how does landfill leachate impact wastewater treatment plants

“Discharging landfill leachate to wastewater treatment plants brings in UV QS. These are chemicals that absorb UV light in water, decreasing its strength and reducing efficiency of UV disinfection

,” says Yang Deng, an associate professor at Montclair State University in New Jersey.

Full Answer

What is the most important implication of landfill leachate?

The most important implication about landfill leachate from related studies is the need to continuously monitor and manage closed landfills to safely control leachate and prevent contamination of area surrounding the landfill. From this perspective, landfill leachate treatment is a crucial component of landfill management.

What are the different types of landfill leachate treatment?

The three main categories of conventional landfill leachate treatment technologies are (1) leachate transfer, (2) biological, and (3) physicochemical methods (Renou et al., 2008). Leachate collected at the landfill can be treated by combining with municipal sewage at the sewage treatment plant.

Does leachate improve plant performance?

Nitrate-N concentrations in the final discharge were highest during the drip-feed phase, indicating that leachate improved plant performance compared to no-leachate and shock loading regimes.

Why is young leachate inhibition observed in wastewater treatment?

There are a number of possible reasons for the observed inhibition in young leachate (10%) treatments for both wastewaters. The most likely of these include leachate toxicity, elevated free ammonia concentrations and unfavourable C:N ratio.

What is landfill leachate?

Is landfilling a legacy problem?

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What is leachate How does leachate impact the environment?

Whenever it rains or snows, the water runs through landfills creating a liquid pollution called leachate. Leachate contains all kinds of harmful chemicals, which are known to cause environmental issues as well as serious harm to human health.

What are the impacts of leachate in landfills?

Leachate that escapes from a landfill can contaminate groundwater, surface waters and soil, potentially polluting the environment and harming human health.

What is the potential impact of the discharge of untreated leachate to a municipal wastewater treatment system?

Once the leachate leached into the environment, environmental hazards such as water pollution and public hazards such as waterborne disease outbreak might be occurred. Polluted leachate will carry different concentration of contaminants such as organic matters and heavy metals depend on the waste composition [2].

What is leachate treatment plant?

Biological leachate treatment is a proven technology for organics and ammonia removal in young and mature leachate. The anoxic/aerobic processes achieve nitrification and denitrification and reduce the oxygen demand for landfill leachate treatment.

How does leachate affect water?

The leachate from Municipal Solid waste landfills is a highly concentrated "chemical soup", so concentrated that small amounts of leachate can pollute large amounts of groundwater, leaving it unsuitable for domestic water use.

How does landfill affect the water?

Leachate is the liquid formed when waste breaks down in the landfill and water filters through that waste. This liquid is highly toxic and can pollute the land, ground water and water ways.

Why is leachate harmful for soil and water?

When landfill waste degrades and rain rinses the resulting products out, leachate is formed. The black liquid contains organic and inorganic chemicals, heavy metals as well as pathogens; it can pollute the groundwater and therefore represents a health risk.

What are the biggest concern associated with leachate from landfills?

Leachate is dangerous because it seeps through the soil into local waterways where it contaminates drinking water supplies and spreads disease. In fact, leachate from landfills is a significant source of pollution for the environment.

What is the effect of leachate on soil and on water?

Thus leachate may flow out and contaminate adjacent soil and groundwater. It is well acknowledged that leachate flows into water bodies such as river, lake and ground water will decrease the water quality subsequently disrupt the natural ecosystems.

What are the options for treatment and disposal of landfill leachate?

There are many methods of leachate treatment [5] such as: Aerobic Biological Treatment such as aerated lagoons and activated sludge. Anaerobic Biological Treatment such as anaerobic lagoons, reactors. Physiochemical treatement such as air stripping, pH adjustment, chemical precipitation, oxidation, and reduction.

What does landfill leachate contain?

Generally leachate has a high biochemical oxygen demand (BOD) and high concentrations of organic carbon, nitrogen, chloride, iron, manganese, and phenols. Many other chemicals may be present, including pesticides, solvents, and heavy metals. The direction of groundwater flow.

What is leachate in solid waste management?

Leachate - formed when rain water filters through wastes placed in a landfill. When this liquid comes in contact with buried wastes, it leaches, or draws out, chemicals or constituents from those wastes. A municipal solid waste landfill (MSWLF) is a discrete area of land or excavation that receives household waste.

Treatment of landfill leachate in municipal wastewater treatment plants ...

Request PDF | On Mar 1, 2017, R.B. Brennan and others published Treatment of landfill leachate in municipal wastewater treatment plants and impacts on effluent ammonium concentrations | Find, read ...

