earth – Anuja Sawant (Sarangdhar)

Climate change, Environmental Science & Technology

Is the earth adapting to climate change?

“Adapt or perish, now as ever, is nature’s inexorable imperative.” – H. G. Wells

Species adapting to their environment is not new to scientists. When a species fails to do so, it is doomed towards extinction is an accepted fact. In one of my blog posts called ‘Global warming? Think again.‘, I mentioned that a type of corals called the Gorgonian corals were flourishing with rise in ocean temperature.

Can the newly discovered life growing on plastic waste be considered another proof of adaptation? A whole new group of microscopic creatures has been found growing of the vast amount of discarded plastic floating in the world’s oceans, according to ABC.net.au. While that is no excuse for us to continue dumping plastic waste in oceans, it offers a fresh perspective on climate change.

It is possible that there might be many more species out there trying to adapt to climate change. As for humans, technology is on their side to help them sustain in such climatic conditions for now. It won’t be too long until we have to struggle for adaptation as well. Current technologies are under scrutiny as to whether they are sustainable to help us to sustain on this planet. Perhaps a rather unconventional route towards adaptation might lie in learning more about the ability of a Dutch world record holder, Wim Hof, commonly nicknamed the Iceman for his ability to withstand extreme cold.

Environmental Science & Technology, Water

Introducing, Ludwick Marishane.

I bet at least one of you who’s reading this hates to have a bath. Well, if not every time, SOMEDAY, you must have wanted to not bathe.

Ludwick Marishane, is the guy who invented water-less bathing lotion, just because he did not like to bathe. Sounds funny, but it has a potential to have profound implications in areas where water is scarce. For some of us, not wanting to bathe is an utter denial of luxury, but not for all.

Well, that is just not it, the lotion creates a biodegradable film that cleanses and moisturizes the skin. Go green!

See how he did it: Ludwick Marishane: A bath without water | Video on TED.com

Environmental Science & Technology

Why do we waste so much?

“You should eat everything that is served in your plate! Don’t waste anything.”, said my mother and she has been saying it ever since I was an infant. Many of us can relate to this in one form or the other, from one person or the other.

Ever wondered why we waste so much? Why do we waste food, water or anything for that matter? Is it something innate to us? What could possibly be the psychology behind such a behavior?

When I was about 20 years old, I heard a yoga instructor say, “Your stomach is not a garbage bin, if you don’t need it, don’t push it inside you, do not eat it. You are causing more harm that good.” She was right, in a way. Only problem I think with this piece of advice is that it needed an iteration of the question ‘why?’ Why did we feel obligated to not waste food? Why is it morally right to not waste food? If we have to waste food, why do we harm our own bodies for being morally right? Why do we create so much food needlessly? What do we think when we do all this?

My main point was that our perception of waste is relative to our experience of scarcity, and for most of us, things like water, food and energy do not feel scarce, even though, taken globally, they are. In so far as there is a solution, it may lie in simulating the experience of scarcity. I do this incidentally once a year when I visit my in-laws in India, where I learn to live with water shortages and power cuts, even in a relatively developed and affluent part of one of their main cities, Bangalore. – Jonathan Rowson, RSAblogs

Did this ever happen to you? Did you ever experience scarcity? I have. We had a 24 hour water supply for a few days, when I moved to a new place. The new society was yet to have a good foundation of rules. After our society was fully populated, new rules were made. Water was then only supplied for two hours, one hour each, morning and evening. We felt the scarcity. It was uncomfortable. We bought new storage tanks to store water. My mother made sure that nobody wasted water in the house. She’s been always the same, she must have experienced scarcity long back but we, the ones who have not ever lived in a world like she has, do not know of scarcity but we are experiencing it now. She always coaxed me into building things from waste, to save resources. She, like many mothers or people alike out there have continued this legacy, for the good.

A layperson may ask, “We have so much water in the oceans, then why do people say ‘Save Water’?

Everyday, something or the other strengthens my belief in this quote from the movie The Day The Earth Stood Still: “People change at the precipice.”

“Fifty-four percent of the world’s food wastage occurs “upstream” during production, post-harvest handling and storage, according to FAO’s study. Forty-six percent of it happens “downstream,” at the processing, distribution and consumption stages.”

