MexicanMexican ExperienceExperience inin ElEl MezquitalMezquital ValleyValley
MM EE XX II CC OO
BlancaBlanca JimenezJimenez MM EE XX II CC OO ¾¾22 millionmillion kmkm2 andand 104104 millionmillion InhabitantsInhabitants ¾¾67%67% ofof thethe countrycountry isis aridarid oror semiaridsemiarid
UseUse ofof waterwater inin MéxicoMéxico WaterWater reusereuse inin MexicoMexico
¾¾171171 m3/sm3/s ofof municipalmunicipal wastewaterwastewater areare produced,produced, fromfrom thisthis volumevolume 78% are reused, for 9Agricultural irrigation (8(86%)6%) 9Municipal uses ((6%)6%) 9Industrial uses (8%) ¾¾InIn 1995,1995, irrigationirrigation waswas performedperformed withwith untreateduntreated wastewaterwastewater ¾¾InIn 2005,2005, 40%40% withwith treatmenttreatment Mexico City and the Mezquital Valley Water Balance in MexicoMexico CityCity Mexico City Water Supply 72.5 m3/s (21 million inhabitants) Industrial reuse 16% 21% Groundwater from other Basin 7.7 m3/s Urban Reuse 45% N 31% Rivers from other Basin
60 m3/s Sewage 52.3 m3/s
53% Groundwater Overexplotation Local 8 m3/s
2240 Mexico Valley Aquifer masl El Mezquital Valley Reuse of Mexico city sewage
¾ 2 % Industries ¾ 6 % Municipal ¾ 5 % Ecological Uses ¾ 87 % to irrigate 85,000 ha in the Mezquital Valley since 110 years BUT The actual deficit is of 7 m3/s and 10 m3/s will be needed for 2010 Xochimilco”chinampas” (wetlands) filled with reclaimed water Chapultepec recreative lake, filled with wastewater Dust Control in the Texcoco Ex-lake, Mexico City Description of Mezquital Valley
99 SemiSemi aridarid ClimateClimate (rainfall(rainfall ofof 550550 mmmm andand evaporationevaporation ofof 11 800800 mm)mm)
99 TheThe soilssoils areare salinesaline veryvery poorpoor (low(low contentscontents ofof nitrogen,nitrogen, phosphorousphosphorous andand organicorganic matter)matter)
9919301930--40s40s thethe GovernmentGovernment waswas thinkingthinking onon movingmoving peoplepeople MezquitalMezquital ValleyValley withwith nono irrigationirrigation MezquitalMezquital ValleyValley irrigatedirrigated withwith rawraw wastewaterwastewater YieldYield IncreaseIncrease duedue toto WastewaterWastewater Yield in Ton ha -1 Crop Untreated Natural % of Wastewater water increase Maize 5 2 150 Barley 4 2 100 Tomato 35 18 94 Oats 22 12 83 Chilli 12 7 71 Alfalfa 120 7 71 Wheat 3 2 50 Metal content, mg/L Gastrointestinal diseases due to wastewater reuse
Parasites Ages Morbidity rates Raw Natural Ratio wastewater water Ascaris lumbricoides 0 to 4 15.3 2.7 5.7 (Helminth) 5 to 14 16.1 1.0 16.0 > 15 5.3 0.5 11.0 Giardia lamblia 0 to 4 13.6 13.5 1.0 (Protozoa) 5 to 14 9.6 9.2 1.0 > 15 2.3 2.5 1.0 Entamoeba 0 to 4 7.0 7.3 1.0 histolytica 5 to 14 16.4 12.0 1.3 (Protozoa) < 15 16.0 13.8 1.2 AscarisAscaris Gastrointestinal diseases mortality rates for children under five years old
Country mortality rate/100 000 inhab
Poland 1 Romania 2 Chile 12 Mexico 17 Peru 34 South Africa 44 India 76 Pakistan 124 NewNew regulatoryregulatory frameworkframework
¾¾NOMNOM--001001-- ECOLECOL--1996,1996, MaximumMaximum LimitsLimits ofof pathogenspathogens inin wastewaterwastewater reusedreused forfor agriculturalagricultural irrigationirrigation
9911 HelminthHelminth OvaOva forfor unrestrictedunrestricted cropscrops andand 55 restrictedrestricted onesones
99FecalFecal coliformscoliforms ofof 10001000 MPN/100MPN/100 mLmL Wastewater Treatment Needs ToTo reducereduce
99 HOHO << 11 ova/Lova/L 99 FCFC << 10001000 MPN/100MPN/100 mLmL but,but,
¾¾ PreservingPreserving BOD,BOD, N,N, andand PP ¾¾ ControllingControlling salinitysalinity problemproblem CONVENTIONAL SCHEMES
Primary Secondary Tertiary ?
