An Analysis of the Risk Posed by Leachate from Dumpsites in Developing Countries
Abstract
:1. Introduction
2. Materials and Methods
- Production of leachate in the landfill;
- Leachate flux through any holes present in the liner system or through the soil (if a liner system is absent);
- Leachate flux through the unsaturated (vadose) zone;
- Leachate mixing with the aquifer;
- Migration of the contaminants through the groundwater.
- Lf = leakage flux through the vadose zone (m3/s);
- Ki = hydraulic conductivity of the soil (m/s);
- A = area of landfill (m2);
- if = vertical hydraulic gradient (-).
- hleac = height of leachate from the bottom of the dumpsite (m);
- di = thickness of the vadose zone (m).
- dd = depth of the bottom of dumpsite respect the soil level (m);
- LGW = distance of the water table respect the soil level (m).
- vGW = K × i = Darcy groundwater velocity (m/s);
- L = dumpsite length parallel to groundwater flow (m);
- Ieff = infiltration rate of leachate in the soil (m/s), which may be calculated as follows:
- Cgw(x,y,z,t) = concentration of the contaminant in function of space and time (mg/L);
- Cgw,0 = initial concentration of the contaminant in the groundwater (mg/L);
- αx = longitudinal dispersivity (calculated as αx = 0.1 αx) (m);
- αy = transverse dispersivity (calculated as αy = 0.33 αx) (m);
- αz = vertical dispersivity (calculated as αz = 0.05 αx) (m);
- λ = first order degradation rate constant (1/d);
- R = time delay coefficient (-);
- u = pore velocity (m/s);
- SW = source width perpendicular to groundwater flow direction (m);
- SD = thickness of aquifer mixing zone (m).
- Hazard identification: Available data are used to determine if a material is likely to pose a hazard to human health. These data are also used to define the type of potential hazard;
- Dose-response assessment: Data are used to estimate the amount of material that may produce a given effect in humans;
- Exposure assessment: Which seeks to determine the extent to which a population is exposed to the material. Fate and transport of the material in the environment, as well as media, pathways and routes of exposure may all be considered in the exposure assessment;
- Risk characterization: Which is the integrating step in the risk assessment process that summarizes the assessment of the effects on human health and of the exposure from multiple environmental media, identifies human subpopulation at elevated risk, combines these assessments into characterizations of human risk, and describes the uncertainty and variability in these characterizations.
- SFij = slope factor for the ith substance, referred to the jth exposure pathway (kg d/mg),
- CDIij = chronic daily intake for the ith substance, referred to the jth exposure pathway (mg/(kg × d)), where the general equation of CDI is the following [38]:
- Cpoe = ith contaminant concentration at the point of exposure of the jth pathway (mg/L);
- CR = contact rate, that is the amount of contaminated medium contacted per unit time or event (e.g., for water ingestion is L/d);
- EF = exposure frequency (d/year);
- ED = exposure duration (year);
- BW = body weight (kg);
- AT = averaging time (d).
- RfDi is the value related to each contaminant;
- Cgw,0−i is the initial concentration of each contaminant in the groundwater.
3. Results
3.1. Baseline Scenario
3.2. Sensitivity Analysis and Different Scenarios
- The concentration of arsenic in the leachate Cgw,0;
- The distance between the bottom of the dumpsite and the water table dWT−D;
- The hydraulic conductivity of the soil Ks;
- The thickness of groundwater da;
- The annual production of leachate Lpr;
- The area of dumpsite A.
4. Discussion
- The proposed model is conservative, as the contaminants are not considered to have degraded (λ = 0);
- The concentration of the contaminants in the leachate is very high and the model is for a dumpsite (without waterproof liner at the bottom), where there is consistent diffusion of very dangerous leachate towards the aquifer.
