Free Essay

Assessing Biological Stability of Drinking Water Without Disinfectant Residuals in a Full-Scale Water Supply System

In:

Submitted By dkred
Words 2616
Pages 11
Assessing biological stability of drinking water without disinfectant residuals in a full-scale water supply system
Frederik Hammes, Cordula Berger, Oliver Ko
̈
ster and Thomas Egli
ABSTRACT
Frederik Hammes
(corresponding author)
Cordula Berger
Thomas Egli
Swiss Federal Institute of Aquatic Science and
Technology (Eawag),
U
̈ berlandstr. 133,
CH-8600, Du
̈
bendorf,
Switzerland
Tel.: +41 44 823 5350;
Fax: +41 44 823 5547
E-mail:
frederik.hammes@eawag.ch
;
www.eawag.ch
Cordula Berger
Oliver Ko
̈
ster
Zu
̈ rich Water Supply (WVZ),
Hardhof 9, P.O. Box 1179,
CH-8021, Zu
̈
rich,
Switzerland
Thomas Egli
Institute of Biogeochemistry and Pollutant
Dynamics, ETH Zu
̈
rich,
CH-8092, Zu
̈
rich,
Switzerland
Biological stability refers to the inability of drinking water to support microbial growth.
This phenomenon was studied in a full-scale drinking water treatment and distribution system of the city of Zu
̈
rich (Switzerland). The system treats lake water with successive ozonation and biological filtration steps and distributes the water without any disinfectant residuals. Chemical and microbiological parameters, notably dissolved organic carbon (DOC), assimilable organic carbon (AOC), heterotrophic plate counts (HPC) and flow-cytometric total cell concentration (TCC), were measured over an 18-month period. We observed a direct correlation between changes in the TCC, DOC and AOC concentrations during treatment; an increase in cell concentration was always associated with a decrease in organic carbon. This pattern was, however, not discerned with the conventional HPC method. The treated water contained on average a TCC of
8.97
£
10
4 cells ml
2
1
, a DOC concentration of 0.78 mg l
2
1 and an AOC concentration of 32 m gl
2
1
,
and these parameters hardly changed in the distribution network, suggesting that the treated water had a high level of biological stability. This study highlights the descriptive value of alternative parameters such as flow-cytometric TCC for drinking water analysis, and pinpoints some of the key aspects regarding biological stability in drinking water without disinfectant residuals.
Key words
|
assimilable organic carbon (AOC), biological stability, drinking water, flow cytometry, total cell concentration (TCC)
INTRODUCTION
Uncontrolled and excessive growth of bacteria in drinking water can lead to a deterioration of the aesthetic water quality, such as the development of undesirable tastes and odours or visual turbidity ( van der Kooij 2000
;
Hammes et al.
2008
). It can also lead to process malfunctioning: for example, the clogging of point-of-use filters, bio-fouling of distribution pipes and bio-corrosion (
Lee
et al.
1980
).
In a worst-case scenario, regrowth can allow the prolifer- ation of pathogenic bacteria (
Vital
et al.
2007
,
2008
), resulting in a hygienic risk to the consumer. One common approach to limit potential regrowth in drinking water is the addition of disinfectants such as chlorine, chlorine dioxide or monochloramine after the treatment train (
LeChevallier
1999
;
van der Kooij 2000
). While this has proven effective- ness, it is also known that some bacteria are resistant to chlorine (
Barbeau
et al.
2005
), that there is a health risk associated with disinfection by-products, and that a negative consumer perception associated with the chlorinous taste exists (
Hambsch 1999
;
Uhl & Schaule
2004
). Some European countries—notably the Netherlands,
Germany, Austria and Switzerland—have taken the approach of distributing high quality drinking water with- out the use of additional residual disinfectants (
Hambsch
1999
;
van der Kooij et al.
1999
). Drinking water treatment in such countries aims to limit microbial regrowth through limitation of the nutrients essential for growth, which is doi: 10.2166/aqua.2010.052
31
Q
IWA Publishing 2010
Journal of Water Supply: Research and Technology—AQUA
|
59.1
|
2010 usually (but not necessarily) organic carbon (
Miettinen
et al.
1997
; van der Kooij 2000
