Study On Separation Of Protein From Potato Starch Wastewater By Functional Materials

Potato production starch wastewater,is a highly concentrated,highly polluted acidic organic wastewater,when entering the ecological environment,the organic matter it contains will naturally ferment to produce H₂S,NH₃,and other polluting environmental gases,causing serious pollution of the ecological environment.At the same time,potato production starch wastewater is rich in protein,is a high-quality vegetable protein,and has a great development and utilization value.Most of the potato production starch enterprises in Dingxi City were built in the 1970s to1980s,and the water treatment system was probably built in the 1990s,mainly for the original potato varieties,and the equipment can only handle potato production starch wastewater with low protein content.In recent years,due to the introduction of new varieties,the protein content of the potato itself has increased,leading to an increase in the protein content of the wastewater,so that the original water treatment facilities can not make the potato production starch wastewater after disposal to meet the standards of discharge.Therefore,before the potato production starch wastewater enters the water treatment facility,a protein separation process is added so that the protein level in the wastewater entering the water treatment facility is close to or lower than the protein content in the original wastewater,ensuring the stable operation of the water treatment facility and the discharge of the wastewater to the standard.The effect of different influencing factors,such as potato starch wastewater material-to-liquid ratio,functional material dosage,reaction p H,reaction time,and reaction temperature,on the separation of protein in potato starch wastewater,was investigated,and scanning electron microscopy and Fourier infrared spectroscopy were used to characterize the adsorption materials.The protein separation mechanism was investigated by using scanning electron microscopy and Fourier infrared spectroscopy to characterize the adsorbent materials:（1）Synthetic functional materials with better adsorption and separation effects were selected through orthogonal experiments:activated carbon loaded with iron chloride,zeolite loaded with sodium chloride,and magnesium silicate loaded with iron sulfate for protein separation experiments in potato production starch wastewater.The optimal conditions were found to be the following:activated carbon loaded with ferric chloride at a material-liquid ratio of 1:1.5,a dosage of 0.2 g,a reaction p H of 3,and a reaction time of 45 min.The separation rate of proteins in potato starch wastewater was 69.53%;the separation rate of proteins in potato starch wastewater was 81.00%for the synthetic functional material 2 zeolite-loaded sodium chloride at a material-liquid ratio of 1:1,a dosage of 0.2 g,a reaction p H of 3 and a reaction time of 30 min;the separation rate of proteins in potato starch wastewater was 81.00%for the synthetic functional material 3 magnesium silicate loaded ferric sulfate at a material-liquid ratio of 1:1.5 and a dosage of 0.6 g,The separation rate of protein in potato starch wastewater was 75.75%at a dose-to-liquid ratio of 1:1.5,a dosage of 0.6 g,a reaction p H of 4and a reaction time of 60 min.The effect of reaction temperature on protein separation was not obvious in the range of 20-40°C but increased slightly when the temperature was higher than40°C.（2）Experiment on the separation of proteins from potato starch production wastewater by naturally modified materials.Potato production starch wastewater after adjusting the material-liquid ratio,the number of functional materials added,reaction p H,reaction time,reaction temperature,and other factors,to explore the effect of protein separation in potato production starch wastewater,found that the optimal conditions:soybean straw material-liquid ratio of1:1.5,the amount of 0.3 g,the reaction p H of 3,the reaction time of 3 h,the separation of protein in potato production starch wastewater The separation rate of protein in potato starch wastewater was 72.11%.The separation rate of protein in starch wastewater from potato production was 79.00%for a wheat straw at a ratio of 1:1.5,a dosage of 0.3 g,a reaction p H of 4,and a reaction time of 7 h.The separation rate of protein in starch wastewater from potato production was 79.52%for sugarcane bagasse at a ratio of 1:1.5,a dosage of 0.4 g,a reaction p H of 4,and a reaction time of 3 h.The separation rate of protein in starch wastewater from potato production was 79.52%for sugarcane bagasse at a ratio of 1:1.5,a dosage of 0.4 g,a reaction p H of 4,and a reaction time of 3 h.79.52%.The effect of reaction temperature on the protein separation effect was not obvious within 20～40℃,and when the temperature was higher than 40℃,the protein separation effect in potato production starch wastewater increased slightly and the protein separation rate increased slightly.（3）The environmental safety evaluation of the naturally modified material after separating the proteins in potato production starch wastewater found that the heavy metal contents of total arsenic,lead,mercury,cadmium,nitrite,and chromium were all below the environmental risk.