Climate change, Environmental Science & Technology

Global warming? Think again.

“More water vapor enters the air as the planet warms, and this should amplify the CO2 -caused run-away heating except for one thing. Every now and again, the water vapor condenses into clouds, and then (sometimes) falls as rain or show. Clouds and snow reflect the incoming sunlight, and this leads to global cooling. Rain and snow drive water vapor from the air, and this leads to accelerated global cooling. To the extent that clouds are chaotic, and out of man’s control, the global climate should be chaotic too. So far, no one has a very good global model for cloud formation, or for rain and snowfall, but it’s well accepted that these phenomena are chaotic and self-similar (each part of a cloud looks like the whole). Clouds may also admit “the butterfly effect” where a butterfly in China can cause a hurricane in New Jersey if it flaps at the right time.” – Enlightening article, read more: http://www.rebresearch.com/blog/global-warming-takes-a-15-year-rest/

I mentioned something similar in one of my previous posts (Keeping an open mind, dated Feb 19, 2013). I said, “Global warming. It is safer to say you don’t know if it is happening than to be blindly sure that it is happening because everyone says so. Who’s to blame? Ineffective communication? I think I do not know much about it to come to a conclusion. When we talk about global warming, it is more of a global phenomenon. There are many problems that are common to all parts of the world, but not all of the problems, some of them need local care. Global warming is just a small part of the puzzle.”

When stony corals die and gorgonian corals flourish as the ocean warms up, when greenhouse emissions warm up the planet while particles; clouds and ice reflect the sun, I don’t know what to believe. Everything around us seems to be adapting or it is extinct and we are all in the same boat, so that applies to us too. So, all in all, I think green seems to be a good way to go about our current problems, especially pollution and waste.

Environmental Pollution Control, Notes, Water

Chemical treatment of wastewater

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“Pollution is nothing but the resources we are not harvesting. We allow them to disperse because we’ve been ignorant of their value.” – R. Buckminster Fuller

Chemicals are used during wastewater treatment in an array of processes to expedite disinfection. These chemical processes, which induce chemical reactions, are called chemical unit processes, and are used alongside biological and physical cleaning processes to achieve various water standards. There are several distinct chemical unit processes, including chemical coagulation, chemical precipitation, chemical oxidation and advanced oxidation, ion exchange, and chemical neutralization and stabilization, which can be applied to wastewater during cleaning.

Wastewater Chemical Treatment

Chemical Precipitation

Chemical precipitation is the most common method for removing dissolved metals from wastewater solution containing toxic metals. To convert the dissolved metals into solid particle form, a precipitation reagent is added to the mixture. A chemical reaction, triggered by the reagent, causes the dissolved metals to form solid particles. Filtration can then be used to remove the particles from the mixture. How well the process works is dependent upon the kind of metal present, the concentration of the metal, and the kind of reagent used. In hydroxide precipitation, a commonly used chemical precipitation process, calcium or sodium hydroxide is used as the reagent to create solid metal hydroxides. However, it can be difficult to create hydroxides from dissolved metal particles in wastewater because many wastewater solutions contain mixed metals.

Chemical Coagulation

This chemical process involves destabilizing wastewater particles so that they aggregate during chemical flocculation. Fine solid particles dispersed in wastewater carry negative electric surface charges (in their normal stable state), which prevent them from forming larger groups and settling. Chemical coagulation destabilizes these particles by introducing positively charged coagulants that then reduce the negative particles’ charge. Once the charge is reduced, the particles freely form larger groups. Next, an anionic flocculant is introduced to the mixture. Because the flocculant reacts against the positively charged mixture, it either neutralizes the particle groups or creates bridges between them to bind the particles into larger groups. After larger particle groups are formed, sedimentation can be used to remove the particles from the mixture.

e.g. Alum and ferric (or ferrous) sulphate are examples of inorganic coagulants.

The optimum pH for alum treatment is 6 to 7 while that for Iron(III)sulfate is 6 to11. Therefore if the pH of wastewater is say 8, we have to use the latter one or neutralize the wastewater to get the pH to 6 or 7 and then use alum, whatever works.

