臭氧氧化法在粪便处理车间除臭的研究

目的 利用臭氧的氧化作用对粪便处理车间臭气物质进行氧化分解,以达到除臭或降低不快感的效果。方法 在对京东某粪便处理车问大规模现场测试(官能法,化学法)的基础上,确定了粪便处理车间的污染源并计算了臭氧氧化法的除臭效率。同时也讨论了臭氧除臭时,粪便处理车间臭氧的控制浓度。结果 在臭氧除臭作用下,粪便处理车间臭氧浓度以及臭气主要成分氨和硫化氢均得到有效控制。结论 在臭氧氧化作用下,在气相中除去硫化氢的效率比氨的效率高。在两个小时连续监测期间,硫化氢总去除率为88％,氨的总去除率为56.5％。     

除臭效果的评价方法探讨

本文对除臭剂和除臭设备的效果评价方法进行了探讨。嗅觉评价宜采用６级强度法。臭气强度与其浓度符合Ｗｅｂｅｒ－Ｆｅｃｈｎｅｒ定律，即：Ｉ＝ａ＋ｂｌｏｇＣ，本文回归求取了６种臭气物质的ｒ、ａ、ｂ值。并由此出发阐明了嗅觉评价与检测评价之间的内在联系，提出了Ｈ２Ｓ、ＮＨ３的浓度随强度降低的“１０倍衰减规律”和“５倍衰减规律”。     

垃圾焚烧厂渗沥液处理站除臭系统探讨

概述垃圾渗沥液处理站产生臭气的成分及来源,结合工程实例,针对垃圾焚烧厂和填埋场特有条件介绍渗沥液处理站除臭系统的建立,分析了负压除臭系统在运用过程中的不足,提出了相应的改进措施。     

乳及乳制品脂肪测定方法探讨

脂肪是评价乳品质量优劣的重要卫生学指标,测定乳制品中脂肪方法较多,有哥特里罗紫法、盖勃氏法、巴布科克氏法等,其中哥特里罗紫法是目前国标方法中使用范围较广、稳定性较好的方法,但不适用酸乳中脂肪的测定。国标法中要求采用盖勃氏法,但受盖勃氏法所用盖勃氏乳脂计市场缺乏     

超声波技术对乳制品中脂肪测定方法的改进

乳及乳制品中脂肪测定的国家标准检验方法(GB/T5009.46-1996),样品处理是经60℃加热后手摇提取脂肪,操作费时繁琐,人为因素影响较大.我们利用超声波所特有的高频率以及超声波在媒质中高速传播为工作原理,对牛乳及其制品中脂肪测定的方法进行了改进.本方法测定时样品不需加热,经超声波提取脂肪,减少醚提取液用量.方法相对标准偏差0.023%～0.122%,合并相对偏差为0.071%.本方法样品处理简便快速,易于统一,适合大批量样品分析.     

HPLC法测定乳制品中糖精钠的样品前处理方法探讨

糖精钠作为一种甜味剂广泛的应用于食品加工业中 ,它是一种限量使用的添加剂。因此 ,在卫生监测部门建立一种快速方便的检测方法是非常必要的。在GB/T5 0 0 9中 ,糖精钠的检验方法第一法只给出了汽水、果汁类、配制酒类样品的前处理方法 ,而对乳制品的样品前处理方法未做规定 ,为了扩大检测含有糖精钠样品的范围 ,我们对含乳制品的前处理方法进行了探讨。该法使用 2mol/L的氢氧化钠调节样品的pH值 ,使用 2 40g/L的硫酸锌作蛋白沉淀剂 ,获得了良好的去除蛋白效果 ,方法的回收率为 92～ 10 3 % ,精密度RSD为 3 .8%。该法可以在含乳制品的…     

城市粪便处理技术及方法

对国内外粪便处理技术进行了分析评价 ,提出了为适合国情应采用的适宜的粪便处理技术     

乳及乳制品中蛋白质测定应注意的事项探讨

蛋白质的测定是食物营养成分分析的必测项目，国家食品卫生标准也对部分食品中蛋白质的含量作了相应规定。测定食品中蛋白质的方法有许多种。凯氏定氮法这种测定蛋白质的经典方法，在实际工作中运用非常广泛，也是国家食品卫生标准检验方法中蛋白质测定的第一法。本文对凯氏定氮法测定乳及乳制品中蛋白质时应注意的事项与同行们交流如下。     

二恶英处理技术的对比

通过对活性炭技术、SCR反应器技术与Remedia技术在二恶英减排以及相应的营运费用之间进行对比.指出Remedia技术是性价比最佳的二恶英处理技术,该技术能彻底摧毁与分解气态二恶英,节省高昂的活性炭投放营运成本,同时烟气中二恶英排放可以稳定达到欧洲标准.     