Treatment of landfill leachate in municipal wastewater treatment plants ...

Landfill leachate is the result of water percolating through waste deposits that have undergone aerobic and anaerobic microbial decomposition. In recent years, increasingly stringent wastewater discharge requirements have raised questions regarding the efficacy of co-treatment of leachate in municip …

Treatment of landfill leachate in municipal wastewater treatment plants ...

Europe PMC is an archive of life sciences journal literature. Landfill leachate is the result of water percolating through waste deposits that have undergone aerobic and anaerobic microbial decomposition.

How to cut contamination in landfills?

Among the main methods, done at landfills, to cut contamination are evaporation and biological treatments. With evaporation, operating and maintaining the equipment can be labor intensive, and the process consumes a lot of energy to boil the water.

Why are POTWs not accepting leachate?

But as POTWs face tighter regulations that impose more stringent discharge limits , the landscape is transforming. Some of these treatment plants have stopped accepting landfill leachate altogether due to river consequences , says Bryan Staley, president and CEO of the Environmental Research and Education Foundation.

Can a landfill work with a POTW?

Landfills working with a POTW or considering working with one should key in on specific aspects of these plants’ operations, says Torrens.

Can treatment plants raise their rates?

These treatment plants can raise their rates quickly. And they can impose new leachate limits, especially as their own situations change, whether those changes be new government regulations or a transition to new technology. And some of these changes are edging out, or can edge out, landfills.

Can you use chlorine to disinfect?

While most POTWs use chlorine to disinfect, some are moving toward UV disinfection as chlorine is dangerous to handle and can create byproducts that are toxic in water. The potential for leachate to interfere with the alternative method may push POTW’s over their limit for their disinfection requirements.

What is landfill leachate?

Landfill Leachate is created by liquid that drains or leaches from the landfill and needs to be treated as there can be materials that are dangerous to enter the sewer system and need to be treated prior to discharge . Rainwater is also a large contributor of the Leachate.

What is a Met-Chem wastewater treatment system?

A Met-Chem Wastewater Treatment Analysis will allow us to design and engineer a WWT (Wastewater Treatment System) to treat your exact wastewater. This allows us to provide the most cost-effective way to treat wastewater, and avoid the purchase of unnecessary treatment equipment to safely discharge the water.

How does a filter press work?

The Filter Press uses pressure filtration to separate the solids from the liquid. The slurry is pumped into the filter press where the solids mass is captured between the filter plates. The filtered water is returned to the holding tank.

Is rainwater a leachate?

Rainwater is also a large contributor of the Leachate. Two types of systems are used for this treatment. The first is for applications where the pH is within a suitable range for discharge to the sewer system. This Leachate and rainwater will go into a large holding tank.

Can landfill leachate be treated?

Landfill Leachate can be a challenge to treat, because it may contain a wide variety of wastewater . Met-Chem will custom build a Wastewater Treatment System specifically designed for your wastewater. Met-Chem is capable of treating standard Leachate with the physical treatment of polymers and precipitation, or more complex wastewater treatment with BOD (Biologically Oxygen Demand) and Activated Sludge.

What is landfill leachate?

Landfill leachate is the result of water percolating through waste deposits that have undergone aerobic and anaerobic microbial decom position. In recent years, increasingly stringent wastewater discharge requirements have raised questions regarding the efficacy of co-treatment of leachate in municipal wastewater treatment plants (WWTPs). This study aimed to (1) examine the co-treatment of leachate with a 5-day biochemical oxygen demand (BOD5): chemical oxygen demand (COD) ratio less than or slightly greater than 0.26 (intermediate age leachate) in municipal WWTPs (2) quantify the maximum hydraulic and mass (expressed as mass nitrogen or COD) loading of landfill leachate (as a percentage of the total influent loading rate) above which the performance of a WWTP may be inhibited, and (3) quantify the impact of a range of hydraulic loading rates (HLRs) of young and intermediate age leachate, loaded on a volumetric basis at 0 (study control), 2, 4 and 10% (volume landfill leachate influent as a percentage of influent municipal wastewater), on the effluent ammonium concentrations. The leachate loading regimes examined were found to be appropriate for effective treatment of intermediate age landfill leachate in the WWTPs examined, but co-treatment may not be suitable in WWTPs with low ammonium-nitrogen (NH4 -N) and total nitrogen (TN) emission limit values (ELVs). In addition, intermediate leachate, loaded at volumetric rates of up to 4% or 50% of total WWTP NH 4 -N loading, did not significantly inhibit the nitrification processes, while young leachate, loaded at volumetric rates greater of than 2% (equivalent to 90% of total WWTP NH 4 -N loading), resulted in a significant decrease in nitrification. The results show that current hydraulic loading-based acceptance criteria recommendations should be considered in the context of leachate NH 4-N composition. The results also indicate that co-treatment of old leachate in municipal WWTPs may represent the most sustainable solution for ongoing leachate treatment in the cases examined.

