Fluoride/bone char presentation and field lab developments, podcasts and crowdfunding for peace in Burma, Spanish translation coming soon
a brief update on several activities...
Thank you for your continued interest in and support of our work! Here’s a brief run-down of some of the irons we currently have in the fire…
Fluoride/bone char research
I am on a personal mission to identify the bare-minimum set of experiments a person needs to perform - given a unique combination of a source water contaminated with excessive fluoride and a locally generated bone char sorbent - to get all the data needed to
design a contactor to treat that water to acceptable levels of fluoride (e.g., below the World Health Organization Guideline Value of 1.5 mg/L),
carry out scenario-building exercises for treating geochemically similar fluoride-contaminated waters, and develop value engineering approaches for designing sustainable treatment processes, and
provide quantitative guidance for targeted monitoring and evaluation of installed treatment units.
As you likely well know, experimental resources (laboratory and analytical equipment, reagents and supplies, staff time, physical space, etc.) are often a constraining factor for WASH (water-sanitation-hygiene) and other “sustainable development” practitioners and organizations.
Accordingly, if you find yourself in the back-of-beyond tasked with setting up household or community water treatment units for removing excessive fluoride from the local groundwater using locally available materials like charcoal made from animal bones (bone char), you’ll necessarily be interested in performing minimal-but-sufficient experimental work necessary to design treatment units for meeting water quality objectives.
By the way, the same philosophy applies to circumstances where you need to remove arsenic, or some cocktail of heavy metals, or a slew of organic chemical contaminants. So this fluoride/bone char work also provides a case study for addressing other water quality concerns using sorption processes.
We were invited to give a virtual poster-style presentation on some of our fluoride/bone char work at a recent WASH conference. It was a nice opportunity to take a pause in the middle of work-in-progress to present some preliminary results. Here’s the short story version:
We’ve identified circumstances where what is perhaps the simplest approach to gathering sorption data - “bottle point” isotherm batch tests - can provide sufficient quantitative information for designing bone char contactors.
We’ve demonstrated success predicting fluoride removal in full-sized bone char contactors using a combination of Rapid Small Scale Column Tests (RSSCTs) and mass transfer modeling.
We’ve shown how fitting a mass transfer model to data collected from one RSSCT can be used to simulate a variety of operational conditions, including treating geochemically similar waters containing different levels of fluoride, and predicting the performance of different sized bone char contactors (i.e., over a range of contact times between water and sorbent media).
Our preliminary work also suggests that sorption kinetics by different bone chars, including several commercially available sorbents, are “similar enough” such that a common set of sorption parameters can be used as model inputs to simulate fluoride removal by different sorbents and rank the sorbents according to their efficacy.
As stated, this is a work-in-progress. But if these conclusions are further supported and borne out by our continued investigation, it will mean that a wealth of design, optimization and value engineering, and monitoring guidance data will be available from a relatively small outlay of experimental resources.
We dive into the science and engineering nerdery of the fluoride/bone char system in a subscribers’ post through narration of our recent WASH conference poster presentation. Consider signing up for a subscription if you are interested in the details!
Field lab developments
Simplified cartoon schematic of an RSSCT apparatus
We’ve been running RSSCTs in Caminos de Agua’s field laboratory for nearly five years now using a rather cobbled-together setup. This experience has allowed us to establish proof-of-concept. But the lynchpin of the whole process is the pump.
A pump is necessary to conduct RSSCTs in a field lab setting, as indicated in the cartoon above. Ideally, the pump needs to be rugged, affordable, capable of providing very consistent flow at low flow rates (i.e., 0.5-10 mL/min) over uninterrupted periods of several hours to several days, and be robust (that is, requiring little to no maintenance).
If anyone knows of a type of pump that meets all of these criteria - inexpensive, bombproof, small and portable, hyper-precise…a true unicorn in the world of pumps! - please contact me right away!
For the past few years we’ve “solved” this problem by refurbishing, and constantly maintaining and repairing, older model used liquid chromatography pumps. Under ideal conditions these pumps meet the precision criteria, but under field lab conditions they are very finicky and need near-constant TLC, which in addition to being frustrating impairs their affordability. They’re also rather heavy, bulky, and fragile and thus difficult to transport. Keeping one of these running for RSSCT work in the field requires esoteric knowledge of pump function and repair, and a willingness to tinker-tinker-tinker. Not ideal.
It’s been on the to-do list for a while to identify a superior approach to robust, precise, low flow rate pumping in a field lab setting that reproducible by WASH practitioners using off-the-shelf available commercial equipment. Thanks to a grant that Aqueous Solutions received for our ongoing collaboration with environmental and public health grassroots groups in the Ecuadorian Amazon, we’re making advancements in the field lab RSSCT equipment department.
If all goes according to plan soon we’ll have a design and equipment list (complete with part numbers, vendors, distributors, etc.) that we feel confident to recommend to other practitioners! As the details get worked out I’ll be posting here - stay tuned!
Podcasts and crowdfunding for peace & democracy in Burma
Last month, in the Field Notebook section of this site, we posted a podcast conversation with “Romeo,” a citizen of Yangon, Burma (Myanmar) who has been living under the violence and repression of the ruling military junta since the coup that occurred over two years ago on the night of February 1/2, 2021. (She goes by the pseudonym “Romeo” for security reasons.) If you haven’t listened to that conversation we urge you to check it out.
Burma cities under martial law. [Image source: Anonymous Facebook account.]
Recently we recorded a follow-up conversation with “Romeo” along with two other colleagues who have a lot of experience working in relief, aid, development, health, and human rights in hill tribe areas along the Thailand-Burma border. In this conversation we discuss some of the history of conflict in Burma, and how grassroots and community based organizations have managed, in times of crisis due to political unrest or natural disasters, to channel aid and support to affected communities when “official” channels have been blocked.
We also discuss potential future roles for cryptocurrency to channel assistance to affected areas and provide a medium of exchange not controlled by the military junta’s banks, and shielded to an extent from the crippling inflation that the currency (kyat) has experienced in recent years.
This podcast episode will be published sometime in the next 2-3 weeks, and will be free to access for all subscribers. To support “Romeo” in her clandestine efforts working with the underground resistance in Yangon promoting peace and democracy, we have just launched an online crowdfunding campaign. Please consider donating!
We plan to continue to check in with “Romeo” as well as speak with other individuals and groups working to provide assistance and relief to people in Burma affected by the conflict and ongoing economic crisis.
Spanish translation of book sections
Soon we’ll be launching a Spanish language version of this site to provide translation of book-in-progress sections. The Chapter 1 translation has been completed and is now with the copy editor. As with the English language site, Chapter 1 will be available free to all. Beginning with Chapter 2, translated book sections will be available to paying subscribers. All of the proceeds from paid subscriptions will support the work of Amisacho Restauracion and the Clinica Ambiental in Ecuador.
Please share our work with your Spanish-speaking colleagues!