Inspiration
A collection entry alone cannot show that a recycler accepted the same material. RecycleProof separates collection from receipt, making handovers easier to trace and disputes easier to investigate.
Track and users
Sustainable Supply Chains: recycling traceability and digital material passports. Intended users are collectors, receiving recycling facilities and a workspace controller who approves portal access.
What it does
The Controller approves accounts. A Collector records a batch, material, registered weight, location, nominated Recycler and optional supporting photo. The Recycler confirms receipt with a receipt/weighbridge reference or reports a mismatch. Each batch has a material passport, separate timestamps and SHA-256 evidence hashes. Reports show registered weights and receipt status.
On Polygon Amoy, a wallet publishes the collection commitment and nominates a separate receiving wallet. Only the nominated wallet can confirm receipt. The portal compares its hashes and weight with current contract state and disables proofs already published. Five languages, Arabic RTL, themes and responsive layouts support different users and screens.
How we built it
PHP and SQLite store shared portal records and check permissions on every request. JavaScript provides the interface; ethers connects to MetaMask. Solidity enforces unique collection identifiers and nominated-wallet receipt confirmation. Wallet approval is required for publishing; read-only contract checks do not need a wallet. Test POL only.
Demonstrated test
RP-2026-1 records 5 kg PET plastic, portal collector Zakir, recycler Rahim and receipt RCV-001. Collection and receipt were signed by distinct wallets and both match the deployed Amoy registry. This is software test data, not independently verified physical recycling. The earlier 12.5 kg DEMO-DHA-001 prototype is a separate illustrative entry.
The updated working-app video also creates RP-VIDEO-20261024 as Bahar (2.5 kg PET, fictional test data) and confirms receipt as Rahim with VIDEO-RCV-002. Its blockchain check correctly returns Not yet published. This new portal test is separate from the already signed 5 kg RP-2026-1 batch. No new transaction is signed during the recording.
Challenges and learning
RPC availability, minimum gas fees, duplicate-proof prevention and readable wallet guidance affected reliability. We learned that a transparent record must distinguish a collection statement, receipt confirmation and completed physical recycling. Automated checks cover contract behavior, portal evidence validation and form guidance.
Impact, adoption and next steps
A shared handover trail could help communities and recycling operators reconcile records and identify missing receipts. The browser-based prototype requires no installation. A supervised pilot with verified facilities is needed to measure usefulness. Next steps include cryptographic wallet-to-account binding, shared transaction indexing, durable evidence storage and mobile-wallet testing.
Boundaries
Blockchain verifies recorded statements, not material quality, facility identity, actual recycling or carbon savings. No carbon credits, measured CO2 reductions or AI classifier are claimed. Registered weights are self-reported. Shared testing accounts are for a disposable judging workspace.
Contributions
Project owner: Zakir. UI/design collaboration: Bahar. AI assisted implementation, design iteration, documentation and submission preparation. The narrated video records interaction with the working app, uses fictional test data and synthesized English speech, and edits pauses/holds some frames for explanation.
Try it
Live app: https://recycle.baharsoftbd.com/ Source and setup documentation: https://github.com/mdzakirhossen23/recycleproof Registry: https://amoy.polygonscan.com/address/0x03BDF96627Cc061676F316Ea07100a2387Fb6F2d Use the hosted login page testing instructions; sample preview requires no login. Never share wallet recovery phrases.
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