Leachate Pollution Index Values Research Articles

Physical and chemical characterization and pollution index applied in the assessment of the polluting potential of leachate from urban landfills.

During the operation of the landfills, leachate should be managed with caution to avoid possible negative environmental impacts. Considering this, the present study aims to evaluate the relationship between different variables in the leachate composition and elucidate the transformation processes through which this effluent passes during the landfill's period of operation. The study was conducted with eight sanitary landfills from the state of Minas Gerais, in southeastern Brazil, and used descriptive statistical analysis, principal component analysis (PCA), correlation analysis, and calculation of the leachate pollution index (LPI). The biochemical oxygen demand (BOD5)/chemical oxygen demand (COD) ratio was between 0.20 and 0.60. We also observed a significant correlation of 0.45 between Cl- and N-NH4+, which reflects the biological degradation processes that contribute to the presence of both variables. The PCA showed that inorganic variables and organic matter dominated the first component, with coefficients above 0.65, indicating the importance of those variables in determining the general data variability. The LPI values were between 15.26 and 25.97, with BOD5, COD, and N-NH4+ having sub-indexes above 35, being the main variables that increase the pollution potential of the leachate. On the other hand, trace metals present sub-indexes below 7 due to precipitation caused by increased pH and the characteristics of the waste discarded in landfills. The study provides essential information regarding the landfill leachate characteristics and its variation over time, which can contribute to the definition of treatment technologies for this affluent in different scenarios.

Characterization and pollution potential of leachate from urban landfills during dry and wet periods in arid regions

Abstract Leachate originating from municipal solid waste landfills poses a serious contamination threat to public health. The study performed a bio-physicochemical characterization of leachate from two landfills in Oman, i.e., Multaqa landfill leachate (MLL) and Barka landfill leachate (BLL) before and after rainfall. Samples were characterized for 92 parameters. Additionally, the leachate pollution index (LPI) was estimated to assess the expected contamination levels and potential environmental health risks. The study found a high value of the leachate parameters without any rainfall incidents. Pearson correlations (±ve) are seen at more than 90% in all cases, which is a strong association (r>0.75) for the measured parameters in both MLL and BLL. Rainfall significantly reduced the concentrations of organic contaminants and solids in leachate due to dilution. The study revealed about 18%–29% and 14%–28% reductions in the LPI sub-index for organic and inorganic contaminants, respectively, after rainfall. The overall LPI values were higher compared with similar findings from the literature. Such deviations could be attributed to the unsegregated nature of solid waste, resulting in the formation of contaminants or from the disposal of a high volume of solid waste in a smaller area. Therefore, the study recommends efficient management strategies for landfills to reduce potential leachate groundwater contamination.

Progress and prospects in mitigation of landfill leachate pollution: Risk, pollution potential, treatment and challenges

The escalating loads of municipal solid waste (MSW) end up in open dumps and landfills, producing continuous flows of landfill leachate. The risk of incorporating highly toxic landfill leachate into environment is important to be evaluated and measured in order to facilitate decision making for landfill leachate management and treatment. Leachate pollution index (LPI) provides quantitative measures of the potential environmental pollution by landfill leachate and information about the environmental quality adjacent to a particular landfill. According to LPI values, most developing countries show high pollution potentials from leachate, mainly due to high organic waste composition and low level of waste management techniques. A special focus on leachate characterization studies with LPI and its integration to treatment, which has not been focused in previous reviews on landfill leachate, is given here. Further, the current review provides a summary related to leachate generation, composition, characterization, risk assessment and treatment together with challenges and perspectives in the sector with its focus to developing nations. Potential commercial and industrial applications of landfill leachate is discussed in the study to provide insights into its sustainable management which is original for the study.

