Menyusuri Sungai Sepanjang Jalan Magelang

Pasca meletusnya gunung merapi yang sudah hampir sebulan lalu, ternyata masih menyisakan bencana-bencana yang terus melanda beberapa desa di daerah kabupaten Magelang bagian timur. Tepatnya daerah Muntilan yang tak kunjung henti dilalui lahar dingin, bahkan sampai mruntuhkan beberapa jembatan yang ada di daerah ini. Sebut saja jembatan sungai Pabelan yang terletak di dusun Srowol, sudah retak saat terjadi letusan gunung Merapi, dan disusul dengan dilaluinya lahar dingin, jembatan ini pun sudah tak kuasa lagi menahan terjangan material vulkanik Merapi. Bahkan, di jembatan lain yang terletak di Desa Tamanagung, Muntilan (Dekat Kolam renang TirtoAji), salah satu Jembatan Kali Mbelan yang juga merupakan jalur akses utama Jalan Jogja-Magelang-Semarang, dikabarkan retak dan ditutup sementara beberapa waktu yang lalu. Hal ini dikarenakan Sungai Pabelan ini adalah salah satu sungai yang dilewati lahar dingin material vulkanik. Mengingat selalu, bisa dibilang, meskipun ukurannya yang lebar, sungai ini termasuk sungai yang airnya surut, tapi semenjak meletusnya Merapi hingga sekarang, sungai ini bahkan alirannya sangat deras (bukan air, melainkan lahar dingin beserta material vulkanik). Namun, ternyata jembatan ini lebih kokoh, hingga akhirnya tak lebih dari 6 jam jembatan ini ditutup untuk kendaraan yang ingin melintas. Meskipun demikian, aliran deras sungai ini sampai tadi pagi (09 Desember 2010, 06.00 am) masih membawa sampah-sampah Merapi.
Bisa dimaklumi sebenarnya, bagaimana tidak terjadi aliran yang sangat deras, dalam dua minggu terakhir ini, daerah Muntilan dan sekitarnya telah dilanda hujan sangat deras tiap sore, malahan bisa dibilang sejak siang. Tak hanya daerah Muntilan, hujan deras ini juga sampai ke daerah perbatasan Magelang-Jogja, yaitu sampai Tugu Ireng (Sungai Krasak).
Puncaknya bisa dibilang mulai pada hari Minggu pukul 11.00 siang, hujan deras melanda daerah muntilan, hingga salah satu sungai di daerah dusun Gempol, Kecamatan Salam pun tak lagi kuasa menampung air hujan beserta setoran material vulkanik dari Merapi dan akhirnya membludak sampai ke badan jalan, mengakibatkan jalan Magelang di daerah ini tak bisa dilewati, sehingga kalau ada pengguna jalan yang ingin ke Jogja, atau Magelang, harus melewati jalan lain (yang lebih jauh, mubeng-mubeng, membingungkan dan kecil) seperti jalan Kalibawang, atau Ngepos. walhasil, Jalan Magelang ditutup sementara dari mulai pertigaan Semen ke arah Ngluwar, karena memang sudah tidak bisa dilewati, kalaupun bisa dilewati malah akan membahayakan jiwa pengguna jalan. Akan tetapi karena saking derasnya hujan, ternyata pukul 06.00 sore, jalan ini sudah bisa dilewati. Hari ini hal ini kembali terulang lagi, bahkan badan jalan ini tertutup pasir sampai ketinggian 1 meter, membuatku enggan untuk pulang ke rumah.


Tapi, sebenarnya memang setiap hal itu mempunyai dua sisi, begitu juga dengan banjir lahar dingin ini, dia punya sisi kebaikan dan keburukan. keburukannya kan udah dirasain, besok pagi tinggal ngerasain kebaikannya, penambang pasir panen raya,, ya gak ya gak..

Segini dulu nulisnya,, besok dilanjut ma foto-foto ter-up to date!!

LAGI BUKAN AKU!!

hUFT..HARI2 KULIAH YANG NGE-bt-IN BANGET..

Ga tau nih, bawaanya pengin pulang terusss...Males banget di kos, padahal malah aku bisa konsen belajar loh kalo d kos, tapi kenapa ya kok malah pengin pulang terus.Banyak banget tugas!!