). Under these conditions, the need to understand and accurately monitor the general quality and microbial stability of drinking water has a high priority.
The inability of drinking water to support microbial proliferation is expressed as the biological stability
(intermittently termed ‘microbial stability’, ‘microbiological stability’, ‘biostability’ or ‘regrowth potential’) of the water
(
Rittmann & Snoeyink 1984
;
Miettinen et al.
1997
; van der
Kooij 2000
;
Laurent et al.
2005
). Simply viewed, biological stability is a function of biologically available organic carbon substrate, and ‘instability’ is measured as an increase of biomass and a concomitant decrease of substrate.
However, different interpretations, coupled to preferences for different parameters and methods, are often applied to the concept of biological stability. For example,
Rittmann &
Snoeyink (1984) defined ‘biostability’ as the lack of microbial growth specifically in the absence of disinfectant residuals, while
Srinivasan & Harrington (2007) modelled biological stability taking into account the presence of disinfectant residuals.
Rittmann & Snoeyink (1984) and van der Kooij (2000) regarded both the quality of water, as well as the growth-supporting nature of the materials used for distribution, as important factors when considering biologi- cal stability. In this regard, van der Kooij (2000) highlighted assimilable organic carbon (AOC) and biofilm formation rate (BFR) as the key parameters of biological stability.
Other groups have disregarded BFR and favoured biode- gradable organic carbon (BDOC) as the most important water quality parameter for biological stability (
Escobar &
Randall 2001
;
Laurent et al.
2005
). Moreover, depending on the composition of the water, inorganic nutrients
(e.g. phosphate), rather than organic carbon, can also be growth limiting (
Kerneı
̈ s et al.
1995
;
Miettinen
et al.
1997
).
One of the more contentious aspects of biological stability is which microbiological parameter should be used to describe and monitor this phenomenon. The most used parameter is conventional heterotrophic plate counts
(HPC) (
Hambsch 1999
;
Carter et al.
2000
;
Mu
̈ ller et al.
2003
;
Srinivasan & Harrington 2007
), even though it is well known that the HPC method does not accurately reflect total microbial abundance in drinking water (
Yokomaku
et al.
2000
;
Hoefel
et al.
2003
;
Hammes
et al.
2008
).
Although the concept of biological stability is well known among drinking water microbiologists, little exper- imental and/or field data exist that underpin the main factors involved, and that adequately demonstrate the presence/absence of biological stability. One reason for this is the complexity of the problem: different countries often have completely different water qualities, different treatment technologies and employ different analytical tools for monitoring (
Miettinen
et al.
1997
; van der Kooij 2000
;
Laurent et al.
2005
). Another reason is a shortage of methods specifically describing the two main parameters: namely biologically available substrate (organic carbon) and microbial biomass. With regard to the latter, we have previously shown that flow-cytometric total cell concen- tration (TCC) is an important parameter for drinking water treatment and distribution systems, and that it holds more descriptive value for the treatment process than conventional HPC measurements (
Hammes
et al.
2008
;
Siebel
et al.
2008
).
Here we present a case study of a full-scale drinking water treatment system that treats surface water through successive ozonation and filtration steps and where the treated water is distributed without the addition of disin- fectant residuals. Conventional drinking water parameters
(HPC and DOC) were complemented with AOC and flow-cytometric TCC measurements during an 18-month sampling campaign. This study highlights the descriptive and complementary value of these two additional parameters for monitoring the microbial quality of drin- king water, and it contributes to a better understanding of the fundamental principles of biological stability of drinking water.
MATERIALS AND METHODS
