Municipal Solid Waste Leachate Research Articles

Effect of Municipal Solid Waste Leachate on Soil Enzymes

Effect of Municipal Solid Waste Leachate on Soil Enzymes

Treatment of Leachate from Open Dumpsite of Municipal Solid Waste by Ozone Based Advanced Oxidation Process

ABSTRACT Open dumping of Municipal Solid Waste (MSW) results in generation of leachate that contains large amounts of organic matter, ammonia, heavy metals, chlorinated organics, phenolic compounds, phthalates, and pesticide residues which irreparably contaminate both surface and groundwater. Advanced Oxidation Processes (AOP) have been reported as one of the effective treatment methods, especially in improving the biodegradability of the leachate as well as effective in removing recalcitrant organics. With AOP pre-treatment rendered the leachate becomes more amenable to further treatment using biological treatment, adsorption, or ion-exchange processes. The study reported in this paper mainly aims at assessing the suitability of ozone and peroxone (O3+H2O2) based advanced oxidation processes (AOP) for the treatment of MSW leachate from the open dumpsite. The effect of reaction time, impact of O3 dose, and H2O2 concentration on the efficiency of COD removal, improvement in the biodegradability of the leachate, and pH change were determined as the performance parameters for the treatment process. The maximum COD removal efficiency was found to be 46% and 82% with ozone alone (3975 mg/L) and with ozone (9275 mg/L) + 50 mg/L H2O2 each with 120 min. reaction time. It is also found that the BOD5/COD ratio has been increased from 0.09 to 0.58 at optimum O3 + 50 mg/L H2O2 treatment would offer as an effective method for increasing the biodegradability.

Comparative analysis on the electrochemical reduction of colour, COD and turbidity from municipal solid waste leachate using aluminium, iron and hybrid electrodes

Comparative analysis on the electrochemical reduction of colour, COD and turbidity from municipal solid waste leachate using aluminium, iron and hybrid electrodes

A combined treatment of municipal solid waste landfill leachate using Opuntia ficus-indica cactus as coagulant and titaniferous sand as filter material

In Morocco, the increasing production of municipal solid waste (MSW) and its by-products, in particular leachate, is a major concern. MSW leachate is a very complex effluent, loaded with organic and inorganic pollutants; it poses a serious threat to human health and the environment. In Agadir city, the leachate generated is stored in seven tanks in the Tamellast landfill. The daily flow of this effluent accelerates the saturation of the storage tanks. Overflowing leachate presents a potential environmental hazard, and proper treatment of the leachate has inevitably become a requirement. Therefore, this study aims to find a simple, inexpensive and efficient leachate treatment system. Two techniques using local natural materials have been combined to achieve significant results: coagulation and infiltration-percolation. Cactus powder and cactus mucilage have been selected to treat leachate by coagulation and titaniferous sand as a filter material for the infiltration-percolation process. Laboratory scale experiments show very interesting results. Due to its effectiveness at a dose of 20 mg / l at pH 11, the effluent treated with cactus mucilage was chosen to undergo secondary treatment (86.54% for turbidity and 14.60% for electrical conductivity). The elimination of turbidity and electrical conductivity achieved after infiltration-percolation is, respectively, 97% and 39%.

The materials flow and membrane filtration performance in treating the organic fraction of municipal solid waste leachate by a high solid type of submerged anaerobic membrane bioreactor

The anaerobic digestion of leachate from organic fraction of municipal solid waste (OFMSW) is a long-standing challenge. A submerged anaerobic membrane bioreactor (AnMBR) embedding three flat sheet membrane was therefore continuously operated for 63 days to investigate the materials flow and membrane performance. The results obtained show that approximately 90% COD was removed and 86% was converted into methane under an OLR of 5.6 kgCOD/m3·d corresponding to a HRT of 10 days. Under the high solid condition (34.5–61.1 g/L total solids in AnMBR) and flux of 5 and 6 LMH, the membranes was operated practically at constant trans-membrane pressure (TMP). When the membrane was operated at a high flux of 7 LMH the TMP rapid increase occurred in 22 h resulting in a non-recoverable permeability. A sustainable flux was thus identified. This study demonstrated the feasibility of AnMBR treating OFMSW leachate under high solid condition with high flux.