Tagihan buat UTS juga, senin depan udah di-booking Environmental Chemistry, terus senin depannya lagi udah ujian Kimia Fisika lagi. Bayangpun...!!!

 Belum lagi tugas akhir Review of High School Curriculum yang belum aku edit juga. Hmmm,,, kayaknya aku butuh sesuatu biar mendongkrak semangatku deh... apa yaa... OLAHRAGA!!!yups,,udah 2 minggu ini malah aku ga olahraga sama sekali..Pantes jadi males gini!!

OK..malam ini, deadline:

-Neliti laporan adik tingkat

-Ngerjain dasar teori laporan KF

-Nyicil Baca Inorganic Chemistry

-Nyatet Manajemen Laboratorium (nyalin dari orek2an)

-Baca2 tugas Review

-Nyoba ngerjain MSDS

-Huuuuwwwwhhhh....

Sayank,, aku kangen banget ni ma kamu, kapan ya bisa ketemu. Akar semua masalahku tu, karena gag ketemu kamu, jadi gag semangat gini deh!!!Kamu baek2 yaa di sana sayank!!

The Mysterious Origin and Supply of Oil

Nature has been transmuting dead life into black gold for millions of years using little more than heat, pressure and time, scientists tell us.
But with gas prices spiking more than $1 per gallon in the United States this year and some experts predicting that the end of oil is near, scientists still don't know for sure where oil comes from, how long it took to make, or how much there is.
A so-called fossil fuel, petroleum is believed by most scientists to be the transformed remains of long dead organisms. The majority of petroleum is thought to come from the fossils of plants and tiny marine organisms. Larger animals might contribute to the mix as well.

"Even some of the dinosaurs may have gotten involved in some of this," says William Thomas, a geologists at the University of Kentucky. "[Although] I think it would be quite rare and a very small and insignificant contribution."
But another theory holds that more oil was in Earth from the beginning than what's been produced by dead animals, but that we've yet to tap it.
How it works

In the leading theory, dead organic material accumulates on the bottom of oceans, riverbeds or swamps, mixing with mud and sand. Over time, more sediment piles on top and the resulting heat and pressure transforms the organic layer into a dark and waxy substance known as kerogen.
Left alone, the kerogen molecules eventually crack, breaking up into shorter and lighter molecules composed almost solely of carbon and hydrogen atoms. Depending on how liquid or gaseous this mixture is, it will turn into either petroleum or natural gas.
So how long does this process take?
Scientists aren't really sure, but they figure it's probably on the order of hundreds of thousands of years.
"It's certainly not an instantaneous process," Thomas told LiveScience. "The rate at which petroleum is forming is not going to be the solution to our petroleum supplies."
The United States' latest reminder of its petroleum dependency occurred when hurricanes Katrina and Rita struck the Gulf of Mexico, where the majority of the country's oil platforms and refineries are located. Many analysts predicted gas prices would surge to $4 and $5 per gallon, but the fears turned out to be overblown. Many of the structures suffered only glancing blows and were operating again soon afterwards.
Still, the average price of regular gas nationwide is about $2.94 a gallon now, according to the American Automobile Association. It was $1.77 at the beginning of the year.
Alternative source
The idea that petroleum is formed from dead organic matter is known as the "biogenic theory" of petroleum formation and was first proposed by a Russian scientist almost 250 years ago.
In the 1950's, however, a few Russian scientists began questioning this traditional view and proposed instead that petroleum could form naturally deep inside the Earth.
This so-called "abiogenic" petroleum might seep upward through cracks formed by asteroid impacts to form underground pools, according to one hypothesis. Some geologists have suggested probing ancient impact craters in the search for oil.
Abiogenic sources of oil have been found, but never in commercially profitable amounts. The controversy isn't over whether naturally forming oil reserves exist, said Larry Nation of the American Association of Petroleum Geologists. It's over how much they contribute to Earth's overall reserves and how much time and effort geologists should devote to seeking them out.
If abiogenic petroleum sources are indeed found to be abundant, it would mean Earth contains vast reserves of untapped petroleum and, since other rocky objects formed from the same raw material as Earth, that crude oil might exist on other planets or moons in the solar system, scientists say.
Both processes for making petroleum likely require thousands of years. Even if Earth does contain far more oil than currently thought, it's inevitable that reserves will one day run out. Scientists disagree sharply, however, on when that will occur. And, some say, a global crisis could begin as soon as increasing demand is greater than supply, a possibility that might be measured in years rather than decades, some analysts argue.

 http://www.livescience.com/environment/051011_oil_origins.html

NOx

Nitrogen oxides - Formation and Relevance

Nitrogen oxides play an important role in atmospheric processes. How are they formed, why are they important?