Is landfilling a legacy problem?

Throughout the world, landfilling is in decline and landfill leachate has become a legacy problem . Unmanned landfill sites will require sustainable leachate treatment options to be developed. These findings indicate that although co-treatment of landfill leachate at WWTPs may be appropriate in some circumstances, the inherent variability in leachate composition and treatability necessitates a conservative approach. The main findings of this study are as follows:

What is Meant by Leachate

The production of leachate is a big problem in municipal solid waste landfills and poses a major threat to surface water and groundwater. Leachate can be defined as a liquid that passes through a landfill and extracts dissolved and suspended matter from it.

Leachate Wastewater Treatment

This vicious cycle can have an end by pre-treating leachate before feeding the membranes, which are still required to reduce salinity and allow for reject compliance.

What is landfill waste?

Landfills are the final depository for much of the solid waste we generate. While it is known that such landfill waste can contain a wide variety of contaminants, little research to date has been conducted regarding contaminants of emerging concern (CECs) in final landfill leachate.

Why were landfills selected?

The landfills were selected to provide a range of hydrogeologic setting, climate, size, and leachate treatment and disposal practices. Ultimately, however, we could only collect samples at landfills that were willing to participate in this research.

What is USGS leachate?

U.S. Geological Survey (USGS) scientists processing leachate samples collected for a national-scale study on the occurrence of contaminants of emerging concern (CECs) in landfill leachate disposed offsite. Photo Credit: Jason R. Masoner, USGS

Why are field protocols used in USGS?

Thus, the field protocols were designed to minimize any personal exposure to the landfill leachate being collected while still collecting samples that are representative of the landfills in question.

How does landfill affect leachate?

The amount of leachate generated in the landfill depends mainly on water availability (e.g. precipitation, surface water, leachate recirculation), characteristics of final cover (soil and vegetation type, impermeable cover, slope), and characteristics of waste (moisture content, density) (Canziani and Cossu, 1989). If the landfill site properties favor infiltration, more leachate will be generated (Figure 2). Other properties of the landfill and surrounding site can also affect leachate formation (Table 1).

How is leachate generated in landfills?

When moisture content exceeds field capacity due to precipitation, decrease of voids, etc., leachate is formed as the gravitational force overcomes the retention force resulting in vertical flow of liquids through the landfill (Equation 3).

What is leachate made of?

Leachate formed from municipal solid waste is composed of various organic and inorganic contaminants (table 2). Its composition may vary depending on the phase of biodegradation, which also is affected partially by landfill age as mentioned (Table 3).

Why is sanitary landfill used?

The sanitary landfill method for disposal of solid waste is widely used due to its economic advantages in terms of exploitation and capital costs (Renou et al., 2008). In addition to the economic advantages, landfills enable controlled decomposition of waste to final stabilized material (Renou et al., 2008). However, there are concerns related to leachate produced from landfills, which can migrate to and contaminate the surface and groundwater and soil environment.

What factors affect characteristics of leachate?

In this report, factors that affect characteristics of leachate are described to identify the difference in composition according to variables such as waste/leachate age. Three main categories of leachate treatment technologies will be reviewed (i.e. leachate transfer, biological and physicochemical methods), with a focus on the suitability of each technology on different types of leachate. Finally, a rising issue regarding contaminants of emerging concern in leachate is discussed to address future implications of closed and ongoing landfill sites.

How is leachate treated?

Leachate collected at the landfill can be treated by combining with municipal sewage at the sewage treatment plant. This method is used for its easy and low-cost operation (Renou et al., 2008). However, leachate co-treatment has limitations due to high contaminant load, organics with low biodegradability, and presence of heavy metals (Quasim and Chiang, 1994; Booth et al., 1996, Çeçen and Aktaş, 2004), which may lead to reduction in the performance of the sewage treatment plant. In addition, concerns were raised regarding the effect of simple dilution rather than treatment of the leachate.

How to identify biodegradation stage?

