Study On The Utilization Of Fatty Acid Wastewater

This paper summarizes the treatment methods and technologies of fatty acid wastewater and similar wastewater.Because of its high acidity,high COD,high salt and high chroma,wastewater is very harmful to the environment and difficult to treat.How to make fatty acid wastewater resource is an important problem in this field.The purpose of this paper is to study the utilization of fatty acid wastewater from three aspects.(1)Recovery of chemical products mirabilite and glycerol.Sodium hydroxide was used to adjust the pH value to 6,and the crude mirabilite was purified by recrystallization after standing at 16 ? for 2.5h.The total recovery was 55.17%,and the purity was more than 95%.After the mirabilite was separated,1.7 times volume of ethanol was added into the waste water,and 10 ml of liquid was separated by silica gel column to obtain glycerol.The yield of glycerol was 12.336g/l,and the infrared matching degree was 96.56%.The silica gel column was regenerated with 10mL1:1acetic acid.(2)Preparation of bacterial protein.Firstly,the photosynthetic bacteria were domesticated,the growth curve was drawn,and the harvest time was 72 hours.Then,the effects of light,the amount of nutrient solution,urea and the amount of bacterial solution on the yield of bacterial protein were investigated,and the optimal growth conditions were determined: 1:1 mixture of wastewater and sterile water,1000 mixture Ml,add 10 ml of nutrient solution,2.0g of urea,use calcium carbonate and sodium bicarbonate to control the pH of the solution between 7 and 8,inoculate 20 ml of photosynthetic bacteria solution,put it into a constant temperature water bath shaker,and adjust the temperature to 30?.Under the condition of 40 W incandescent lamp and other illumination,the culture time was controlled at 72 h.The yield of bacterial protein was 112.2g/l and the content of protein was 35.85%.Finally,theapplication experiment and feeding experiment for one month showed that the growth condition of the fish was good,which proved that the bacterial protein could be used as the bait of the fish.(3)Preparation of bioflocculant.Using yeast as Angel yeast,the strain XXH was domesticated with fatty acid production wastewater.It was identified as Fusarium fujikuroi.The results showed that the activity of supernatant was lower than that of sediment.Therefore,the main purpose of this experiment is to study the precipitate,which is named flocculant XXH-F.Through ninhydrin test,biuret test,thermal stability test and infrared spectrum characterization,it is proved that xxh-f contains protein.After quantitative analysis by Coomassie brilliant blue test,its protein content is 12.15%;after Mohs test,Fehling test and infrared spectrum characterization,XXH-F contains polysaccharide.After phenol sulfuric acid test,its polysaccharide content is 29.17%.The effects of pH,temperature,rotation speed and growth curve of the solution on the yield and flocculation rate of XXH-F flocculant were investigated.The results are as follows: when the volume of water sample is 200 mL,adjusting pH value of wastewater with sodium hydroxide is 9.0,rotating speed is 150R/min,controlling culture temperature is 30?,and culture time is 96 h.The reproducibility experiment showed that the average yield of flocculant XXH-F was 1.2529g/200 mL wastewater,RSD was 0.19%,average flocculation rate was 99.1%,RSD was 1.1%.In the experiment of flocculation conditions of XXH-F,4g/L diatomite suspension was used as the treatment object,and the concentration of flocculant XXH-F solution was 0.5g/L.The effects of the dosage of flocculant XXH-F solution,the type of coagulant aid,the dosage of coagulant aid solution and sample pH on the flocculation effect of flocculant XXH-F were investigated.The results are as follows:take 100 ml concentration as 4g/L,pH value was adjusted to 7,the best dosage of flocculant is 3mL,use 5ml of 1% CaCl2 solution as coagulant aid,stir quickly(near200r/min)for 3min,slowly(near 50r/min),and then settle for 30 min.Thereproducibility test showed that the average flocculation rate of the flocculant XXH-F to the diatomite solution was 99.2%,RSD was 0.09%.At the same time,the flocculant of XXH-F is also discussed.In conclusion,fatty acid wastewater can be recycled and treated innocuously in the future after a series of experiments.