Monitoramento contínuo da qualidade da água: proposta de ações para melhoria da confiabilidade

Abstract

The sensors used for continuous monitoring of water quality can be contaminated, which affects the continuity of the readings and requires periodic maintenance, and it is desirable to extend the period between the beginning of the monitoring and the maintenance. The methodology included experiments with probes and measurements performed in four phases, with weekly data collection of probes immersed continuously in several periods between June 2017 and February 2018. In the first phase, tap water was used to establish reference between continuously immersed probes and clean probes. In the second phase, the contaminated water from a stream was used to check the time of reliable readings of the probes. In the third phase, water contaminated in three containers, one with probes using PVC guard, and two other with probes using copper guards developed to take advantage of the characteristics of copper as an antifouling material. Also at this stage and using contaminated water, a probe with a PVC guard coated with a mixture of copper powder and enamel paint, lead to results similar to those obtained with the copper guard. In the fourth phase, two probes were continuously immersed in a stream, one probe using a copper guard, and the other a regular PVC guard associated with a water injection mechanism to prevent the accumulation of dirt. In the four phases, clean probes were used to obtain weekly reference data. As a result, additional reliability periods were verified using copper guards, copper powder ink and the cleaning mechanism, demonstrating their usefulness both for lentic and lotic environments.