Each biodegradation stage can be identified by examining the concentration of different indicators (i.e. chemical oxygen demand (COD), ammonia nitrogen (NH 4+ -N), dissolved solid (DS), suspended solid (SS), xenobiotic organic compounds (XOCs), heavy metals, salts) (Schiopu and Gavrilescu, 2010) . These indicators may be similar to those found in conventional municipal wastewater. However, landfill leachate generally has a comparatively diverse mixture of contaminants at higher concentrations (Schiopu and Gavrilescu, 2010), and requires a different or modified treatment method than those used for municipal wastewater.

The need for change

Following a study by the U.S. Public Interest Research Group in 2000, all sites that discharge into the creek became subject to stricter ammonia permits on all wastewater being released. In its un-ionized form, ammonia is toxic to aquatic life in receiving waters as it causes increases in both temperature and pH levels.

How it works

Wastewater from the landfill is first collected in two equalization tanks, which allows operators to control the flow rate to the system. From the equalization tanks, water is pumped through the metals removal system. Metals removal is accomplished by the addition of sodium hydroxide (caustic) as well as ferric chloride.

Updating the towers

The retrofit of the first bio-tower to a BioPortz MBBR reactor was completed within six months. Updating the towers one at a time ensured minimal disruption and downtime for the landfill.

Upgraded system performance

The average influent flow rate the Seneca Landfill towers experienced in the first 10 months of operation was 69 L/min. The new system, designed to achieve effluent ammonia concentrations of 4.7 mg/L, has been consistently able to achieve this limit or less, therefore enabling them to safely discharge their wastewater.

What is the most important factor in landfill leachate?

The single most influential factor on the volume of landfill leachate is precipitation. The most influential factor regarding leachate quality is that leachate typically contains high concentrations of organic compounds, ammonia and other forms of nitrogen, metals, and dissolved solids.

Is leachate wastewater expensive?

Managing landfill leachate and wastewater treatment are increasingly challenging and costly for landfill owners and operators. In some cases, publicly owned treatment works (POTWs) are required to impose limitations on liquids received at their facilities, resulting in increased charges, or the POTW could refuse to permit or process the leachate wastewater altogether. These developments are due in part to more stringent discharge requirements and the shift to newer disinfection technology that has limited the POTW’s ability to accept higher strength wastewaters. As a result, many facilities and landfill operators are facing higher costs and fewer options for disposal.

What is landfill leachate?

Landfill leachate is the result of water percolating through waste deposits that have undergone aerobic and anaerobic microbial decom position. In recent years, increasingly stringent wastewater discharge requirements have raised questions regarding the efficacy of co-treatment of leachate in municipal wastewater treatment plants (WWTPs). This study aimed to (1) examine the co-treatment of leachate with a 5-day biochemical oxygen demand (BOD5): chemical oxygen demand (COD) ratio less than or slightly greater than 0.26 (intermediate age leachate) in municipal WWTPs (2) quantify the maximum hydraulic and mass (expressed as mass nitrogen or COD) loading of landfill leachate (as a percentage of the total influent loading rate) above which the performance of a WWTP may be inhibited, and (3) quantify the impact of a range of hydraulic loading rates (HLRs) of young and intermediate age leachate, loaded on a volumetric basis at 0 (study control), 2, 4 and 10% (volume landfill leachate influent as a percentage of influent municipal wastewater), on the effluent ammonium concentrations. The leachate loading regimes examined were found to be appropriate for effective treatment of intermediate age landfill leachate in the WWTPs examined, but co-treatment may not be suitable in WWTPs with low ammonium-nitrogen (NH4 -N) and total nitrogen (TN) emission limit values (ELVs). In addition, intermediate leachate, loaded at volumetric rates of up to 4% or 50% of total WWTP NH 4 -N loading, did not significantly inhibit the nitrification processes, while young leachate, loaded at volumetric rates greater of than 2% (equivalent to 90% of total WWTP NH 4 -N loading), resulted in a significant decrease in nitrification. The results show that current hydraulic loading-based acceptance criteria recommendations should be considered in the context of leachate NH 4-N composition. The results also indicate that co-treatment of old leachate in municipal WWTPs may represent the most sustainable solution for ongoing leachate treatment in the cases examined.

Is landfilling a legacy problem?

Throughout the world, landfilling is in decline and landfill leachate has become a legacy problem . Unmanned landfill sites will require sustainable leachate treatment options to be developed. These findings indicate that although co-treatment of landfill leachate at WWTPs may be appropriate in some circumstances, the inherent variability in leachate composition and treatability necessitates a conservative approach. The main findings of this study are as follows: