Grantee Research Project Results

2012 Progress Report: Use of Bone Char for the Removal of Arsenic and Uranium from Groundwater at the Pine Ridge Reservation

EPA Grant Number: SU835069
Title: Use of Bone Char for the Removal of Arsenic and Uranium from Groundwater at the Pine Ridge Reservation
Investigators: Werth, Charles J , Becraft, Jacob , Nell, Marika , Freeck, Jason , Mosiman, Daniel , Knaizer, Brendon , Llewellyn, Brett , Bollinger, Drew , Llewellyn, Alex , Parker, Kimberly M , Salvatore, Michelle , Genchanok, Yana , Dam, Emily Van , Feeney, Connor , Wang, Hanting , Nguyen, Tien-Hung
Current Investigators: Werth, Charles J , Llewellyn, Alex , Parker, Kimberly M , Salvatore, Michelle , Becraft, Jacob , Genchanok, Yana , Dam, Emily Van , Freeck, Jason , Wang, Hanting , Nell, Marika , Feeney, Connor , Nguyen, Tien-Hung , Llewellyn, Brett , Marcinkevicius, Algimantas , Benson, Nora , Wisniewski, Alexander , Hou, Serena , DeMarco, Vanessa , Bollinger, Drew , Mosiman, Daniel , Knaizer, Brendon , Michelson, Kyle , Choe, Jong Kwon , Bergquist, Allison
Institution: University of Illinois Urbana-Champaign , Oglala Lakota College
EPA Project Officer: Page, Angela
Phase: II
Project Period: August 15, 2011 through August 14, 2013 (Extended to August 14, 2014)
Project Period Covered by this Report: August 15, 2011 through August 14,2012
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2011) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Awards , Sustainable and Healthy Communities

Objective:

In August of 2009, our team traveled to the Pine Ridge Reservation in South Dakota, home of the Oglala Lakota Tribe. The purpose of the trip was to verify a U. S. Geological Survey (USGS) report from the 1990s which indicated that much of the groundwater on the reservation was contaminated with arsenic (As) and uranium (U) above the Environmental Protection Agency (EPA) maximum containment limits (MCLs). Samples of private wells, municipal sources, and spring sources were taken and it was confirmed that 35% of private wells contained As above the MCL, while 6% contained U above the MCL. While some residents have access to contaminant-free municipal water sources, many prefer the taste of their non-chlorinated private well water.

The goal of the project is to develop a cost-effective filter that can remove both arsenic and uranium focusing on people, prosperity, and planet. The Pine Ridge Reservation is home to 28,000 people, many of whom do not know the dangers of drinking contaminated water. Efforts are being taken to inform their community of the issues and develop an educational program in partnership with the Oglala Lakota College (OLC) to further understanding of the need for clean drinking water on the reservation.

Phase I objectives were completed last year, and included: 1) evaluating As and U contamination in the Pine Ridge Reservation 2) characterizing bone char (BC), 3) assessing U and As removal capacity and kinetics using actual BC, and 4) developing a BC filtration device.

The specific objectives of Phase II efforts are to 1) further test drinking water used by the residents of the Reservation, 2) to design and test a BC filter, 3) to help establish a small business for water treatment on the reservation, and 4) to educate students at Illinois and the OLC. Additionally, an educational program is under development with the OLC to further understanding in the tribe about the importance of safe drinking water.

Phase II continues the work on arsenic and uranium removal capacity and removal kinetics using actual bone char. Although the mechanism of the removal process is not known, removal capacity and kinetics are being evaluated in order to optimize filter design. Water samples from the reservation have revealed the presence of arsenic (III), which, unlike arsenic (V), has proven difficult to remove with bone char. Our efforts to oxidize the arsenic (III) to arsenic (V) using iron oxides have suggested successful removal. Finding the optimal mix of bone char and iron oxides for plausible implementation is now the focus of experimental columns being run.

Research using a 30 minute retention time column of only bone char has been completed. The column was 5 cm long and 0.5 cm in diameter. Water contaminated with 80 ppb U was sent through the column and U was removed below the MCL for 53 days before breakthrough occurred. This suggests a breakthrough of well over 1 year for a full-size model. Initial tests with a 15 minute retention time column are complete and indicate a similar breakthrough time period as the 30 minute retention time column. A full breakthrough experiment is currently underway.

Currently, a column containing 70% bone char and 30% iron oxides is being tested with water containing 40 ppb U. The column is set at a 15 minute retention time and aims to demonstrate that the mixture of iron oxides and bone char continues to effectively remove U. Once the bone char and iron oxide mixture has been tested for U, column tests will be expanded to test for arsenic (III) removal.

The design and testing of a BC filter, as well as establishment of a small business for water treatment on the reservation, must wait on the results of the column testing. However the last objective of Phase II is currently underway. A video is being produced to increase awareness of the contamination of water, its effects, and our efforts to create a solution for the problem. The video will be sent to the PBS "Planet Forward" initiative to further broadcast our team's goals. The video will showcase individual members of the team discussing their project involvement.  Furthermore, our team works parallel to the efforts of Engineers Without Borders, hoping to increase involvement and awareness as the project progresses.

Aside from the research progress being made, the team has also been working with Dave Johnson and the Bureau of Drinking Water and Groundwater for Oconto County, Wisconsin.  It is believed that the water in this area has been contaminated with arsenic and samples from this area will be used to test the BC filter. Our goal is to diversify the number and quality of water sources that the filter design is based on. In addition to this, the team is exploring the possibility of getting samples from a Navajo reservation in Arizona, which is believed to be contaminated with uranium. This area could be another place where the BC filter design could be used to alleviate health risks.

Team members are also currently working on developing an educational program for elementary students in the Oglala Lakota tribe. The program focuses on water purification ideas and techniques and will serve as a bridge into implementing our design. It also increases awareness in a nonintrusive manner.

Since receipt of Phase II, many advancements on the social and scientific fronts of our project have been made.  In August 2011, a UIUC team again revisited the Pine Ridge Reservation to collect water samples and survey the contamination.  At the Reservation, samples were collected from 13 additional locations across the reservation.  Samples were collected from a variety of sources including indoor faucets, outdoor wells, and an outdoor pipe that was continuously flowing.  All of these locations were of frequent use for the residents of the Pine Ridge Reservation, and covered a wide representative area on the reservation.

While collecting samples, the team also spoke with the residents and local Oglala Lakota College leaders on the reservation to discuss a prototype of the filter design and to see whether or not the filter would actually be of use in their homes.  The team collected valuable design feedback.  They also discussed technical feasibility of BC production on the Reservation with science leaders at the college

Progress Summary:

Below are the results of the first bench-scale column experiment.  The column used in this experiment was 5 cm in length and 1 cm in diameter.  The column contained approximately 2.16 g of bone char that ranged between 300 uM and 2 mm in particle size.    

While the full length of the experiment was 69 days in total (estimates for breakthrough was at ~60 days), there were gaps in the continuous flow-through experiment due to normal student conflicts with breaks, excess testing during a certain week, etc.  Because our research group recorded all of the missed times, we were able to accurately calculate the full run time of the column, a cumulative time of 52.6 days.  Using a rough estimate of the porosity of the bone char at ρ = 0.5, the column volume V = 3.93 cm³, and the flow rate of Q = 4.00 ml/h, the number of pore volumes that flowed through the column over the length of the experiment was calculated to be V_P = 2527 pore volumes.  Throughout the length of the experiment, effluent samples were analyzed using Ion Coupled Plasma - Mass Spectrometry.  These results are plotted below.

The breakthrough curve plotted above shows that after 52.6 days of run time, breakthrough in the column started but did not reach completion.  The highest concentration was less than 6% of the influent concentration, and the average concentration was less than 1% for nearly 40 days.  In the last 12 days, however, the concentration rose sharply, signaling the beginning of breakthrough. 

A new column was then started with a retention time of 15 minutes. Due to scheduling conflicts, this column was stopped after 30 days, but breakthrough had not occurred over the 30 day period.  The results suggest that breakthrough for a 15 minute retention time exceeds 30 days, and beak through for a 30 minute retention time exceed 50 days.  This is excellent news, and suggest that a full-scale column will be in operation for a year or more.

Future Activities:

Our team is presently setting up a new experiment to measure breakthrough for two columns with a 15 minute retention time. The column used to analyze the breakthrough time of uranium (in the form of uranyl chloride) will contain bone char only. Experiments using this column are already underway and are expected to be complete by the end of November. The second column will be used for testing the breakthrough time of arsenic contaminated water, so it will contain 70% bone char and 30% zero valent iron by weight.

These column studies are necessary for determining full-scale filter design that will safely clean arsenic and uranium contaminated water for a known period of time.  Once we have a reliable filter design, we will discuss full-scale filter designs with the Oglala Lakota College (OLC), in addition to implementation plans.  We have already discussed the feasibility of implementing the filter with the communities at the Pine Ridge Reservation.  This occurred during a site assessment and data collection trip in Summer 2011.  The OLC seemed very positive regarding filter implementation, so we look forward to continue the dialogue to advance our legitimacy with the community and move towards implementation.

For future plans for the project in the upcoming year, we have the following goals:

Fall 2012 :

• Determine a full breakthrough curve for U removal with bone char media.
• Begin column experiments with Arsenic(III) removal in column experiments that use a composite of 70% bone char and 30% zero-valent iron particles.  The porous media to zero-valent iron ratio was determined by P. Calabro et al. in Estimate of the Optimum Weight Ratio in Zero-Valent Iron/Pumice Granular Mixtures' (2011). 
• Determine a full breakthrough curve for As(III) removal in zero-valent iron/bone char column.
• Determine accurate porosity of bone char.
• Reconnect with KOLA, a philanthropic business student organization that we formerly partnered with to create a business plan for the manufacture of bone char filtration units on and for the Pine Ridge Reservation.

Spring 2013:

• Design of in-home bone char filtration unit.
• Possibly take an assessment trip to talk to communities at PRR, and take household pipe measurements.
• Development of community water education program.

Journal Articles:

No journal articles submitted with this report: View all 4 publications for this project

Supplemental Keywords:

Bone char, hydroxylapatite, hydroxyapatite, arsenic, uranium, human health, Oglala Lakota, Pine Ridge Reservation

Progress and Final Reports:

Original Abstract

2013 Progress Report

Final Report

P3 Phase I:

Use of Bone Char for the Removal of Arsenic and Uranium from Groundwater at the Pine Ridge Reservation  | Final Report