Views
8 months ago

galvis

Water treatment

SUMMARY 1. This thesis

SUMMARY 1. This thesis addresses the major problem of providing ‘safe’ drinking water to small rural and urban populations, which are dependent upon polluted surface water sources. The problem is addressed in the context of the Andean highlands of Colombia and based on gravity flow systems, but the solutions proposed may be applicable in other parts of the world. 2. The central hypothesis of the thesis is that the appropriate combinations of different type of filtration stages provide a uniform quality of water of low risk to consumers. Where institutional and community development make chemical disinfection constantly reliable, the addition of low dose terminal disinfection should be enough to ensure that the drinking supply is safe. 3. The hypothesis was initially tested in the Cauca River valley at pilot scale. A range of designs of upflow, downflow and horizontal flow coarse gravel filters followed by slow sand filtration were compared in an intensive evaluation for their ability to remove key water quality parameters. A novel dynamic fine gravel filter was developed by the author and introduced in advance of the coarse gravel filters to cope with peaks of suspended solids. 4. Highly improved filtrates were achieved during the pilot scale trials and detailed comparative analyses demonstrated the strengths and weaknesses of all component stages. Bacteriological and turbidity removals were particularly impressive compared with earlier studies in Peru and elsewhere. The most efficient combinations of filtration stages consistently achieved five-log faecal coliform removal and this contributed to the full-scale application of the technology within the region. 5. Full scale systems in a range of locations in the Cauca Valley, and elsewhere in Colombia, have demonstrated convincingly that the combination of dynamic gravel filtration, single or multistage coarse gravel filtration and slow sand filtration provide a robust, reliable and efficient technology. It can be successfully operated and maintained at community level, and even without terminal disinfection, multistage filtration provides a consistently low risk drinking water. The inclusion of terminal disinfection provides a fail-safe barrier against occasional high peaks of pollution. 6. The work carried out during the course of this thesis has established multistage gravel filtration as an essential technology when dealing with polluted waters of highly variable quality, and more appropriate and economical than so-called ‘conventional’ water treatment for small to medium size rural and urban communities. 7. The research has introduced and established dynamic fine gravel filters as a vital and economical component in multistage filtration, which is capable of dealing with occasional high peaks of pollution within established routines of maintenance. 8. The studies on full-scale systems over the past 5 to 10 years have demonstrated that the technology is sustainable in the hands of local operators as a result of a participatory and jointlearning project approaches. 9. The limits of the technology with respect to extremes of raw water quality have been defined. A selection procedure to identify and combine filtration stages in a treatment plant is proposed. It is based on a set of treatment objectives, contamination levels in raw water sources, and removal efficiencies expected at each treatment stage. i

ACKNOWLEDGEMENTS To my supervisor, Professor Barry J. Lloyd, my special thanks for his attitude and support during the research project activities in Colombia and England, and for his patience in guiding me to complete this thesis. The major part of this research project was developed in the context of the Research and Demonstration Project on Pre-treatment Technologies for Community Water Supply, which was implemented between 1989 and 1997. It was co-ordinated by Eng. J. T. Visscher, for IRC, International Water and Sanitation Centre, in The Netherlands and by the author as Director of the Cinara Institute of the Universidad del Valle, in Colombia. The Government of the Netherlands and the Ministry of Economic Development, the Ministry of Health, and the National Planning Department of the Government of Colombia funded most of the project. Support was also provided by international institutions including PAHO/WHO; UNICEF; IDRC, based in Canada, IHE, based in the Netherlands; SANDEC/EAWAG and EPFL, based in Switzerland; the British Council; the University of Surrey (England), and the University of Sao Paulo (Brazil). National institutions including, EMCALI, ACUAVALLE, Coffee Growers’ Organisation of the Cauca Valley Department, ICFES, FINDETER, and COLCIENCIAS, also provided support. The project and my academic activities benefited from the interdisciplinary environment of Cinara, and from personal contacts with well recognised academicians or professionals, including Professors L. Di Bernardo, H. Gibzen, G. Alaerts, and N. Graham; Drs. M. Pardón and M. Siebel; and Engs. J. Smet, M. Wegelin, B. Clarke, J. Arboleda and D. Rengifo. I would like to thank the enthusiastic and very dedicated support of all my colleagues at Cinara in Univalle and the many people who have contributed to the research activities in Cinara’s research station in Puerto Mallarino, especially Fabiola, Viviana, Alberto, Javier, and Noel. To Ramón, Edgar and all the members of the management team of Cinara for taking over part of my duties while I was writing this thesis. My thanks are also due to Rodrigo and the staff at the Documentation Unit, for their opportune assistance. I would like also to thank all the students who have participated in activities of the project, including data analyses and drawings for this research work. Also, the staff involved in the monitoring programme of the full-scale plants in the field have helped to provide a solid information base for this research project. Furthermore, local communities and caretakers of full-scale plants have significantly contributed in developing the technology described in this thesis. I also thank Ms O. Edwards and C. Jones for their support and assistance during my visits to the Centre for Environmental Health Engineering at the University of Surrey. I wish to thank my family for their support during my trips to complete this project. Finally, my special thanks to Nancy for sharing the joy and sorrow of the writing period of this research. This thesis is dedicated to my children Beatriz Eugenia, Andrés Felipe and Alejandro ii

