Application of Vacuum Freeze Drying Technology in Sludge Treatment
Sludge is a by-product of sewage treatment, and it is a composite product of various colloids, organic matter, and inorganic matter. The untreated sludge has a complex composition. In addition to ash, it also contains a large amount of organic matter, refractory organic matter Various trace elements, pathogenic microorganisms, parasitic eggs, heavy metals and salts. Sewage and sludge systems are complex and have many interfering components, which brings certain difficulties to the analysis. Therefore, it is required that the method of removing impurities and other components must be reasonable and effective. In addition, due to the low content of the target compound (usually at the trace or ultra-trace level), in addition to ensuring the sensitivity of the analytical method, the method of removing impurities is also required to the target research group. The safety of the centrifuge is due to the fact that ordinary drying methods have a certain destructive effect on certain research components. Therefore, vacuum freeze-drying technology is used as an effective method for drying sludge in such studies. When Li Anan and others studied the glycan bacteria in the sludge system, the pretreated sludge sludge cake was freeze-dried for 24 hours and used in the follow-up research; Ye Xin [2] et al. In the activated sludge 6 In the article of quantitative determination of endocrine disruptors, the pretreated sludge was freeze-dried for one week, and then used a 100 mesh nylon sieve for subsequent analysis; , Chen Yuehua [3] directly lyophilized the collected sludge, and then grinded it into a powder, passed through a 40 mesh sieve, protected from light and used for subsequent analysis; Chen Jianhua [4] et al. After freeze-drying the pretreated sludge for 48 h, the freeze-dried sludge was crushed in a mortar and sieved through a 60-mesh standard sieve for subsequent analysis. After pretreatment of the sewage sample, it was freeze-dried for 6 hours Used for follow-up research; Shen Gang [5] and other phenolic endocrine disruptors in sewage and sludge analysis, freeze-dried for one night and then screened for analysis. From the published literature, freeze-drying is required for the analysis and research of certain trace or ultra-trace substances in sewage or sludge, and freeze-drying is also required for the study of some fungi. Whether the sample needs to be pre-treated before lyophilization is determined by the specific experimental design, and whether it needs to be ground or sieved after lyophilization is also based on the condition of the sample and the needs of subsequent analysis. Zhejiang Hisun Electrical Appliance Co.,Ltd , https://www.cn-hisun.com