Proposed formulations for error reduction in leachate pollution index (LPI) estimation due to the absence of leachate parameters

The applications of leachate pollution index (LPI) as an environmental index to express the overall leachate-contaminating ability of landfills are increasing. Majority of these applications wrongly quantify LPI due to the absence of various leachate parameters. The traditional linear weighted aggregation equation used in LPI estimations, result in larger errors as missing parameters increase. In this article, error reduction equations were established to predict LPI values more accurately. Approximately 1797 unique combinations of leachate weights ( ∑ wi) were randomly assigned to cover the missing parameters and augment the accuracy of the proposed error reduction equations. The upper and lower boundaries of LPI were accurately estimated in each case, starting from 1 missing parameter to 12 missing parameters. Various linear equations were generated, when possible, to ease the calculations. Subsequently, the arithmetic, geometric, and harmonic averages were applied between the LPI limits in five different case studies to demonstrate the validity of the developed error reduction equations. These equations were capable of providing reliable LPI values even when up to twelve leachate pollutants were absent. It was found that the harmonic average was the best average to be applied between the LPI boundaries, which mostly resulted in errors around ± 20% for ∑ wi values up to 0.3. • Modified LPI formulations for error reduction of leachate pollutants absence. • Random data generation was applied to cover most possible LPI combinations. • Harmonic average outperformed peer arithmetic and geometric averages. • Reliable values of LPI can be estimated mostly with errors up to ± 20%.

Leachates From Landfill Sites In Thessaloniki, Greece: Effect Of Aging

Sanitary landfilling still is one of the most common management systems of solid urban wastes. The persistent environmental impact of landfills depends on leachate characteristics. The present study aimed at the characterisation of leachate from two landfill sites in the prefecture of Thessaloniki, Greece. Mavrorachi landfill stands in our study as a representative Greek active landfill site, that started operating in 2008. Tagarades landfill has stopped receiving waste from 2008 after 27 years of full operation. In this investigation, leachate samples were physico-chemically characterised so as to assess their pollution potential and their concentration in regard to the type and age of landfill. Elevated concentrations of inorganic and organic constituents were observed in the leachate composition. COD ranged from 2,490 mg/L to 19,700 mg/L, while the respective range for BOD was 390-14,850 mg/L during a 35-year period. The pH values of the leachate samples presented more moderate fluctuations between 7.3 and 8.5. In addition, the ammoniacal nitrogen content increased as landfill age increased, whereas heavy metals concentrations showed significant variations with a slight decreasing trend. The results presented in this paper proved that as time passed, the values of most parameters decreased as the biodegradable compounds are broken down while the refractory compounds resist to biodegradation. Thus, the age has a pronounced influence on the composition of leachate. This study also focused on quantifying the level of contamination that leachates can be potentially cause on a comparative basis by Leachate Pollution Index (LPI). LPI values showed that pollution load was declining but is still not negligible after 33 years.

Leachate characterizations and pollution indices of active and closed unlined landfills in Malaysia

Leachate is one of the most serious environmental hazards associated with landfills especially which are unlined and uncontrolled. Thus, this study aims to characterize and compare raw leachate from active landfills (Ulu Maasop and Kampung Keru) and closed landfill (Pajam), then subsequently quantify the potential leachate contamination from each landfill using Leachate Pollution Index (LPI). The results obtained from the current study were compared with data from previous publications and indicated higher physico-chemical characterizations, especially for BOD and COD, than that of the other similar landfill categories. Based on the current findings, the low ratio of biodegradability and slightly alkaline pH values in leachate samples indicated that the sites (both active and closed landfills) were characterized by methanogenic conditions. Moreover, heavy metal concentrations, Cr, Fe and Se levels were higher than the leachate discharge standards for all leachate sampling sites. The As, Cu, and Mn, also surpassed the leachate discharge standards for the active landfill sites tested in this study (Ulu Maasop and Kampung Keru landfills). Next, the LPI calculated for Ulu Maasop, Kampung Keru, Pajam (1 and 2) landfills were 15.28, 13.89, 12.91 and 11.51, respectively, all exceeding the LPI for discharge standard of 5.696. Based on the leachate characterizations and the LPI values, these landfills pose a significant threat to the environment through the dissipation of leachate to the surface and groundwater, especially with the presence of BOD, COD, As and Cr. Thus, remedial actions such as rehabilitation of such unlined landfills and post-closure monitoring are crucial for both active and closed landfills to ensure the generated leachate is stabilized. Such actions will reduce and control the threat to the environment.