  • Page 1: Development and Evaluation of Multi
  • Page 5 and 6: ABBREVIATIONS ABNT: Acuavalle: ACV:
  • Page 7 and 8: SOCs: Synthetic Organic Chemicals S
  • Page 9 and 10: u c V V f Vs uniformity coefficient
  • Page 11 and 12: TABLE OF CONTENTS 1. INTRODUCTION 1
  • Page 13 and 14: 4 MULTISTAGE FILTRATION EXPERIENCIE
  • Page 15 and 16: 1 INTRODUCTION Water is essential f
  • Page 17 and 18: Table 1.2 Access to WS&S in Colombi
  • Page 19 and 20: Table 1.5 Safe drinking water cover
  • Page 21 and 22: 1.2 Multiple Barriers Strategy and
  • Page 23 and 24: 2 OVERCOMING THE LIMITATIONS OF SLO
  • Page 25 and 26: adjustment, are among the technolog
  • Page 27 and 28: On January 14, 1829, Simpson’s on
  • Page 29 and 30: With increasing life expectancy, en
  • Page 31 and 32: Table 2.2 Treatments steps recommen
  • Page 33 and 34: In table 2.3, WHO guideline values
  • Page 35 and 36: 2.5 The Slow Sand Filtration Proces
  • Page 37 and 38: When the particles are very close t
  • Page 39 and 40: in which p 0 is the clean media por
  • Page 41 and 42: Yao et al (1971) related the remova
  • Page 43 and 44: compensate for the increase in the
  • Page 45 and 46: can be applied, but intermittent op
  • Page 47 and 48: Table 2.4 Comparison of design crit
  • Page 49 and 50: Although accepted as indirect indic
  • Page 51 and 52: 50% when the temperature falls from
  • Page 53 and 54:

    Figure 2.9 Flow diagram of the wate

  • Page 55 and 56:

    ut higher running costs, since more

  • Page 57 and 58:

    Headloss and flow control. Final he

  • Page 59 and 60:

    Figure 2.13 Influence of flow condi

  • Page 61 and 62:

    Operation and maintenance (O & M).

  • Page 63 and 64:

    in parallel (Galvis, 1983; Smet et

  • Page 65 and 66:

    cleaning simple, DyGF should behave

  • Page 67 and 68:

    case of Dortmund (Germany), the HGF

  • Page 69 and 70:

    Table 2.9 Data about three experien

  • Page 71 and 72:

    Some points of discussion about HGF

  • Page 73 and 74:

    and 600-800 NTU) and different filt

  • Page 75 and 76:

    the HGF units of Aesch (see table 2

  • Page 77 and 78:

    in spite of the low removal efficie

  • Page 79 and 80:

    order to overcome the water quality

  • Page 81 and 82:

    full-scale units. In this research,

  • Page 83 and 84:

    3 MULTISTAGE FILTRATION STUDIES WIT

  • Page 85 and 86:

    in the case of UGFL. Initially, it

  • Page 87 and 88:

