Grantee Research Project Results

2019 Progress Report: Beneficial reuse of PCBs (poly-chlorinated biphenyls) as new materials through a low cost process

EPA Grant Number: SV839354
Title: Beneficial reuse of PCBs (poly-chlorinated biphenyls) as new materials through a low cost process
Investigators: Lu, Mingming , Xu, Juan , Johnson, Kevin
Current Investigators: Lu, Mingming
Institution: University of Cincinnati
EPA Project Officer: Page, Angela
Phase: II
Project Period: March 1, 2018 through February 29, 2020 (Extended to February 28, 2021)
Project Period Covered by this Report: March 1, 2019 through February 29,2020
Project Amount: $74,958
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2017) Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Chemical Safety , Sustainable and Healthy Communities

Objective:

The goal of this research is to validate in laboratory a low-cost technology for PCB decontamination. This technology is promising, as it can be carried out with high dechlorination rates at atmospheric conditions and does not require high temperatures (below 80C). The objective remains unchanged. The Phase II project will continue the Phase I effort in evaluating a low-cost technology for the reduction of select PCB congeners. Phase I tested the feasibility of catalytic hydrodechlorination (HDC) by converting two simple PCBs compounds, 3 chloronbiphenyl (3-PCB) and 2,3-dichloronbiphenyl (2,3-PCB),  into non-chlorine containing chemicals.  In Phase II, the team plans test with more complex PCBs compounds, such as 2,4,4’ trichlorobiphenyl (PCB-28) and Arochlor 1232, together with student mentoring, education and outreach.

Progress Summary:

Task 1, Student recruitment, team update, and safety and sustainability training (2 months). Up to now, 8 students have worked on this project, out of which 5 are female and 2 are minority (Jasmine and Kolawole).

Task 2. Hydrodecholorination of PCBs with increased chlorine contents than 2,3-PCB. (9 months). This task is ongoing but near completion.  For a more complex PCB than Phase I we selected 2,4,4’trichlorobiphenyl (2,4,4’-PCB, or PCB- 28, based on the congener list) after careful literature review. Experiments were performed and also instrumental analysis.  We found that the ortho position chlorine is harder to remove, and consequently HDC of 2-PCB was also harder to remove.

Task 3. Interim result summary and reporting (1 month). A project status report to EPA will be submitted. This is completed annually and the last project report will also be completed.

Task 4 Hydrodecholorination of Aroclor compounds, at different concentrations. Effecting parameters will also be investigated. (9 months)” This task is on-going. 

After careful literature review, we selected Aroclor 1232 as our representative compound. Unlike Arochlor 1254 or 1248, there is limited study on this compound. We did literature view on this compound, and found its composition matches well with  individual PCB compounds we’ve studied.  We’ve run 6 test experiments and are waiting for instrument analysis results.   

For Tasks 2 and 4, we ran HDC reactions under room temperature, 50C and 77C conditions (Fig. 1). We further investigated the role of Et3N triethylamine on HDC reactions by varying its loads.

Next step: We will continue to work theoretical calculations, such as the activation energy, for Tasks 2 and  4,  in order to support experimental data. We will further evaluate temperature, time and Et3N to chlorine does and their impacts to the HDC reaction.

Summary of Outputs/Outcomes:

• 8 Students (three graduate and 5 undergraduate students) from various disciplines have worked on this project, out of which 5 are female and 2 are minority (Jasmine and Kolawole from last reporting period).
• A conference paper has been presented as listed in publications. Dr. Lu made the virtual presentation.
• The MS student defended her thesis at the end of September, and is working on modifications. A MS thesis will be expected for next project period with detailed data summary.

 

Future Activities:

Future work: We will further explore the practical aspects of this reaction, e.g. can Pd/C be recycled? When will this recycle be practical? Which controlling factor is more significant, with respect to reaction time, temperature and Et3N dosage? We will also explore more practical PCB removal/stabilization technologies. 

The standardized procedures we developed to do experiments and analysis helped streamlined the process for this reporting period.  The project is behind schedule due to  lab closure for more than 3 months and also the  slowdown in chemical and supply purchasing, and delay in result analysis. Another reason is that we repeated experimental runs to ensure data quality, which is the right thing to do even though this takes time. Overall, we’ve made sufficient progress in  meeting the milestones described in the research plan.

Journal Articles:

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

Supplemental Keywords:

PCBs, hydrodechlorination, Arochlor 1232, 2,4,4’ trichlorobiphenyl

Progress and Final Reports:

Original Abstract

2018 Progress Report

Final Report

P3 Phase I:

Beneficial Reuse of PCBs  | 2017 Progress Report  | Final Report