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Analysis of a Municipal Solid Waste Landfill in Jalisco,
Mexico and Mitigation Strategies Caroline J. Saul1, Alberto Rodríguez Gómez1, Nadya Selene Alencastro1
Contact: [email protected], [email protected], [email protected]
Figure 2.
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Assessment
Introduction
Materials + Methods
Leachate The results of a laboratory leachate analysis from the four leachate ponds identified above, were compared with the federal discharge limits for wastewater and used to calculate LPI for the landfill. Ponds 2 and 4 are near the working face of the landfill and ponds 9 and 11 are close to the receiving area and oldest garbage. Table 1 exhibits how all of the wells had at least double the allowable chromium concentration. Wells 2 and 4 exhibited the most problematic water, exceeding legal discharge limits for BOD5, Fats, Oils and Total Suspended Solids. The LPI calculations in Table 2 show that the organic pollutants are of great concern for all wells, especially Wells 2 and 4.
Currently receiving over 900,000 tons of waste per year, Los Laureles is a landfill in El Salto, Jalisco, Mexico that receives municipal and special-handling solid waste from five of the eight cities in the Guadalajara Metropolitan Zone. The landfill consists of an intake area, 46 hectares of waste receiving land, partial passive landfill gas venting and several open leachate ponds and is situated 500 meters west of the Santiago River. Los Laureles has been receiving waste since 1986. Photographs from the site as well as accounts from the State Environmental Agency employees and newspapers report that the site is not utilizing appropriate waste management practices, which could lead to harm against the surrounding community and environment, and were not in compliance with solid waste legislation.
Discharge Limit
Well 2 Well 4 Well 9 Well 11 Exceeding
Wells
BOD Total 150 >15000 4231 201 21 2,4,9
Fats and Oils 25 190.3 113.9 14.4 16.4 2,4
Total Phosphorous 30 27.6 28.6 34.0 18.0 9
Total Suspended Solids
125 6680 605 85 300 2,4,11
Chromium 1 3.027 2.49 2.079 3.279 All
Landfill Gas Landfill gas production was modeled with LandGEM and Modelo Mexicano de Biogás 2.0. As can be seen in Figure 4 , both models predicted similar peak production levels and times. According to the LandGEM simulation, the landfill has released 265 Gt of CH4 since it became operational in 1987, but in the next twenty years it will produce over 4 times as much.
Using average monthly precipitation, evapotranspiration values and estimates of leachate generation due to waste decomposition, the annual leachate production is estimated to be 384 m3/day, which is comparable to the landfill’s measurement of 300m3/day, considering the prevalence of leaks (i.e. leaks in the liner).
Figure 3: Site Images. (a) Leakage form torn lining; (b) Haphazard installation of new liner; (c) Unprotected worker digs free flowing leachate channel ; (d) Gas build-up poses risk of explosion
Lagoon 2 Lagoon 4 Lagoon 9 Lagoon 11 Discharge Standard
LPI Organic 78.3 68.6 41.3 39.2 -
LPI Inorganic 24.6 35.5 34.5 27.1 -
LPI Heavy Metals
6.6 6.1 5.7 7.1 8.5
Total LPI 25.9 25.6 19.2 18.1 -
Table 1: Pollutants Exceeding National Discharge Limits. Temperature, Total Settleable Solids, Total Nitrogen, As, Cd, Cu, Cyanide, Hg, Ni, Pb and Zn were all within limits.
Table 2: Leachate Pollution Index and Sub-Index scores
Figure 4: Projected annual landfill gas production and composition simulated with LandGem and Modelo Mexicano de Biogas 2.0
The current and future behavior of Los Laureles were simulated and analyzed to identify potentially threatening environmental impacts:
Leachate A Leachate Pollution Index (LPI) score was calculated for four leachate ponds at the land fill in accordance with the procedures developed by Kumar and Alappat [1] using data provided by Los Laureles. The index ranges from 5-100, with higher pollutant concentrations associated with higher values.
Leachate production was calculated using average monthly precipitation and evapotranspiration values from a local weather station. .
Landfill Gas The landfill’s production of gas was simulated using LandGEM and Modelo Mexicano de Biogás 2.0, both of which were developed by the U.S. EPA. These simulations were considered in conjunction with gas chromatography results of analysis of samples from the gas vents.