 

1. Traffic - still an important source of nitrogen oxides.(c) FreeFoto.com

Where do nitrogen oxides come from?

The most important nitrogen oxides are nitrogen monoxide NO and nitrogen dioxide NO₂. Both together are called NO_x. The nitrogen molecules (N₂) in the air are very stable and it is not easy to oxidise them. A few bacteria have developed special mechanisms to crack the N-N triple bond and to form oxidised compounds. But by far more relevant are processes where the bonding is cracked by heat. This can only happen under extreme conditions. One example is during the combustion of fuel in a car engine. Most anthropogenic (= human made) NO_x comes from this source. It can also happen during other very hot reactions, e.g. in the hottest parts of biomass burning flames. Finally lightning is a major source. In the flash channel temperatures reach up to 30,000 degrees Celsius and easily crack nitrogen bonds.

2. right: Lightning is another important source of nitrogen oxides.
picture by Bernhard Mühr  Karlsruher Wolkenatlas

 Where are they involved?

We find NO_x (= NO + NO₂) and other nitrogen oxides nearly everywhere in atmospheric chemistry. During the night, nitrate radicals NO₃ are formed and are the most active oxidants. Radicals are chemical species, which are very instable and usually react extremely fast.
If N₂O₅ is formed in polluted areas, it can react on droplets or wet surfaces with water and nitric acid HNO₃ is formed. HNO₃ contributes to the acid character of the rain. Nitric acid, which can also be formed during the day by oxidation of NO₂, is the main way how nitrogen oxides are removed again from the atmosphere, either by dry or by wet deposition (wash out by rain).
Nitric acid is also part of polar stratospheric clouds. Nitric acid tryhydrate forms the particles on which the ozone hole developed (details in 'Higher atmosphere - More - Unit 2').

Where do nitrogen oxides come from? The most important nitrogen oxides are nitrogen monoxide NO and nitrogen dioxide NO2. Both together are called NOx. The nitrogen molecules (N2) in the air are very stable and it is not easy to oxidise them. A few bacteria have developed special mechanisms to crack the N-N triple bond and to form oxidised compounds. But by far more relevant are processes where the bonding is cracked by heat. This can only happen under extreme conditions. One example is during the combustion of fuel in a car engine. Most anthropogenic (= human made) NOx comes from this source. It can also happen during other very hot reactions, e.g. in the hottest parts of biomass burning flames. Finally lightning is a major source. In the flash channel temperatures reach up to 30,000 degrees Celsius and easily crack nitrogen bonds. 2. right: Lightning is another important source of nitrogen oxides. picture by Bernhard Mühr  Karlsruher Wolkenatlas

3. Where are nitrogen oxides involved in atmospheric processes? The scheme gives a little (not complete) overview of important processes in atmospheric chemistry. Please click the scheme to enlarge! (100 K) by Elmar Uherek for ESPERE

Where are they involved? We find NOx (= NO + NO2) and other nitrogen oxides nearly everywhere in atmospheric chemistry. During the night, nitrate radicals NO3 are formed and are the most active oxidants. Radicals are chemical species, which are very instable and usually react extremely fast. If N2O5 is formed in polluted areas, it can react on droplets or wet surfaces with water and nitric acid HNO3 is formed. HNO3 contributes to the acid character of the rain. Nitric acid, which can also be formed during the day by oxidation of NO2, is the main way how nitrogen oxides are removed again from the atmosphere, either by dry or by wet deposition (wash out by rain). Nitric acid is also part of polar stratospheric clouds. Nitric acid tryhydrate forms the particles on which the ozone hole developed (details in 'Higher atmosphere - More - Unit 2').

