| Due to the implementation of the two-carbon policy,the heat of environmental protection is revived.Direct discharge of waste from potato starch processing will not only pollute the environment,but also cause material waste.At present,the consumption of waste treatment is far greater than the income,so the treatment method is difficult to popularize.In this experiment,the content of each substance in waste water and waste residue of potato starch processing waste was measured and analyzed along with the storage time,in order to explore the best treatment time or reuse time of organic pollutants in waste.In addition,bentonite and fly ash were used as additives to prepare soil amendments A and B from potato starch processing wastewater and waste residue.The optimal treatment technology was explored by measuring the contents of ammonium nitrogen,nitrate nitrogen,available phosphorus and available potassium at different addition ratios and treatment times.The reasons for the changes of various substances in waste and soil amendments were studied and discussed by correlation analysis.The results of this experiment are as follows:1.The four substances detected in wastewater were ranked by the highest content(mg/m L)as reducing sugar(8.49)> anthocyanin(0.26)> total phenol(0.03)> flavonoid(0.003).Among them,flavonoids are not easy to use;Reducing sugar is best used immediately after wastewater production.Anthocyanins are best used around the 3rd day of storage.The optimum utilization of total phenol was around the 7th day.According to the highest content(mg/g)of the eight substances detected in the waste residue,the order was as follows: pectin(184)> acid detergent fiber(71)> protein(30)> reducing sugar(9.3)>fat(3.2)> flavonoids(0.08)> anthocyanins(0.016)> total phenols(0.009).Among them,total phenol is not easy to use;Acid detergent fiber,fat,flavonoids are best used immediately after the production of waste residue;The best utilization of pectin and reducing sugar was around the third day of storage.Anthocyanin is best used around the7 th day of storage.It was found that most enzymes were damaged during starch processing,and the preservation time of each substance in potato was reduced,and there was a significant positive correlation between some substances(P < 0.05).In addition to the pollution caused by the above organic matter,the waste also contains a large number of nitrogen and phosphorus compounds,which will increase the risk of water eutrophication if discharged directly without treatment.Therefore,this experiment further explores the way to realize the reuse of potato waste while solving the problem of eutrophication.2.The test results show that the optimum addition amount of bentonite is 3 g and the optimum treatment time is 1 d for treating 10 m L wastewater.Under these conditions,the maximum conversion benefit of soil conditioner A can be guaranteed.Under these conditions,ammonium nitrogen content is 5.9 mg/100 g,nitrate nitrogen content is 0.62mg/g,available phosphorus content is 0.17 μg/g,available potassium content is 2.5 μg/g.The optimum amount of fly ash is 25 g and the optimum treatment time is 21 d.Under these conditions,the ammonium nitrogen content of soil amendment B is 0.98 mg/g.The optimum addition amount of fly ash was 10 g and the optimum treatment time was 3 d.Under these conditions,the content of available P and available K of soil amendment B was high,which were 22.5 μg/g and 59.5 μg/g,respectively.In addition,it was found that potato waste residue can promote the release of potassium on fly ash,indicating that soil amendment B has internal interaction to promote the release of elements,which proves that the soil amendment can provide nitrogen,phosphorus and potassium nutrients for soil,create a suitable growth environment for plants,and ensure the normal development of plants.The above results show that potato starch processing waste under natural storage conditions,according to different treatment methods,utilization methods,extraction substances,select different storage time before reuse,can effectively reduce the environmental oxidation pressure and reuse efficiency.In addition,the soil amendment prepared from the waste is low-cost and controllable,which can effectively solve the problem of pollutant eutrophication,and provide a theoretical basis for the reuse of potato starch processing waste. |
