Municipal Solid Waste (MSW) is collected, transported, and disposed of in an unorganized and disordered manner in lower- and middle-income countries. Improper waste disposal in landfills can have ...severe environmental consequences in terms of groundwater, soil and air contamination, resulting in numerous health hazards. In India, Landfills require 1240 ha of land per year and only 21% of MSW is adequately managed. The remaining MSW is not reprocessed or recovered through treatment technologies and is generally disposed of in an un-hygienic landfill. Urban or rural solid waste is usually dumped in low-lying areas, which adds to the greenhouse gas emissions, obnoxious odor production and causes fire hazards that adversely affect the local ecosystem. Landfills contribute to CH4 production and about 29% of all GHGs emissions, which is more than 15% of the average global contribution. It is also noticed that by 2030 and 2050, global GHGs emissions will rise to 64% and 76% due to uncontrolled waste disposal systems. The study highlights effective solid waste management practices and discusses ways to manage it sustainably through resource recovery. As a result, the study concentrated on using waste-to-energy technologies that still require significant support for execution. The study concluded that waste-to-energy technologies need adequate financial and government support. Further, extreme resource recovery from the waste must be linked with a secure waste disposal system via engineered landfill construction and waste-to-energy plants' operation. Solid waste management also needs local corporations to effectively manage the waste services following national-specific policies and standards, including community awareness and participation, system responsibilities and use of emerging technologies. This will aid in reducing the adverse effects of MSW disposal and achieve the UN's sustainable development goals.
Phthalates or phthalic acid esters (PAEs) are chemical compounds whose use is exceptionally widespread in everyday materials but, at the same time, have been proven to have harmful effects on living ...organisms. Effluents from municipal wastewater treatment plants (WWTP) and leachates from municipal solid waste (MSW) landfills are important sources of phthalates with respect to naturally occurring waters. The main aim of this research was determination, mass loads, removal rates and ecological risk assessment of eight phthalates in municipal wastewaters, landfill leachates and groundwater from Polish WWTPs and MSW landfills. Solid-phase microextraction and gas chromatography with mass spectrometry were used for the extraction and determination of analytes. Summed up concentrations of eight phthalates ranged from below LOD to 596 μg/L in influent wastewater with the highest concentration found for bis-2-ethylhexyl phthalate (DEHP) (143 μg/L). The average degree of phthalate removal varies depending on the capacity of a given treatment plant with larger treatment plants coping better than smaller ones. The highest treatment efficiency for all tested treatment plants, over 90%, was reported for dimethyl phthalate (DMP) and diethyl phthalate (DEP). Overall concentrations of phthalates in leachates ranged from below LOD to 303 μg/L while the highest maximum concentration was registered for DEHP (249 μg/L). Overall concentrations of phthalic acid esters in groundwater from upstream monitoring wells ranged from below LOD to 1.8 μg/L and from LOD to 27.9 μg/L in samples from wells downstream of MSW landfills. The obtained data shows that diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), DEHP, and diisononyl phthalate (DINP) pose a high risk for all trophic levels being considered in effluent wastewaters. In the case of groundwater high environmental risk was recorded for DBP and DEHP for all tested trophic levels. Phthalates, in concentrations that pose a high environmental risk, are present in Polish municipal after-treatment wastewater as well as in groundwater under municipal solid waste landfills.
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•PAEs were determined in wastewater, landfill leachates and groundwater from Poland.•Larger WWTPs usually show better PAEs removal efficiency.•MSW landfills cause phthalate pollution of groundwater in the area.•Some PAEs emitted from Polish WWTPs and MSW landfills pose a high environmental risk.
Leachate treatment is an essential and integral part of solid waste management system, and its efficient treatment becomes more crucial when the leachate is produced from industrial or hazardous ...waste landfills (HWLs), as it is multi-fold more toxic than the leachate produced from municipal solid waste landfills (MSWLs). Electrocoagulation has appeared to be a promising technology for treating complex wastewater including MSWL leachate, but specific treatability studies dedicated to HWL leachate are rarely available, and thus pose a demand for fundamental and advance research in this area to bridge the existing gap. The current study delves into systematic design of experiments to check the treatability of HWL leachate through electrocoagulation, considering reduction (maximum) in chemical oxygen demand (COD) as a response variable. Response Surface Methodology (RSM) was used for design of experiments and process optimization and three-dimensional surface response was also created to understand the relationship among process parameters and response variables. After extensive experimental trials and data analysis, it was observed that electrocoagulation can be used as a potential treatment technology for leachate with Galvanized Iron (GI) as preferable electrode material and it resulted up to 90% reduction in COD under optimized condition. Significant reduction in other parameters was also observed with a removal efficiency of 58.1%, 63.6%, 42.4%, 52.5%, 54.7% and 84% for cadmium, zinc, phenolic compounds, lead, TOC, and colour, respectively. The results showed that Electrocoagulation can be used as a replacement of currently practised energy extensive treatment technologies like multiple effect evaporators, which are used by landfill operators for managing their HWL leachate. The methodology and results from this research may be utilized by the researchers and operators of HWL landfills to decide the treatment trail for HWL leachate.