5. Conclusions
Author Contributions
Funding
Conflicts of Interest
Appendix A
Site | Country | Source | Cd | Cu | Pb | Ni | Zn | As |
---|---|---|---|---|---|---|---|---|
Aba Eku dumpsite—Ibadan | Nigeria | [43] | 0.3 | 0.36 | 1.54 | |||
Lapite dumpsite—Ibadan | Nigeria | [43] | 0.13 | 0.19 | 1.61 | |||
Awotan dumpsite—Ibadan | Nigeria | [43] | 0.12 | 0.16 | 0.83 | |||
Olusosun dumpsite—Lagos | Nigeria | [43] | 2.2 | 0.39 | 11.8 | |||
Solous 3 dumpsite—Lagos | Nigeria | [43] | 0.07 | 0.23 | 1.45 | |||
Solous 2 dumpsite—Lagos | Nigeria | [43] | 1.38 | 1.09 | 8.95 | |||
Matale | Sri Lanka | [44] | 0.1 | 0.57 | 1.78 | 1.15 | 6.88 | 0.52 |
Bandaragama | Sri Lanka | [44] | 0.09 | 0.23 | 0.48 | 0.91 | 5.36 | 0.72 |
Kolonnawa | Sri Lanka | [44] | 0.02 | 0.06 | 0.42 | 4.47 | 11.76 | 0.71 |
Gampola | Sri Lanka | [44] | 0 | 0.73 | 0.03 | 0.33 | 0.466 | 0.16 |
Gohagoda | Sri Lanka | [44] | 0 | 0.33 | 0.02 | 0.33 | 0.39 | 0.15 |
Wennapuwa | Sri Lanka | [44] | 0.05 | 0.43 | 0.09 | 0.4 | 0.41 | 0.94 |
Rathnapura | Sri Lanka | [44] | 0.05 | 0.63 | 0.17 | 1.31 | 1.68 | 1.55 |
Negombo | Sri Lanka | [44] | 0.05 | 0.54 | 0.33 | 0.67 | 2.06 | 0.85 |
Dhapa, Kolkata | India | [45] | 0.32 | 0.6 | 0.51 | 7.61 | 0.03 | |
Dhapa, Kolkata | India | [45] | 0.27 | 0.69 | 0.43 | 3.26 | 0.22 |
References
- UNEP; ISWA. Global Waste Management Outlook; United Nations Environment Programme: Nairobi, Kenya, 2015; ISBN 978-92-807-3479-9. [Google Scholar]
- Vaccari, M.; Di Bella, V.; Vitali, F.; Collivignarelli, C. From mixed to separate collection of solid waste: Benefits for the town of Zavidovici (Bosnia and Herzegovina). Waste Manag. 2013, 33, 277–286. [Google Scholar] [CrossRef] [PubMed]
- Perteghella, A.; Vaccari, M. Organic waste valorization through composting process: A full−scale case study in Maxixe, Mozambique. Environ. Eng. Manag. J. 2017, 16, 1819–1826. [Google Scholar]
- Collivignarelli, C.; Vaccari, M.; Di Bella, V.; Giardina, D. Techno−economic evaluation for the improvement of MSW collection in somaliland and puntland. Waste Manag. Res. 2011, 29, 521–531. [Google Scholar] [CrossRef] [PubMed]
- Nnaji, C.C.; Kumar Yadav, K.; Kumar, V. Status of municipal solid waste generation and disposal in Nigeria. J. Environ. Sci. 2015, 37, 206–217. [Google Scholar] [CrossRef]
- Nwagbie, N.M.; Wirlen, Y.L.; Yinda, G.S.; Vander Zaag, A.C. Quantifying greenhouse gas emissions from municipal solid waste dumpsites in Cameroon. Waste Manag. 2018, in press. [Google Scholar]
- Ojuri, O.O.; Ayodele, F.O.; Oluwatuyi, O.E. Risk assessment and rehabilitation potential of a millennium city dumpsite in Sub-Saharan Africa. Waste Manag. 2018, 76, 621–628. [Google Scholar] [CrossRef] [PubMed]
- Oyelami, A.C.; Aladejana, J.A.; Agbede, O.O. Assessment of the impact of open waste dumpsites on groundwater quality: A case study of the Onibu-eja dumpsite, Southwestern Nigeria. Procedia Earth Planet. Sci. 2013, 7, 648–651. [Google Scholar] [CrossRef]
- Yan, H.; Cousins, I.T.; Zhang, C.; Zhou, Q. Perfluoroalkyl acids in municipal landfill from China: Occurrence, fate during leachate treatment and potential impact on groundwater. Sci. Total Environ. 2015, 524–525, 23–31. [Google Scholar] [CrossRef] [PubMed]
