Low cost hyperspectral measurement system to identify harmful materials in construction and demolition (C&D) materials

Because C&D materials constitute a significant waste stream, increasing the diversion of C&D materials, through recycling and reuse, is identified as an area of need in EPA’s Sustainable Materials Management (SMM) Program Strategic Plan. Due to a lack of technologies to quickly identify harmful constituents, C&D-materials recyclers often dispose of potentially usable materials as a matter of precaution. There is a need for inexpensive technologies that can quickly identify constituents prior to deconstruction or in C&D recycling facilities. In addition, equipment that can improve sorting efficiency for all C&D waste is desirable.

Hyperspectral imaging is emerging as a non-destructive, real-time detection tool for industrial sensing. This technology has been applied to a broad range of environmental, agricultural and industrial inspection applications and has made possible the rapid spatial assessment of grade, contamination, and constituent characterization of mixed, raw, and processed materials. However, hyperspectral sensors have historically been too expensive for broad-scale application. The long-term goal of the proposed work is to realize a hyperspectral measurement system for C&D materials inspection by utilizing a novel optical system containing a set of low-cost components to achieve cost and performance goals. The system may be configured as a handheld sensor or as a fixedmount sensor that could be combined with existing industry equipment like conveyor lines, air sorters, and robotics. In either case, the sensor would be affordable to the waste industry and designed to withstand typical industrial environments. In addition, it would be reconfigurable to allow future adjustment based on changing market requirements.

The Phase I effort included: identifying how the technology can be adapted for use within C&D materials inspection applications; detailed design development; and proof-of-principle experimental testing/demonstration clearly showing technical feasibility. The Phase II effort will focus on: detailed total system design; several rounds of prototyping and testing; and working with C&D industry partners for field testing. This development plan should favorably position Sporian to transition the technology for post-Phase II customer-driven testing, certification, and commercialization.

The target market for the innovation is the C&D industry as well as organizations that specialize in waste collection and materials recovery. Users include inspectors and planners, construction and demolition crews, C&D recycling facilities, and buyers purchasing materials for recycling/reuse. The primary environmental benefit of the system is an increased ability to detect hazardous materials during the deconstruction and recycling process so they can be managed appropriately while increasing diversion of materials from landfill.