon fiber technology.The ACF surface area is full of orifices and groove-shaped,enabling ACF to have features of easy adsorption and desorption,short routes in the adsorption and desorption as well as big driving forces.Therefore,ACF has advantages of fast adsorption and desorption,a big adsorption capacity and high efficiency.ACF adsorption isotherms of aniline with the Freundlich adsorption model.At the same equilibrium concentration of aniline,It is found that the dosage of ACF is greater at 303 K than 293 K.The adsorption of aniline by ACF was greatly affected by p H value,and the adsorption efficiency increased obviously with the increase of p H value in the solution.The optimum p H should be maintained between 7 and 8 in the adsorption environment during the aniline adsorption,and this condition can give full play to ACF's adsorption of aniline.2.Used the activated carbon fiber to adsorb the heavy metals in the water: using nitric acid to implement modified process on ACF,the quantity of the oxygen-containing acidic functional groups on the modified ACF has significantly increased compared to the quantity before the modification,which has risen to 1.846 mmol/g.Moreover,the quantities of the carboxyl group,lactone group and phenolic hydroxyl group on the surface of the modified ACF have all increased,and the carboxyl group content increased from 0.012 mmol/g to 0.848 mmol/g,respective account for 78.87% of the total of the groups,indicating that nitric acid's modification on ACF is mainly the increased in the number of carboxyl groups on the ACF surface.The p HPZC of the modified ACF is reduced from 4.47 before the modification to 2.43.With the increase of acidic groups on the surface of ACF,the adsorption efficiency of modified ACF increased from 45% to more than 95%,and the adsorption rate increased by nearly 3 times in the fast adsorption stage.3.Used the cation-loaded adsorbent material to enrich viruses in large water samples: applying the gelling method of coating 60-100 column-layer chromatographic silica gel with positive charge gel to prepare the cation-loaded adsorbent material.As the scanning electron microscopy result shows,the cation-loaded adsorbent material is the layer of gel coated on the silica gel surface with the average particle size of 271.59 ?m.Fill the plexiglass filter column with the inner diameter of 84 mm and the height of 40 cm with the prepared cation-loaded adsorbent material,and finally the height of the cation-loaded adsorbent material is 30 cm.After the filtration on the 100 L water sample containing the coli phage f2 at a concentration of 102 PFU/m L,and the cation-loaded adsorbent material has the 4 recovery rate for coli phage f2 of over 90%.The elution effects from 5 elutes for the virus on the cation-loaded adsorbent material are respectively tested,including triple nutrient broth,3% beef powder,glycine,glycine mixed with the triple nutrient broth and glycine mixed with 3% beef powder.The result shows that only the glycine has recovery rate of about 60%,much lower than the other four types of eluents.By the segment detection on the contents of coli phage f2 in their first concentrated solutions,it's discovered that only the external eluent of the glycine mixed with the triple nutrient broth has no tail-out.Therefore,the glycine mixed with the triple nutrient broth is determined as the eluent in this method.Through tests on each parameter of the gathering method,the optimum flow rate in the gathering process is determined as 500 m L/min;the recovery rate of E.coli phage f2 are very stable when the p H values of the water samples are within the range of 5-9 and the temperature is between 4 ° C and 30 ° C,which is maintained above 90%;The bacterial concentration in the water has little effect on the E.coli phage f2.Compared with 1-MDS membrane method recommended APHA from US,the gathering method with the cation-loaded adsorbent material has the advantages of low requirements on the water quality and a high recovery rate.Through the tests on the virus enriching effects in different water bodies,we found that the cation-loaded adsorbent material has good enriching effects for viruses in the tap water,surface water and hospital sewages from different regions.In conclusion,this research has implemented detailed tests on ACF's performance of removing the organic aniline from the water,meanwhile applies the nitric acid for the ACF modification and observes modified ACF's removal efficiency for the heavy metal lead in the water.There's a rapid removal process of aniline and lead(about 5 min)for ACFs both before and after the modification,and the aniline and lead removal efficiency is above 80% in the equilibrium.Homemade cation-loaded adsorbent material have good gathering effects for viruses in large water samples,and when the glycine mixed with the triple nutrient broth is the eluent,the flow rate is 500 m L/min;the p H value is within the range of 5-9 and the temperature is between 4 ° C and 30 ° C,the recovery rate could be above 90%.Based on the adsorption technology,this research respectively tests the effects of ACF's removal of organic matter-aniline in the water,modified ACF's removal of heavy metal-lead in the water and homemade cation-loaded adsorbent material's enriching effect for viruses in large water samples,and all of them have achieved good results,indicating that the adsorption technology has a wide range of application prospect in China's water pollution control. |
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