WB 2015 – MSU Ecological Engineering in the Tropics

Costa Rica – MSU / UCR – December 26, 2015 – January 9, 2016

Dec. 27-28 – Dan

Daily Update

Sunday, December 27

The majority of the group arrived to Costa Rica on Saturday and spent the evening at the hotel in Alajuela, getting acquainted with each other and enjoying a delicious meal. On Sunday, we had breakfast at the hotel before embarking on our first journey. We stopped at the supermarket and a farmers market to view some of the local products before heading to downtown San Jose. First, we ate lunch at a local restaurant, which consisted of casados– a plate full of rice, beans, meat, fried plantains, potatoes, and a salad– and cas juice. Next, we walked over to the National Museum of Costa Rica, where were learned about the history and culture of Costa Rica, making connections to American culture and engineering. One piece of history that Costa Ricans take much pride in is that Costa Rica abolished its army in 1948 (2). They also highly value their biodiversity, with a massive focus on engineering and living sustainably.


Several members of the group walk through a farmer’s market in Alajuela, checking out the local produce including avocados, bananas, mangoes, and papaya. Photo by Charlie Pynnonen (2015).


Several members of the group walk through a farmer’s market in Alajuela, checking out the local produce including avocados, bananas, mangoes, and papaya. Photo by Charlie Pynnonen (2015).

After walking around downtown San Jose for a while, we proceeded for the event of the evening– a bullfight! The final members of the group had arrived in the afternoon and were able to meet us at the fight. The atmosphere was incredible, with lots of audience engagement. There were many activities as part of the bull fight, ranging from bull riding to competitions to capture a ribbon or cloth pinned onto the bull, including a special portion of the fight dedicated to the cowgirls. We were thrilled to experience this cultural event and learn about a sport unfamiliar to many of us. What an awesome way to cap off our first day in the country!


Live action at the bullfight, “Toros a la Tica!” Challengers attempt to grab the ribbon from the bull’s right shoulder. The winner from this competition and all the others were entered into a drawing to win a motorcycle. Photo by Daniel Buhr (2015).

Monday, December 28

In the morning, the students and faculty made the short trip over to Fabio Research Station to tour the anaerobic digester, constructed treatment wetland, laboratory, and walking trails. First, we saw the solar panels that heat water before it enters into the storage tank as a means of helping maintain the temperature of the thermophilic digester at 50C, the typical temperature of these that is high enough to kill pathogens (4). Water from the storage tank is mixed with a feedstock of chicken litter (80%) and food waste like pineapple and cucumbers (20%) as it enters the anaerobic digester. It is important to diversify the feedstock to provide the optimal nutrients for the microbes in the digester. The reactor is operated as a fed-batch mixed reactor, meaning feedstock is added in increments and the liquid is agitated by a pump. Gas produced by the microbial activity is captured, and the useful gases like methane (CH4) and carbon dioxide (CO2) to run generators to produce electricity for the system while harmful gases like hydrogen sulfide (H2S) is burned off. (3) One team project is focused on reducing the amount of H2S produced by the anaerobic digestion system.


Solar panels that are used to heat water to keep the anaerobic digester operating at a thermophilic temperature of around 47-50C, high enough to kill most pathogens. Photo by Daniel Buhr (2015).


A photo of the anaerobic digester showing the green storage tank and the large gray anaerobic digester (20 cubic meters). The biogas collection ball is behind the digester. Photo by Daniel Buhr (2015).











Next, we learned about the constructed treatment wetland system, which receives water from the anaerobic digester that has had solids removed and settled out. There are four cells through which the wastewater moves through as it is treated. The first cell is a sand filter through which water percolates and solids are removed. Water then flows to a vertical flow wetland where is passed vertically through a matrix of plants like iris, papyrus, and canna indica. Solids are captured on a geotextile to reduce clogging, and the water can be reapplied several times at the expense of losing some to evaporation. The next wetland cell is full of plants like water hyacinth and water lettuce on floating mats. These plants are also used in the final cell, except without the mats. The biggest issue with these last two cells is harvesting the vegetation for use and to allow the remaining plants to thrive. (5) This topic of constructed wetlands was very helpful toward both my individual project and the team project focused on reducing harvesting labor and time requirements (much more on this in other posts).


Dr. Reinhold explains the details of the constructed treatment wetlands to some of the students. Each cell is 100 square meters. Photo by Daniel Buhr (2015).

We finished out the tour at Fabio by walking around the facility and seeing and trying many of the local fruits before taking a quick look at the laboratory. The importance of sustainability to Costa Rica was quite apparent after the Fabio tour. We learned that in 2015, Costa Rica pulled 99% of its energy from renewable sources (1). The anaerobic digestion and treatment wetland system can reduce landfill waste and purify water almost entirely using solar energy or electricity that the system produces itself (6). When walking around the facility and seeing the amazing biodiversity of fruits that many of us take for granted, such as bananas, mangoes, and tangerines, it was easy to understand why Costa Rica would want to push sustainability in an effort to protect this biodiversity. On the road from Alajuela to Tilaran, we made two stops for lunch and ice cream. Once in Tilaran, we were free to explore the small city.

