麻辣兔肉丁的综合保鲜技术研究

根据栅栏因子保鲜理论,采用多种栅栏因子科学合理的组合,并通过改进工艺,对麻辣兔肉丁进行了综合保鲜研究。结果表明,添加复合防腐剂(0.05% Nisin、0.05% 溶菌酶、2% 乳酸钠)组成的天然复合保鲜液,采用瞬间翻炸、水浴热处理(85～90℃、水浴杀菌30min、2 次,中间急速冷却)的综合保鲜技术可使麻辣兔肉丁在常温下(15～20℃)贮藏240d。     

Hydrogen peroxide production by water electrolysis: Application to disinfection

Hydrogen peroxide was produced by direct current electrolysis using only two electrodes, a carbon felt cathode and a RuO₂ coated titanium anode. The required oxygen was supplied by oxidation of water and by transfer from the atmosphere or by pure oxygen injection. The current was maintained below a maximum value to avoid peroxide reduction. A high peroxide production rate was reached and a 15 mg l^–1 concentration was maintained. The electrolysis removed turbidity and dissolved organic carbonaceous compounds from municipal sewage plant effluents. Real effluents were significantly disinfected owing to the direct effect of electric current and the indirect effect of peroxide. A residual effect was also observed.     

磁场水处理的杀菌性以影响研究

本文主要进行了含菌水样经磁处理后杀菌性能的影响研究,发现磁场水处理的杀菌性能随pH值,温度和磁处理时间的升高而升高。     

饮用水消毒副产物生物毒性与调控策略的研究

饮用水消毒可以有效除去病毒、细菌等有害微生物,但消毒剂会与水中的有机物反应生成多种消毒副产物(DBPs),危害人类健康。基于对消毒副产物种类、生成及污染现状的探讨,归纳总结了DBPs的典型生物毒性及其毒性作用机制。为有效防控DBPs环境风险,深入探讨了针对去除DBPs前体物、优化消毒剂及消毒过程、DBPs毒性的调控策略。最后对DBPs生物毒性作用机制及调控策略的研究进行了展望,为DBPs污染防治提供理论与技术支持。     

Theoretical and Experimental Insight into the Mechanism for Spontaneous Vertical Growth of ReS2 Nanosheets

Rhenium disulfide (ReS₂) differs fundamentally from other group‐VI transition metal dichalcogenides (TMDs) due to its low structural symmetry, which results in its optical and electrical anisotropy. Although vertical growth is observed in some TMDs under special growth conditions, vertical growth in ReS₂ is very different in that it is highly spontaneous and substrate‐independent. In this study, the mechanism that underpins the thermodynamically favorable vertical growth mode of ReS₂ is uncovered. It is found that the governing mechanism for ReS₂ growth involves two distinct stages. In the first stage, ReS₂ grows parallel to the growth substrate, consistent with conventional TMD growth. However, subsequent vertical growth is nucleated at points on the lattice where Re atoms are “pinched” together. At such sites, an additional Re atom binds with the cluster of pinched Re atoms, leaving an under‐coordinated S atom protruding out of the ReS₂ plane. This under‐coordinated S is “reactive” and binds to free Re and S atoms, initiating growth in a direction perpendicular to the ReS₂ surface. The utility of such vertical ReS₂ arrays in applications where high surface‐to‐volume ratio and electric‐field enhancement are essential, such as surface enhanced Raman spectroscopy, field emission, and solar‐based disinfection of bacteria, is demonstrated.     

浅析空调净化系统的日常维护

在查看国内外文献、读书和实践的基础上,对空调净化系统各个部分的清洁消毒和维护进行讨论,包括高、中、初效过滤器的清洁更换、管道的清洁、仪表的校验、阀门的检查以及整个系统的消毒灭菌等,着重阐述其清洁消毒和维护的重要性,期望能够得到企业的重视。     

Comparison of chlorination and chloramination practices on microbial inactivation efficiencies within a scaled‐up water distribution network using central composite design

Disinfection practices reduce the incidence of water‐borne diseases but may result in formation of disinfection byproducts (DBPs) in raw water that are reported to be carcinogenic. Central composite design (CCD) was employed in the present study for optimization of disinfectant dose and contact time with the rationale to evaluate if an optimal balance could be achieved between minimal DBPs formation and effective microbial inactivation with either free or combined chlorine in treated water within a lab‐scale prototype network to simulate real water distribution network conditions. After a series of experimental runs based upon design of experiments (DoE) by CCD, dose was found to be the most significant factor (P < 0.01) in determining DBPs formation in both disinfectant’s applications. Where, contact time significantly (P < 0.01) affected bacterial inactivation in chlorination experiments, in contrast, dose was effective in chloramination experiments. Thus, it was concluded that the optimal balance may be achieved in the water networks with the help of multifactorial optimization when disinfectant dose was maintained near 3 mg/L as applied chlorine dose in both disinfection cases, while contact time was 62 and 155 min for chlorine and chloramine, respectively.     

腐殖酸特性及其对三卤甲烷形成的影响

以提取腐殖酸和商品腐殖酸为对象,研究了不同腐殖酸对加氯消毒后三卤甲烷生成量的影响,并对腐殖酸特性进行了分析。结果表明,伊春腐殖酸比松花江腐殖酸和商品腐殖酸具有更高的三卤甲烷生成量、生成速度和更高的卤代活性。松花江腐殖酸和商品腐殖酸中的芳香结构、不饱和双键的分子较少,分子质量较大,而伊春腐殖酸中芳香结构和不饱和双键的分子较多,分子质量较低。小分子质量和含不饱和双键的有机物通常是消毒副产物的主要前体物,因而伊春腐殖酸加氯消毒后的三卤甲烷生成量比松花江腐殖酸和商品腐殖酸高。     

氯消毒副产物及其影响因素的研究概况

氯消毒因其效果可靠、操作简便、价格便宜等优点而成为污水消毒中广泛采用的方法,但氯消毒过程中产生的有毒副产物可能带来的化学安全问题则成为越来越受关注的焦点.本文主要是研究氯消毒副产物的生成及其影响因素,为污水氯消毒实践中消毒条件的选择、水质控制及相关水质安全标准的制定提供依据.     

Effects of primary sludge particulate (PSP) entrapment on ultrasonic (20 kHz) disinfection of Escherichia coli

The role of primary sludge particulates (PSPs) in ultrasonic disinfection of Escherichia coli (E. coli) was investigated. Entrapment of E. coli by PSP was directly observed through scanning electron microscope (SEM) after E. coli and PSP were incubated together in water for 24 h at 35 °C. Entrapment coefficient was proposed for the first time to reflect the ability of PSP to entrap E. coli and was estimated as 1.4 × 10³ CFU/mg PSP under our experimental conditions. Ultrasonication (20 kHz) of different E. coli-PSPs solutions showed that the entrapped E. coli cells were protected by PSP from ultrasonication and the unentrapped cells were not. However, the protection of entrapped E. coli cells gradually decreased as ultrasonication proceeded, suggesting the ability of power ultrasonication to deprotect the entrapped E. coli cells. SEM studies suggested a two-step mechanism for ultrasonic (20 kHz) disinfection of entrapped E. coli: breakdown of the protective PSP refugia and disinfection of the exposed E. coli cells. This research will enable more informed decisions about disinfection of aqueous samples where porous PSP are present.