Endotoxin inactivation by selected drinking water treatment oxidants

Exposure to endotoxins in treated drinking water can occur through ingestion, dermal abrasions, inhalation of water vapor, intravenous injection or during dialysis. While the risks associated with endotoxin ingestion and entry through dermal abrasions are not well quantified, adverse effects of intravenous injection and dialysis are well known and some studies indicate that inhalation of moisture-laden air may impact human health. This study quantifies the inactivation of endotoxin derived from Escherichia coli O55:B5 by three substances used either as disinfectants or oxidants in drinking water treatment: chlorine, monochloramine and potassium permanganate. Inactivation rates were found to be 1.4, 1.0 and 0.7 endotoxin units (EU)/mL h, for free chlorine, potassium permanganate and monochloramine, respectively. These rates are relatively slow given that contact times in drinking water distribution systems are typically less than 48 h. While small amounts of endotoxin may be removed by oxidation the observed removals are much less than those provided by physical removal processes. The significance of this finding is important for dialysis considerations but is as yet unclear with regard to inhalation, as the risk of inhaling sufficient quantities of endotoxin-containing aerosolized water droplets to adversely affect human health has not yet been adequately quantified.     

Potassium sorbate—A new aqueous copper corrosion inhibitor: Electrochemical and spectroscopic studies

This work presents the novel nature of 2,4-hexadienoic acid potassium salt (potassium sorbate (KCH₃CHCHCHCHCO₂)) as an effective copper aqueous corrosion inhibitor. The influence of pH and potassium sorbate concentration on copper corrosion in aerated sulfate and chloride solutions is reported. Degree of copper protection was found to increase with an increase in potassium sorbate concentration; an optimum concentration of this inhibitor in sulfate solutions was found to be 10 g/L. Copper is highly resistant to corrosion attacks by chloride ions in the presence of potassium sorbate. X-ray photoelectron spectroscopy (XPS) studies suggest that copper protection is achieved via the formation of a mixed layer of cuprous oxide, cupric hydroxide and copper(II)-sorbate at the metal surface.     

高铁酸钾的研究现状

简要介绍了高铁酸盐的研究历史、高铁酸钾的制备方法、应用领域及展望.     

替代法低盐酿造酱油品质研究

目的 为降低酱油中氯化钠的含量,采用氯化钾(K组)与乙醇(乙组)替代酱油中的氯化钠,对比研究两种低盐酱油的品质和安全性。方法 通过高盐稀态一贯型发酵酿造高品质低盐酱油,测定了不同氯化钾(K组)与乙醇(乙组)低盐酱油的氨基酸态氮,总酸,食盐,呈香物质等指标。结果 与CK组相比,氯化钾与氯化钠比例为4∶6,5∶5和6∶4时能显著增加酱油中氨基酸态氮的含量;乙醇和氯化钠的浓度比例分别为3∶20,4∶19,5∶18和6∶17时会降低酱油中总酸的含量。K组和乙组成品酱油中的食盐含量均随替代比例的增大而显著降低,且乙组降低更为显著。另外,氯化钾与氯化钠比例为4∶6的酱油成品挥发性香气物质的种类最多;乙醇和氯化钠比例为5∶18的酱油成品挥发性香气物质的种类最多且含量最高。结论 适量的氯化钾和乙醇替代氯化钠进行高盐稀态发酵可以获得高品质的低盐酱油,从安全性角度则是适量氯化钾优于乙醇,本研究为低盐酱油的酿造提供了一定理论基础。     

山东弱石灰反应土壤烤烟钾肥定位试验研究初报

本文总结了在山东弱石灰反应粉沙质土壤上进行的烤烟钾肥定位试验３年结果。通过对烤烟产量、外观质量、叶片含钾量与定位条件下不同施钾量的关系研究，初步探明了钾肥肥效的变化以及对烤烟的影响，提出了在试验土壤上适宜的施钾量。研究表明，在本试验条件下，烤烟对土壤钾素耗竭较大，钾肥的后效作用不明显，需要施钾肥补充；同时发现钾肥用量对烤烟产量存在直线回归关系，产量受其它因素影响大，上等烟比例随施钾量增加，呈上升趋势，但存在拐点（Ｋ２Ｏ３００ｋｇ／ｈｍ２）；叶片含钾量受上年度烤烟产量及本年施钾量影响；产值在施钾处理间差异不显著；为保证烟叶含钾（Ｋ２Ｏ）量＞２％，建议在试验土壤上的施钾量为３００ｋｇ／ｈｍ２左右为宜     

