It's been a while...

It has been quite some time since I updated this blog. A lot has happened, but mostly we were waiting on supplies to be shipped to us and also our container was repaired (just in time for RAIN!).

Tonight I want to share a little bit about the beautiful country we are in. We have had some time to do some sightseeing while the system was shut down. We got to see one of SANAA's water treatment plants (these never get old - hopefully we'll get to see more before we leave!) and got to get outside of Tegucigalpa for a few day trips. Our UPi partners have been kind enough to show us a few of their favorite parts.

SANAA's "Los Laureles" Water Treatment Plant

While our container was being repaired (day 1 of repairs), we took a trip to one of the surface (river) water treatment plants that serves the Tegucigalpa area. I got my notes a little mixed up, but I think the plant supplies 25-30% of the City's drinking water needs. The plant first uses aeration followed by a combination of polymer and flocculant addition with settling tanks to remove turbidity (a measure of bacteria and other undesirable contaminants typical in surface water sources). The next step is a sand filter to further polish the water. Finally, the water is chlorinated prior to being delivered to customers.

We also got to see the water quality laboratory at this facility. This lab performs several analyses, ranging from conductivity (measure of salinity) and pH (measure of acidity), to dissolved constituents like calcium and arsenic, and microbiological contaminants (bacteria, viruses). We hope to be able to have SANAA analyze some of our samples, since shipping is expensive.

Aeration area is seen through the trees. When the reservoir is full, water falls by gravity. When it is lower, they pump to the top of the hill and water falls down.

Clarifying water using settling and filtration (after adding polymer & flocculant)

Dissolved metals analysis using ICP and AA in the SANAA laboratory

San Matías and Las Cascadas de (Rio?) Guaralalao
(We went to the one in Francisco Morazán Department)

(thanks Google for the map)

UPi had a party for its incoming students and we were invited to go. We had a chance to get just outside of Tegucigalpa and get some elevation and even see some waterfalls. The party was pretty neat. We got to eat goat (in taco form, of course!) and there was a lady making delicious pupusas. The incoming students and upperclassmen played a friendly soccer game and there were other fun things to do as well. We got to try our hand at archery (I was so much better at this in elementary and middle school!) and we even had a friendly (mostly) volleyball game.

Prior to the festivities, Ing. Luis Eveline took us to see some lovely waterfalls on the Rio Guaralalao. We had a great time walking around the area and got a few good pictures. The area is very serene and I could imagine escaping to this area regularly if I lived here. We saw a few small farms and evidence of gorgojo (bark beetles) in the forests. It was sad to see so many dead and dying trees, but the views were beautiful otherwise.

The brown areas are dead/dying trees related to Gorgojo

Las Cascadas (one of the views, at least)

Fresh baby corn from Ing. Luis' garden. He also had coffee, bananas, yuca, and a few others that I didn't write down). What a gorgeous location!

La Tigra National Park

(thanks Google for the map)

National Parks are some of my favorite places to visit. I am grateful to have access to beautiful National Parks in the US, so when we were offered a chance to see one of the parks in Honduras, I jumped at the opportunity (plus, we were still waiting on shipments...). We hiked the Bosque Nublado and La Cascada trails to get to the waterfalls, then back on La Cascada and an easier final portion on what I think was the Reales Minas trail. It was about 7 km (4.3 miles), but it had a lot of steep sections. Thankfully, there were plenty of rest stations. It rained on us for the hike back and it was cold, but fun!

My phone (and photography ability) just don't do this place justice. I'm including a group picture and a photo that I thought captured the essence of the cloudy day.

Bosque Nublado (cloud forest)

Group UTEP-UPi pic
(thanks to Clara's phone & a nice woman we met on the trail!)

Valle de Ángeles

(thanks Google for the map)

This is a fun little touristy area close to Tegucigalpa. Several UPi students, one professor (Prof. Sergio Handal), and Rusbel traveled for a short trip, as we were still waiting on deliveries. Clearing customs is always fun with international shipments. Clara and I liked it so much we came back a second time (with more money) since we had to leave early enough for the students to return to classes the first time.