Preparation of AOC-free glassware
Borosilicate glass sampling bottles (250ml) with glass caps were used for sampling, while 20ml borosilicate glass vials were used for the AOC assays. Sterile, carbon-free glassware was prepared by heat-treatment (500
8
C, 6h) as described previously (
Greenberg
et al.
1993
;
Hammes & Egli 2005
).
Teflon-coated caps for the AOC vials were cleaned of
32
F. Hammes et al.
|
Biological stability of drinking water
Journal of Water Supply: Research and Technology—AQUA
|
59.1
|
2010 residual AOC by soaking in warm persulfate (60
8
C, 1h) as described previously (
Greenberg
et al.
1993
).
Layout of the full-scale drinking water treatment plant and sampling sites
The full-scale plant that was monitored in this study produces roughly 50% of the drinking water for the city of
Zu
̈ rich (Switzerland) by treating surface water (Lake
Zu
̈ rich) through sequential ozonation and filtration steps.
The treatment train consists of the following specific steps
(
Figure 1
): (1) pre-ozonation (ozone dose 1.1mgl
2
1
^
25%, hydraulic contact time 50min, ozone residual after contact time c
. 0.15mgl
2
1
); (2) rapid sand filtration (RSF) (double layer filter with 50cm of pumice stone and 80cm of quartz sand; filter flow rate 1.4–4mh
2
1
); (3) intermediate ozon- ation (ozone dose 0.5mgl
2
1
, hydraulic contact time 26min, ozone residual after contact time 0.28mgl
2
1
); (4) granular active carbon (GAC) filtration (double layer filter with
130cm of GAC (Norit ROW 0.8 supra) and 40cm of quartz sand, filter flow rate 4.6–13.2mh
2
1
); (5) slow sand filtration
(SSF) (quartz sand
,
65cm, filter flow rate
0.18–0.52mh
2
1
); and (6) reservoir in the plant. Samples
(250ml) were taken roughly every two weeks over an
18-month period. Samples were taken before and after each step and also of the raw water and of the water coming from the reservoir (Reservoir 1) in the plant after treatment.
Two points in the distribution network (DN) were sampled.
Both points received their water from the same reservoir
(Reservoir 2) in the distribution network which is located
2.4km from the treatment plant (
Figure 1
). Point DN-1 was located a further 1km from this reservoir, and point DN-2 was located 6.1km from the reservoir. Assuming a retention time of one day in the reservoir, the water collected at points
DN-1 and DN-2 have hydraulic retention times in the network of 29h and 43.5h, respectively. All samples were collected in AOC-free glassware and transported in cold- storage containers to the laboratory, where they were processed within four hours of sampling.
Total cell counts with fluorescence staining and flow cytometry (FCM)
Bacterial cells were stained with 10 m lml
2
1
SYBR
w
Green I
(1:100 dilution in dimethylsulfoxide (DMSO); Invitrogen) and incubated in the dark for at least 15min before measurement. Where necessary, samples were diluted in filtered (0.22 m m; Millex w -GP, Millipore) bottled mineral water (Evian, France) just before analysis, so that the con- centration measured with the flow cytometer was always less than 2
£
10
5
cellsml
2
1
. Flow cytometry was per- formed using a PASIII flow cytometer (Partec, Hamburg,
Germany) equipped with a 25mW solid state laser (488nm) and volumetric counting hardware. Green fluorescence was collected in the FL1 channel (520
^
20nm), red fluorescence (also resulting from SYBR w Green I) was collected in the FL3 channel (
.
615nm) and all data were processed with the Flowmax software (Partec). Electronic gating with the software was used to separate positive signals from noise. All samples were collected as logarith- mic (3 decades) signals and were triggered on the green
Figure 1
|
Schematic presentation of the full-scale drinking water treatment plant
(Lengg, Zu
̈
rich, CH) monitored in this study. Water samples were taken during 18 months before and after every treatment step and, additionally, at two points in the distribution network (DN-1 and DN-2).
33
F. Hammes et al.
|
Biological stability of drinking water
Journal of Water Supply: Research and Technology—AQUA
|
59.1
|
2010 fluorescence channel (FL1). The standard instrument error on the FCM measurements was experimentally determined to be below 5%.