Influence of real and synthetic municipal solid waste leachates on consolidation and shear strength behaviour of bentonites.

For safe disposal of wastes in landfills, compacted bentonite is recommended as bottom liners due to their significant cation exchange (CEC) and swelling capacity, low permeability and large specific surface area (SSA). The present investigation carried out various experimental studies determining the compressibility behaviour and unconfined compressive strength (UCS) of two different compacted bentonites in the presence of municipal solid waste (MSW) and synthetic MSW leachates. Various examinations were conducted determining alterations in consolidation parameters like the coefficient of consolidation (cv), time taken for 90% consolidation (t90) and compression index (Cc) with both leachates. The outcomes reveal that Cc and t90 values of both bentonites declined; however, cv value rose. Results also indicated that under any given consolidation pressure, a lesser void ratio was achieved for leachates. UCS of both bentonites reduced with leachates' interaction yet, lying within the recommended a value higher than 200 kPa. A comparative assessment of the two bentonites displayed that bentonite having higher CEC and swelling capacity, and SSA unveiled more excellent Cc and t90 values and a reduction in the UCS. A higher variation in behaviour of bentonites was perceived in the existence of MSW leachate in comparison to synthetic MSW leachate.

Understanding metal dissolution from solar photovoltaics in MSW leachate under standard waste characterization conditions for informing end-of-life photovoltaic waste management

The upcoming end-of-life solar photovoltaics (PV) waste stream is a huge concern before solid waste professionals due to presence of hazardous metals like lead or cadmium. The objective of present study was to understand the metal dissolution from PVs under four standard waste characterization regulatory tests of U.S., Germany, and Japan and their representativeness with actual landfill leachate. Modules were exposed to real municipal solid waste (MSW) landfill leachate for extended extraction duration, agitation and diluted leachate to investigate the effect of various parameters on metal dissolution. The results indicated that extractions using landfill leachates resulted in lower metal release than standard methods. The leached metal concentrations were found to be within the threshold limits except for cadmium, copper, lead and selenium, with maximum lead release from amorphous-PV of 8.68 mg/L and 6.91 mg/L with respect to TCLP and WET tests, respectively. Arsenic showed negligible release with maximum concentration of 0.046 mg/L from copper indium gallium de-selenide(CIGS) PV. Regardless of small size (1–2 cm pieces) and agitation, Germany and Japan’s standard tests resulted in minimal release except of copper from copper indium gallium de-selenide PV. Leaching without agitation, showed negligible release from all photovoltaics whereas when agitation is applied to diluted leachate, significant release was observed with aluminum and copper leached up to 145.32 mg/L (multi-crystalline silicon) and 139.01 mg/L (amorphous-PV), respectively. CIGS was found to be most hazardous with a Metal Hazard Score (calculated on the basis of magnitude of leached metals with respect to their threshold limit and subsequent health effects) of 23.19, when exposed to standard tests. For all scenarios, increased metal release was observed with decrease in sample size and increase in leachate dilution and thus, leaching in highly acidic conditions are by no means representative for modules dumping in realistic conditions.

Multimetal Adsorption Isotherm Studies of Ground Granulated Blast Furnace Slag from Municipal Solid Waste Leachate

Abstract This paper aims to study the simultaneous adsorption of multiple heavy metal ions present in municipal solid waste (MSW) leachate. Leachate samples have been found to contain the heavy met...