Assessment of groundwater pollution by landfills in India using leachate pollution index and estimation of error

Unsystematic dumping of municipal solid waste affects soil, water and air by generating leachate, which effects the environment and human health. Considering this, present study investigates the leachate pollution index (LPI) of Indian landfills using leachate characteristics already published and by calculating the physico-chemical characteristics of landfill leachate from Chandigarh, SAS Nagar and Panchkula cities. LPI is a grade system (ranging from 5 to 100), which represents the capacity of leachate to contaminate the ground water through subsoil. Calculation of LPI shows that most of the Indian landfills have higher LPI than the acceptable limit (7.378). The error involved in LPI calculation was also studied using tricity (Chandigarh, SAS Nagar and Panchkula) LPI data. Higher sub-index and lower sub-index parameters were considered for error analysis. According to the results, ignoring higher sub-index parameters increases the error 79.2%, 68.5% and 67.8% in Chandigarh, SAS Nagar and Panchkula respectively. Whereas, LPI of landfills decreases 5 in Chandigarh, 7 in SAS Nagar and 5 in Panchkula. Based on the current study, It was observed that LPI values of Chandigarh, Mohali and Panchkula during pre- monsoon were 33.18, 26.17 21.94 and during post monsoon were 25.5, 20.32 and 19.49 respectively. it can be inferred that landfill leachate in India has significant potential to contaminate the groundwater resources. Considering this, the study also discusses some suitable remedial measures to reduce the ground water pollution by landfill leachate and demands more policy intervention to reduce the environmental and human health impact of MSW landfills.

Contamination assessment of dumpsites in Ughelli, Nigeria using the Leachate Pollution Index method

The leachate pollution index (LPI) technique has been used to quantify pollution potential in Ughelli, Nigeria. Water samples were collected from boreholes around four dumpsites for laboratory analysis and estimation of their LPI. The values were found to be 11.95, 11.32, 8.47 and 10.08, for Omotor Dumpsite (OD), Iwhreko Dumpsite (ID), Divine Dumpsite (DD) and Ughelli Market Dumpsite (UMD) respectively. These values are higher than the standard of 7.378. Therefore, Leachate characterization and the LPI values revealed that the groundwater in the area has been impacted due to leachate percolation. It is recommended that remediation procedures should be put in place as soon as possible for better water quality in the area. Keywords: Pollution index; remediation; biodegradation; water quality; hydrogeochemical analysis, pollutant variables

Leachate Characterization and Leachate Pollution Index from Landfill Dump Sites in Warri Metropolis, Nigeria

The paucity of standard engineered landfills in Nigeria has given rise to the proliferation of open waste dumpsites. The environment can be impacted by leachates from these dumpsites if not properly managed. This study assessed the characteristics of leachates from three open dumpsites in Warri Metropolis and its contamination potential using leachate pollution index (LPI). The dump sites had low pH with acidic level lower than the recommended limit. The calculated LPI values of the three sites ranges from 6.377 to 7.438. These values are low when compared to open dumpsites in other metropolitan areas of similar climatic conditions. The low value of LPI for leachate indicates relatively lower contaminant potential due to low concentrations of heavy metals, relatively young age of the landfill as well as low population and organic origin of the wastes. The calculated low LPI value does not in any way preclude the continuous monitoring of the dumpsites as the values recorded are just slightly below the threshold level. It is recommended that there should be an upgrade of all open dumpsites to a standard engineered landfill with a robust and effective monitoring put to curtail future release of deleterious materials from these dumpsites.

Leachate Characterization and Leachate Pollution Index from Landfill Dump Sites in Warri Metropolis, Nigeria

The paucity of standard engineered landfills in Nigeria has given rise to the proliferation of open waste dumpsites. The environment can be impacted by leachates from these dumpsites if not properly managed. This study assessed the characteristics of leachates from three open dumpsites in Warri Metropolis and its contamination potential using leachate pollution index (LPI). The dump sites had low pH with acidic level lower than the recommended limit. The calculated LPI values of the three sites ranges from 6.377 to 7.438. These values are low when compared to open dumpsites in other metropolitan areas of similar climatic conditions. The low value of LPI for leachate indicates relatively lower contaminant potential due to low concentrations of heavy metals, relatively young age of the landfill as well as low population and organic origin of the wastes. The calculated low LPI value does not in any way preclude the continuous monitoring of the dumpsites as the values recorded are just slightly below the threshold level. It is recommended that there should be an upgrade of all open dumpsites to a standard engineered landfill with a robust and effective monitoring put to curtail future release of deleterious materials from these dumpsites.

Physico-Chemical Characterization and Pollution Index Determination of Leachates from Warri Waste Dumpsite, Southern Nigeria

This study characterizes the leachates quality of an active dumpsite in Warri, Delta State and also analyses its contamination or pollution potential. Leachate Pollution Index (LPI) - a tool for quantifying pollution potential of leachates generated from dumpsites - has been used to quantify the leachates contamination potential of the dumpsite. The LPI values for the different sample locations L1, L2 and L3 were computed to be 5.69, 6.18 and 5.89 respectively with a mean value of 5.80, while the control had a value of 4.82. These LPI values were also compared with the LPI standard (7.38) for treated leachates. Comparison of the mean LPI value (5.80) with the standard (7.38) indicated a relatively low contamination potential of the leachates. Moreover, it was observed that the concentration of the individual parameters of the leachates is quite variable. The organic strength (BOD5 divided by COD) of the dumpsite was less than 0.5, while the pH values indicated that all sample locations in terms of age was mature, an indication of dumpsite stabilization. The study recommends continuous monitoring of leachates and upgrade to an engineered landfill to forestall possible pollution problems in future.Keyword: Dumpsites, Leachates, Leachate Pollution Index, Leachates Quality, Municipal Solid Waste, Physico-chemical Parameters, Warri

Leachate contamination potential of a waste dumpsite in Effurun City, Southern Nigeria using the leachate pollution index

The leachate pollution index (LPI) has been used to quantify the leachate contamination potential of a dumpsite in Effurun, Southern Nigeria. Leachate samples were collected from 3 locations in the dumpsite and labeled L1, L2 and L3. Replicates were collected and a representative sample was then derived for each location. The individual pollutant variables of the leachates obtained from the analyses were compared with their corresponding disposal standards. All parameters fell below the permissible limits of treated leachates discharged into inland surface water except total dissolved solids (TDS), biological oxygen demand (BOD) and Pb. The LPI values for the sample locations L1, L2 and L3 were 5.68, 6.16 and 4.75 respectively with a mean of 5.64, while the control had a value of 4.52. Comparison of the mean LPI value (5.64) with the standard for treated leachates (7.38) indicated a relatively low contamination potential of the leachates. It is advised, however, that individual contaminants meet the discharge standards before discharge because the pollutant variables that exceeded the permissible limits may cause significant damage to the health of aquatic biota. The study also recommends continuous monitoring of leachates and upgrade of the dump site and others into well engineered landfills to forestall possible pollution problems in the future.

Leachate Characteristics and Evaluating Leachate Contamination Potential of Landfill Sites Using Leachate Pollution Index

The developing and under developing countries hazardous industrial waste is also mixed with municipal solid waste (MSW). The dumping of MSW in uncontrolled landfills can cause major impact on human health and surrounding environment. Leachate is the main culprit, causing pollution of surface water bodies and ground water. Ground water once contaminated, is very difficult task to improve. The aim of research study is to determine the leachate characteristics of Alevoor landfill near Udupi, India. The pH of samples was 8.21 and 7.77 respectively. This paper also presents the leachate contamination potential of Alevoor landfill using Rand Corporation Delphi Technique. The leachate pollution index (LPI) represents the level of contamination potential of given landfill. LPI is a single number express the overall leachate contamination potential of landfill based on several leachate pollution parameters at a given time. The LPI is also used to compare the contamination potential of different leachate sampling stations of Alevoor landfill. The LPI values of the Alevoor landfill is significantly high and proper treatment is required before the discharge of the leachate.