河南烟区土壤钾素含量与分布

对河南烟区 2 116个土样钾素含量进行了分析 ,结果表明 :河南省土壤速效钾含量平均为188.88mg/kg ,全钾含量平均为 2 .2 8%。从不同烟区来看 ,土壤速效钾含量状况排序为 :豫西 >豫东 >豫西南 >豫南 >豫中 ;全钾含量排序为 :豫东 >豫西 >豫中 >豫南 >豫西南。从主要植烟土壤类型看 ,速效钾含量排序为 :红粘土 >潮土 >褐土 >砂姜黑土 >黄褐土 >黄棕壤 ;全钾含量排序为 :黄棕壤 >红粘土 >潮土 >褐土 >黄褐土 >砂姜黑土。根据河南烟区植烟土壤钾素含量及分布特点 ,提出了相应的施肥措施。     

脱氢醋酸钠及其抗菌性试验

本文研究了脱氢醋酸钠在不同的pH环境下的抑菌特性 ,以及热处理对抑菌效果的影响 ,并将结果与山梨酸钾进行比较。试验表明脱氢醋酸钠是一种高效、广谱的食品防腐剂     

Greek dry-salted olives: Monitoring the dry-salting process and subsequent physico-chemical and microbiological profile during storage under different packing conditions at 4 and 20 °C

Naturally black olives cv. Thassos were processed in dry salt according to industrial procedure by uniformly dispersing 40 kg of coarse salt in 100 kg freshly harvested olives. Dry-salting process was monitored by measuring selected physico-chemical (weight loss, NaCl content, pH, a_w, reducing sugars) and microbiological parameters (total viable counts, lactic acid bacteria, enterobacteria, yeasts, pseudomonads). Total weight loss amounted to 21 g/100 g after 80 days of dry-salting. Salt content in the fruits increased to 7.4 g/100 g followed by a decrease in water activity from 0.98 to 0.76. The pH did not change significantly presenting a slight decrease from 5.25 to 4.92. The initial microflora of the fruits comprised of lactic acid bacteria (4.1 log₁₀ cfu/g), yeasts (5.7 log₁₀ cfu/g), enterobacteria (3.7 log₁₀ cfu/g ) and pseudomonads (4.0 log₁₀ cfu/g). In the end of dry-salting, no microbial groups were enumerated apart from yeasts, due to the low water activity of the product. After dry-salting, olives were packed in HDPE bags under air (control samples) and 100 ml/100 ml CO₂. Another lot of fruits was dipped in 1 g/100 ml solution of potassium sorbate for 10 min prior to packing in the same bags under aerobic conditions. All packages were stored at 4 and 20 °C for a period of 180 days. During storage, the microbial flora comprised of yeasts, while no lactic acid bacteria, enterobacteria, pseudomonads or Staphylococcus aureus were detected as the low water activity/high salt content does not favour their growth. At 4 °C, the population of yeasts declined steadily throughout storage, but to a different extend depending on the packing treatment. At 20 °C, only potassium sorbate was effective in suppressing yeast growth. All packing treatments prevented fungal growth at both storage temperatures, apart from the samples stored in air. The pH, a_w and salt content did not change significantly throughout storage.     

常温下光卤石与芒硝制取硫酸钾的试验研究

本文介绍以光卤石和芒硝为原料，在常温下制取硫酸钾和氯化钾的原理及工艺过程。这种工艺具有工艺简单、成本低、节能降耗的优点。     

烤烟烟叶钾含量的遗传分析

运用主基因—多基因混合遗传理论对烤烟南卡58和中烟14两亲本及其F1、F2、F3家系的烟叶钾含量的遗传特征进行了研究。在主基因—多基因混合遗传模型分析中,采用了F2代图形分析法和P1、P2、F1、F2、F3家系多世代联合分析法分别对烤烟烟叶钾含量的遗传进行分析,从F2代图形分析的结果可初步判断烤烟烟叶钾含量的遗传有主基因的存在;P1、P2、F1、F2、F3家系多世代联合分析表明烤烟烟叶含钾量的遗传符合模型D,即一个主基因+多基因模型;综合两种方法分析得出:烤烟烟叶钾含量遗传最适合的模型为一个主基因+多基因混合遗传模型;对遗传效应的分析认为,烤烟烟叶钾含量的遗传以负显性效应为主(h=-0.612),加性效应很小(d=-0.05),主基因遗传率为52.78,多基因遗传率为2.78%,总遗传率为55.55%。