Bio-coagulation-flocculation (BCF) of municipal solid waste leachate using Picralima nitida extract: RSM and ANN modelling

The performance of Picralima nitida extract (PNE) in bio-coagulation-flocculation (BCF) for the reduction of chemical oxygen demand (COD) in municipal solid waste leachate (MSWL) was studied. The PNE was characterised via Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). The process was modelled using both the response surface methodology (RSM) and artificial neural network (ANN) methods, and their prognostic capabilities established. The coagulant precursor was found to contain protein (28.4%) which is an active component of a good coagulant for neutralisation and adsorption of the colloidal particles. C=O, O–H, and N-H functional groups were present in the extract which are preferred for BCF process. This process was effectively optimised (COD ​= ​75.25 ​± ​0.5%) to achieve the best removal at pH ​= ​2.3, PNE dosage ​= ​0.38 ​g/L, and time ​= ​28.22. min. The analysis of variance indicated that the RSM model was statistically suitable for the interpretation of the processes at the studied range. The RSM and ANN were capable of predicting the COD reduction process with the latter giving the best prediction with lesser error and nonlinear relationship. Though ANN had superior accuracy, RSM has the advantage of giving a predictive equation and showing the effect of operating factors and their interactions on the response compared. The mechanisms of the process were charge neutralisation, adsorption and bridging.

Evaluation of the Phytotoxicity of Leachate from a Municipal Solid Waste Landfill: The Case Study of Bukov Landfill

Municipal solid waste landfilling, landfilling process and landfill reclamation result in leachate, which may be dangerous to the environment. Municipal solid waste leachate phytotoxicity tests were performed using the toxicity test and a subchronic toxicity pot experiment by direct application of leachate to reference soil in 5, 25, and 50% concentration for a period of 28 days. White mustard (Sinapis alba L.) seeds were exposed to different leachate dilution. Leachate were collected monthly in 2018 in the period from April to September. Furthermore, pH, conductivity, and dissolved oxygen were measured. The inhibition results on Sinapis alba L. seeds in the tested leachate samples ranged from −18.02 to 39.03%. Lower concentration of leachate showed a stimulating effect (only for Sample 1 and Sample 2 at 5% concentration). It was found out that leachate taken at the landfill is phytotoxic. The results of measurements are based on rainfall which affects the quantity and quality of the leachate. The values of germinated seeds/growing plants from the subchronic toxicity pot experiment ranged from 80 to 104%; therefore, the leachate is considered phytotoxic. However, it was confirmed that leachate may be used for landfill irrigation.

Potential of medium chain fatty acids production from municipal solid waste leachate: Effect of age and external electron donors

A large quantity of leachate is generated during municipal solid waste collection operation and in landfills due to the large amount of organic waste and high humidity. The content of medium chain fatty acids (MCFAs) in the leachate is a low cost feedstock for bio-based chemical and fuel production processes. The aim of this study is to investigate the MCFA production potential of three leachate ages through chain elongation process under uncontrolled pH batch test. Moreover, the effect of using different external electron donors (ethanol, methanol and a mixture of both) is studied. The experiment consists of characterizing the samples then adding external electron donors with a specific ratio to leachate samples under mesophilic temperature. For this investigation, also a statistical analysis is done, which shows the production of MCFAs is highly influenced by leachate age. The results indicate that the production of even-numbered acids increase from 600 to 1,000 mg/L by the end of the ethanol chain elongation experiment for young leachate. However, a higher MCFA production of more than 1,000 mg/L is achieved by using the mixture of methanol and ethanol as electron donor. Furthermore, all methanol chain elongation experiments lead to an odd-numbered production of MCFAs, such as pentanoic and heptanoic acids. These results confirm the potential improvement of MCFA production from leachate through choosing the optimal leachate age and electron donor. Overall, producing MCFAs from leachate is a good example of circular bio-economy because waste is used to produce biochemicals, which closes the material cycle.