Conventional water parameters
The heterotrophic plate count (HPC) method was performed according to the Swiss guidelines for drinking water (
SLMB 2000
). In short: 1ml of the water sample was transferred to a sterile Petri dish and mixed with about
15ml plate count agar (PCA, Oxoid). The agar was kept at
46
8
C before plating. The samples were incubated at 30
8
C for 3 days. Phytoplankton in the lake water was measured as described in
Mu
̈ ller et al.
(2003)
. Dissolved organic carbon (DOC) (after 0.45 m m filtration) and particulate organic carbon (POC) (concentrated on a fibreglass filter
(Whatman GF/F)) were measured on a Dimatoc 2000
TOC analyser equipped with a Dima 1000 Universal detector. Water temperature was measured on site during sampling. Assimilable organic carbon (AOC)
AOC was determined with a batch growth assay as described previously (
Hammes & Egli 2005
;
Vital et al.
2007
). In short: the pasteurised and filtered water samples
(15ml) were inoculated with 10 m l(1
£
10
4
cellsml
2
1 initial concentration in the assay) of a bacterial AOC test- inoculum. These suspensions were then incubated at 30
8
C for three days (until stationary phase was reached) and the resulting growth was measured with flow cytometry (see above). The AOC test-inoculum comprised autochthonous bacteria from the treatment plant that was studied, and was prepared as described previously (
Vital
et al.
2007
).
The same bacterial community was used for all AOC determinations throughout the present study. As standard quality control prior to use, the performance of this inoculum was compared with bacterial AOC test-inocula used in previous studies in our group (
Hammes
et al.
2006
;
Vital
et al.
2007
), using different types of natural surface water as media. A difference of less than 10% in the average
AOC values was deemed acceptable for use. AOC ( m gl
2
1
)is
estimated from cell concentrations (cellsml
2
1
) using a theoretical conversion factor (
Hammes
et al.
2006
)
(Equation 1). All assays were performed in triplicate.
The detection limit of the method was 10 m gl
2
1 and the average standard deviation was
^
10%.
AOC
ð m gl
2
1
Þ¼
netgrowncells ð cellsl
2
1
Þ
conversionfactor ð 1
£
10
7
cells m g
2
1
Þ
ð
1
Þ
Data presentation and calculations
Given the large set of data collected over an 18-month period, we have opted to present the data as box plots to illustrate the spread of the data, and we have used the geometrical mean values of all data for the calculations.
RESULTS AND DISCUSSION
Water supply without the addition of disinfection residuals The configuration of the Zu
̈
rich drinking water treatment plant targets specifically the production of biologically stable, high quality drinking water that can be distributed without the need for additional disinfectants (
Figure 1
).
The raw water (Lake Zu
̈
rich) has a low organic carbon content (POC
¼
0.22 (
^
0.1) mgl
2
1
; DOC
¼
1.3 (
^
0.1) mgl 2
1
; AOC
¼
0.023 (
^
0.017) mgl
2
1
), which means that relatively low ozone dosages are required during treatment.
Two ozonation steps are meant to serve as double disinfective barriers against any malignant microorganisms that may enter the system through the raw water, while also oxidising possible micropollutants in the water (
Mu
̈ ller et al.
2003
;
Von Gunten 2003
). The ozonation also transforms stable, dissolved natural organic matter (NOM) molecules and organic particles (e.g. phytoplankton) into typical AOC molecules (
Von Gunten 2003
;
Hammes et al.
2006
,
2007
).
Three separate biological filtration processes (rapid sand filtration, granular activated carbon filtration and slow sand filtration) are the basis for the removal of organic carbon from the water. We have demonstrated previously that these filters are biologically active with high AOC removal capacity (
Hammes
et al.
2006
;
Velten
et al.
2007
). As a result, regrowth of microorganisms occurs in the biological filters together with the removal of biologically available
34
F. Hammes et al.
|
Biological stability of drinking water
Journal of Water Supply: Research and Technology—AQUA
|
59.1
|
2010