Related links:

General information on Alajuela and San Jose

Costa Rican biodiversity information

Costa Rica history timeline

Fun facts about Costa Rica

Information on Costa Rica abolishing their army

Costa Rican bullfighting

General explanation of anaerobic digestion, note temperature classifications

Constructed wetlands information, from Purdue University

Introductory information for Tilaran


(1) Agence France-Passe. (2015, December). Costa Rica Boasts 99% Renewable Energy in 2015. Retrieved December 30, 2015, from http://phys.org/news/2015-12-costa-rica-renewable-energy.html.

(2) Gonzalez Sanz, M. A. (2014, December). Costa Rica celebrates 66th anniversary of the abolition of its army. The Tico Times News.

(3) Liao, W. (2015, December). Anaerobic Digestion Discussion. Lecture at Ecological Engineering in the Tropics Study Abroad in Costa Rica.

(4) Moset, V., Bertolini, E., Cerisuelo, A., Cambra, M., Olmos, A., & Cambra-López, M. (2014). Start-up strategies for thermophilic anaerobic digestion of pig manure. Energy, 74, 389-395.

(5) Reinhold, D. (2015, December). Wetland Discussion. Lecture at Ecological Engineering in the Tropics Study Abroad in Costa Rica.

(6) Rodriguez, W. (2015, December) Fabio Research Facility Tour. Conversation at Ecological Engineering in the Tropics Study Abroad in Costa Rica.

Pre-trip Information

Sunday, December 27– San Jose and Alajuela

San Jose is the capital city of Costa Rica and also the most populous. It is located near the center of the country and is a bustling place. For information about the city and some activities, please follow this link: http://www.anywherecostarica.com/destinations/san-jose.


Map of Costa Rica featuring San Jose and Alajuela, from http://www.mapsofworld.com/costa-rica/.

Weather: 86F/72F, 10-15 mph winds, 20% chance precipitation

In the morning, we will be discussing the value of biodiversity on both a micro and a macro scale during a tour at the National Biodiversity Institute (INBio). Due to the extreme biological wealth found in Costa Rica, many organizations and facilities have been created to regulate and study the country’s natural resources. Founded in 1989, INBio is a private, non-profit research center near San Jose that studies ways to conserve biodiversity and enhance the quality of life for humans. INBio has received many awards for its contributions to sustainability and conservation in Costa Rica. While there, students will find an inventory of more than 3 million arthropods, mollusks, fungi, and plants. There are several ongoing projects involving chemical substances and genes found in these specimens, which have useful implications for food, agriculture, and other industries. More information about INBio can be found at its official website, http://www.inbio.ac.cr/en/.

After lunch, we will be visiting the National Museum of Costa Rica to learn about local culture. The museum was first founded in 1887 as a place to collect the country’s natural and artistic artifacts. It has been housed in four different establishments, including its current location in the Bellavista Headquarters in San Jose. There are many exhibits showcasing historical collections of everyday objects like furniture and personal artifacts and scientific objects. The barracks and old historical buildings are also on site and available for touring. During our visit, we will focus on how culture is incorporated into engineering. More information on the museum can be found at http://www.museocostarica.go.cr.

We will be spending the night in Costa Rica’s second-largest city– Alajuela, the same location as the previous night. Alajuela has the Rio Celeste waterfall (see below), Poas Volcano, Central Park, and coffee tours. Follow several of the links below for more information on activities in Alajuela.


Photo of the Rio Celeste waterfall, from http://www.riocelestehideaway.com/.

Top Restaurants, including the #1 recommended, Jalapenos Central, a Mexican restaurant: http://www.tripadvisor.com/Restaurants-g309224-Alajuela_Province_of_Alajuela.html

Poas Volcano National Park hiking and walking trails http://costa-rica-guide.com/nature/national-parks/poas-volcano/

Shopping at Central Market or Souvenir Museum Verdes and Colones. Other top activities include a zoo, coffee tours, and the La Paz waterfall. See below: http://costarica.com/destinations/alajuela/attractions/

Monday, December 28– Alajuela and Tilaran

Alajuela Weather: 85/71F with afternoon showers

Tilaran Weather: 80/70F with a chance of evening rain showers

During the morning, we will be touring Fabio, a research station in Alajuela affiliated with the University of Costa Rica. While there, we will see some of their natural resources-related projects, highlighted by the anaerobic digester and treatment wetland. There will be a detailed discussion about the facility in general and an introduction to our team projects. The website for Fabio is: http://eefb.ucr.ac.cr

Afterward, we will be traveling north to Tilaran, a 3-4 hour drive depending on traffic. Tilaran is a small town of about 2,500 people, located in the hills along the western shore of Lake Arenal. It is a fantastic location for outdoor activities like rafting, hiking, and especially windsurfing.


