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Tag Archives | ammoniacal nitrogen

leachate indicator parameters

The 3 Most Important Leachate Indicator Parameters

There are three very important leachate indicator parameters which are used as indicators to identify leachate contamination in any water sample analysed in a water quality laboratory. These three parameters can give an initial guide to anyone investigating what appears to be pollution occurring in the vicinity of a landfill, as to whether the source […]

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membrane bioreactor

How a Membrane Bioreactor is Used to Treat Landfill Leachate

In principle, a membrane bioreactor combines biological treatment with a separation process using microfiltration membranes. A Membrane Bioreactor consists of a reactor tank and a microfiltration unit. In the reactor, the micro-organisms (mostly bacteria) transform dissolved polluted matter into biomass, and ammoniacal nitrogen (“ammonia”) into nitrate. Thus biodegradable organic pollutants are eliminated by the bioreactor […]

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High Strength Leachate

When people refer to high strength leachate they are normally referring to the landfill leachate from a sanitary landfill which has percolated slowly through the waste. That is leachate and has been extracted by the leachate collection and pumping system. Usually high strength leachate has ammoniacal nitrogen concentrations above 500 mg/l up to 3.500 mg/l, […]

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Landfill leachate composition - image for page

Landfill Leachate Composition

Landfill leachate composition for United Kingdom Landfills was first published in the Waste Management Papers published by the UK Department of Environment. Waste Management Paper 26 contains the most recent table of Landfill Leachate Composition before the WMP series was superseded by later documents, notably the DoE’s Leachate Report of 1995. However, the original table, […]

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Anaerobic Digestion of Landfill Leachate for Energy Generation: Pipe-Dream or an Opportunity?

Anaerobic digestion is becoming increasingly popular in this age of high energy prices, and many more people are realising that whereas aerobic treatment systems consume large amounts of expensive energy, anaerobic digestion is a process which does the opposite. In fact it produces a net energy output.   It is not surprising therefore, that many […]

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Software Resources

Mogden Calculator - Trade Effluent Charge Formula Calculator

We plan to add a number of leachate software applications to this page over the next few months, which our visitors can download and install, and which will provide solutions to a number of problems experienced by leachate treatment plant operators. Our first two are now available, a handy conversion calculator (see below), and (see right) our Trade Effluent Charges Calculator here.

Ammonia to Ammoniacal Nitrogen “Expressed as N” – Free Conversion Calculator

There are two methods used by analytical laboratories for expressing the quantity of ammonia in contaminated water. The first is that provided bythe majoirty of water quality analytical laboratories when reporting the quality of a polluted water. They provide a weight of ammonia as the weight of the nitrogen (elemental N), “ammoniacal- N” and that is the method  used by the Enviroment Agency UK.

However, some water quality labs report the weight of “ammonia”, (ie the whole NH4 molecule) which includes the weight of the hydrogen atoms as well as the nitrogen atoms, and landfill site operators may at times erroneously think that they are closer to their maximum permitted ammoniacal nitrgen strength for discharge, than they really are.

To help landfill operators correct for the difference between the two methods of expressing ammoniacal nitrogen values we devised the software below, which will walk you through how to calculate Ammoniacal-N (ammonia expressed in mg/l as N) concentrations (as used in UK Trade Effluent charging and dicsharge consents and environmental permits).

Get started now using our software, in three steps, as follows:

1. Simply download the zipped file below and unzip it into its own new directory location on your hard drive where you will be able to go back to it later.

2. Double click on the executable file (file extension “.exe”) called “ammonia-converter.exe”, and the software will load up and you can start to use it.

3. Follow the instructions given inside the software program.

For your free software DOWNLOAD click here >>>Ammonia to Ammoniacal-N Converter Software Package Version 1

Please give us your feedback by filling in a comment below about our Ammonia as Nitrogen (N) converter software, and if we like your suggestions we may be able to incorporate them into a later version.

Trace Contaminants Found in Leachate: Fact Files for You to Download

£d Image of Fact file ebook coverIf you have a problem with a substance found in leachate, we are here to help you! Our fact files, which are based on publicly published UK government research, are unique. You can save huge amounts of time hunting down this information which is otherwise spread very widely in published papers in libraries and on research databases, and is only partially accessible from the web.

What Are Trace Contaminants?

Landfill leachate invariably contains a host of different substances in addition to the major substances present (COD, BOD, Suspended solids, Metals in solution, Salinity, Ammoniacal nitrogen etc), which although only dissolved in tiny quantities (parts per million (ppm) and parts per billion (ppb)) still may represent a potential hazard to the environment and public health due to their extreme toxicity. To make a distinction between much higher concentrations of the main contaminants which are present in parts per thousand and more, and these lower concentration but much more toxic substances, the term “Trace Contaminants” is applied.

National and international standards have been set for the maximum permissible concentrations of many of these toxic (or “dangerous”) substances in drinking water, and under the EU Groundwater Directive no such substances are in principle permitted to be discharged to groundwater. In the UK these substances are often described as List 1 Substances, however since the creation of that list many more substances and species of contaminants have beeen identified which can now be analysed, and routinely reported upon within the description of “Dangerous Substances” as now applied by the environment Agency (EA).