Similar Documents

Premium Essay

Nanotechnology Applications for Clean Water Solutions for Improving

...NaNotechNology applicatioNs for cleaN Water Micro & NaNo TechNologies series editor: Jeremy ramsden Professor of Nanotechnology Microsystems and Nanotechnology Centre, Department of Materials Cranfield University, United Kingdom the aim of this book series is to disseminate the latest developments in small scale technologies with a particular emphasis on accessible and practical content. these books will appeal to engineers from industry, academia and government sectors. for more information about the book series and new book proposals please contact the publisher, Dr. Nigel hollingworth at nhollingworth@williamandrew.com. http://www.williamandrew.com/MNt NaNotechNology applicatioNs for cleaN Water edited by Nora savage Office of Research and Development, US Environmental Protection Agency and (in alphabetical order) Mamadou Diallo Materials and process simulation center, Division of chemistry and chemical engineering, california institute of technology Jeremiah Duncan Nanoscale Science and Engineering Center, University of Wisconsin-Madison anita street Office of Research and Development, US Environmental Protection Agency and Center of Advanced Materials for the Purification of Water with Systems, University of Illinois at Urbana-Champaign richard sustich N o r w i c h , N Y, U S A copyright © 2009 by William andrew inc. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying...

Words: 90139 - Pages: 361

Premium Essay

Flocculation & Coagulation Processes in the Production of Potable Water

...THE PRODUCTION OF POTABLE WATER SUBMISSION DATE: 14 August 2012 COURSE COORDINATOR : Dr. Netatollah Rahmanian GROUP MEMBERS’ NAMES: Derek Lai Chai Zern 14233 Derek Lai Chai Zern 14233 Sean Suraj Jeremiah 14286 Nabila Syahira Bt Azizuddin 14295 Hazwan Farid B Muhammad Puzi 14382 Karrthik S/O Subramaniam 15450 Kiveeyashini D/O Govindasamy 17252 INTRODUCTION Human settlements have always been centred around sources of clean drinking water. As the population increases and the quality of fresh water declines, it has become an engineering challenge to supply sufficient potable water to the meet demands. Of the many unit processes and operations used in water treatment, coagulation and flocculation required a unique combination of chemical and physical phenomena for producing water acceptable for human consumption. Aggregation of fine particulate matter into larger particulates by the use of coagulation and flocculation facilities permits cost-effective removal in subsequent solid separation processes. Particulates inorganic origin such as clay, silt, and mineral oxides generally enter surface water by natural erosion processes and can decrease the clarity of the water to an unacceptable level. Organic particulates, such as colloidal humic and fulvic acids are a product of decay and leaching of organic debris and litter which have fallen in the water source. These particulates impart a color to the water which in some extreme cases can...

Words: 14355 - Pages: 58

Free Essay

Third Edition

...Geneva 27, Switzerland (tel: +41 22 791 2476; fax: +41 22 791 4857; email: bookorders@who.int). Requests for permission to reproduce or translate WHO publications – whether for sale or for noncommercial distribution – should be addressed to Publications, at the above address (fax: +41 22 791 4806; email: permissions@who.int). The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dotted lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and...

Words: 50038 - Pages: 201

Free Essay

Abbot

...Upgrading Water Treatment Plants E. G. Wagner and R. G. Pinheiro ISBN 0-419-26050-1 (pbk) 0-419-26040-4 Published on behalf of the WORLD HEALTH ORGANIZATION London and New York First published 2001 by Spon Press 11 New Fetter Lane, London EC4P 4EE Simultaneously published in the USA and Canada by Spon Press 29 West 35th Street, New York, NY 10001 Spon Press is an imprint of the Taylor & Francis Group © 2001 World Health Organization The authors alone are responsible for the views expressed in this publication. Printed and bound in Great Britain by TJ International Ltd, Padstow, Cornwall All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. Publisher's Note This book has been prepared from camera-ready copy provided by the authors. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data A catalogue record has been requested Foreword The availability of safe water, and in particular...

Words: 62528 - Pages: 251

Premium Essay

Dac Test Document

...Establishment Ltd Requests to copy any part of this publication should be made to: CRC Ltd Building Research Establishment Bucknalls Lane Watford, WD25 9XX BRE material is also published quarterly on CD Each CD contains BRE material published in the current year, including reports, specialist reports, and the Professional Development publications: Digests, Good Building Guides, Good Repair Guides and Information Papers. The CD collection gives you the opportunity to build a comprehensive library of BRE material at a fraction of the cost of printed copies. As a subscriber you also benefit from a 25% discount on other BRE titles. For more information contact: CRC Customer Services on 020 7505 6622 Construction Research Communications CRC supplies a wide range of building and construction related information products from BRE and other highly respected organisations. Contact: post:...

