Grantee Research Project Results

Evaluation of Traditional Charcoals and Gasifier Biochars as Sustainable Low-Cost Adsorbents for Water Treatment Serving Developing Communities

EPA Grant Number: FP917472
Title: Evaluation of Traditional Charcoals and Gasifier Biochars as Sustainable Low-Cost Adsorbents for Water Treatment Serving Developing Communities
Investigators: Kearns, Joshua Perry
Institution: University of Colorado at Boulder
EPA Project Officer: Hahn, Intaek
Project Period: August 1, 2012 through July 31, 2015
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2012) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Environmental

Objective:

It is hypothesized that locally generated gasifier biochars exhibit enhanced sorption properties compared with charcoals produced by traditional methods, and can be cost-effectively applied in decentralized water treatment for removal of synthetic organic contaminants (SOCs) such as pesticides.

Approach:

The study first will generate a representative selection of chars using a traditional charcoal kiln, programmable laboratory pyrolyzer, and small and pilot-scale biomass gasifier systems. These chars then will be subjected to physico-chemical characterization and batch-mode SOC uptake assessment in the presence of background dissolved organic matter and competitive sorbates to identify sorbents with low, medium and high potential for application in water treatment. The study then will carry out laboratory bench-scale column tests to quantify the efficacy of selected representative chars for SOC removal under dynamic, field-relevant conditions. Finally, pilot column and field data will be collected and used to develop a scaling approach for predicting full-scale system performance.

Expected Results:

This research will break new ground in elucidating connections between principal char manufacture variables and the development of enhanced sorption characteristics in the char product. These variables include feedstock identity (biomass precursor) and form (i.e., whole logs used for traditional charcoaling versus chipped or pelletized material used in gasifiers), peak temperature, duration of heating, and gas sweep rate during pyrolysis. The innovative work proposed here will extend beyond extant studies of equilibrium SOC uptake by chars under ideal laboratory conditions to demonstrate the roles of mass transport kinetics, fouling by background dissolved organic matter and competitive sorption under “real-world” conditions. Moreover, these results will provide novel baseline performance data scalable for engineered char adsorber units applicable in both water treatment and environmental remediation strategies (e.g., municipal stormwater and agricultural runoff passive treatment barriers, acid mine effluent attenuation), and in so doing provide scientific support for domestic and international entrepreneurship in the application of sustainable environmental technologies.

Potential to Further Environmental/Human Health Protection

This work realizes a triple-benefit for human health, environmental sustainability and local economies to: (1) offer economical and technologically accessible water treatment where currently none exist; (2) offset polluting and energy-inefficient charcoal production with a “green” technology; and (3) support village-level microenterprise in the manufacture of enhanced sorbents. This research thus exemplifies potentially “game-changing innovation” in sustainable engineering where benefits realized abroad also imply positive domestic environmental and economic outcomes.

Supplemental Keywords:

biochar, decentralized water treatment, developing communities

Progress and Final Reports:

2013

2014

Final