On the first trip, we had pupusas and refrescas naturales (aguas frescas in El Paso/Cd. Juarez). The second time, I had nachos, which were very different from what I'm used to, but they were delicious! Clara had a craving for tacos al pastor. These were also different from what we're used to in the El Paso/Cd. Juarez area, but they looked tasty as well. Between the two trips we have nearly accomplished all of our souvenir shopping for friends and family back home.

The restaurant we went to (second trip) had a place to make your mark. Clara made sure that UPi and UTEP are represented (at least until they paint over it!)

The view from the restaurant. Very pretty here.

Sunday Drive to Comayagua and La Esperanza

(thanks Google for the map)

Chancellor Funes and Ing. Luis Eveline offered to take us to La Esperanza, where a fair had was held (oops, we missed it!) and Comayagua, where the oldest operating clock in Central America is located. Along the way, we saw beautiful vistas and even a few farms. And the food was delicious. We stopped outside of La Esperanza at a restaurant called Finca & Restaurante San Augustin and had fried tilapia and plantains. In Comayagua, we stopped and had these wonderful bean mixtures that are served in clay pots that are heated from below (I haven't learned what these are called yet, but will do so. These need to be in my life.) This was a long day, but was wonderful.

Group pic at lunch (photo credit: Clara Borrego)

Cathedral in main plaza in Comayagua. The clock is the oldest in Central America (and one of the oldest in the Americas, according to some accounts)

Cabbage and other crops being grown outside of La Esperanza

Clara and me in front of the valley outside of La Esperanza

We used some of our recovered salt!

Catching up on our progress - this is the third post from tonight. It's been a hectic week!

One of the great parts about having a high recovery system is that you don't produce much waste. This is also a challenge, at least when you have deadlines for reporting milestones, because you need to operate for several days to obtain enough fluid to test the evaporation system. In any case, we were able to operate the evaporation system for several days to determine what a preliminary capacity for evaporation of our ZDD waste stream. Even with more than double the capacity from what we had in El Paso, we are so far obtaining about a third of the evaporation rate. We are operating our pilot in what could be considered a challenging time of year. It has been mostly cloudy and occasionally rainy the last few weeks. We will try some additional enhancements over the next few weeks to see if we can improve the evaporation rate even further.

More troubleshooting and some thoughts on how to solve problems

In between our participation in two seminars/tours and waiting on container repairs, we have continued to operate our system and attempt to get data. Also, we had a final report due to our funding agency (USAID ) on August 15.

We are continuing to have problems related to the particulates from the Los Almendros well. Particles, like sand and other things, are common with wells. The Los Almendros well is able to produce much more flow than what our pilot needs, so we are cycling the well multiple times per day to fill a tank which feeds our system.Wells aren't normally cycled like this, or, if they are, a sand strainer is installed prior to a membrane system. We didn't know about the particles prior to our arrival, so we don't have this level of pre-treatment. The particles seem to be causing problems in our the RO/NF and EDM systems (here's a link describing our process if this is the first post you have read). We will need to change out our cartridge filters much more often than what is normally done with a brackish well water pilot. This is a fair amount of work and Clara and I, try as we might, just can't get the housings loose all the time.

Cartridge filters and evidence of particles from the well. From top left, going clockwise:
1-Clara and I trying to get the cartridge filter loose (failed). 2-Bottom cartridge filter vs new filter. 3. Three filters showing 1 week's worth of particle filtration, 2 day's worth of particle filtration, and a brand new filter for comparison. 4. sample of the water in the cartridge filter housing with particles rejected by the filter. 5. Scale and particles in the EDM feed manifold.

The high level of alkalinity (Wikipedia describes it pretty well) present in the Los Almendros well has caused precipitation to occur without acid pre-treatment or a lot of water for dilutions. In previous pilots with high alkalinity, acid pre-treatment or substantial dilutions to the concentrate stream were implemented to prevent scale. We have attempted to operate without both of these because increased dilutions reduce the overall recovery and the Desal Prize and piloting objectives prioritized less chemicals. However, sulfuric acid is a common chemical and is relatively easy to procure and use safely. The minimum recovery with dilutions alone will be determined in the coming weeks. Acid pre-treatment will also be attempted to show the maximum recovery possible.