Words: 167696 - Pages: 671

Free Essay

Environmental Studies

...Environmental Studies For Undergraduate Courses Erach Bharucha Textbook for Environmental Studies For Undergraduate Courses of all Branches of Higher Education Erach Bharucha for University Grants Commission Natural Resources i Preliminary Pages.p65 1 4/9/2004, 5:06 PM Credits Principal author and editor – Erach Bharucha Unit 1 – Erach Bharucha Unit 2 – Erach Bharucha, Behafrid Patel Unit 3 – Erach Bharucha Unit 4 – Erach Bharucha Unit 5 – Shamita Kumar Unit 6 – Erach Bharucha, Shalini Nair, Behafrid Patel Unit 7 – Erach Bharucha, Shalini Nair, Behafrid Patel Unit 8 – Erach Bharucha, Shambhvi Joshi Case Studies – Prasanna Kolte Co-ordination and compilation – Behafrid Patel Textbook Design – Narendra Kulkarni (Mudra), Sushma Durve Manuscript review and editing – Chinmaya Dunster, Behafrid Patel Artists – Sushma Durve and Anagha Deshpande CD ROM – Jaya Rai and Prasanna Kolte © Copyright Text – Erach Bharucha/ UGC, 2004. Photographs – Erach Bharucha Drawings – Bharati Vidyapeeth Institute of Environment Education and Research All rights reserved. Distributed by University Grants Commission, New Delhi. 2004. ii Environmental Studies for Undergraduate Courses Preliminary Pages.p65 2 4/9/2004, 5:06 PM Vision The importance of Environmental Studies cannot be disputed. The need for sustainable development is a key to the future of mankind. The degradation of our environment is linked to continuing problems of pollution, loss...

Words: 125061 - Pages: 501

Free Essay

Spa & Wellness Industry

...Industry http://www.nckvietnam.com This page intentionally left blank http://www.nckvietnam.com Understanding the Global Spa Industry: Spa Management Marc Cohen and Gerard Bodeker AMSTERDAM • BOSTON • HEIDELBERG • LONDON • NEWYORK • OXFORD • PARIS • SAN DIEGO • SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Butterworth-Heinemann is an imprint of Elsevier http://www.nckvietnam.com Butterworth-Heinemann is an imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP, UK 30 Corporate Drive, Suite 400, Burlington, MA01803, USA First edition 2008 Copyright © 2008 Elsevier Ltd. All rights reserved No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the publisher Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone ( 44) (0) 1865 843830; fax ( 44) (0) 1865 853333; email: permissions@elsevier.com. Alternatively you can submit your request online by visiting the Elsevier web site at http:/ /elsevier.com/locate/permissions, and selecting Obtaining permission to use Elsevier material Notice No responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material...

Words: 153860 - Pages: 616

Free Essay

Labs

...Singapore • Sydney • Tokyo • Toronto Editor-in-Chief: Serina Beauparlant Project Editor: Sabrina Larson PhysioEx Project Editor: Erik Fortier Editorial Assistant: Nicole Graziano Managing Editor: Wendy Earl Production Editor: Leslie Austin Composition: Cecelia G. Morales Cover Design: Riezebos Holzbaur Design Group Senior Manufacturing Buyer: Stacey Weinberger Marketing Manager: Gordon Lee Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings, 1301 Sansome St., San Francisco, CA 94111. All rights reserved. Manufactured in the United States of America. This publication is protected by Copyright and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission(s) to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, 1900 E. Lake Ave., Glenview, IL 60025. For information regarding permissions, call (847) 486-2635. Many of the designations used by manufacturers and sellers to distinguish their products...

Words: 120457 - Pages: 482

Premium Essay

Blood Work

...College Phoenix, Arizona Fifth Edition Cathee M. Tankersley, BS, MT (ASCP) Acquisitions Editor: Peter Sabatini Product Manager: Meredith L. Brittain Marketing Manager: Shauna Kelley Designer: Holly McLaughlin Production Services: Aptara, Inc. Fifth Edition Copyright © 2012, 2008 by Lippincott Williams & Wilkins, a Wolters Kluwer business. Two Commerce Square 2001 Market Street Philadelphia, PA 19103 351 West Camden Street Baltimore, MD 21201 Printed in China All rights reserved. This book is protected by copyright. No part of this book may be reproduced or transmitted in any form or by any means, including as photocopies or scanned-in or other electronic copies, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews. Materials appearing in this book prepared by individuals as part of their official duties as U.S. government employees are not covered by the above-mentioned copyright. To request permission, please contact Lippincott Williams & Wilkins at Two Commerce Square, 2001 Market Street, Philadelphia, PA 19103, via email at permissions@lww.com, or via website at lww.com (products and services). 9 8 7 6 5 4 3 2 1 Library of Congress Cataloging-in-Publication Data McCall, Ruth E., author. Phlebotomy essentials / Ruth E. McCall, Retired Director of Phlebotomy and Clinical Laboratory Assistant Programs, Central New Mexico Community...