Names of nitrogen compounds: Formula Systematic Name Common Name NO nitrogen monoxide nitric oxide N2O dinitrogen monoxide nitrous oxide NO2 nitrogen dioxide nitrogen peroxide N2O5 dinitrogen pentoxide nitric anhydride N2O3 dinitrogen trioxide nitrous anhydride HNO3  - nitric acid NH3  - ammonia

Nitrogen oxides as gases are very important for the formation and degradation of tropospheric ozone, because they are involved in catalytic cycles. This is mainly, because NO₂ can be photolysed by the sunlight. It forms NO and this NO is oxidised again to NO₂. Ozone as well as organic peroxi-radicals (instable oxidised compounds) can be involved in this cycle as we see in detail in the next text.
The main reason for the invention of the catalytic converter for cars was, to avoid strong emissions of nitrogen oxides. We emit too much of them in combustion processes, especially in cars, and disturb the equilibrium in the air.
Nitrous oxide N₂O is formed for example by baceteria in so called degradation processes. The microbiology of such tiny living organism plays a big role in the nitrogen cycle. But N₂O does not react in the troposphere. It goes directly to the stratosphere, where it is split by sunlight (photolysed).
Ammonia NH₃ is the most important basic gas in the atmosphere. Coming e.g. from livestock farming and fertilization, but also from microbiological degradation (bacteria), it can form salt particles of NH₄NO₃ together with nitric acid.

Nitrogen oxides at the crossways of atmospheric chemistry

Even if we do not have a closer look on nitrogen oxide chemistry, we can keep in mind, that these compounds are a little bit the heart of atmospheric chemistry. A major part of the chemical compounds, which are oxidised and removed from the atmosphere or transformed into other compounds come into touch directly or indirectly with NO or NO₂.

4. Nitrogen oxides - in the centre of atmospheric chemistry
image: Elmar Uherek

 

Related pages:
Nitrate radicals play a special role at night. Read more about it in:
Lower atmosphere - More - Unit 1 - Night and nitrate
You find further information about the chemistry of nitrogen oxides in the ozone hole at:
Higher atmosphere - More - Unit 2 - Chlorine chemistry

 

Oxides of Nitrogen

Nitrogen gas, normally relatively inert (unreactive), comprises about 80% of the air. At high temperatures and under certain other conditions it can combine with oxygen in the air, forming several different gaseous compounds collectively called oxides of nitrogen (NO_x). Nitric oxide (NO) and nitrogen dioxide (NO₂ - the criteria pollutant) are the two most important.

Sources

Major sources of nitrogen oxides include

• Fuel combustion in power plants and automobiles.
• Processes used in chemical plants.

Health Effects

Certain members of this group of pollutants, especially nitrogen dioxide (NO₂), are known to be highly toxic to various animals as well as to humans. High levels may be fatal, while lower levels affect the delicate structure of lung tissue. In experimental animals this leads to a lung disease that resembles emphysema in humans. As with ozone, long-term exposure to nitrogen oxides makes animals more susceptible to respiratory infections. Nitrogen dioxide exposure lowers the resistance of animals to such diseases as pneumonia and influenza. Humans exposed to high concentrations suffer lung irritation and potentially lung damage. Increased respiratory disease has been associated with lower level exposures.
The human health effects of exposure to nitrogen oxides, such as nitrogen dioxide, are similar to those of ozone. These effects may include:

• Short-term exposure at concentrations greater than 3 parts per million (ppm) can measurably decrease lung function.
• Concentrations less than 3 ppm can irritate lungs.
• Concentrations as low as 0.1 ppm cause lung irritation and measurable decreases in lung function in asthmatics.
• Long-term lower level exposures can destroy lung tissue, leading to emphysema.

Children may also be especially sensitive to the effects of nitrogen oxides.

Other Effects

Oxides of nitrogen also can:

• Seriously injure vegetation at certain concentrations. Effects include:
  • Bleaching or killing plant tissue.
  • Causing leaves to fall.
  • Reducing growth rate.
• Deteriorate fabrics and fade dyes.
• Corrode metals (due to nitrate salts formed from nitrogen oxides).
• Reduce visibility.

Oxides of nitrogen, in the presence of sunlight, can also react with hydrocarbons, forming photochemical oxidants, as discussed in the section on ozone. Also, NO_x is a precursor to acidic precipitation, which may affect both terrestrial and aquatic ecosystems.

http://dnr.wi.gov/air/aq/pollutant/oxides.htm