Evaluation of Leachate Contamination Potential of Lagos Dumpsites Using Leachate Pollution Index

Leachate generated from municipal solid wastes is a threat to surface and groundwater integrity. The leachate contamination potential of four different dumpsites in Lagos, Nigeria, that is Soluos dumpsite (SD), Ewu Elepe dumpsite (EED), Epe dumpsite (ED) and Olusosun dumpsite (OD) were evaluated using leachate pollution index (LPI) technique which is a tool for quantifying pollution potential of leachate generated from dumpsites. The LPI values were computed to be 17.85, 16.87, 18.99 and 23.54 for SD, EED, ED and OD respectively. These LPI values were compared with the standard and it was revealed the LPI values of all the dumpsites evaluated were above the standard which indicated the leachates generated from these dumpsites are contaminated and remediation measures should be put in place. The LPI value is also a useful tool to prioritise the order of attention, which in this work, OD should be given the first attention.

Analysis and Selection of Appropriate Aggregation Function for Calculating of Leachate Pollution Index of Landfill Lysimeter

A technique to quantify the leachate pollution potential of solid waste landfills on a comparative scale using an index known as the leachate pollution index (LPI) developed. The LPI is a quantitative tool by which the leachate pollution data of the landfill sites can be reported uniformly. It is an increasing scale index and has been formulated based on Delphi technique. The formulation process involved selecting variables, deriving weights for the selected pollutant variables, formulating their sub-indices curves and finally representing the pollutant variables to arrive at LPI. The aggregation function is one of the most important steps in calculating any environmental index. If aggregation function is ambiguous, the result will raise an unnecessary alarm, indicating a comparatively less polluted environmental situation as mere contaminated. Similarly, if the aggregation function is eclipsed a false sense of security may be created, indicating a highly polluted environmental situation as less polluted. In this paper, the concept of LPI is briefly described. In order to select the most appropriate aggregation function, various possible aggregation functions are described and used to calculate LPI values for pilot scale landfill lysimeter at KUET campus, Khulna, Bangladesh. Based on obtained results, it is concluded that the weighted linear sum aggregation function is the best possible aggregation function for calculating LPI. Sensitivity analysis of the six short-listed aggregation functions is performed to substantiate this conclusion.

Variability of Parameters Involved in Leachate Pollution Index and Determination of LPI from Four Landfills in Malaysia

Landfill sites are potential sources of human and environmental hazards. Leachate produced form these waste dumping sites is heterogeneous and exhibits huge temporal and seasonal variations. Leachate pollution index (LPI) provides an overall pollution potential of a landfill site. The parameters required to calculate LPI from a landfill site are discussed in terms of their variations over time, and their significance has been highlighted in the context of LPI. The LPI values of two semiaerobic and two anaerobic landfill sites in Malaysia have been calculated in this study. Pulau Burung Landfill Site (PBLS) was found to have the highest LPI score while Ampang Jajar Landfill Site (AJLS) showed the lowest LPI as compared to other landfills. It is concluded that LPI value can be used as a tool to assess the leachate pollution potential from landfill sites particularly at places where there is a high risk of leachate migration and pollution of groundwater.

Selection of the Appropriate Aggregation Function for Calculating Leachate Pollution Index

A technique to quantify the leachate pollution potential of landfills on a comparative scale using an index known as the Leachate Pollution Index (LPI) has been developed and reported elsewhere. The LPI is a quantitative tool by which the leachate pollution data of the landfill sites can be reported uniformly. It is an increasing scale index and has been formulated based on the Delphi technique. The formulation process involved selecting variables, deriving weights for the selected pollutant variables, formulating their subindices curves, and finally aggregating the pollutant variables to arrive at the LPI. The aggregation function is one of the most important steps in calculating any environmental index. If the aggregation function is ambiguous, the result will raise an unnecessary alarm, indicating a comparatively less polluted environmental situation as more contaminated. Similarly, if the aggregation function is eclipsed, a false sense of security may be created, indicating a highly polluted environmental situation as less polluted. In this paper, the concept of LPI is described in brief and the various possible aggregation functions are described and used to calculate LPI values for an actual landfill site to select the most appropriate aggregation function. Based on the results, it is concluded that the weighted linear sum aggregation function is the best possible aggregation function for calculating LPI. Sensitivity analysis of the six short-listed aggregation functions is performed to substantiate this conclusion.