Map showing Tilaran in relation to Lake Arenal and Arenal Volcano, from http://www.govisitcostarica.com.

For more information on Tilaran regarding activities and restaurants, visit these websites:

Tilaran information and activities: http://www.govisitcostarica.com/region/city.asp?cID=63

Tilaran general information: https://en.wikipedia.org/wiki/Tilarán

Top local restaurants: http://www.tripadvisor.com/Restaurants-g315766-Tilaran_Province_of_Guanacaste.html


11 thoughts on “Dec. 27-28 – Dan

  1. In what ways does culture affect engineering?


    • In the case of Costa Rica, culture can positively affect engineering because the vast majority of the population has adopted new technologies for renewable energy production, with the main purpose of conserving the environment and get economic sustainability. This is because the population has always shown respect for the environment.


  2. What percentage of the Costa Rican population resides in San Jose and Alajuela? How do you think urban development impacts sustainability?

    Liked by 1 person

    • I believe that Juan Francisco said that 75% of Costa Rica’s population is in San Jose and Alajuela. However, using data from the 2011 Costa Rican Census, I calculated that the populations in the provinces of San Jose (1.4 million) and Alajuela (850,000) made up approximately 48% of the total population in Costa Rica of 4.65 million (1). The population distribution certainly could have changed in the past four years, but this estimate seems reasonably close.

      One way in which urban development impacts sustainability because there is an increased strain on resources in a concentrated area. As cities expand in both size and density, the available resources are used more frequently, making the call for sustainable practices increase. It becomes more important to integrate sustainability into the systems for food and energy production, as well as human-based aspects of the water cycle. We learned that Costa Rica has an alarmingly high number of home septic tank systems, despite the construction of wastewater treatment plants. Both wastewater and surface runoff must be managed properly to reduce their impacts on local water bodies. Sometimes this water directly enters rivers or oceans and has quite a detrimental impact on the local watershed. To meet the increased food and energy demands in a region, these resources must be produced more sustainably in order to not only meet the demands but make the resources available. One way that food is sustainably provided to the urban areas is through farmers market containing products from locally grown farms. By having local farmers sell their produce, this helps to meet the needs for food and also stimulate the economy in the region, all while producing food in a sustainable way.

      This is just one explanation for how urban development impacts sustainability, specifically in Costa Rica.

      (1) El Instituto Nacional de Estadística y Censos. (2011). Cierre de oficinas. Retrieved 2015, from http://www.inec.go.cr/Web/Home/pagPrincipal.aspx


  3. Thanks for the update Dan. Hope you are finding enough to eat there–sustainably!
    Was the bull killed at the end of the fight like those in Spain?
    Take care, Dad


  4. Dan, good update to your daily page.


  5. Culture can have a great effect on engineering, from my perspective. A solution may be cost effective or efficient, but that does not guarantee it will be popular or fit in with local culture. Unfortunately, public opinion plays a large role in the allocation of resources (i.e. money and manpower) which can be withheld if the public receives the solution as culturally unacceptable. An example of this would be residents of northern Michigan protesting wind turbine development because they are simply, “different,” or “ugly.”

    Great post, Dan!

    Liked by 1 person

  6. Lauren, from your perspective as an urban planning student, what did you observe as to the sustainability of San Jose and Alajuela?


  7. Dan, from a heat transfer standpoint do we know if glycol has been considered for use in the solar water heaters? One of the major drawbacks to using a glycol/water mixture is that it typically requires more pumping force to draw through the circulating system. However, at Fabio the temperatures are high enough that I believe they would be able to significantly lower the viscosity to a point where this would not be an issue. Using glycol in the circulating fluid would reduce the heat transfer coefficient and allow for more effective heat transfer.

    Furthermore, the heat collection system is separate from the system that heats the digester, so adding in glycol would only affect the heat collection system and nothing else. At the very least, it would be very easy to test the effects of adding glycol to the system and see how it affects the ability to collect and transfer heat.

    I would like to bring these points up when we return to Fabio in the next few days. If anyone has any additional thoughts, please feel free to let me know.



    • Charlie, you bring up a valid point about using glycol in the solar panels. Although, I haven’t taken a heat transfer course yet, I do remember learning that it is commonly used for solar panels in a more temperate climate such as ours in Michigan. In the case of Fabio, where the weather is much warmer and solar radiation consistently higher than in Michigan, glycol probably does not offer many more benefits than water does. Water probably works just as well as glycol and is more readily available and potentially more sustainable to cycle throughout the system. If the solar panels were in a different climate, you would likely be correct in assuming glycol is an excellent working fluid, but it brings an unnecessary cost at this point.


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