- Ojuri, O.O.; Taiwo, O.A.; Oluwatuyi, O.E. Heavy metal migration along a rural highway route: Ilesha-akure roadside soil, southwestern, Nigeria. J. Glob. NEST 2018, 18, 742–760. [Google Scholar]
- Gollapalli, M.; Kota, S.H. Methane emissions from a landfill in north−east India: Performance of various landfill gas emission models. Environ. Pollut. 2018, 234, 174–180. [Google Scholar] [CrossRef] [PubMed]
- Kumarathilaka, P.; Jayawardhana, Y.; Basnayake, B.F.A.; Mowjood, M.I.M.; Nagamori, M.; Saito, T.; Kawamoto, K.; Vithanage, M. Characterizing volatile organic compounds in leachate from Gohagoda municipal solid waste dumpsite, Sri Lanka. Ground Water. Sustain. Dev. 2016, 2–3, 1–6. [Google Scholar] [CrossRef]
- Han, D.; Currell, M.J. Persistent organic pollutants in China’s surface water system. Sci. Total Environ. 2014, 580, 602–625. [Google Scholar] [CrossRef] [PubMed]
- Maiti, S.K.; De, S.; Hazra, T.; Debsarkar, A.; Dutta, A. Characterization of leachate and its impact on surface and groundwater quality of a closed dumpsite—A case study at Dhapa, Kolkata, India. Procedia Environ. Sci. 2016, 35, 391–399. [Google Scholar] [CrossRef]
- Kamaruddin, M.A.; Yusoff, M.S.; Rui, L.M.; Isa, A.M.; Zawawi, M.H.; Alrozy, R. An overview of municipal solid waste management and landfill leachate treatment: Malaysia and Asian perspectives. Environ. Sci. Pollut. Res. 2017, 24, 26988–27020. [Google Scholar] [CrossRef] [PubMed]
- Gidarakos, E.; Havas, G.; Ntzamilis, P. Municipal solid waste composition determination supporting the integrated solid waste management system in the island of Crete. Waste Manag. 2006, 26, 668–679. [Google Scholar] [CrossRef] [PubMed]
- An, C.J.; Huang, G.H.; Yao, Y.; Sun, W.; An, K. Performance of in−vessel composting of food waste in the presence of coal ash and uric acid. J. Hazard. Mater. 2012, 203–204, 38–45. [Google Scholar] [CrossRef] [PubMed]
- Di Bella, V.; Vaccari, M. Constraints for solid waste management in Somaliland. Waste Resour. Manag. 2014, 167, 62–71. [Google Scholar] [CrossRef]
- Caniato, M.; Vaccari, M. How to assess solid waste management in armed conflicts? A new methodology applied to the Gaza Strip, Palestine. Waste Manag. Res. 2014, 32, 908–917. [Google Scholar] [CrossRef] [PubMed]
- Al-Khatib, I.A.; Kontogianni, S.; Abu Nabaa, H.; Alshami, N.; Al-Sari’, M.I. Public perception of hazardousness caused by current trends of municipal solid waste management. Waste Manag. 2015, 36, 323–330. [Google Scholar] [CrossRef] [PubMed]
- Adelopo, A.O.; Haris, P.I.; Alo, B.I.; Huddersman, K.; Jnkins, R.O. Multivariate analyses of the effects of age, particle size and landfill depth on heavy metals pollution content of closed and active landfill precursors. Waste Manag. 2018, 78, 227–237. [Google Scholar] [CrossRef]
- Aboyeji, O.S.; Eigbokhan, S.F. Evaluations of groundwater contamination by leachates around Olusosun open dumpsite in Lagos metropolis, southwest Nigeria. J. Environ. Manag. 2016, 183, 333–341. [Google Scholar] [CrossRef] [PubMed]
- Demesouka, O.E.; Vavatsikos, A.P.; Anagnostopoulos, K.P. Suitability analysis for siting MSW landfills and its multicriteria spatial decision support system: Method, implementation and case study. Waste Manag. 2013, 33, 1190–1206. [Google Scholar] [CrossRef] [PubMed]