Miscellaneous Legislation, scientific literature, interviews with landfill and government employees newspaper articles and photographs were consulted with regard to waste management practices and the public opinion thereof in Jalisco and in Mexico.
Aims • To identify and quantify environmental threats created by the landfill and its operations
• To propose a treatment and remediation strategy that:
o Brings the landfill into compliance with local, state and national legislation
o Demonstrates sensitivity towards environmental and social effects of the landfill
o Considers economic, geographic and geologic feasibility
The Site Figure 2: Waste Composition Analysis of Guadalajara [3]
1. École des Mines de Nantes
Figure 1: Global position and history of Los Laureles. Stage 4 accepted tannery sludge until 2007. [2]
U.S.A.
Mexico
Pacific Ocean Jalisco
Pond 2
Pond 4
Pond 9
Pond 11
Image: jigzone.com
N
Many thanks to Babu Alappat and Josiane Nikiema for technical and industrial guidance. Eng. Adrian Giombni provided access to operating procedures and data from Los Laureles. SEMADES (Secretaría de Medio Ambiente para el Desarrollo Sustentable) supplied images and data from the Guadalajara Metropolitan Zone. We would like to extend our gratitude to the European Commission for their support of the ME3 program as well as CONACYT and IJJ for their endorsement of international education.
Mitigation Opportunities
Acknowledgements
Organics Diversion: Composting • Increase the lifespan of the landfill •Decrease the leachate & biogas production • Production of nutrient rich of organic fertilizer • Can be applied as biofilter for final cover • Improve social acceptance of Los Laureles • Potential revenue stream • Eligible for carbon credits • Legislation mandates segregation of organic
components at the generation source •Available market for the compost products. • Long term reduction of landfill operating costs •High organic content of waste means plenty of
input material.
The operating conditions and pollution potential of Los Laureles were assessed and quantified. Based on this a three-fold mitigation approach was developed, which will reduce the organics and heavy metals concentrations in the effluent, decrease the greenhouse gas emissions and extend the life of the landfill by reducing the rate of incoming refuse.
Further work must be done to determine a cost-effective composting system, proper wetland design, type of chromium treatment fly ash and to hone other parameters. Additionally, other attributes of the landfill will be quantified, like noise and aesthetics as well as impacts on the ecosystem.
Constructed Wetlands are a low maintenance and relatively inexpensive way to treat leachate. The chromium is primarily Cr(VI), a carcinogen. So it is of great concern. A pre-treatment to reduce chromium concentration will be necessary, if discharge limits are to be met. A fly ash adsorption process could be appropriate.
[1] Kumar, D., & Alappat, B. (2005). Analysis of leachate pollution index and formulation of sub-leachate pollution indices. Waste Management & Research 22, 230-239. [2] Bernache-Pérez, G. (2009). El impacto social de las operaciones del vertedero Los Laureles. Iberoamerica Symposium of Waste Engineers. [3] Bernache-Pérez, G. et. al (2001) Solid waste characterisation study in the Guadalajara Metropolitan Zone, Mexico. [4] Hummer, M., & Lechner, P. (2001). Design of a landfill cover layer to enhance methane oxidation – Results of a two year field investigation. 8th International Waste Management and Landfill Symposium.
Stage Surface
(ha) Depth
(m) Operation
years
1 6.63 22.3 1986 - 1992
2 7.99 26.5 1992 - 1996
3 24.82 35 1996 - 2004
4 3.1 12.7 Until 2007
5 2.84 11 In operation
1
2
3
4
5
(c)
(b) (a)
(d)
Biofilter Cover
Cap system
CH4 +CO2
Compost with methanophiles
0
50
100
150
200
250
300
1986 2006 2026 2046 2066 2086
An
nu
al G
as P
rod
uct
ion
( 1
06 m
3)
Year
Total Landfill Gas: LandGEM
Methane: LandGEM
Total Landfill Gas: Modelo Mexicano
Methane: Modelo Mexicano
Constructed Wetland
Figure 5: Schematic of the effect a biofilter landfill cover can have. [4]
CH4 + CO2
Waste
Gas Distribution Media
Conclusions
Paper & Cardboard
9%
Plastics 14%
Glass 9% Organic
Matter 46%
Textiles 2%
Other Metals 2%
Ferrous Metals
0,31
Pottery & Ceramics
1% Sanitary Waste
9%
Others 8%