Words: 129902 - Pages: 520

Free Essay

Documents

...Clinical guidelines Diagnosis and treatment manual for curative programmes in hospitals and dispensaries guidance for prescribing 2010 EDITION © Médecins Sans Frontières – January 2010 All rights reserved for all countries. No reproduction, translation and adaptation may be done without the prior permission of the Copyright owner. ISBN 2-906498-81-5 Clinical guidelines Diagnosis and treatment manual Editorial Committee: I. Broek (MD), N. Harris (MD), M. Henkens (MD), H. Mekaoui (MD), P.P. Palma (MD), E. Szumilin (MD) and V. Grouzard (N, general editor) Contributors: P. Albajar (MD), S. Balkan (MD), P. Barel (MD), E. Baron (MD), M. Biot (MD), F. Boillot (S), L. Bonte (L), M.C. Bottineau (MD), M.E. Burny (N), M. Cereceda (MD), F. Charles (MD), M.J de Chazelles (MD), D. Chédorge (N), A.S. Coutin (MD), C. Danet (MD), B. Dehaye (S), K. Dilworth (MD), F. Fermon (N), B. Graz (MD), B. Guyard-Boileau (MD), G. Hanquet (MD), G. Harczi (N), M. van Herp (MD), C. Hook (MD), K. de Jong (P), S. Lagrange (MD), X. Lassalle (AA), D. Laureillard (MD), M. Lekkerkerker (MD), J. Maritoux (Ph), J. Menschik (MD), D. Mesia (MD), A. Minetti (MD), R. Murphy (MD), J. Pinel (Ph), J. Rigal (MD), M. de Smet (MD), S. Seyfert (MD), F. Varaine (MD), B. Vasset (MD) (S) Surgeon, (L) Laboratory technician, (MD) Medical Doctor, (N) Nurse, (AA) Anaesthetist-assistant, (Ph) Pharmacist, (P) Psychologist We would like to thank the following doctors for their invaluable help:...

Words: 86687 - Pages: 347

Premium Essay

Business

...assignment, you suddenly develop an enormous desire to straighten your books, water your plants, or sharpen your pencils for the fifth time. If this situation sounds familiar, you may find it reassuring to know that many professionals undergo these same strange compulsions before they begin writing. Jean Kerr, author of Please Don’t Eat the Daisies, admits that she often finds herself in the kitchen reading soup-can labels—or anything—in order to prolong the moments before taking pen in hand. John C. Calhoun, vice president under Andrew Jackson, insisted he had to plow his fields before he could write, and Joseph Conrad, author of Lord Jim and other novels, is said to have cried on occasion from the sheer dread of sitting down to compose his stories. To spare you as much hand-wringing as possible, this chapter presents some practical suggestions on how to begin writing your short essay. Although all writers must find the methods that work best for them, you may find some of the following ideas helpful. But no matter how you actually begin putting words on paper, it is absolutely essential to maintain two basic ideas concerning your writing task. Before you write a single sentence, you should always remind yourself that 1. You have some valuable ideas to tell your reader, and 2. More than anything, you want to communicate those ideas to your reader. These reminders may seem obvious to you, but without a solid commitment to your own opinions as well as to your reader, your prose...

Words: 234754 - Pages: 940

Premium Essay

Manager

...Learning with Cases INTRODUCTION The case study method of teaching used in management education is quite different from most of the methods of teaching used at the school and undergraduate course levels. Unlike traditional lecture-based teaching where student participation in the classroom is minimal, the case method is an active learning method, which requires participation and involvement from the student in the classroom. For students who have been exposed only to the traditional teaching methods, this calls for a major change in their approach to learning. This introduction is intended to provide students with some basic information about the case method, and guidelines about what they must do to gain the maximum benefit from the method. We begin by taking a brief look at what case studies are, and how they are used in the classroom. Then we discuss what the student needs to do to prepare for a class, and what she can expect during the case discussion. We also explain how student performance is evaluated in a case study based course. Finally, we describe the benefits a student of management can expect to gain through the use of the case method. WHAT IS A CASE STUDY? There is no universally accepted definition for a case study, and the case method means different things to different people. Consequently, all case studies are not structured similarly, and variations abound in terms of style, structure and approach. Case material ranges from small caselets (a few paragraphs...

Words: 239776 - Pages: 960