#nitrate

[postcard-from-the-past]

A pile of 25.000 tons of potassium nitrate in the Auby Chemical Works, French Flanders region of northern France

French vintage postcard

[filmnoirfoundation]

Don't miss the closing weekend of NOIR CITY Hollywood, Eddie Muller and Alan K. Rode in person. NIGHTMARE ALLEY will screen in nitrate. Tix and full festival schedule: https://bit.ly/3Ij9Mc2

[tenth-sentence]

The interior anaerobic zone then becomes a site where heterotrophic bacteria can carry on their denitrifying activity (Fig. 16.6).

"Environmental Chemistry: A Global Perspective", 4e - Gary W. VanLoon & Stephen J. Duffy

[aquariuminfobureau]

I mostly write about organisms and not the principles of fishkeeping. However people often ask me about two related phenomena, cycling and stocking. Aquariums are safe for fish and other animals because of the nitrogen cycle. This is what determines, moreso than the water volume, the carrying capacity of the tank. But many people seem to be confused - what is the nitrogen cycle?

'Cycling' refers to the cycle by which the toxin ammonia, which is excreted as waste by organisms, before it is turned to nitrite and then to nitrate by biological actors. In aquarist parlance 'cycling' refers to the process and duration of time, during which the nitrogen cycle becomes established and stable. Properly the cycle continues throughout the operation of the aquarium.

Ammonia, which contains nitrogen, is the principal excretory product of living animals, and they void it because it is a toxic byproduct of their own metabolic processes. Human urination is an example of a way in which animals lose excess ammonia, but other kinds of animal may excrete ammonia by means of different methods.

Fortunately other organisms can find a positive use for ammonia, which animals don't want. Their own metabolisms create nitrite from the ammonia they intake, by breaking it down and adding oxygen to the nitrogen. Then yet more microscopic organisms convert the nitrite to the similarly named and chemically related nitrate, which must also be maintained at low levels, but is far less harmful. Traces of nitrate are in fact beneficial to some aquarium organisms.

The nitrogen cycle originates from the decomposition of amino acid, and this is why test kits are available to test for dissolved organics, which are not themselves inherently harmful, but their buildup indicates strain upon the system. How much strain is acceptable depends on the kinds of animals that are living in the aquarium. There isn't really a single standard as to when there are too many dissolved organics, or even nitrate. But regular and sensibly proportionate water changes, help to keep both under control.

Because it involves the processes of different organisms, the nitrogen cycle is very obviously an ecological, as well as a chemical phenomenon. Both the natural processes of the cycle, and the technology by which the effects of the benign organisms are maximised, are known as biological filtration, or biofiltration. It is different from physical and chemical filtration, although the functions of filter media may overlap.

The good bacteria that are involved, colonise available surfaces throughout the aquarium. They are present on rocks and on substrates such as sand and gravel. Similarly they colonise sponges and various proprietary items such as 'bio balls'. At this point, I wish to explain the introductory principles of biofiltration, not to cover its different expressions. It is however worth pointing out, the more the better.

Stocking levels are problematic principally because the living animals themselves create strains upon the biofiltration. Furthermore they require inputs of food, excesses of which contribute to dissolved organics, and therefore the nitrogen cycle, when they are uneaten - thus, messy feeders create more bioload than other organisms, lowering the carrying capacity of the aquarium system.

Feeding behaviors thus determine the 'footprint' animals have on the biofiltration in their aquarium, moreso than their size. It is also the mass of an animal that contributes to its output of wastes, moreso than any single dimension, such as its total length. Another determinant is the metabolic rate of the animal in question, which determines the speed at which its wastes are generated and churned out into the water.

The nitrogen cycle is also why overfeeding is bad, because excess food must inevitably decompose. By definition, the aquarist can't be overfeeding, from the perspective of the nitrogen cycle, when the supplied food is being eaten; overfeeding as in overeating is a different problem. However if feeding your livestock and keeping them healthy begins to stress the cycle, then you have too much bioload in your aquarium.

Often in marine aquariums, 'live rock' and 'live sand' are mentioned. These terms mystify many people, although they are relevant to filtration. The rocks and sand in question are substrates already colonised by microscopic organisms, as play a role in the nitrogen cycle. All items already this colonised are thus 'live' biofiltration media.

Unfortunately there is a misconception that 'live' rock needs transporting from the sea. Such rock is shipped damp but emersed, killing benign and desirable organisms, and necessitating a period called 'curing' in which photosynthesizers are denied an energy source, and further mortality and decomposition ensues. The result is that only 'tough as boots' organisms survive, and some of these species are harmful to corals and such.

Clearly despite the appeal of 'live rock' as a ready made, natural reef, it's use is problematic and self defeating. A distinction just be made, between the use of 'living' filtration media, and the importation of artificially depauperate microenvironments for aquariums. It is better to take rock and sand from an established reef tank instead, to avoid unwanted guests. Although even impoverished live rock can introduce interesting and useful 'friends', these can arrive also from established, nuisance-free tanks

A counterpart to the use of live rock and sand in reef aquariums, is the Walstad style of freshwater aquarium. The Walstad type of tank is one in which living plants and soil substrates are employed instead of artificial filtration; more common than a strict Walstad setup, is a hybrid system that employs both naturalistic and 'normal' approaches in its running.