- Nannoni, F.; Santolini, R.; Protano, G. Heavy metal accumulation in evernia prunastri lichen transplants around a municipal solid waste landfill in central Italy. Waste Manag. 2015, 43, 353–362. [Google Scholar] [CrossRef] [PubMed]
- Adamcová, D.; Radziemska, M.; Ridošková, A.; Bartoň, S.; Pelcová, P.; Elbl, J.; Kynický, J.; Brtnický, M.; Vaverková, M.D. Environmental assessment of the effects of a municipal landfill on the content and distribution of heavy metals in Tanacetum vulgare L. Chemosphere 2017, 85, 1011–1018. [Google Scholar] [CrossRef] [PubMed]
- Liu, H.; Liang, Y.; Zhang, D.; Wang, C.; Liang, H.; Cai, H. Impact of MSW landfill on the environmental contamination of phthalate esters. Waste Manag. 2010, 30, 1569–1576. [Google Scholar] [CrossRef] [PubMed]
- Porowska, D. Determination of the origin of dissolved inorganic carbon in ground water around a reclaimed landfill in Otwock using stable carbon isotopes. Waste Manag. 2015, 39, 216–225. [Google Scholar] [CrossRef] [PubMed]
- Ilyas, M.; Sudaryanto, A.; Setiawan, I.E.; Riyadi, A.S.; Isobe, T.; Tanabe, S. Characterization of polychlorinated biphenyls and brominated flame retardants in sludge, sediment and fish from municipal dumpsite at Surabaya, Indonesia. Chemosphere 2013, 93, 1500–1510. [Google Scholar] [CrossRef] [PubMed]
- Batu, V. Applied flow and solute transport modeling. In Aquifers: Fundamental Principles and Analytical and Numerical Methods; CRC Press: Boca Raton, FL, USA, 2006; ISBN 978970-8493-3574-7. [Google Scholar]
- Butt, T.E.; Alam, A.; Gouda, H.M.; Paul, P.; Mair, M. Baseline study and risk analysis of landfill leachate—Current state-of-the-science of computer aided approaches. Sci. Total Environ. 2017, 580, 130–135. [Google Scholar] [CrossRef] [PubMed]
- Bear, J.; Cheng, A. Modeling Groundwater Flow and Contaminant Transport; Bear, J., Ed.; Springer: Dordrecht, The Netherlands, 2010; ISBN 978-1-4020-6681-8. [Google Scholar]
- APAT. Criteri Metodologici per l’Applicazione Dell’Analisi Assoluta di Rischio Alle Discariche; Agenzia per la Protezione Dell’Ambiente e per i Servizi Tecnici: Rome, Italy, 2005. Available online: http://www.isprambiente.gov.it/it/temi/siti-contaminati/analisi-di-rischio (accessed on 13 June 2018).
- Goltz, M.; Huang, J. Analytical Modeling of Solute Transport in Groundwater; John Wiley & Sons: Hoboken, NJ, USA, 2017; ISBN 9780470242346. [Google Scholar]
- Dubey, A.; Chakrabarti, M.; Pandit, D. Landfill mining as a remediation technique for open dumpsites in India. Procedia Environ. Sci. 2016, 35, 319–327. [Google Scholar] [CrossRef]
- US EPA. Soil Screening Guidance: Technical Background Document, 2nd ed.; U.S. Environmental Protection Agency: Washington, DC, USA, 1996.
- Domenico, P.A. An analytical model for multidimensional transport of a decaying contaminant species. J. Hydrol. 1987, 91, 49–58. [Google Scholar] [CrossRef]
- Fjeld, R.A.; Eisenberg, N.A.; Compton, K.L. Quantitative Environmental Risk Analysis for Human Health; John Wiley & Sons: Hoboken, NJ, USA, 2007; ISBN 13: 978-0-471-72243-4. [Google Scholar]
- APAT. Criteri Metodologici per l’Applicazione dell’Analisi Assoluta di Rischio ai siti Contaminati; Agenzia per la Protezione dell’Ambiente e per i Servizi Tecnici: Rome, Italy, 2008. Available online: http://www.isprambiente.gov.it/it/temi/siti-contaminati/analisi-di-rischio (accessed on 13 June 2018).