TSS BOD N, P $$$$$ Reuse
“COMPACT” SCHEMES
Treatment for reuse
$ Wastewater Reuse CorrelationCorrelation TSSTSS--HOHO inin untreateduntreated WasteaterWasteater
HE= 0.9016 TSS + 6.1139 60 2
r = 0.90 50
40
(He/l) 30
Helminth eggs Helminth 20
10
0
7 0 6 3 4 2 2 2 0 8 0 0 2 2 4 4 0 0 8 2 5 7 8 9 2 6 4 8 2 6 9 1 2 4 8 8 1 1 1 1 1 2 2 3 3 4 4 4 5 5 5 5 6
TSS (mg/l) WastewaterWastewater TreatmentTreatment forfor AgriculturalAgricultural ReuseReuse AdvancedAdvanced PrimaryPrimary TreatmentTreatment Disinfection (Cl or Cl/UV) Polymer (high weight and Coagulant high charge density)
Flocculation-coagualtion
Grit removal Sedimentation
Sand Filtration Effluent Removal of pollutants during treatment
Parameter Influent APT Filtration Disinfection Helminth Ova 90 3 <1 <1 Fecal Coliforms 108 108 107 102 Salmonella 107 107 106 ND Protozoan Cysts 1080 310 200 25 P. Aeruginosa 105 104 104 ND TSS 370 35 19 9 TKN 25 18 12 12 TP 12 8 4 4 COD 460 180 170 170 Treatment Cost
Capacity: 38 m3/s Type of Treatment USD Advanced Primary Treatment + Filtration + Disinfection 0.058
Activated sludge + Filtration + Disinfection 0.105
- For all cases, sludge stabilization using quick lime was consider - Disinfection been performed by a chlorination system APTsAPTs inin MexicoMexico 80% for agricultural irrigation 25% of the total WW treated
SITESITE WTPWTP Flow,Flow, mm3/s/s Acapulco,Acapulco, GroGro 11 1.351.35 CiudadCiudad JuarJuaréézz 22 33 CuliacCuliacáán,n, SinSin 11 1.71.7 PueblaPuebla 44 3.63.6 SanSan PedroPedro Atocpan,Atocpan, 11 0.0350.035 DFDF SanSan LuisLuis PotosPotosíí,, SLPSLP 1.051.05 TOTALTOTAL 10.73510.735 Ciudad Juárez, North 2500 L/s and South 1000 L/s Water balance in the Mezquital Valley 38 m3/s Mexico City raw 5.2 m3/s extraction wastewater 38% agriculture 33 % industry Since 1900 17% domestic Tula Valley aquifer consumption 12% other uses
7.8 m3/s to 25 m3/s infiltration other valleys from irrigation (13 fold natural recharge) High Irrigation rate combined with 688 km unlined channels for wastewater distribution MEZQUITAL OR TULA VALLEY
99< year 1900 the groundwater level was at least at 50 m below 99 Since 1997, artesian wells with flows from 100 to 600 L/s 99 Groundwater main source of drinking water of 500,000 inhabitants Reuse of Excess Volumes of Well La Noria in Swimming Pools at Mezquital Valley, Mexico TezontepecTezontepec SpringSpring Phase I
Rapid assessment of the quality of the water been used to supply people in the Mezquital Valley Preliminary water quality Assessment
ANALYZED GROUP PARAMETERS Inorganic compounds 9 Organic compounds 221 Physical 2 Metals 18 Non-metals 6 Microbiological 8 Organoleptic 3
Total 288 WATER QUALITY AT DRINKING WATER SUPPLY SITES IN MEZQUITAL VALLEY
PARAMETERS RESULT Viruses ND Helminth eggs ND Acute toxicity (Microtox®) ND Pesticides ND Atrazine < 0.5 ppb Carbofuran < 0.5 ppb 2,4-D < 0.1 ppb Other compounds “Chomatogram picks”
ND = NOT DETECTED ResultsResults 99 NoNo mainmain problemsproblems
99 WaterWater waswas lightlight salinesaline
99 InIn wellswells builtbuilt withwith nono carecare somesome microbiologicalmicrobiological problemproblem
WhyWhy notnot usingusing itit forfor MexicoMexico citycity supply?supply? PhasePhase 22
99ToTo determinedetermine thethe qualityquality inin aa numbernumber ofof representativerepresentative sitessites ofof waterwater supplysupply systemssystems forfor populationpopulation (175(175 000000 inhab)inhab) Location of sampling sites EVALUATION OF DRINKING WATER SUPPLIES