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•Treatability of landfill leachate through electrocoagulation (EC) was studied.•Design of experiments was done with COD reduction as a response variable.•Process was optimized through response surface methodology.•Qualitative and quantitative analysis of sludge was done.•Results showed 90% reduction in COD and significant reduction in other parameters.
This work is centered on the comparative appraisal of various waste gas mixtures which can be utilized for electric power and heat generation using solid oxide fuel cells (SOFCs), on the main sources ...of these gases, and on technological aspects related to their use. Particular emphasis is given to the waste gases produced by municipal solid waste landfills and industry, including coke oven, blast furnace and converter gases from metallurgy, gas from underground coal mines, agricultural and food industry produced biogas, and hydrogen-containing wastes from chemical industrial processes. The advantages and limitations of SOFCs are analyzed with respect to the mature technologies based on reciprocating internal combustion engines and gas turbines, where successful pilot projects of the waste gas utilization were well documented in the literature, and other types of fuel cells. The high-calorific waste generation dynamics, gas purification methods and state-of-the-art SOFC developments are briefly addressed.
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•Landfills, coal mining and chemical industries are sources of high-calorific gases.•Waste gases can be utilized in fuel cells for electrical energy and heat generation.•Solid oxide fuel cells (SOFCs) are among most promising technologies for these goals.•Advantages and limitations of SOFCs with respect to other technologies are reviewed.•Waste gas generation dynamics and purification methods are briefly addressed.
White stork (
Ciconia ciconia
) may act as a reservoir and vehicle of cephalosporin resistant (CR)
Escherichia coli
. Between 2011 and 2014, we sampled white storks from colonies exposed to different ...degrees of anthropic pressure across the major areas of natural distribution of white storks in Spain. Cloacal swab samples (
n
= 467) were obtained from individuals belonging to 12 different colonies from six different regions. Additionally, 70 samples were collected from recently deposited droppings at the base of nesting platforms. We phenotypically characterized
E. coli
isolates, confirmed presence of CR genes and classified plasmids. Risk factors for acquiring these genes were assessed. Overall, 8.8% (41 out of 467) storks carried CR
E. coli
in their cloaca and five (7.1%) were identified from recently deposited droppings; therefore, 46 isolates were further characterized. Of them, 20 contained
bla
CTX–M–
1
, nine
bla
CMY–
2
, six
bla
CTX–M–
14
, four
bla
SHV–
12
, three
bla
CTX–M–
15
, two
bla
CTX–M–
32
, one
bla
CTX–M–
1
together with
bla
CMY–
2
, and one
bla
CTX–M–
1
together with
bla
SHV–
12
. All were multidrug-resistant, and four harbored the plasmid-mediated colistin resistance
mcr-1
gene. CR genes were associated with the presence of IncI1, IncFIB, and IncN replicon families.
Xba
I-macrorestriction analysis revealed a great diversity among most of the
Xba
I-PFGE types, but indistinguishable types were also seen with isolates obtained from different locations. Clonal complex 10 was the most common among CR
E. coli
and two
bla
CTX–M–
15
positive isolates were identified as B2-ST131. Carriage of CR
E. coli
was significantly higher in colonies located close to solid urban waste disposal sites in which foraging on human waste was more likely and in one case to cattle grazing. The co-occurrence of
bla
CMY–
2
and
mcr
-1 on plasmids of
E. coli
isolated from wild birds as early as 2011 is of note, as the earliest previous report of
mcr
-1 in wild birds is from 2016. Our study shows that foraging at landfills and in association with cattle grazing are important risk factors for the acquisition of CR
E. coli
in white storks.
The long-term performance of three multilayered textured white conductive-backed geomembranes (GMBs) is compared to the comparable textured nonconductive GMBs and their smooth edge/equivalent to ...investigate the effect of the conductive layer on their longevity. Oven immersion in synthetic municipal solid waste leachate is used at a range of temperatures to accelerate the ageing during an incubation period of 50 months. It is shown that the conductive layer can antagonistically or synergistically affect the antioxidant depletion of conductive-backed GMBs relative to nonconductive GMBs produced by the same GMB manufacturer and formulated using the same nominal resin and antioxidant package. However, their relative degradation at 85 °C does not necessarily follow their relative antioxidant depletion times implying that the manufacturing process and the interaction between the additive packages of these GMBs can affect their relative degradation beyond the antioxidant depletion stage. Arrhenius modelling predicts the antioxidant depletion stage at field temperatures ranging between 180 and 1400 years at 20 °C for two different conductive-backed GMBs produced by two different manufacturers. With such variation in the long-term performance of conductive-backed GMBs currently available in the market, their durability should be investigated before their use in barrier systems to ensure they can meet the required design life of the desired geoenvironmental application.