Water samples from pilot. Having solids precipitate is uncommon from the UTEP team's experience (especially precipitation within 4-6 hours!)

The high level of silica and higher than expected rejection by the RO/NF is causing scale in the RO/NF. It is possible that the particles (possibly iron, or sand with iron) from the well are enhancing this problem. We will test operations with a silica bleed (send a partial stream of RO/NF reject to drain) to see if the problem is mitigated. We cleaned the RO/NF and installed a bleed on the RO/NF to test whether it will help with reducing scale buildup. We will attempt to identify the minimum waste flow to protect the RO/NF and estimate the additional evaporation capacity necessary to maintain the zero liquid discharge aspect of the system.

Our container will be repaired over the next few days, so we will have our system off. We expect to be up and running for the next several weeks and hope to have good news to report based off our findings thus far.

Final Training Session

It's been a week since I updated the blog. Time sure does fly! We have been very busy for the last week. I am going to spread the work out into several posts.

Making New Partnerships.
Chancellor Funes (UPi), me (UTEP), and Mr. Rodriguez (AHJASA)
(photo credit: Victoria Amador)

The third seminar was held on August 10 at UPi’s campus. Nine representatives from a combination of regional governmental agencies and a rural water organization called  the Asociación Hondureñas de Juntas Administradoras de Sistemas de Agua (AHJASA) attended. AHJASA is a rural water association that provides benefits such as training and equipment monitoring to its members in various communities in rural parts of Honduras. The representatives from AHJASA included Mr. Lenin Alberto Rodriguez, who works with rural communities. Mr. Rodriguez provided valuable information about the problems with salinity and access to clean water in the southern part of Honduras. The other AHJASA representatives were from member communities in Valle and Choluteca. Since this was the final presentation, UPi students were invited to learn about desalination and the USAID project. Eleven students attended the seminar. After lunch, all participants were transported to the UTEP-UPi pilot site for a tour and demonstration of the equipment.

Final Seminar Participants (photo credit: Victoria Amador)

Visiting the Los Almendros well and talking the AHJASA representatives

We were interviewed onsite - LIVE - during our tour. We were nervous and didn't know she was truly live. There's a joke about now, now, or later, later here. It's really funny watching this after the fact. I understand what I was asked and could have responded (in English, of course), but totally froze. Oh well, it's great that the Hoy Mismo came to learn about our project and I hope they (and others) will come back. We enjoyed meeting the reporter, Gabriela Castillo. Mr. Rusbel got volunteered to be the videographer (it is really amazing what you can do with a cell phone...) for this.

Here's what we wanted to say, English and Spanish (courtesy of Clara):

• The goal of the project is to demonstrate that our technology (called Zero Discharge Desalination) is capable of producing water for both irrigation and drinking purposes while having no liquid waste leave the site. We produce a useful solid byproduct (gypsum) which can be used by farmers to improve soil conditions and a liquid product (NaCl, or table salt) which is used by the technology.

• El objetivo del proyecto es demostrar que nuestra tecnología (llamada Desalinización con Descarga Cero) es capaz de producir agua para riego y potable ademas no deja residuos líquidos el sitio. Se recupera un subproducto sólido útil (yeso) que puede ser utilizado por los agricultores para mejorar las condiciones del suelo y un producto líquido (NaCl o sal de mesa) que utiliza la tecnología.

Fixing Pumps and Making a Video

We have kept our system off because we thought our container was going to be repaired. Since they will need to use grinders, which will make sparks, we want to keep our batteries from charging (and releasing hydrogen). The EDM also produces hydrogen when we are desalinating, so everything has to be off for the repairs. We have had miscommunication about timing, but hopefully we can operate for the rest of the week to obtain data for our final report to USAID.

I meant to include a picture earlier of Mr. Rusbel. Occasionally, Clara and I find something that we can't do without a little help. As I mentioned in my troubleshooting post, we needed to install cartridge filters with smaller pores to protect our membranes from particles from the well. Clara and I were able to get one replaced, but it was leaking. But, we couldn't get the other one replaced because we couldn't get the housing loose. Mr. Rusbel, with his characteristic smile, jumped right in and (with Clara's assistance) tightened the loose one and replaced the other. He's a great guy.

Mr. Rusbel & the cartridge filters (the bottom one is the one we couldn't remove without his help)
(Photo Credit: Clara Borrego)

So, what did we do today? Well, first, we performed surgery. Some of the previous problems with previous precipitation in the EDM feed ended up causing our pump to fail last night. The stack is operating fine, but the pump wouldn't pump. The scale (precipitated salts) were causing friction on the pump. These are really cool pumps, by the way. They have a magnetic drive, so there are very few moving parts. Another cool thing about them is that they use DC energy, so we can use power directly from the sun - no need to convert to AC power! This and other modifications reduced our electrical load by at least 33%. We took apart the pump and scrubbed off the scale. It's working like a champ now!

Before (left) and After (right) pictures of EDM pump

While waiting for the repair guys to arrive today, Jose Eveline (UPi student) came by to get some more footage for a video he is preparing for our UTEP-UPi project. He already has some footage of the system operating and today was slated for interviews. It was a lot of fun. Jose is also the one that took us to get coffee on our first weekend here in Tegucigalpa. 

How to get a shot with a short interviewee (haha!)
(Photo credit: Clara Borrego)

Clara, the sound engineer 

Clara, being filmed

Training Session #2

Time is surely passing by quickly!  Today was a day for training and meeting with contractors. (and a trip to the doctor for me...)

UPi this way!

One of the important goals of our project is to transfer knowledge to people in Honduras. Today we had the pleasure of giving a seminar and tour to local government officials in several agencies. We had representatives from SANAA (Servicio Autónomo Nacional de Acueductos y Alcantarillados), DGE (Dirección General de Energia), and DGA (Dirección General del Ambiente).  This means we had water and wastewater, energy, and environmental representatives - an excellent mixture for our discussions. Ing. Luis Eveline is great at putting together the right groups. 

We started the day at UPi to present on water quality (agriculture and drinking water), desalination as a potential source of water for Honduras farmers, and ended with a summary and discussion of the technology that we have brought to Tegucigalpa, Zero Discharge Desalination (ZDD). After some tasty snacks we hopped in a bus and drove to the pilot site. As expected, Mr. Rusbel knows the best ways to navigate a busy city! Everyone got to see the equipment and ask additional questions. A few of the SANAA folks are going to come back and visit when we are operating. After the pilot site, we drove back to UPi for lunch and presentation of certificates.

I love when people are genuinely excited about certificates. Here's a picture with me, Chancellor (Rectora) Carolina Funes (UPi), and another Victoria!
(Photo credit: Victoria Amador)

Here's our whole group, including Rectora Funes and Ing. Luis Eveline (front, right)
(Photo credit: Victoria Amador)

Visiting the Pilot Site
(Photo credit: Victoria Amador)

Zero Discharge Desalination with Salt Recovery & Enhanced Evaporation. Clara does almost all of the talking, since I am still learning Spanish. Occasionally, I am able to stumble through a few sentences.
(Photo credit: Victoria Amador)

The view from the second floor of UPi near the classroom we were using. It is open air and the colors are lovely at UPi.

More troubleshooting

Well, we had a few more setbacks, but we are still making progress. We have had trouble with our membrane systems and what we thought was scale (precipitation from dissolved constituents that are at high concentrations), but we weren't sure why it was happening - especially in the primary desalter (RO/NF; here's a link for a previous post if you haven't read it). I have double-checked calculations, so I was pretty stumped. Last night, after running all day, we made the decision to shut down because we had lost flow in the EDM feed. After inspecting equipment and tanks, we made some changes to cartridge filters on the brackish water feed (installed ones with smaller pores). Sometimes particles can increase the chance of precipitation, so hopefully we have solved the problem with new filters. We also removed and cleaned the EDM stack.

It turns out that we didn't quite have enough waste to run our evaporation system just yet. Having high recovery means that it takes days to produce enough waste to recover salts. But, we did operate for a few hours and Victoria got to learn how to track the progress by measuring each tank's water level, temperature, and conductivity.

Tomorrow we will test the system for a while tomorrow and are preparing for some more seminars and tours of the pilot system next week.

Piloting = Troubleshooting

Well, today was a mixed bag. We are having all of the usual challenges for a pilot just getting started. Every brackish water has a unique blend of dissolved constituents. You can try to estimate settings and operational checks, but a lot of pilot work involves trying something and seeing if it works. C'est la vie!

One of our flow sensors wasn't working fully in our system. Industrial Water Services really helped us out by taking calls, texts, and emails from me requesting assistance on how to troubleshoot the sensor and wiring. I had almost searched every possible loose wire when Victor stepped in. He has studied electronics and electrical systems - and he even brought his own screwdrivers (I need the really small ones - like the ones for fixing eyeglasses). After a few minutes of searching, he found a loose wire and reconnected it. We restarted the system and now the flow sensor is working! Victor has class in the afternoons so he normally doesn't get photographed. I thought it would be nice to post a picture of his success.

Successful wire hunting! (photo credit: Clara Borrego)

Clara and Mr. Rusbel finishing up on the RO/NF

After having a good start yesterday, we had to shut it down because we had precipitation in one of our EDM streams and our RO/NF (here's a link to a previous post in case you haven't read about our system yet). The RO/NF membranes had been installed since we were optimizing in El Paso. During the month-long journey to Tegucigalpa, some sulfate reducing bacteria (I'm basing this on the smell after we rinsed the membranes during startup) found a happy home. I kept the membranes in for the initial week because we have a very tight deadline for a funding milestone and the water quality was still acceptable. We replaced the RO and NF membranes (two of each) this morning and the system seems to be OK. We're still fine-tuning the operations. Today, Mr. Rusbel helped out with removal and re-installation of some of our flow monitoring equipment. He drives us around and shows us the city in between our apartment and the pilot (and grocery shipping, hardware stores, pharmacies, etc.). Many of the roads here are very windy and steep. And the traffic is absolutely nuts! I'm glad he drives!

Our system shut down automatically late tonight. We will investigate what happened tomorrow morning and hope to have the system operational again by the afternoon.

I like to end things on a good note. After nearly 24 hours of operation, we have finally accumulated enough of our EDM concentrate streams to start producing gypsum and recovering NaCl. We made a short video to document the occasion. One interesting thing to note is that we recorded the video at 6:30 pm here and we needed a flashlight to see the equipment clearly. The daylight hours are so different from El Paso!

Salt Recovery & Enhanced Evaporation (how we achieve zero liquid discharge)

This week (so far) we have focused on on the final piece of our technology: salt recovery and enhanced evaporation. As mentioned on an earlier blog, we can achieve up to 98% recovery and we are expecting at least 95% recovery. This means that there is 2-5% of the initial volume and all of the salts removed in the process leftover. Our plan is to mix our two EDM concentrate streams together. One is rich in calcium salts and the other is rich in sulfate salts. When mixed, calcium sulfate (gypsum) is precipitated and the remaining fluid contains sodium chloride (table salt). The gypsum can be used by farmers to mix into their soil and improve its quality (more calcium relative to sodium can increase water infiltration). The sodium chloride can be used in the ZDD system, but it needs to be concentrated first. To accomplish this step, we are using a deconstructed evaporative cooling system (those in the desert will recognize the media we are using). The solution is pumped to the top of six evaporative tank/media systems and water evaporates. Over time, the concentration will increase enough that we will be able to use the salt solution to minimize salt purchases. So, we will produce two water streams (irrigation and drinking water), a solid byproduct (gypsum), and a liquid byproduct (sodium chloride). No liquid waste will leave the site. Pretty neat, right? I'm including a few photographs and a video below.

Salt Recovery / Enhanced Evaporation System Installed in Tegucigalpa, Honduras (picture credit: Clara Borrego)

We finished with an all female team since Victor has class in the afternoons (picture credit: Clara Borrego)