Phytoaccumulation of heavy metals from municipal solid waste leachate using different grasses under hydroponic condition

Grasses have been used widely to remediate contaminants present in domestic wastewater, but leachate generated from municipal solid waste that usually contain some concentrations of heavy metals has never been reported to be treated with grasses, especially Rhodes grass. A series of experiments was performed to investigate the contaminant uptake from municipal solid waste leachate by Chloris gayana (Rhodes grass) grown in combination with two commonly available grass varieties namely Vetiveria zizanioides (Vetiver grass) and Pennisetum purpureum (Elephant grass). Leachate used for the experiments had high values for chemical oxygen demand (5 g/L), pH (8.5), electrical conductivity (9.0 mS/cm), nitrates (182.1 mg/L), phosphates 6.4 mg/L along with heavy metals i.e. copper, zinc and manganese. Different dilutions of leachate ranging from 0 to 100% were applied in batches and their result showed that collectively all the grasses reduced overall contaminant concentrations. These were reported for chemical oxygen demand, electrical conductivity, nitrates, and phosphates reduced up to 67, 94, 94, and 73%, respectively. Metals uptake by grasses also showed a significant decrease in applied dose i.e. zinc (97%), copper (89%), and manganese (89%). Plant analysis showed that all grasses showed preference to heavy metals uptake e.g. Rhodes grass favoured up taking zinc, Elephant grass for copper and Vetiver grass preferred manganese. Overall growth performance of Rhodes grass was better in dilute leachate, whereas in more concentrated leachate, Rhodes grass did not perform better and production of biomass decreased. In Vetiver grass, root and shoot lengths decreased with increasing leachate strength, but the biomass did not change significantly.

Anaerobic mono and co-digestion of organic fraction of municipal solid waste and landfill leachate at industrial scale: Impact of volatile organic loading rate on reaction kinetics, biogas yield and microbial diversity

The present study was aimed to demonstrate a semi-commercial biomethanation plant based on anaerobic gas lift reactor (AGR) for the mono and co-digestion of organic fraction of municipal solid waste (OFMSW) and landfill leachate (LL) for 47 weeks. The reactors were commissioned at a volatile organic loading rate (VOLR) starting from 0.4 to 6.2 kg VS/(m3·day) to investigate the impact of VOLR on the organic matter removal rates, substrate utilization rate using Stover-Kincannon reaction kinetics, biogas yield and microbial diversity. 16s-metagenomic sequencing of the species present in the inoculum that was acclimatized with OFMSW, LL separately and in combination was also performed to identify the dominant microbial species in the mixed microbial consortia. Results revealed that the VS reduction in AGR 1, AGR 2 and AGR 3 at full load was 46%, 42% and 47% respectively with a corresponding biogas generation of 73.8 m3/day, 42 m3/day and 60.8 m3/day. The biodegradability in AGR 1 was between 73% and 81% whereas in AGR 2 and AGR 3, it was between 57% and 78% and 64% and 86% respectively. The operational strategy of digestate recirculation facilitated in the reduced usage of buffering chemicals which impacted on overall financials of the plant. The techno-economic analysis suggests that these kinds of biomethanation plants are remunerative.

A feasibility study on optimization of combined advanced oxidation processes for municipal solid waste leachate treatment

Municipal solid waste (MSW) leachate, mostly comprised of organic and inorganic substances originated from discarded organic matters, chemicals, and liquors at MSW dumpsite. Pollutant composition and toxic compounds of leachate necessitate the effective treatment before its disposal. In the current study, advanced oxidation processes; ozonation, peroxone process and photolytic ozonation were employed for the treatment of complex MSW leachate. Central Composite Design (CCD) of Response Surface Methodology (RSM) was applied to optimize the various operating parameters in the treatment system. The optimized condition of pH: 9.0; contact time: 60 min and Ozone dose: 5 g/h for a litre of leachate provided the maximum COD and NH3–N reduction of 72 % and 80 % respectively for photolytic ozonation (under 15 W–UVC; λ:254 nm) whereas under the same operating conditions, ozonation process provided 45 % of COD removal and 50 % of NH3-N removal. Peroxone process with H2O2 concentration of 800 mg/L, showed the maximum COD and NH3-N removal efficiencies of 61 % and 59.7 % respectively. The developed models have confirmed the interaction between the selected parameters; have good agreement with each other; have the best fit. The present approach provided the knowledge to adopt an efficient way of treatment to the complex MSW leachate to proceed further for pilot-scale treatment.

