Macroinvertebrados bentônicos são afetados pela alteração dos sistemas aquáticos, que diminuem ou aumentam sua população. O conhecimento sobre macroinvertebrados bentônicos pode ser utilizado para conhecer a qualidade da água de lagos e rios, pois estes organismos respondem às variações nas condições ambientais. O objetivo deste estudo foi utilizar a estrutura de comunidades de macroinvertebrados como indicador de qualidade ambiental em dois rios de abastecimento público no município de Erechim, Estado do Rio Grande do Sul. As coletas foram realizadas mensalmente de novembro de 2014 até abril de 2015, utilizando-se amostrador tipo Surber. Para a avaliação das condições ambientais foi aplicado um protocolo de avaliação rápida (PAR). Foram identificados 4.096 macroinvertebrados, distribuídos em 41 táxons de Annelida, Nematoda, Crustacea, Aracnida e Insecta. Os dois rios apresentaram trechos com alteração antrópica nas margens e os ambientes mais alterados foram associados com a maior abundância do grupo trófico coletor-catador. Integrar o método de avaliação da diversidade de habitats com análises da comunidade bentônica pode ser um método eficiente para obtenção de parâmetros mais completos da qualidade da água e da degradação dos sistemas aquáticos.

Aim This study aimed to evaluate the water quality of streams that are used for public supply, through an integrated analysis using a biotic index, as well as physicochemical and microbiological parameters. Methods The data were obtained monthly, from November 2014 to April 2015, at eight locations in two rivers in the south of Brazil. The landscape is predominantly rural, with the occurrence of small reforested areas, as well as yerba mate and grape cultivations. Macroinvertebrate samples were collected monthly using a Surber sampler. Water temperature and dissolved oxygen concentration were measured in the field using a portable oximeter. The following parameters were measured in the laboratory: pH, Turbidity, BOD, Conductivity and Nitrate. Results The evaluation carried out in the rivers revealed good water quality, but some sample sites presented reduced water quality. The waters of the Leãozinho River were classified as doubtful at site 1 and as good at sites 2, 3 and 4. Ligeirinho River presented an acceptable rating at sites 1 and 4 and was classified as good at sites 2 and 3. The BMWP’ index was significantly correlated with the abundance of macroinvertebrates, EPT richness and BOD. The abundance and richness of macroinvertebrates in Leãozinho and Ligeirinho Rivers were associated with the physical, chemical and microbiological parameters. Conclusion This study reinforces the importance of biomonitoring in the evaluation of water quality for human consumption, considering that environmental management and monitoring practices should integrate physicochemical, microbiological and biological parameters.

Alkali-activated materials derived from industrial waste are promising alternatives to Portland cement for geotechnical applications. However, their environmental safety under realistic exposure conditions remains poorly understood, particularly due to the limitations of conventional chemical assessments, which may not capture early-stage curing effects, leaching behavior, and associated ecotoxicological risks. This study investigates whether conventional chemical assessment methods are sufficient to evaluate the environmental performance of such materials. An alkali-activated cement produced from photovoltaic module glass and hydrated oyster shell lime was evaluated through an integrated approach combining leaching tests and ecotoxicological assays. Leaching behavior was assessed at curing ages ranging from 7 to 91 days. Ecotoxicological effects were evaluated using extracts obtained from the alkaline cement after 7 days of curing, with zebrafish embryos under both acetic acid‑extracted and water-extracted conditions. Leaching tests showed a progressive reduction in several regulated metals; however, Ba, Cd, Cu, Ni, Pb, and Zn exceeded regulatory thresholds at specific curing ages. All mixtures produced highly alkaline leachates (pH > 13), and non-regulated elements (Ga, In, K, and Li) were also detected. Ecotoxicological assays revealed acute toxicity in acetic acid‑extracted leachates and sublethal effects in water- extracted leachates, including impaired hatching and reduced spontaneous movement. The results demonstrate that reductions in leached concentrations and compliance with conventional chemical criteria do not necessarily correspond to biological safety, highlighting the need to integrate ecotoxicological assays into environmental assessments of sustainable cementitious materials. Graphical Abstract