•First investigation into the degradation behaviour of conductive-backed geomembranes.•Examines the effect of texturing on the durability of conductive-backed geomembranes.•Estimates antioxidant depletion time of multilayered geomembranes at field temperatures.
Leachates are one of the main factors polluting the ground and water environment in the vicinity of landfills. This is connected with the need to systematically control the elements of the ...environment that are exposed to the negative impact of landfill emissions. In Poland, the scope of landfill leachate quality monitoring includes 10 obligatory parameters (pollution indicators). The paper presents an example of the application of selected statistical methods (basic statistics, statistical tests, principal component analysis) to assess the impact of individual pollution indicators on the quality of landfill leachates. Four landfills from the area of Lower Silesia were selected for analyzes, for which in the years 2018–2019 tests of leachate properties were conducted in an extended scope (in relation to the scope applicable during monitoring). Analyses of the obtained results showed significant differences between landfills, depending mainly on their age and method of operation. Specific factors for assessing differences between landfills were as follows: electrolytic conductivity, chemical oxygen demand (COD(Cr)), organic nitrogen, ammonium nitrogen, chlorides and calcium. The values of some of the parameters included in the monitoring studies did not show variability, remaining below the limit of quantification. The conducted analyses permit the determination of the level of leachate contamination from selected landfills and the proposal of indicators that could complement the monitoring range of landfills for many years.
AbstractThe longevity of two white multilayered textured geomembranes, manufactured with a smooth edge for welding, is examined when immersed in synthetic municipal solid waste leachate at five ...temperatures (40, 55, 65, 75, and 85°C) for 50 months. The textured and smooth parts of the geomembranes had similar initial chemical and physical properties, but the core of the smooth edge was thinner. It is shown that, depending on the relative effects of the difference in the core thickness and the surface area exposed to a solution, antioxidant depletion of the textured portion may be either faster or slower than the smooth edge. However, due to the lesser core thickness of the smooth edge of both geomembranes, the degradation in the tensile stress at break properties at 85°C is faster for the smooth edge than for the textured portion of the roll even when the antioxidant depletion was faster for the textured part. Thus, any assessment of the likely service life of the textured geomembrane requires consideration of both the smooth and textured portions of a multilayered textured geomembrane.
Ecological remediation with native plants is the main measure to control the pollution of solid waste in Northwest China. However, the heavy metal transport characteristics of these native plants are ...still unidentified. This study analyzed the distribution of 16 heavy metals in native plants in the desulfurization gypsum yard (DGY), the gangue yard (GY) and the fly ash yard (FAY). The results showed that the soil contained many heavy metals in high concentrations. For instance, As concentrations were comparable to the global soil background values, whereas Cr and Mn concentrations in the area were 2–3 times greater than the global soil background values. The content of heavy metals in the plant root system increased first, then decreased as the distance from the yard increased. Ni, Pb, and Cd migrated well in Artemisia frigida Willd and Artemisia sieversiana Ehrhart ex Willd, with A. sieversiana showing a particularly strong migration in GY. A. sieversiana, on the other hand, was more successful at migrating Cd at DGY and had a similar capability for Mg migration in all three locations. Festuca rubra L was potentially suitable for planting in GY for Ni removal. In conclusion, the migration patterns of different heavy metals were not alike for plants in the three landfills. The results provided a basis for plant selection for ecological restoration in arid and semi-arid regions.
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•Horizontal migration laws of plants are similar in the three landfills.•Different plant species have different abilities to transfer heavy metals.•Screening of plants with heavy metal migration advantage in different landfills.
•A novel method for assessing the environmental safety of inert waste landfills.•Presence of chemically reactive waste is investigated, revealing potential risks.•Batch and column test confirmed ...heavy metals and metalloids in the leachate.•Trapping infiltrated leachate is almost none for fiber sized < 10 cm.•Soil layer installation is effective for sorption of heavy metals.
Inert waste landfills are strictly limited to inert or non-reactive waste materials, nevertheless, due to human negligence or unavoidable circumstances, sometimes, small amounts of biodegradable or chemically reactive waste are mixed and disposed together with the inert waste. Over time, leachate generated from these biodegradable wastes may come into contact with rainfall water and percolate into groundwater and surrounding ground, degrading water quality. Additionally, the large sized industrial plastics present inside the inert waste landfill may trap and store the leachate thus enhancing the risk of contamination due to increased contact time and reducing the mechanical stability of the landfill. In this research, inert waste materials were collected from a Japanese inert waste landfill, and laboratory batch and column leaching tests were performed to determine the leaching behavior of the waste materials with variation in fibrous contents (FC) as 2% and 10% of total inert waste materials. From the batch leaching test, the inert waste was characterized as highly alkaline with a pH value of 10.3 and moderately reduced with a redox potential (Eh) value of 300 mV. The results from the column leaching test indicated that landfilling with 10% FC, comprising sizes below 10 cm, along with an installation of soil layer reduced the concentrations of heavy metals, metalloids, and total organic carbon in the leachate, thus confirming the environmental safety of the inert waste landfill.
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