Views
3 months ago

galvis

Water treatment

due to poor catchment

due to poor catchment protection persists, 19% of the Colombian municipalities and 38% of the population will suffer shortage of water supply (IDEAM, 1998). Table 1.4 Distribution of the surface area, population, and available water at different height ranges of Colombia, Ministerio del Medio Ambiente (1996) Height 1 Surface Area (%) Population (%) Water Offer (%) >3,000 9 1 4 1,000-3,000 35 66 34

Table 1.5 Safe drinking water coverage in the urban part of a sample of 641 municipalities of Colombia in 1997. (Ministerio de Salud, 1998a) Population range Urban population in the range Safe drinking water coverage (%) 500,000 8’017,571 100 2 Total 21’379,380 1 70 1. Colombia had 1,068 municipalities in 1996 with a urban population of 27’769,687 and a total population (urban + rural) of 39’511,000 (DANE, 1999) 2. It seems to be that the limitations of coverage and quality of the services in urban fringe areas were not considered in presenting this value. Table 1.6 illustrates the types of technologies used in these water treatment plants. This summary also shows that only 42% (395) of the plants were using laboratory facilities, either inside the plant (24%) or outside (18%). Since there is not a regular water surveillance programme at national level, it is not clear how this infrastructure is performing. However, in a sample of 85 plants it was found that 29% had problems to obtain chemical reagents and 31% did not have equipment to control their treatment processes (Cinara, 1998). Table 1.6 Water treatment technologies used in urban areas of Colombia (Mondragón, 1998) Water treatment technology Number % Rapid filtration (202 compact type) 789 84 Slow sand filtration (SSF) 113 12 Multistage filtration (SSF + gravel pref.) 19 2 Others 15 2 TOTAL 936 100% The great majority of these plants are based on rapid filtration (RF) of water, which is chemically coagulated. RF has evolved quickly during recent decades and is used worldwide. Latin American engineers have made important contributions in the upgrading of the unit processes involved in RF and in the simplification of the equipment, thus facilitating operation and maintenance (O&M) and reducing investment and operational costs (Arboleda, 1993; Di Bernardo, 1993). However, O&M of this technology still continue to be demanding. In effect, the requirements for administration, buying, transporting, storing, and properly dosing chemical compounds, strongly limits the wider application of this type of technology in rural communities, and smaller municipalities. Slow sand filtration (SSF) has been successfully applied in the northern part of Europe and North America, but treating surface waters with relatively low levels of contamination (Rachwal et al, 1988; Sims and Slezak, 1991). However, in Latin American countries, like Brazil (Hespanhol, 1969; Di Bernardo, et al., 1999), Peru (Canepa, 1982; Pardón, 1989) and Colombia, the experience with SSF has not been successful, because the technology was not used in harmony with the local conditions. Multistage filtration (MSF), a combination of SSF and gravel filters, is an emerging technology, aiming to overcome part of the limitations of SSF. The development of MSF started in Latin America in the 1980s with promising results (Pardón, 1989; Galvis et al, 1989) and is being gradually introduced into the water supply systems in Colombia and other LAC countries. 5

  • Page 1 and 2: Development and Evaluation of Multi
  • Page 3 and 4: ACKNOWLEDGEMENTS To my supervisor,
  • 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: Table 1.2 Access to WS&S in Colombi
  • 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

Pall Aria™ AP-Series Packaged Water Treatment ... - Pall Corporation
Water Treatment Improvements and Plant Capacity ... - Ohiowater.org
The best solutions in water treatment - Istobal
Screen Filtration for Ballast Water Treatment Applications - Cross ...
Council Bluffs Water Works South Water Treatment Plant – Planning ...
Technical Advances in the Treatment of Water and Air for ... - IAAPA
Weatherford in Waste Water Treatment (WWT)
Pall Aria™ AP-Series Packaged Water Treatment ... - Pall Corporation
Drinking Water Treatment for Small Communities - P2 InfoHouse
P01073 ZTF - ZEKS Compressed Air Solutions
Freshwater-Aquarium-Manual
Systematic Approach to Water Treatment Plant ... - Ohiowater.org
Water treatment for the aquaculture industry
Water Quality Report - 2010 - Presidio Trust
The Treatment of Scottish Water for Private Communities
High Heat Filtration with Industrial Air Filter Bags
advanced water treatment and recycling processes - International ...
Advances in Water Treatment and Enviromental Management
Microorganisms (The Coliform Group Bacteria)
Pilot Testing and Evaluation of Three Filtration Technologies - pncwa
Water Treatment Products - Colorfil
Capacity Charts for Water Treatment Systems
Comline - First for Filters Catalogue_web.compressed
Artificial ground-water recharge at Peoria, Illinois. - Illinois State ...
Advanced oxidation process treatment of membrane filtration ...
waste water treatment at the Hilltop Brewery - Great Lakes Water ...
Precursor Removal from Ground Water Using GAC ... - Ohiowater.org
Wastewater Treatment Options - Saudi Arabian Water Environment ...