Sometimes it is said that planted tanks do not cycle, or that adding plants stops the cycle. Nothing could be further from the truth. True aquatic plants and the organisms called algae, play a role in the cycle, which is why algae bloom during the cycling period of a new aquarium, when the lighting is switched on. Adding plants to freshwater tanks, and macroalgae to marine aquariums, should be thought of as assisting the stabilisation of the nitrogen cycle.

[whats-in-a-sentence]

The volume-weighted mean concentrations (over the 1987 growing season) of major constituents at all five sites are given in Table 5.3.

"Environmental Chemistry: A Global Perspective", 4e - Gary W. VanLoon & Stephen J. Duffy

[techtuv]

Mirror making with silver nitrate started in the 1800s.

[tomoleary]

Dave McKean “Nosferatu” from the Nitrate series

Source

[eaglesnick]

“Water is life's matter and matrix, mother and medium. There is no life without water.”

Albert Szent-Gyorgyi

Remember headlines similar to this?

“England’s rivers, lakes and streams ‘among worst in Europe’ amid concern over sewage and farm pollution.”  (Independent: 15/09/21)

And more recently:

“Sewage entered rivers and seas on average 825 times a day last year Water companies released raw sewage into rivers and seas in England for more than 1.75 million hours last year. (BBC News: 31/03/23)

Does our Tory government care? No, not one jot. This is what we read in the media today.

“Michael Gove is set to announce a weakening of water pollution rules placed on housing developers in England, in a move that has angered groups across the UK’s green economy.”  (edie.net: 29/08/23)

Gove is doing this to encourage more house building which up until now has been supposedly held back by anti-pollution laws and the cost this has for housing developers. From now on the building industry will not be held accountable for increases in nitrates and phosphates into out waterways.

In October 2021 the Tory government published a paper entitled: Nitrates: challenges for the water environment.  In it they listed the dangers of too much nitrate in our waterways:

Risk to human health

Eutrophication of lowland surface waters (Eutrophic waters are often murky and may support fewer large animals, such as fish and birds, than non-eutrophic waters.)

Acidification and eutrophication of upland waters

Adverse impact on Groundwater Dependent Terrestrial Ecosystems.

In short, nitrates poison the water both above and below ground and can be a risk to human health as well as to birds, animals and aquatic life in general.

In December 2022, the government published another report:.

It found that phosphates cause eutrophication in the same way nitrates do:

“Eutrophication increases the cost of drinking water abstraction and treatment, adversely affects angling, water sports and other recreational activities, and causes the loss of sensitive plants and animals in rivers and lakes.” (Environment Agency: Phosphorus and freshwater eutrophication: challenges for the water environment./ December 2022)

So, we have a government who knows the dangers of increasing the levels of nitrates and phosphates in our waterways yet they  decide to relax laws controlling these chemicals  regardless of the environmental consequences.

 Why!

The answer is, as is so often the case, “follow the money”.

Craig Bennett, Chief Executive of the Wildlife Trust had this to say on the Today programme this morning.

“I've been at the last few Conservative Party conferences over the last few years, and when you walk into the exhibition space, the biggest, fanciest exhibitions are by the big house building organisations. The most lavish parties and receptions put on at the Conservative Party conference over the last few years have been from the house building industry. They seem to have plenty of money when it comes to them lobbying, and guess what? - we discover this morning that money talks.”

To back up this claim, we find that in 2021, "property developers gave Tories £892,00 in the first three months of that year. And in May this year we read that:

“Millions in Tory donations at risk as property developers hit back. Housebuilders and developers - who in the past have accounted for around a fifth of all donations - have turned off the taps.”(Independent: 30/05/23)

There is a sneaking suspicion that the relaxation of water pollution laws has more to do with Tory Party funding than the housing shortage. Given the housing industry is one of the Conservative Party’s biggest donors, is it any wonder that under the new law, developers will no longer have to dip into their profits to offset nutrient pollution from new homes.

And just to prove the Tory Party has a sense of humour, not only will our waterways be more polluted than ever before but:

“Scrapping housebuilder water pollution rules in England to cost taxpayer £140m”  (Guardian: 29/08/23)

[thefitlittlegirl]

So beet poisoning is a thing!

It shall not happen again

05/15

[postcard-from-the-past]

Grating potassium nitrate in the Auby Chemical Works, French Flanders region of northern France

French vintage postcard

[johniac]

SciTech Chronicles. . . . . . . . .Mar 17th, 2025

[tenth-sentence]

These bacteria mediate reduction processes in which sugars and carbohydrate and other organic compounds in the wastewater serve as electron donors and the soluble nitrate is converted into nitrogen gas (reaction 16.18).

"Environmental Chemistry: A Global Perspective", 4e - Gary W. VanLoon & Stephen J. Duffy

[biology-geology-beaches-india]

Angaria delphinus, October 13-14, Kuta Beach, Bali, Indonesia.

Weight: 48.3 grams

Width: 6 centimeters

Length: 5 centimeters

Height: 4 centimeters

There was an outer reef that held in the waters of this seashore, and the huge run-off of nitrate and phosphate reach sewage into the bay likely accounted for the gigantism of gastropod species that I observed on this beach.

Phylum: Mollusca, Class: Gastropoda, Subclass: Vetigastropoda, Order: Trochida, Family: Angariidae.

[pandoramsbox]

Sci-Fi Saturday is on hold again due to my responsibility and pleasure at be Social Media Correspondent for #nitrateshow at @eastmanmuseum

My travels will stop for awhile after this trip, so interruptions shouldn't be cropping up as often.

[rodglacial]

Livre POLAR80 (Décembre 2023)