Role of oxidants and disinfectants on the removal, masking and generation of tastes and odours

2004 ◽  
Vol 49 (9) ◽  
pp. 297-306 ◽  
Author(s):  
A. Bruchet ◽  
J.P. Duguet
Keyword(s):  
Hydrogen Peroxide ◽  
Case Studies ◽  
Potassium Permanganate ◽  
Chlorine Dioxide ◽  
Masking Effect ◽  
Negative Effects ◽  
Anthropogenic Pollutants ◽  
Drinking Waters ◽  
By Products

This paper summarises the positive and negative effects of the most commonly used oxidants and disinfectants: chlorine, chloramines, chlorine dioxide, potassium permanganate ozone, and advanced oxidation with ozone/hydrogen peroxide on tastes and odours present in natural and drinking waters. The case studies reported illustrate the generation of odorous by-products such as chlorophenols, iodoforms, aldehydes, the masking effect between earthy-musty and chlorinous odours, and the removal of odorous algal metabolites or anthropogenic pollutants by ozone alone or by ozone coupled with hydrogen peroxide.

Understanding the Role of Chlorine and Ozone to Control Postharvest Diseases in Fruit and Vegetables: A Review

2020 ◽  
Vol 16 (4) ◽  
pp. 455-461
Author(s):  
Gabriela M. Baia ◽  
Otniel Freitas-Silva ◽  
Murillo F. Junior
Keyword(s):  
Chlorine Dioxide ◽  
Broad Spectrum ◽  
Fruits And Vegetables ◽  
Low Cost ◽  
Residual Effects ◽  
Pathogenic Microorganisms ◽  
Postharvest Diseases ◽  
Post Harvest ◽  
By Products

Fruits and vegetables are foods that come into contact with various types of microorganisms from planting to their consumption. A lack or poor sanitation of these products after harvest can cause high losses due to deterioration and/ or pathogenic microorganisms. There are practically no post-harvest fungicides or bactericides with a broad spectrum of action that have no toxic residual effects and are safe. However, to minimize such problems, the use of sanitizers is an efficient device against these microorganisms. Chlorine is the most prevalent sanitizing agent because of its broad spectrum, low cost and well-established practices. However, the inevitable formation of disinfection by-products, such as trihalomethanes (THMs) and haloacetic acids (HAAs), is considered one of the main threats to food safety. Alternative sanitizers, such as chlorine dioxide (ClO2) and ozone, are becoming popular as a substitute for traditional post-harvest treatments. Thus, this review addresses the use of chlorine, chlorine dioxide and ozone emphasizing aspects, such as usage, safe application, spectrum of action and legislation. In order to ensure the quality and safety of final products, the adoption of well-prepared sanitation and sanitation programs for post-harvest fruits and vegetables is essential.

The role of individual adaptive practices for sustainable adaptation

2015 ◽  
Vol 6 (1) ◽  
pp. 6-29 ◽  
Author(s):  
Christine Wamsler ◽  
Ebba Brink
Keyword(s):  
Case Studies ◽  
Single Case ◽  
Institutional Development ◽  
Developed Countries ◽  
Negative Effects ◽  
Group Discussions ◽  
Content Type ◽  
Development Policies ◽  
Practical Implications

Purpose – This paper aims to investigate the strategies used by Swedish citizens to adapt to changing climate variability and extremes. There is an increasing consensus that individual adaptive capacities are critical to successfully adapt to climate change and achieve sustainable development. However, little is known about individual adaptive practices, particularly in developed countries. Design/methodology/approach – The study covered a variety of geographical areas and included single-case studies of specific locations, cross-case studies and country-wide studies. Data were collected through literature review, interviews with at-risk people, observation and group discussions with municipal staff. Findings – The paper provides an overview of Swedish citizens’ adaptive practices and highlights how institutional development efforts affect individuals and their activities, including the equitable distribution of adaptation needs and resources. The paper concludes that individual adaptive capacities do not necessarily translate into adaptation. Practical implications – The results show that planned interventions are required. They emphasise the importance of more people-oriented adaptation planning that fosters the sustainable transformation of cities, together with the role that South-North knowledge transfer can play in this context. Originality/value – The paper offers critical insights into the positive and negative effects of citizens’ adaptation strategies (based on criteria such as effectiveness, sustainability and equity), and it discusses their relevance in the formulation of development policies and programmes.