Chemical Oxidation and Advanced Oxidation

With the introduction of an oxidizing agent during chemical oxidation, electrons move from the oxidant to the pollutants in wastewater. The pollutants then undergo structural modification, becoming less destructive compounds. Alkaline chlorination uses chlorine as an oxidant against cyanide. However, alkaline chlorination as a chemical oxidation process can lead to the creation of toxic chlorinated compounds, and additional steps may be required. Advanced oxidation can help remove any organic compounds that are produced as a byproduct of chemical oxidation, through processes such as steam stripping, air stripping, or activated carbon adsorption.

Ion Exchange

When water is too hard, it is difficult to use to clean and often leaves a grey residue. (This is why clothing washed in hard water often retains a dingy tint.) An ion exchange process can be used to soften the water. Calcium and magnesium are common ions that lead to water hardness. To soften the water, positively charged sodium ions are introduced in the form of dissolved sodium chloride salt, or brine. Hard calcium and magnesium ions exchange places with sodium ions, and free sodium ions are simply released in the water. However, after softening a large amount of water, the softening solution may fill with excess calcium and magnesium ions, requiring the solution be recharged with sodium ions.

Chemical Stabilization

This process works in a similar fashion as chemical oxidation. Sludge is treated with a large amount of a given oxidant, such as chlorine. The introduction of the oxidant slows down the rate of biological growth within the sludge, and also helps deodorize the mixture. The water is then removed from the sludge. Hydrogen peroxide can also be used as an oxidant, and may be a more cost-effective choice.

Reference: Thomasnet

Environmental Pollution Control, Notes, Water

Biological treatment of wastewater

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“Don’t forget that the flavors of wine and cheese depend upon the types of infecting microorganisms.” – Martin H. Fischer

Biological treatment aka secondary treatment:

In wastewater treatment, the treatment process that follows primary treatment. It is used to remove the remaining organic solids that have not been removed in primary treatment together with the 90% or more of the dissolved organics. Aerobic biological treatment is commonly used. Secondary treatment may also incorporate nitrification and biological phosphorus removal.

Reference: Dictionary of waste and water management, Elsevier

Secondary treatment, usually biological, tries to remove the remaining dissolved or colloidal organic matter. Generally, the biodegradation of the pollutants is allowed to take place in a location where plenty of air can be supplied to the microorganisms. This promotes formation of the less offensive, oxidized products. Engineers try to design the capacity of the treatment units so that enough of the impurities will be removed to prevent significant oxygen demand in the receiving water after discharge.

There are two major types of biological treatment processes:

attached growth
suspended growth

In an attached growth process, the microorganisms grow on a surface, such as rock or plastic. Examples include open trickling filters, where the water is distributed over rocks and trickles down to underdrains, with air being supplied through vent pipes; enclosed biotowers, which are similar, but more likely to use shaped, plastic media instead of rocks; and so-called rotating biological contacters, or RBC’s, which consist of large, partially submerged discs which rotate continuously, so that the microorganisms growing on the disc’s surface are repeatedly being exposed alternately to the wastewater and to the air. The most common type of suspended growth process is the so-called activated sludge system. This type of system consists of two parts, an aeration tank and a settling tank, or clarifier. The aeration tank contains a “sludge” which is what could be best described as a “mixed microbial culture”, containing mostly bacteria, as well as protozoa, fungi, algae, etc. This sludge is constantly mixed and aerated either by compressed air bubblers located along the bottom, or by mechanical aerators on the surface. The wastewater to be treated enters the tank and mixes with the culture, which uses the organic compounds for growth– producing more microorganisms– and for respiration, which results mostly in the formation of carbon dioxide and water. The process can also be set up to provide biological removal of the nutrients nitrogen and phosphorus. Refer to Figure 1 for a simplified process flow sheet.

bio

Reference: Handbook of Waste water treatment technologies by Nicholas Cherimisinoff

Some people are rather skeptical when it comes to biological treatment. Here’s why:

Slow rate of treatment
Large volumes require more floor area
Often needs engineered microorganisms which translates into shelling out a lot of money