OSC Recycling & Sustainability Service Group

A reflective blog exploring recycling & sustainability initiatives at the Overseas School of Colombo

Archive for April 2019

Catching a Flame: Biogas Explorations Part II

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Biogas_Temp_Measurement_4(MR)(04_19)

First flame: burning biogas and heating a liter of water. One of the first trials by the Class of 2020 ES&S class.

Sri Lanka is experiencing significant challenges with a power deficit in the last month and the outlook does not look good into the foreseeable future. There are now scheduled blackouts of about 4-5 hours in most parts of Sri Lanka every working day (see article below for analysis on cause and consequences). Meanwhile at OSC we are making slow progress with our school biogas plant. This system was installed in October it has taken a while to be fully functioning. In the first month of April 2019 we made the first successful trials of heating water using a stove and gas from the tank.

Though the system was installed in October 2018, it took several months to get the anaerobic bacteria charged inside the digester. To enable this, we fed the system with fresh cow dung every 2-3 days.  Team from OSC’s maintenance department was put in charge of feeding it regularly. Unfortunately, the biogas plant was unintentionally neglected over the winter holidays and we had to start all over again in January. It is a reminder of the importance of maintaining and being consistent with the inputs int the system.

The problem that we have had at the beginning stages of the biogas plant was controlling the CO2 levels. The inputs were almost all cow dung (with no food waste) but our outputs were high in CO2 and relatively low in methane (CH4). We attempted to measure samples of the gas with the Vernier CO2 gas sensor/probe. However, every attempt to monitor the CO2 showed very high readings that were off the charts (@ 10,022 ppm). After many failed attempts we were advised by Sunil to keep giving it cow dung.

We finally got a flame at the end of March. At, first after putting a match to the burner, we were unaware that the gas was lit. However, we tried putting some paper over the burner and it lit (see linked video)! The gas has an odor but when burnt this goes away. Since the first firing we have been heating up a liter of water and recording data every 2-3 days. It takes the biogas tank about 72 hours to digest and produce enough gas. At this stage the inputs are being controlled by maintenance and we need to get better data on their additions (both in quantity and quality and frequency). We will start adding food waste to the system after returning from our April break.

 

FIRST BURN_ HEATING A LITER OF WATER WITH BIOGAS (TEMPERATURE CHANGE AND FLOAT HEIGHT) (2)

Data recorded on first run of the OSC biogas plant on 1 April 2019. Data recorded and processed by the OSC ES&S Class of 2020 (Nehe & Shivani) with input from their teacher.

REFERENCES & FURTHER READING

Lanka Biogas. Web.

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Written by ianlockwood

2019-04-09 at 2:36 PM

Visits to the Pelawatte Scrap Dealer

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Class of 2020 DP Geography students learning about the economics of the scrap and recycling business at our local scrap dealer.

On Monday April 1st the DP1 Geography class visited our local scrap dealer to get a better sense of what happens to school recyclables.  This short field trip followed up a longer two week field investigation  into solid waste patterns in the OSC neighborhood (see separate post). The group of eight students took several bags of mixed paper as well as some folded cardboard. The scrap dealer is based out of an old shipping container on the side of Panipitiya road. Students were able to ask a series of questions and learn more about the economics of recycling from the perspective of this dealer. We also sold our mixed paper (12kg) and cardboard (5 kg) for a grand total of 146 LKR. Students also got a chance to speak with Matt Jackson, a patron and OSC community member. He outlined what he does in terms of collecting and sorting recyclables which are deposited at the dealer. He doe not take any money for his materials.

2019 Data

2018 Data

The class has updated the buying (and selling) costs of the materials that our scarp dealer deals with in. Some prices have climbed while others have decreased since we gathered the same data last year. These are purely based on what our dealer is telling us and we know from past studies that we could probably get better prices at other locations. Our goal, however, is to reduce solid waste and not to earn more money. We remain interested in patterns of recyclables and commodity prices.

 

REFERENCES

Salman, Malaika and Dominic Harding. “Recycling Paper in the OSC and Pelawatte community: A 2018 Update.” Recycling & Sustainability Blog. 22 March 2018. Web.

Written by ianlockwood

2019-04-03 at 1:22 PM

OSC Neighborhood Solid Waste Study 2019

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Preparing to run a solid waste survey at a modern house east of the OSC campus.

The 2nd semester is a time of class field trips to various recycling and solid waste operations in the OSC neighborhood.  The DP Geography class is preparing to conduct field research in Sinharaja so as a trial they conducted a field survey of solid waste patterns in the OSC neighborhood. There were several stages to this operation:

  1. Taking a preliminary observation-based walk to assess the study area.
  2. Devising the research questions
  3. Creating an appropriate survey using Survey 123
  4. Preparing a base map using OpenStreeMap as well as new 1:10,000 data from the Sri Lanka Survey Department. Revieiwng and updating data on OSM for the OSC neighborhood
  5. Conducting the field work (over two lessons)
  6. Compiling, processing and graphing the data.
  7. Sharing the data in a poster, individual assignments and online (this post)

Field Work Skills task sheet 2019

Screen grab showing Survey 123 raw data and map area.

As a part of the project the class worked with a variety of maps to get a sense of their study area.  OpenStreetMap is a great source but most of the building have not yet been mapped. Previous classes of OSC students have mapped the school campus but the Class of 2020 worked to expand the area. The maps below show the progress that they made on this ongoing project.

 

CONCLUSION

The field study was completed after two blocks of data collection in the OSC neighborhood. Together the class was able to survey 26 different households near to the OSC campus. We have a much better sense of of our neighborhood though it would be good to continue the study and get more houses surveyed. There were a few conclusions.

  • Most residents are getting some sort of municipal solid waste pick up. 23 of 26 respondents(86.5%). Respondents mostly appeared satisfied with this arrangement abut several remembered times when the collection system had broken down in the past 2-3 years.
  • 23 of the 27 (92.3%) respondents are separating waste. This makes sense as it is now required by the municipality.
  • A few residents stated that they did weekly burns of leaves and paper. (3 of 26 or 11.5% households surveyed). However it seems, based on observation, that other items (Tetrapacks, plastic bits) are being mixed in with these burn piles.
  • Only a few households were composting (3 of 26 or 11.5% households surveyed).

 

REFERENCES

“Analysis & Recommendations.” Curious Geographer. February 2019 Web.

ESRI. ArcGIS Book(s). Web.

Hunter College Department of Geography. “The geographic inquiry process: a way to problem solve.” Web.

Nagel, Garrett & Briony Cooke. Geography: For the IB Diploma, 2nd Edition. Oxford: Oxford University Press, Print.

Nagel, Garrett & Briony Cooke. “5 Skills for DP Geography.” Web/PDF.