How Does a Person Tasked With Deciding Whether a Leachate Contains Significant Quantities of Trace Contaminants Find Out About Them?

The first step is to analyse for them. Contact your water quality analytical laboratory and request a list of the subtsances they analyse when asked to complete what are variously called “List1”, “Dangerous Substances”, “or Comprehensive Prescribed List” analysis reports. Before you head off to the landfill to collect the necessary samples you will also need to await a package of special bottles which te analytical laboratory staff will prepare and send to you. Some of the se bottles wil include fixitive chemicals designed to prevent decay of some substances while en-route to the analytical test laboratory.

OK. So the Analytical Report Showed Some Dangerous Chemicals to be Present at Trace Concentrations. Does it matter? What Now?

Most leachates, especially those from older landfills, will show the presence of some of these chemicals. The next step is to decide whether they present a real hazard when the discharge route is taken into account. To do that we are writing and publishing a series of Leachate Contaminant Fact Files, each one of which will discuss the nature of a hazardous substance, or species of substances, and identify research papers written on the contaminant, to assit the reader in deciding whether the presence of the substance is significant and assist them in the decision either to treat the leachate to remove the susbtance, or to make a scientifically based case to the regulatory body or waste water treatment plant operator that negligable risk exists from the dangerous chemical at the concentration seen during water quality analysis.

Our first Leachate Contaminant Fact Files are Now Available. For more information, and purchase for immediate download, please click on the linked text below:

£d Image of Fact file ebook cover Leachate Trace Contaminant Fact File 1 – PCBs

Leachate Trace Contaminant Fact File 2 -Phenols

Leachate

Leachate with a high iron content in a polluted streamLeachate starts as rainfall.

Rain falling on the top of the landfill is the main contributor to the generation of leachate, and is by far the largest contributor for modern sanitary landfills which do not accept liquid waste. In old unlined and un-engineered landfills, some leachate is produced from groundwater entering the waste. Some, additional leachate volume is produced during waste decomposition, and some additional surface water will sometimes run onto waste from its surroundings.

The decomposition of carbonaceous material produces some additional water, and a wide range of other materials including methane, carbon dioxide and a complex mixture of organic acids, aldehydes, alcohols and simple sugars, which dissolve in the leachate cocktail.

The precipitation percolates through the waste and takes in dissolved and suspended components from the biodegrading waste, through physical and chemical reactions.

Leachate history graphic adMost landfills are designed to minimise the amount of leachate they create during their lifetimes. However, there are good scientific reasons to suggest that it would be better to flush all landfills out and to do this, would produce more leachate, faster. Landfills where the latter philosophy is adopted, are called, “bio-reactor” landfills. In Europe, bioreactor landfills are effectively prohibited by EU directives, leading them to be called “dry tombs” by some, due to their rapid capping, and minimised leachate production.

The environmental risks of leachate generation arise from it escaping into the environment around landfills, particularly to watercourses and groundwater. These risks can be mitigated by properly designed and engineered landfill sites. Such sites are those that are constructed on geologically impermeable materials or sites that use impermeable liners made of  geotextiles  or engineered  clay . The use of linings is now mandatory within both the United States and the European Union, except where the waste closely controlled and genuinely inert.

Most toxic and difficult materials are now specifically excluded from landfill. However, despite much stricter statutory controls the leachates from modern sites are currently stronger than ever. They also contain a huge range of contaminants. In fact, anything soluble in the waste disposed will enter the leachate. Within the lists of substaces present in leachate are very low concentrations of “trace contaminants” which can have quite strongly contaminating effects. These are nowadays most often derived  from materials in household and domestic retail products which enter the waste stream perfectly legally.

Unfortunately, the leachate draining from most landfills will continue to reflect the contaminants of past years, when regulatory controls were less.

These substances in include extremely low concentrations of heavy metals (for example from batteries), herbicides and pesticides (as used in gardens), etc. However, leachate is becoming less contaminated with difficult substances as time goes forward, and public awareness, recycling and increased statutory control over these substances, throughout the industrialized world is making leachate less harmful in this respect.

“Leachate has a very high ammoniacal nitrogen concentration”

The concern about environmental damage from waste leachate, largely arises from its high organic contaminant concentrations and much higher ammoniacal nitrogen than commonly found in any other organic effluent.  Pathogenic   microorganisms and toxic substances that might be present in it have in the past been described as the most important. However, pathogenic organism counts reduce rapidly with time in the landfill, so this only applies to the youngest leachate and leachate is seldom removed from the landfill in this condition.

One of the most comprehensive scientific studies yet undertaken worldwide on leachate, was published by the United Kingdom, DOE., in 1995. It is titled: “A review of the composition of leachate from domestic wastes in landfill sites”; Department of Environment Research Report No. CWM 07294, and still provides much essential data on the range of contaminands present in Municipal Solid Waste, and Commercial and Industrial Waste landfill leachate.