Removal of ammonia from municipal solid waste (MSW) landfill using hydrated lime

Leachate is known as a vigorous wastewater in terms of its organic matter and ammonia content. It is a major problem for municipal solid waste (MSW) landfill. It posed threat to surface water and groundwater. This study focusing on the removal of ammonia-nitrogen (NH3-N) by coagulation on a raw leachate sample taken from Rimba Mas municipal solid waste (MSW) landfill. The landfill leachate is tested for COD, colour and NH3N. Morphological features of calcium oxide are studied using XRF and SEM. Optimum dosage of coagulant for ammonia nitrogen removal from MSW leachate is investigated. The method used in this research was coagulant-flocculation treatment: jar test apparatus. The coagulant was conducted using hydrated lime, Ca(OH)2 with varying amount of coagulant to find the optimum dosage for ammonia nitrogen removal. A raw leachate sample taken from Rimba Mas landfill was treated with a different amount of hydrated lime (2, 4, 6, 8, 10 g/L) and 0 as a control to investigate the removal of ammonia nitrogen. The results showed that the pH of leachate (9.09) after treated with hydrated lime is increased when the dosage of hydrated lime is increased. Results showed that the best value of removal efficiency from leachate of colour, COD and NH3N were 54.70%, 56.22% and 85.25% respectively. We can conclude that as the optimum dosage increases, removal efficiency is increases.

Waste type, incineration, and aeration are associated with per- and polyfluoroalkyl levels in landfill leachates

Per- and polyfluoroalkyl substances (PFAS) are found in many consumer products which will be ultimately disposed in landfills. Limiting environmental contamination and future exposures will require managing leachates from different types of landfills, each with different PFAS levels depending upon the source of the waste. The objective of this study was to evaluate the influence of waste type and on-site treatment on PFAS levels in landfill leachates. Eleven PFAS species (7 carboxylic acids, 3 sulfonic acids, and 5:3 fluorotelomer carboxylic acid) were evaluated in leachates from municipal solid waste (MSW), construction and demolition (C&D), MSW ash (MSWA), and a mixture of MSWA and MSW with landfill gas condensate (MSWA/MSW-GC). Leachates were also analyzed before and after on-site treatment at two of these facilities. Results indicate that MSWA leachate had significantly lower PFAS levels relative to other leachate types. Lower total PFAS concentrations in MSWA leachates were correlated with an increase in incineration temperature (R2 = 0.92, p = 0.008). The levels of PFAS in untreated C&D and untreated MSW leachate were similar. The levels of targeted PFAS species in MSW leachate for one of the facilities evaluated increased after on-site landfill treatment presumably due to the conversion of PFAS precursors in the untreated leachate sample.

Degradation of di-(2-ethylhexyl) phthalate by Bacillus aquimaris isolated from Ajakanga municipal solid waste leachate

Degradation of di-(2-ethylhexyl) phthalate by Bacillus aquimaris isolated from Ajakanga municipal solid waste leachate

Evaluation of the Hydraulic Conductivity of Compacted Laterite-Metakaolin Mixtures for Solid Waste Leachate Containment

This paper presents the results of a study conducted to investigate the benefits of using metakaolin (MK) with laterite as liner material for containment of municipal solid waste (MSW). Laboratory tests were conducted on laterite specimens treated with MK at concentrations of 0 - 20 % by weight of the soil and compacted using four types of compaction energies. Hydraulic conductivity was determined based on permeation of the compacted laterite - MK mixtures with deionized water (DW) and municipal solid waste leachate (MSWL), respectively. Deionized water was the reference permeant fluid. The results showed that hydraulic conductivity generally decreased with increase in the percentage addition of MK to the soil. From an economic and sustainability point of view, it has been found from the results that 5 % MK can be added to soil and compacted at moulding water content of 14.1 % using the West African Standard (WAS) compaction energy to achieve the regulatory hydraulic conductivity of less than or equal to 1 x 10-9 m/s for compacted soil liner. The natural logarithm of the hydraulic conductivity experimental results were computed and used to develop regression equations for estimating hydraulic conductivity given MK contents and compaction energies. The results of the two-way analysis of variance (ANOVA) test carried out at 5 % level of significance showed that calculated F-statistics are statistically significant and the measured values of hydraulic conductivity compare well with the predicted values. The developed models can therefore be used to give good estimates of hydraulic conductivity of soils having similar properties with the laterite investigated in this study. Therefore, the developed models can be used to give good estimates of hydraulic conductivity of soils having similar properties with the laterite investigated in this study. Keywords ­_ Deionized water, Hydraulic conductivity, Leachate, Metakaolin, Municipal solid waste.

Фильтрат полигонов ТКО: образование, характеристика и обезвреживание

The present article discusses the negative impact of municipal solid waste (MSW) landfills on the environment due to the migration of leachate formed during waste decomposition. The leachate contains an extensive list of pollutants that migrates in soils, surface and underground waters. The article provides a review of literature regarding the main stages of leachate formation and changes in its chemical composition during the landfill’s life cycle. Landfill waste undergo biogeochemical decomposition in aerobic and anaerobic conditions. At the initial stages of waste degradation, easily decomposable organic compounds oxidize leading to high values of chemical and biological oxygen demand (COD and BOD) in the formed leachate, lowering the pH of the medium to 4-5. This in turn leads to the transition of metal ions to the liquid phase due to an increase of their activity in acidic mediums. In anaerobic conditions, further waste degradation takes place producing carbon dioxide, methane, ammonia, mercaptans, hydrogen sulfide, organic acids and water. In the leachate formed after 10 years of landfill operation, the content of organic carbon decreases, the fraction of bioresistant components increases, the pH of the medium increases to 7.5-8.5, metal ions form hardly soluble compounds and sulfates are reduced to sulfides. The chemical composition of the leachate, presented in this article, demonstrates its changes depending on the stage of the landfill’s life cycle. Also, basic schemes of treatment plants for MSW leachate used in Russia and abroad are described based on a combination of traditional wastewater treatment methods (mechanical, biological and physicochemical methods).

Hybrid Phytoremediation: an Ultimate Bio-Solution for Leachate

<p>In the recent era, utmost attention is paid towards exploring the alternative source of energies, being more specific green energies. In modern days, when growing energy scarcity is a hot topic and considered as a global threat, in that context a green technology capable of sustainably addressing waste management issues and synthesize waste-derived end-product such bio-diesel from Jatropha Curcas linnaeus (JCL) and Chlorella vulgaris shall be paid ancillary attention. The attribution of the above-mentioned species and Lemnagibba L towards the purification of the municipal solid waste (MSW) leachate by utilizing its bioaccumulation properties and ultimately yielding several value-added co-products could be the solution of the era in terms of sustainable leachate treatment. A specially designed ridge furrow phytoremediation wetland was fabricated under the controlled environment associated with a pre-treatment facility and bottom lining system to captivate the downward percolation. A 1.5 m high Jatropha species were planted at an interval of 1 m on the ridges and the root for the same found to reach a depth of 0.8 m on an average over a period of 3 months. Leachate was supplied by means of free flow into the furrows with an initial addition rate of 1 m3 per day for a 10 m x 10 m remediation hybrid pond system and simultaneously the loading was elevated up to 80 m3/ha/day. Prior to the active remediation zone, a pre-treatment unit was installed which works on the bio-accumulation property of the vetiver grass (Chrysopogon zizanioides). A packed bed system of gravel, marble chips, sand, and coconut coir as a medium of filtration was installed to bring the concentrate waste juice up to the wetland treatment standard. Moreover, the bleaching influence of the sunlight also found to be effective against pathogen removal, active evaporation, and evapotranspiration. The ultimate treatment capacity for the designated size was assessed as ~ 0.03 m3 per day ascertained with an HRT value of 45 days. The ultimate outcome was on par with the influent characteristics obligatory for the tertiary units with a comprehensive efficacy value evaluated as approx. 60%. Thus, it’s quite evident to claim the feasibility of the present study towards the bio-remediation of the enormous quantity of leachate generation associated with the handling of solid waste which is otherwise, a costly affair.</p>