Parameter Sources not complying with drinking water standards % Number % Volume TDS 64 95 Sodium 38 73 Fecal coliforms 42 25 Nitrates 31 12 Chlorides 24 10 Hardness 31 9 Sulfates 18 2 Fluorides 18 1 Without problem 13 5 Fecal Coliforms means a problem (disinfection) Other parameters mean only aesthetc problems, but fluorides PhasePhase IIIIII
99IdentifyingIdentifying PICKSPICKS inin chromatogrameschromatogrames StudyStudy ofof selectedselected compoundscompounds inin wastewaterwastewater andand groundwatergroundwater ll (( µg/L)µg/L) Importance of soil treatment capabilities, specifically for organic compound removal
Compound Wastewatwe Site 1 Site 2 Site 3
Methyl (1-methy- 5-10 < 5 < 5 < 5 ethyl)- benzene 1,1-oxy-bis-benzene 10-50 <5 < 5 < 5
4-nonyl phenol 1000 5-10 10-50 5-10 1,2,4 5-10 <5 < 5 < 5 trichlorobenzene Benzenes 100 <5 < 5 < 5 Phenols 1500 10 50 10 PAH 25 <5 < 5 < 5 PHASE IV Treatment processes for the Mezquital Valley groundwater
Activated Membranes (NF, Well Filtration water Carbon RO)
Treated UV Disinfection effluent Chlorine
Treatment Processes for the secondary effluent WWTP Activated Carbon Sand Secondary Ozonation filtration (1) effluent Filtration
Activated UV Membranes Treated Carbon Disinfection (NF+RO) effluent filtration (2) Chorine Application of membrane processes
Raw Wastewater
Cerro Colorado Spring
Well 115 Nanofiltration effluent
Chromatograms of the raw wastewater, infiltrated water (Tezontepec and Cerro Colorado) and the nanofiltration effluent SpringsSprings waterwater treatmenttreatment resultsresults 99FiltrationFiltration withwith ReverseReverse OsmoseOsmose oror NanofiltrationNanofiltration
99ChromatogramChromatogram pickspicks disappear,disappear, TDSTDS lessless thanthan 7070 mg/L,mg/L, andand pHpH acidacid
99TooToo cleanclean
99StudiesStudies stillstill undergoingundergoing PHASE V To identify and evaluate the flora and animal life present in the “Cerro Colorado Spring and for to estimate some impact for the presence to toxics compounds Cerro Colorado Spring
Origin It appeared 35 years ago as a natural exit of the Mezquital Valley aquifer due to the overload with raw wastewater Diverse aquatic populations usually presented in non polluted systems
SITE 1 SITE 2 SITE 3 SITE 4 SITE 5 10000
1000
100 NUMBER
10
1 shrimp Snails Anelides Asellus Stentor Hyalellas Ostracoda
Fresh water Macrocyclops Platyhelminthes PercentagePercentage ofof femalesfemales andand malesmales inin fishesfishes
Family Poecilidae Genus Heterandria Family Goodeidae Species H. jonesi Genus Allotoca Species A. regal is 100 90 80 70
s 60 fi 50 of
% 40 30 20 10 0 1234 Male 24 45 35 55 Female 76 55 65 45 Samples ARTHROPODS,ARTHROPODS, knownknown asas “Mexican“Mexican acocil”,acocil”, “indicators”of“indicators”of veryvery cleanclean waterwater Supply altenatives for Valley of Mexico (2240 masl)
SOURCE Capacity Head Distance Cost m3/s m km ($/m3) Temascaltepec 5.0 1570 80 5.8 Amacuzac 13.5 1700 100 8.6 Tecolutla 9.8 1266 116 8.5 Mezquital Valley 10 400 70 2.5 Further work 9Epidemiological and Toxicological studies 9Disinfection byproducts study for the Mezquital area 9Research on contaminant removal mechanisms and fate of contaminants in the natural system (on going) 9Industrial Pretreatment programs 9Evaluation of membrane treatment processes at pilot scale (on going) 9Education and communication programs 9Development of an appropriate regulation