In cities everywhere, trash is typically collected in a single bin that contains a mix of food scraps, paper, plastic, and everything else, all mixed together. This makes recycling difficult and causes landfills to overflow faster than they should. Valuable materials get wasted, and the environment suffers. Manual sorting isn’t much better. It’s messy, slow, and often inaccurate. Workers are exposed to unhygienic conditions, and mistakes in sorting can contaminate entire batches of recyclable waste. It’s simply not a scalable solution. What’s missing is a more innovative, low- cost way to separate waste, right when it’s thrown away automatically. That's where the Smart Dual-Compartment Waste Separator Bin comes in. This intelligent system utilizes moisture and ultrasonic sensors to detect whether an item is wet (such as food scraps) or dry (like paper or plastic). An Arduino microcontroller processes the data and activates a servo motor to direct the waste into the correct compartment, eliminating the need for user input. The ultrasonic sensor also monitors the level of each bin and sends alerts when it’s nearly complete. Prototype testing showed over 90% accuracy in sorting, and volume estimates were reliably within a 5% margin. The hardware is modular and includes built-in error handling, making it easy to upgrade with features like metal detection, AI-based material recognition, or even integration with municipal waste systems. In short, this bin offers a practical, scalable way to make waste sorting cleaner, easier, and more efficient, right at the source.