- Faure, M.; du Plessis, W. The Balancing of Interests in Environmental Law in Africa; Pretoria University Law Press: Pretoria, South Africa, 2011; ISBN 978-1-920538-05-7. [Google Scholar]
- WHO (World Health Organization). Guidelines for Drinking-Water Quality, 4th ed.; World Health Organization: Geneva, Switzerland, 2011; ISBN 9789241548151. [Google Scholar]
- APAT. Criteri Metodologici per l’Applicazione dell’Analisi Assoluta di Rischio ai siti Contaminati—Appendici; Agenzia per la Protezione dell’Ambiente e per i servizi Tecnici: Rome, Italy, 2008. Available online: http://www.isprambiente.gov.it/it/temi/siti-contaminati/analisi-di-rischio (accessed on 13 June 2018).
- Istituto Superiore di Sanità. Banca Dati ISS−INAIL per AdR. Available online: http://old.iss.it/iasa/?tipo=40 (accessed on 19 June 2018).
- Oketola, A.A.; Akpotu, S.O. Assessment of solid waste and dumpsite leachate and topsoil. Chem. Ecol. 2015, 31, 134–146. [Google Scholar] [CrossRef]
- Sewwandi, B.G.N.; Takahiro, K.; Kawamoto, K.; Hamamoto, S.; Asamoto, S.; Sato, H. Evaluation of leachate contamination potential of municipal solid waste dumpsites in Sri Lanka using leachate pollution index. In Proceedings of the Sardinia 2013, Fourteenth International Waste Management and Landfill Symposium, Santa Margherita di Pula, Italy, 30 September–4 October 2013. [Google Scholar]
- Ziyang, L.; Youcai, Z.; Tao, Y.; Yu, S.; Huili, C.; Nanwen, Z.; Renhua, H. Natural attenuation and characterization of contaminants composition in landfill leachate under different disposing ages. Sci. Total Environ. 2009, 407, 3385–3391. [Google Scholar] [CrossRef] [PubMed]
Variable | Adopted Value |
---|---|
IR = ingestion rate | 1 L/d for children 2 L/d for adults |
EF = exposure frequency | 350 d/year |
ED = exposure duration | 6 year for children 30 year for adults |
AT = averaging time | 365 d/year × ED for non carcinogens 365 d/year × 70 year for carcinogens |
BW = body weight | 15 kg for children 70 kg for adults |
Parameter (Symbol) | Value |
---|---|
Dumpsite length parallel to groundwater flow (W) | 100 m |
Dumpsite length orthogonal to groundwater flow (SW) | 100 m |
Area of dumpsite (A) | 10,000 m2 |
Distance between the bottom of dumpsite and the soil level (dd) | 10 m |
Distance between water table and soil level (LGW) | 20 m |
Thickness of aquifer (da) | 20 m |
Hydraulic conductivity of the soil (Ks) | 10−8 m/s |
Hydraulic gradient of the aquifer (i) | 0.002 |
Distance between bottom of dumpsite and the water table (dGW-D) | 10 m |
Annual production of leachate per hectare of dumpsite (Lpr) | 3000 m3/(ha × year) |
Substance | CL (mg/L) | RfDingestion (mg/(kg × d) | SFingestion (kg × d)/mg |
---|---|---|---|
Arsenic (As) | 1.55 | 0.0003 | 1.5 |
Cadmium (Cd) | 0.1 | 0.001 | - |
Copper (Cu) | 0.73 | 0.04 | - |
Lead (Pb) | 2.2 | 0.0035 | - |
Nickel (Ni) | 4.47 | 0.02 | - |
Zinc (Zn) | 11.76 | 0.3 | - |
Parameter | Value |
---|---|
SAM | 0.5 |
LDF | 1 |
EMadult,carc | 0.0117 |
EMadult,tox | 0.0274 |
EMchild,carc | 0.0055 |
EMchild,tox | 0.0639 |
x (m) | y (m) |
---|---|
0.10 | −50.05851589 |