Oxidative Disinfectants Activate Different Responses in Vibrio parahaemolyticus

2019 ◽  
Vol 82 (11) ◽  
pp. 1890-1895
Author(s):  
KAI-MING TSO ◽  
BIN NI ◽  
HIN-CHUNG WONG
Keyword(s):  
Hydrogen Peroxide ◽  
Mutant Strain ◽  
Chlorine Dioxide ◽  
Peracetic Acid ◽  
Vibrio Parahaemolyticus ◽  
Reverse Transcription Pcr ◽  
Rpos Mutant ◽  
Global Concern ◽  
Regulator Genes

ABSTRACT Vibrio parahaemolyticus is a prevalent seafoodborne enteropathogen that has become a global concern since the spread of its pandemic strain in 1996. This study investigates the responses of this pathogen to the oxidative disinfectants hydrogen peroxide, chlorine dioxide, and peracetic acid. Expression of the regulator genes oxyR and rpoS, determined by reverse transcription PCR, in V. parahaemolyticus wild-type, oxyR mutant, and rpoS mutant strains exhibited similar patterns in response to the tested oxidative disinfectants. The transcription of the rpoS gene was markedly enhanced in the oxyR mutant strain in the exponential phase. The expression of catalase KatE1 was tracked by using a LacZ fusion reporter in these strains. The experimental results revealed that KatE1 was a significant scavenger of hydrogen peroxide and peracetic acid in V. parahaemolyticus, and RpoS may partially compensate for the regulatory role of OxyR in the oxyR mutant strain. In contrast to its responses to hydrogen peroxide and paracetic acid, KatE1 was not the primary scavenger of chlorine dioxide in these V. parahaemolyticus strains. This study shows that these disinfectants activated a basic oxidative response in this pathogen with different features.

Products of cyclooxygenase mediate the responses of the guinea pig trachea to hydrogen peroxide

1993 ◽  
Vol 74 (5) ◽  
pp. 2105-2111 ◽  
Author(s):  
Y. Gao ◽  
P. M. Vanhoutte
Keyword(s):  
Hydrogen Peroxide ◽  
Guinea Pig ◽  
Thromboxane A2 ◽  
Isometric Tension ◽  
Thromboxane B2 ◽  
Low Concentrations ◽  
The Difference ◽  
By Products ◽  
A2 Receptors

The role of products of cyclooxygenase was investigated in the responses of isolated airways to H2O2. Strips of guinea pig trachea, in some of which the epithelium had been removed mechanically, were suspended in organ chambers, and isometric tension was recorded. Under basal conditions, H2O2 induced indomethacin-sensitive contractions, which were larger in preparations without than in those with epithelium; the difference was abolished by inhibitors of thromboxane synthase or thromboxane A2 receptors. During contractions to acetylcholine, low concentrations of H2O2 induced relaxation in preparations with but had no significant effect in those without epithelium. At higher concentrations of H2O2, the epithelium-dependent relaxation was attenuated but an epithelium-independent relaxation appeared. The epithelium-dependent but not the epithelium-independent responses to H2O2 were blocked by indomethacin. Under basal conditions, prostaglandin E2 (PGE2; < or = 10(-7) M), U-46619, prostaglandin PGF2 alpha (PGF2 alpha), prostaglandin PGD2 (PGD2), and prostacyclin (PGI2) caused contractions. During contractions to acetylcholine, PGE2 induced larger relaxations in preparations with than in those without epithelium. Radioimmunoassay revealed that lower concentrations of H2O2 predominantly increased the release of PGE2 and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha); in preparations without epithelium, the release of thromboxane B2 was augmented also. At higher concentrations of H2O2, the release of PGE2, PGF2 alpha, PGD2, 6-keto-PGF1 alpha, and thromboxane B2 increased in preparations with and without epithelium. These findings demonstrate that the responses of the guinea pig trachea to H2O2 are mediated mainly by products of cyclooxygenase and that the effects of H2O2 are modulated by the epithelium.

‘The Indispensable Agent’: Coal and Its Displacements in Victorian Britain

2020 ◽  
Author(s):  
Colin Fanning
Keyword(s):  
Nineteenth Century ◽  
Fossil Fuels ◽  
Negative Effects ◽  
Victorian Britain ◽  
Cultural Terms ◽  
History Of ◽  
Industrial Modernity ◽  
Cultural Interest ◽  
By Products

Abstract Despite the prominent role of fossil fuels in the technological and social shifts of nineteenth-century Britain, coal—as a tangible thing that touched many aspects of Victorian life—has often been left out of histories of design. A topic of keen political and cultural interest in the period, coal was both an object of displacement (extracted, circulated, consumed) and its agent, reworking Britain’s economic and geological landscapes. This article argues that the ‘coal fetishism’ of Victorian Britain was not an inevitable outgrowth of the material’s proliferation, but was produced in part through the activity of designers, civil servants and manufacturers. Examining coal through the paired notions of display and concealment, I first consider how the substance was elevated in cultural terms at spectacles like the Great Exhibition of 1851, where conjoined strategies of pageantry and didacticism reinforced its centrality to national prosperity. I then turn to explore the coal-burning devices shown in these same spectacular events, showing how the fuel forced designers and manufacturers to contain, conceal or otherwise displace its negative effects and by-products. Attempting to re-place the messy materiality of coal into the history of Victorian design, I argue, thus illuminates the larger tensions and ambiguities of industrial modernity.

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