Efficient removal of contaminants like oil and toxic dyes from water sources is an issue of global importance. Oil spills can be devastating to both the environment and the economy because cleanup is costly and damage to the ecosystem is sometimes irreparable.

Marine oil spills are typically contained and removed using booms and skimmers, or chemicals are dumped into the water to break down the oil and speed up natural biodegradation — processes that can be expensive, time consuming, and not always 100 percent effective.

Toxic dyes — common water pollutants in the textile industry — tend to escape conventional wastewater treatment because of their chemical properties.

To address these problems, NYU Abu Dhabi scientists have come up with a new way to remove toxic contaminants from water they believe could be more efficient and less costly than current methods.

Dinesh Shetty, lead researcher and chemist at NYUAD, said CalP — a light brown powder — “offers a new way to remove toxins from water sources and can absorb up to seven times its weight of oil from an oil and water mixture.”

The basic material has been around for decades, he explained, but this is the first porous organic calix[4]arene-based polymer synthesized in the lab for the purpose of purifying water.

Inside the the Trabolsi Research Group chemistry lab in the Experimental Research Building at NYU Abu Dhabi.

CalP Explained

Ali Trabolsi, NYUAD assistant professor of chemistry, said CalP is able to remove “oil from water so efficiently, in just minutes, because it has several distinct properties:

• it floats, has high surface area, and low density;
• it has pores both from calix[4]arene cavity and hypercrosslinked 3D structure that collect toxins inside;
• the material is superhydrophobic which means it repels water and it has an excellent ability to absorb a range of pollutants.”

Lab experiments were conducted using two types of oil: used engine oil and commercial grade crude oil.

They have developed the first calix[4]arene based superhydrophobic, porous material that repels water and attracts oil and dye kind of like a sponge. They call it CalP.

It’s Reuseable

Another distinct quality of CalP is that it can be washed and reused to absorb oil products over and over again with the same efficiency, potentially reducing the cost of cleaning large oil spills.

“It’s an important part of our discovery,” said Ilma Jahovic, NYUAD chemistry major and student researcher, “because we found it was very easy to regenerate the material” even after it was soaked in oil or dye. “We did multiple cycles and its efficiency was maintained.”

“Other similar materials can be reused but require cleaning at high temperatures and it’s expensive,” she explained, whereas this material requires only mild washing with diethyl ether, ethanol, or a light acidic solution.

What’s Next?

The next step in the research is to improve the absorption efficiency of oil products even further, and find ways to make production cheaper. CalP could also be used to further other areas of petroleum research such as gas separation to make cleaner fuel, added Jahovic.

The material is not yet practical for cleaning large oil spills, she stressed, because “we are only at gram scale” in the lab environment.

This post is by Andy Gregory, NYUAD Public Affairs, and originally appeared here.

Designing meaningful experiments is a familiar challenge for scientists. In the fast-growing field of experimental social science, however, researchers may encounter difficulties quite different from those facing white-coated laboratory investigators.

As a member of NYU Abu Dhabi’s Social Science Experimental Laboratory (SSEL), Jonathan Rogers has been seeking a way around one such constraint. His approach may prove useful for scholars throughout the Middle East and North Africa (MENA), and beyond.

Rogers, political science instructor, explained that in social science, “experiments let us study human behavior by stripping interactions down to their basic components.”

For example, classic economic theory suggests that if you have $100 and are free to give some of it away, you’ll give nothing. But when experimental economists ask test subjects to play this “dictator game”, many do donate some money. This suggests that there can be a self-serving reason to donate; in the jargon, generosity gives you a “warm glow”.

Often these games involve risk and reward. In the Bomb Risk Elicitation Task (BRET) you face a grid of 100 boxes; each one you open pays $1, but one contains a “bomb” – if you open that one, you lose everything and the game ends. How many boxes would you open before you quit?

Other experiments are less simple. “If we want to study cooperation,” Rogers said, “we can put subjects in a situation where they only have the choice to either cooperate or not. Then we can change one aspect of the game and if we see different behavior, we can infer that the change caused that difference.”

Many games test risk tolerance: are people more likely to enter a lottery if the chance of winning is high but the prize is small, or vice versa?

Jonathan Rogers is working in Abu Dhabi to come up with ways to study social behaviors that are respectful of religious beliefs. Phillip Cheung / NYUAD

Such “risk elicitation mechanisms” are often “incentivized” – that is, test subjects can keep the small sums they may win. In other words, some games often involve gambling; others involve interest payments. This creates a problem for researchers in the MENA region: gambling and interest are both prohibited for Muslims.

In a paper now under review for publication Rogers tests a potential way around this difficulty: What if the reward goes to charity?

In 2014-15, 40 NYUAD student volunteers played the BRET game twice each, while 69 others played BRET and another game once each. Each student kept the winnings from one game; proceeds of the other were given by pre-arrangement to Operation Smile, a charity subsidizing surgery for children with facial deformities. Winnings averaged about AED 57, or $15.50 USD.

The results were clear: “Subject behavior under the two conditions is almost identical” Rogers’s paper reports. That’s good news, because it appears to mean that research done on this basis, among Islamic populations, can give useful results. “We still need to repeat this experiment with other subject pools, in different countries, and with different types of charities,” Rogers said. But this is a first step.

SSEL members, Rogers said, hope to “attract researchers who want to conduct studies in MENA countries … Academics want to study refugees, revolutionaries, people in developing countries, and attitudes toward extremist groups, but some of the tools that are considered standard in the West can come into conflict with cultures and norms in the places where these people live. If researchers break local customs, people may refuse to participate.”

“(But) If charitable incentives become accepted as an alternative for payments in risk experiments, maybe we can find a similar workaround for experiments about things like interest on investments.”

By Brian Kappler for NYUAD Public Affairs

This post originally appeared on the NYU Abu Dhabi Salaam blog and is available here.