100.00 | −108.0540149 |
200.00 | −159.263278 |
300.00 | −202.8877164 |
400.00 | −239.7397805 |
500.00 | −269.8516474 |
600.00 | −293.2173686 |
700.00 | −309.7434434 |
800.00 | −319.1689787 |
900.00 | −320.9862189 |
1000.00 | −314.3114564 |
1100.00 | −297.6151914 |
1200.00 | −268.0616333 |
1446.21 | 0 |
1200.00 | 268.0616333 |
1100.00 | 297.6151914 |
1000.00 | 314.3114564 |
900.00 | 320.9862189 |
800.00 | 319.1689787 |
700.00 | 309.7434434 |
600.00 | 293.2173686 |
500.00 | 269.8516474 |
400.00 | 239.7397805 |
300.00 | 202.8877164 |
200.00 | 159.263278 |
100.00 | 108.0540149 |
0.10 | 50.05851589 |
x (m) | y (m) |
---|---|
0.1 | −50.082136 |
100.00 | −131.7928697 |
200.00 | −208.4954584 |
300.00 | −280.0226457 |
400.00 | −347.6746693 |
500.00 | −411.8695975 |
600.00 | −472.7682353 |
700.00 | −530.6104992 |
800.00 | −585.5937807 |
900.00 | −637.8924357 |
1000.00 | −687.6562402 |
1500.00 | −902.3287908 |
2000.00 | −1066.524568 |
2500.00 | −1184.747167 |
3000.00 | −1258.006789 |
3500.00 | −1284.471258 |
4000.00 | −1258.909276 |
4500.00 | −1170.459383 |
5000.00 | −993.823005 |
5797.30 | 0 |
5000.00 | 993.823005 |
4500.00 | 1170.459383 |
4000.00 | 1258.909276 |
3500.00 | 1284.471258 |
3000.00 | 1258.006789 |
2500.00 | 1184.747167 |
2000.00 | 1066.524568 |
1500.00 | 902.3287908 |
1000.00 | 687.6562402 |
900.00 | 637.8924357 |
800.00 | 585.5937807 |
700.00 | 530.6104992 |
600.00 | 472.7682353 |
500.00 | 411.8695975 |
400.00 | 347.6746693 |
300.00 | 280.0226457 |
200.00 | 208.4954584 |
100.00 | 131.7928697 |
0.10 | 50.082136 |
Input Parameter | Value | Factor of Input Change from Baseline | Model Output x (m) | Factor of x Difference from Baseline | Relative Sensitivity S |
---|---|---|---|---|---|
Cgw,0 (mg/L) | 1.55 (baseline) | −−− | 5797.3 | −−− | 0.5783 |
0.155 | 0.1 | 1831.2 | 0.33 | ||
3.1 | 2 | 8200.7 | 1.50 | ||
dWT−D (m) | 10 (baseline) | −−− | 5797.3 | −−− | 0.1492 |
5 | 0.5 | 6693.6 | 1.22 | ||
40 | 4 | 3666.5 | 0.67 | ||
Ks (m/s) | 10−8 (baseline) | −−− | 5797.3 | −−− | 0.0002 |
10−10 | 0.01 | 5797.3 | −−− | ||
10−6 | 1000 | 5680.1 | 0.98 | ||
da (m) | 20 (baseline) | −−− | 5797.3 | −−− | 0.4712 |
10 | 0.5 | 4100.7 | 0.71 | ||
40 | 4 | 8198.4 | 1.41 | ||
Lpr (m3/year) | 3000 (baseline) | −−− | 5797.3 | −−− | 0.0001 |
1000 | 0.33 | 5795.0 | 0.9996 | ||
10,000 | 3.33 | 5797.3 | −−− | ||
A (m2) | 10,000 (baseline) | −−− | 5797.3 | −−− | 0.0384 |
2500 | 0.25 | 4100.2 | 0.70 | ||
250,000 | 25 | 9607.0 | 1.66 |
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Vaccari, M.; Vinti, G.; Tudor, T. An Analysis of the Risk Posed by Leachate from Dumpsites in Developing Countries. Environments 2018, 5, 99. https://doi.org/10.3390/environments5090099
Vaccari M, Vinti G, Tudor T. An Analysis of the Risk Posed by Leachate from Dumpsites in Developing Countries. Environments. 2018; 5(9):99. https://doi.org/10.3390/environments5090099
Chicago/Turabian StyleVaccari, Mentore, Giovanni Vinti, and Terry Tudor. 2018. "An Analysis of the Risk Posed by Leachate from Dumpsites in Developing Countries" Environments 5, no. 9: 99. https://doi.org/10.3390/environments5090099