    • Bigger and better-instrumented

  • Page 89 and 90:

    l Figure 3.7 Plan view of Cinara's

  • Page 91 and 92:

    The present research work was divid

  • Page 93:

    Table 3.1. Design parameters, grave

  • Page 96 and 97:

    Figure 3.9. Piezometer distribution

  • Page 98 and 99:

    were used to collect samples for DO

  • Page 100 and 101:

    were poured into a funnel using fil

  • Page 102 and 103:

    H 0 : H a : Treatment levels workin

  • Page 104 and 105:

    3.2 Results and Specific Discussion

  • Page 106 and 107:

    3.2.2 Dynamic gravel filtration (Dy

  • Page 108 and 109:

    Mean faecal coliform removal effici

  • Page 110 and 111:

    Table 3.10 Comparative analysis of

  • Page 112 and 113:

    DyGF-A had flow reductions in the r

  • Page 114 and 115:

    The experimental data used to produ

  • Page 116 and 117:

    Previous observations were further

  • Page 118 and 119:

    ates (figure 3.17 B). However, at t

  • Page 120 and 121:

    Longer “initial-ripening” perio

  • Page 122 and 123:

    Table 3.17. Descriptive statistics

  • Page 124:

    100 Filtration rate = 0.3 mh -1 100

  • Page 127 and 128:

    After the present experience, faeca

  • Page 130 and 131:

    nature of the organic matter and th

  • Page 132 and 133:

    Table 3.24 Comparative analyses of

  • Page 134 and 135:

    3.2.4.3. Filtration run lengths and

  • Page 136 and 137:

    deep bed filter (data not included

  • Page 138 and 139:

    and operational considerations Pard

  • Page 140 and 141:

    than in sand samples from other SSF

  • Page 142 and 143:

    Step dose tracer tests were made at

  • Page 144 and 145:

    for HGFS and from 3 to 5 for HGF. T

  • Page 146 and 147:

    Constant and declining filtration r

  • Page 148 and 149:

    The efficiency levels summarised be

  • Page 150 and 151:

    Surface area of CGF and SSF units.

  • Page 152 and 153:

    community based organisations and l

  • Page 154 and 155:

    systems. All these systems were fed

  • Page 156 and 157:

    Parts of the suburban settlements o

  • Page 158 and 159:

    Figure 4.2. Layout of Retiro MSF pl

  • Page 160 and 161:

    Traditionally, in the WS&S of Colom

  • Page 162 and 163:

    Photo 4.10. Partial cleaning activi

  • Page 164 and 165:

    Figure 4.3 Location of full-scale M

  • Page 167 and 168:

    4.4.1.3 Main characteristics of mul

  • Page 169 and 170:

    Figure 4.4 Layout of Restrepo MSF p

  • Page 171 and 172:

    Figure 4.6 Layout of Javeriana MSF

  • Page 173 and 174:

    Figure 4.9 Layout of Cañasgordas M

  • Page 175 and 176:

    Figure 4.11. Layout of Ceylan MSF p

  • Page 177:

    Table 4.4 Descriptive statistics fo

  • Page 180 and 181:

    Water sources in the coffee region

  • Page 182 and 183:

    Filterability results seem to under

  • Page 184 and 185:

    Table 4.8 Mean removal efficiencies

  • Page 186 and 187:

    The length of this ripening period

  • Page 188 and 189:

    in Peru (Pardon, 1989) and Colombia

  • Page 190 and 191:

    Photo 4.24 Drainage facilities in u

  • Page 192 and 193:

    the Cauca Valley. This is not the c

  • Page 194 and 195:

    Pardon (1989) reports similar evide

  • Page 196 and 197:

    5. COST OF MULTI-STAGE FILTRATION P

  • Page 198 and 199:

    ecame formally established as WS en

  • Page 200 and 201:

    Models for assessing construction q

  • Page 202 and 203:

    MSF system can then be calculated o

  • Page 204 and 205:

    5.7 Cost Model for the Cali Area an

  • Page 206 and 207:

    Table 5.8. Annual labour costs due

  • Page 208 and 209:

    5.8 General Discussion The followin

  • Page 210 and 211:

    systems. The differences between MS

  • Page 212 and 213:

    guideline for colour is < 15 PCU (W

  • Page 214 and 215:

    Table 6.1. Individual (at each trea

  • Page 216 and 217:

    Table 6.3. Individual (at each trea

  • Page 218 and 219:

    As shown in tables 6.1 and 6.3, col

  • Page 220 and 221:

    UGFL 0.45 UGFS 0.45 (32;51;85) (44;

  • Page 222 and 223:

    Table 6.4. An example of identifica

  • Page 224 and 225:

    MSF technology showed great flexibi

  • Page 226 and 227:

    In harmony with the new development

  • Page 228 and 229:

    epresents the risk the community ha

  • Page 230 and 231:

    The selection of MSF alternatives i

  • Page 232 and 233:

    scouring and transporting away prev

  • Page 234 and 235:

    REFERENCES ABNT, (1989) NB-592 Proj

  • Page 236 and 237:

    Craun, G.F., Bull, R.J., Clark, R.M

  • Page 238 and 239:

    Drinking Water Disinfection, ed. by

  • Page 240 and 241:

    Huisman, L. (1989) Plain Sedimentat

  • Page 242 and 243:

    Mendenhall, W. and Sincich, T. (199

  • Page 244 and 245:

    Ridley, J.E. (1967) Experience in t

  • Page 246 and 247:

    Visscher, J.T. and Galvis, G. (1992

  • Page 248 and 249:

    ANNEXES Annex 1: Accessories for Mu

  • Page 250 and 251:

    aw water. The red colour is used fo

  • Page 252 and 253:

    Annex 2: Design of Manifolds Manifo

  • Page 254 and 255:

    + q 2 Q1 (1.2 qn + qn) (2.2 qn) = =

  • Page 256 and 257:

    R 1 = (total orifice area / lateral

  • Page 258 and 259:

    0.30 0.25 0.20 0.15 0.10 0.05 0.00

  • Page 260 and 261:

    Table A.4-2 General notation for th

  • Page 262 and 263:

    Box A4-3. Sum of Square Error (SSE)

  • Page 264 and 265:

    Annex 5: Residence times in coarse

  • Page 266 and 267:

    Table A5-1 Percentage of incoming w

  • Page 268 and 269:

    Annex 6 Number and Type of Valves N

  • Page 270:

    Table A7-1. Descriptive statistics

  • Page 274 and 275:

    Tables A7-3 Removal efficiencies of

  • Page 276 and 277:

    Tables A7-5 Removal efficiencies of

  • Page 278 and 279:

    Construction quantities of DyGF com

  • Page 280:

    Net present value (US$) of MSF and

Screen Filtration for Ballast Water Treatment Applications - Cross ...
Precursor Removal from Ground Water Using GAC ... - Ohiowater.org
Pall Aria™ AP-Series Packaged Water Treatment ... - Pall Corporation
Water Treatment Improvements and Plant Capacity ... - Ohiowater.org
Pall Aria™ AP-Series Packaged Water Treatment ... - Pall Corporation
2003 City of Roanoke Water Quality Report - Western Virginia Water ...
FILTRATION - Environmental Protection Agency
Filter housings catalogue
Chemicalfree Water Treatment - Necon
Commercial water treatment solutions - CMS
Evaluation of Treatment Options for the Raspberry ... - Loudoun Water
Information You Need to Know When Considering ... - Ohiowater.org
environmentally responsible water treatment - Promolife
lauren@kelman.ca
Omnipure catalogue - The Water Shop
The Treatment of Scottish Water for Private Communities
Simple Ways To Enhance Your Water Treatment ... - Ohiowater.org
A Working Ballast Water Treatment Solution Only ... - Auramarine
Twin Air Dual-Stage Air Filters - Synpsg
Astrasand Continuous Backwash Filter - Siemens Water Technologies
Sartorius Capsules – Filter for Wash Water Filtration in Hospitals
Using Compact Combined Constructed Wetland as Post Treatment ...
Water Treatment Products - Colorfil
Download this project as a low-resolution pdf
lifa_renovation_h_le.. - Lifa.net