Versatile and low-cost sensor interface for IoT-ready odor monitoring in wastewater management

The monitoring of pollutants in industrial plants is a major concern, in order to satisfy the requirements dictated by the related norms. Recently, the problem of odor monitoring gained importance since, despite the generally low dangerous nature of the emission, people usually correlate bad smell to unhealthy air condition. In this paper, we focus on the wastewater treatment application scenario and propose a versatile air pollution control solution. In particular, a distributed eN ose, based on low-cost, but highly configurable sensing probes, is suggested. The Internet of Things (IoT) paradigm has been followed, thanks to the adoption of a communication infrastructure based on the widely adopted LoRaWAN technology. Such an approach, on one hand, would allow to easily cope with the administration and local population; on the other hand, it paves the way to use analytics to predict emission events in advance. The need for managing multiple transducers per each probe has been solved using an innovative acquisition strategy, exploiting both the volt-amperometric and resistance-to-time (integral) approaches, implemented by low-cost microcontroller and ancillary electronics. A proof-of-concept prototype has been realized and preliminary experiments have been carried out. Experimental results have demonstrated the solidity of the proposed approach, with relative error below 1 % and relative standard deviation below 0.5% over the whole considered resistive range of more than two decades.