The influence of dairy product consumption on body composition

Recent epidemiologic research suggests that dairy product intake or its components (calcium, vitamin D, and amount or source of protein) are associated with lower body weight or body fat. Clinical intervention trials designed to test this association during weight loss are promising, but still controversial. Few data are available on the effect of calcium or dairy products on prevention of weight gain in long-term trials. The mechanisms proposed to mediate the putative effect of dietary calcium are primarily the formation of fecal fatty acid complexes to reduce fat absorption and the regulation of energy metabolism, including lipolysis from adipocytes and fatty acid oxidation, through the calciotropic hormones, parathyroid hormone, and 1,25-dihydroxyvitamin D. Increased energy expenditure, increased satiety, or a shift from fat to lean mass must accompany these changes in lipid metabolism to achieve changes in fat mass; however, measurable changes in these other parameters either have not been tested or have not been noted uniformly. If dairy products or their components have an effect on altering fat mass, it is likely to be a small change that may have a substantial effect on the incidence of obesity over time.     

The impact of calcium and dairy product consumption on weight loss

OBJECTIVE: Recent evidence suggests that diets high in calcium and dairy products are associated with lower body weight, particularly lower body fat levels. The purpose of this study was to compare weight and body fat loss on a calorie-restricted, low-dairy (CR) vs. high-dairy (CR+D) diet. RESEARCH METHODS AND PROCEDURES: Fifty-four subjects (BMI 30 +/- 2.5 kg/m2, 45 +/- 6.6 years, 4 men) were randomly assigned to calorie-restricted (-500 kcal/d) low-dairy calcium (n = 29; approximately 1 serving dairy/d, 500 mg/d calcium) or high-dairy calcium (n = 25; 3 to 4 servings dairy/d, 1200 to 1400 mg/d calcium) diets for 12 months. Main outcome measures included change in weight (kilograms) and body fat (percentage). RESULTS: There were no significant differences between groups at baseline. At 12 months, weight and body fat loss were not significantly different. Subjects in the CR vs. CR+D conditions lost 9.6 +/- 6.5 vs. 10.8 +/- 5.9 kg (p = 0.56) and 9.0 +/- 3.8 vs. 10.1 +/- 3.6 kg body fat (p = 0.37). DISCUSSION: These findings suggest that a high-dairy calcium diet does not substantially improve weight loss beyond what can be achieved in a behavioral intervention.     

Antimicrobial resistance in Escherichia coli isolated in wastewater and sludge from poultry slaughterhouse wastewater plants

The authors investigated the antimicrobial resistance of Escherichia coli isolates in 22 samples of crude inflow, treated effluent, and sludge collected at the wastewater treatment plants of eight poultry slaughterhouses in Portugal. A total of 549 E. coli strains were recovered and tested for resistance to 12 antimicrobial agents. Multidrug resistance was present in 55.7 percent of the isolates. Resistance to tetracycline, ampicillin, trimethoprim/sulfamethoxazole, streptomycin, and enrofloxacin was found in 80.7 percent, 56.5 percent, 47.5 percent, 39.2 percent, and 18.4 percent of the isolates, respectively. Resistance rates of E. coli to nearly all of the tested antibiotics were higher in the strains obtained from the six slaughterhouses that handled conventional broilers than in the two slaughterhouses that handled free-range broilers. Wastewater treatment resulted in an E. coli decrease of between 0.5 log and 3 log; nevertheless, an average of 5.2 x 10(5) CFUs/100 mL were present in the outflow of the plants. These data indicate that the use of antimicrobials in poultry production leads to the selection of a large pool of resistance genes and that wastewater treatment processes are unable to inactivate the bacteria and thus will result in dissemination of resistant E. coli into the environment.