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Summer 2013 Blog - Chun Man Chow

Chun Man Chow is spending ten weeks in Kolkata, India working at the Gadgil Lab.

August 4, 2013


Environmental Engineering Division at Jadavpur University.

Time really flies! My time here in Kolkata is coming to an end, with only a few days left for me to finish up the experiments, absorb the Indian culture as much as I can, and eat all those Bengali sweets. Living in Kolkata is really enlightening and humbling, as the contrast between the wealthy and the poor jumps right in my face as I tread through the streets, but the friendliness of the people and the smiles on their faces make the city a welcoming place to stay. I will definitely miss the people at Jadavpur University and Dhopdopi school, the man at the to-go place who can mass-produce hundreds of rotis with his bare hands in half an hour, and the traffic noise in the background—the non-stop honking of cars, rickshaws, and motorcycles and the barking stray dogs.

Looking back at the past few months, I have really learned a lot in the lab, in the field, and about an unfamiliar living environment. Although a lot of areas related to electrocoagulation still invite further investigation, I hope that the ECAR system can be implemented in the communities suffering from chronic arsenic poisoning soon so people can benefit from it. The last few weeks I have been involved in testing parameters that might affect plate passivation rate. In the early field tests of the prototype, we saw that there was extensive rust-build up on the iron electrodes that drove the electrolysis voltage up and resulted in a lower amount of iron generated over time. We discovered that switching polarity of the plates can slow down the passivation, though the optimum polarity change frequencies corresponding to different charge dosage rates are yet to be determined.

I have really enjoyed my time in India, and I have bonded really well with the ECAR team. The Cal Energy Corps program is definitely a rewarding experience and I can’t wait to hear more about all the other interns’ experiences at the Cal Energy Corps Symposium in the fall!
July 22, 2013


Chun Man working in the lab.

Hello from Kolkata! The monsoon season has arrived, the scorching heat has dissipated, and the days are cooler. The past few weeks have been pretty hectic, with times when we spent over 10 hours in the lab or in the field. The hard work has paid off though! Using the beaker-scale models as a proxy for the much larger ECAR prototype, we examined parameters that might change the rate of electrode passivation. We observed that the amount of iron generated tends to get lower and lower with time, and that polarity change at a low dosage rate can slow down the passivation in twelve hours, but we have yet to run experiments that go for days to understand the full long term effect. In addition, thicker plates produce more iron with a given charge loading compared to thin ones, though they still cannot reach the 95% of the theoretical faradaic iron concentration that was achievable at the Gadgil Lab at Berkeley. Since iron concentration is directly proportional to the amount of arsenic removed from the water, further analysis of the groundwater at the field is needed to deduce potential reasons for the lower amount of iron generated in the field. Furthermore, a program was written using Mathematica and Matlab for energy efficiency analysis to deduce the optimum inputs.

Working in India has taught me to be patient and resourceful. It takes quite some time to get to the field from the university, and there is only a limited amount of time we can work there. However, it is crucial to work in the field to get a better understanding of the actual environment where the ECAR system will be installed. The lack of instruments and distilled water here also makes me appreciate the research environment we have at Berkeley. It’s okay not to have spatulas, we can use screwdrivers instead. Not enough volumetric flasks for iron measurements? No problem, we just have to run the tests many times and clean everything in between before the day ends and the standards prepared degrades.

I have definitely learned a lot in the past weeks and I can’t believe there are only three weeks left before I have to go, but it’s all right because I’ll be sure to make the most out of the rest of my time here in India!
June 20, 2013

Namaste! As the days grows hotter, the hours in which I am drenched in water become longer and longer. Sweat beads glide from my forehead, down my neck, chest, and get absorbed by my poor T-shirt. Other times when the rain starts pouring down my poor T-shirt will get soaked again, but this time due to the grace of the showers from the sky. Despite the ever-changing weather, the ElectroChemical Arsenic Remediation (ECAR) team in Kolkata persists, and we’ve been making some progress! In the lab, we are trying to make a dewatering system that will reduce the water content of the sludge that results from the settling process of the arsenic-rust particles in order to maximize the amount of clean water we can get from the ECAR system.


Prototype of the dewatering system.

In addition to working in the lab at the Civil Engineering Department of Jadavpur University, I started visiting rural areas with my supervisor to do some field research and testing. To get to the site, we had to take a local train for forty minutes, switch to either an auto-rickshaw or man-powered rickshaw and ride for another thirty minutes, and then walk to Dhopdhopi School. There, we will did beaker scale experiments (instead of the large water tanks that will ultimately be used in communities) to look at the effect of electrode thickness on the arsenic removal ability of ECAR in varying charge dosing rates. The field study is important because we are using the actual contaminated groundwater as opposed to the arsenic-spiked water we use in the lab. The groundwater we are testing might differ in chemical composition and thus might result in slightly different results.

Apart from work, we travelled to Darjeeling in the Lesser Himalaya last weekend to get some fresh air in the mountains. Darjeeling is a nice city, about 600 km north of India, and from there we can see Kangchenjunga, the third highest peak in the world standing at 8586m. We woke up at 3 in the morning to travel to Tiger Hill to see the famous sunrise and Mt. Everest, but the weather let us down and all we could see was fog. Nevertheless, India is full of surprises and it’s definitely an eye-opening experience!


June 7, 2013


A street in India, nearby to where Chun Man is living.

The weather that greeted me when I first stepped out of the Kolkata (aka Calcutta) Airport wasn’t the expected immense heat that I’ve been hearing about, but the storm and rain and the extreme humidity that adds a layer of stickiness on top of the skin. There I met my supervisor, Siva, a wonderful, helpful, and friendly scholar whom I will be living with for the next 10 weeks at his apartment at the southern part of the city, which is some 15 minutes away from the research lab at Jadavpur University, and 45 minutes from the rural area that I will be working at.

Trying to understand how the traffic system works in India would be impossible: cars, auto-rickshaws, buses swirled around and zoomed past each other, honking constantly in chaos (but apparently there is a system to it). On the streets, I caught glimpses of people showering outside their houses as water gushed out of the pipes and stray dogs roaming around. Not so far away, though, modern buildings and malls seemed to spring out of nowhere in the midst of the common world.


Part of the ECAR (Electro-Chemical Arsenic Remediation) system.

The project I will be helping with this summer is called ECAR (Electro-Chemical Arsenic Remediation), a system developed by scientists and engineers at the Lawrence Berkeley National Laboratory. The model addresses the health problems faced by an estimated 60 million low income South Asians, particularly in Bangladesh and West Bengal by removing naturally occurring arsenic in groundwater, thus offering an inexpensive but effective way to provide clean water for consumption. Adverse effects of arsenic poisoning include skin lesions, cancer in the lungs, bladder, and kidneys, problems in the heart and reproduction system. ECAR involves the use of electrolysis and electrocoagulation—the oxidization of an iron electrode allows the formation hydrous ferric oxide that combines with the arsenic in the water to form flocs that can be removed from the water.

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