Comparison of Landfill Leachate Properties by LPI and Phytotoxicity-A Case Study

The formation of leachate is one of the inevitable consequences associated with the operation of landfills. In addition to the study of physicochemical composition, toxicity is an important parameter taken into account, among others because of the need to subject leachate to treatment before discharge into the environment. The aim of this study was to determine the degree of leachate contamination using LPI and toxicity index. An analysis of the relationship between the toxic effect on plants and the calculated LPI values was also carried out to assess whether they could provide a measure of leachate toxicity when selecting a treatment method. The research conducted was to determine the degree of leachate contamination using LPI and toxicity index. An analysis of the relationship between the toxic effect on plants and the calculated LPI values was also carried out to assess whether they could provide a measure of leachate toxicity when selecting a treatment method. Calculated values of the leachate pollution index showed that leachates from selected Polish landfills are characterized by low and medium levels of LPI values. The variation in index values obtained was particularly evident between active and closed landfills and was related to the physicochemical composition of leachates. In closed landfills this value ranged from 7.4 to 11.1, while in active landfills from 12.9 to 15.9. The variation in index values obtained was particularly evident between active and inactive landfills and was related to the physicochemical composition of leachates. Phytotoxicity tests showed that leachate at low concentrations can promote plant growth. At higher concentrations (50 and 100%), leachates caused inhibition of root and shoot growth, which correlated with high LPI values. The results confirmed the relationship between the toxic effect on plants and the LPI values, so it can be considered as a reliable indicator of leachate toxicity.

Characterizing Seasonal Variation in Landfill Leachate Using Leachate Pollution Index (LPI) at Nam Son Solid Waste Landfill in Hanoi, Vietnam

The improper treatment of landfill leachates is one of the major problems associated with waste landfilling and causes serious environmental pollution at waste landfill sites and their surroundings. To develop a suitable landfill leachate treatment system and to minimize the risk of environmental pollution, it is important to characterize seasonal and temporal variations of landfill leachates. This study investigated the leachate quality of the Nam Son waste landfill in Hanoi, Vietnam in 2017–2019 and characterized the potential risks of landfill leachate using a leachate pollution index (LPI). The results of this study showed that the seasonal and temporal variation of the overall LPI during the monitoring period was small and in the range of 20–25 (values 2.5 times higher than the maximum permissible limits of Vietnam National Technical Regulation on Industrial Wastewater). The LPI sub-indices attributed to organic and inorganic pollutants were major components of the LPI. Especially, the annually averaged values of LPI of inorganic pollutants were 7.7 times higher than the maximum permissible limits, suggesting that the treatment of inorganic pollutants, such as ammonium-nitrogen (NH4+–N) and total nitrogen (TN), is highly required at Nam Son landfill to prevent environmental pollution surrounding the landfill site.

Geostatistical Modelling of Groundwater Quality at Rumuola Community, Port Harcourt, Nigeria

The groundwater quality of Rumuola community of Rivers State, Nigeria was investigated. This study was done to determine the pollution potential of a solid waste open dump in a borrow pit in the community. The leachate pollution index was calculated for the borrow pit at the centre of the community using weighted additive leachate pollution index. The result showed that the LPI value was 5.31 and has low pollution potential. It was discovered that the groundwater in the entire community was acidic with pH levels ranging from 3.6 to 4.2, which is below NSDWQ’s permissible range of 6.5-8.5. Nickel and arsenic also showed concentrations that were above permissible limits with nickel values averaging 0.033 mg/l which is slightly above the limit of 0.02 mg/l. Arsenic had concentrations that ranged from 0.16 to 1.57 mg/l which is above permissible limits of 0.01 mg/l. WQI was determined using weighted arithmetic water quality index analysis. As a result of the high concentrations of arsenic, the WQI values were very high with values ranging from 144 to 1367 and this shows that the water in the study area is unsuitable for drinking. In modelling the water quality index of Rumuola community, geostatistical methods were applied. Ordinary kriging, Empirical Bayesian kriging (EBK), inverse distance weighting (IDW) and cokriging interpolations methods were used to produce surface maps showing the distribution of variables using ARCGIS software. The best interpolators were: EBK for pH, TDS, Sulphate and nitrate; Ordinary kriging for Nickel and Hardness; IDW for Iron and arsenic; Cokriging for WQI.

Assessment of Age Effect of Dumpsite on Biodegradability and Pollution Potentials of Leachate

The increase in world’s population has led to increase in waste generation and is a source of concern for stakeholders across the world. These wastes end up in dumpsites which undergo different stages of decomposition thereby producing Leachate which have a tendency of polluting groundwater. This study assessed biodegradability and Leachate Pollution Index (LPI) of dumpsite relative to its age. Three dumpsites Orile (O), Solous 3 (S3) and Solous 1 (S1) dumpsites with different ages: – less than 5, between 5-10 and greater than 10 years old respectively were studied. Leachate samples were collected from each dumpsite; Physico-chemical parameters: pH, chloride, Iron, Zinc, Arsenic, Total nitrogen, Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Total Dissolved Solid, Electricity Conductivity and heavy metal: Lead, Chromium and Copper were analysed to determine the LPI while BOD5/COD was determined to ascertain the level of biodegradability of the dumpsites. The BOD5/COD results for O, S3 and S1 leachates were in the decreasing order of 0.37, 0.29 and 0.21 respectively while LPI results for: O, S1 and S3 leachate were 10.00, 11.20 and 15.68 respectively which were above the standard limit of 7.38. The results showed that O and S1 dumpsite leachate had least and highest sign of biodegradability respectively. The LPI result showed that O and S1 dumpsite leachates had the highest and the least pollution potentials respectively. Leachate from dumpsites less than 5 years has higher pollution potentials and lesser biodegradable than leachates from dumpsites more than 5 years. Leachate from O dumpsite will impact negatively on groundwater quality than leachates from S1 and S3 dumpsites. The age of a dumpsite leachate determines its pollution potential and biodegradability.