As the population increasingly grows, the impacts of climate change rise and the lack of clean water start to surround us, the need for the restoration of waterbodies increase. Thus, new technologies have to be developed aiming to improve the water quality of rivers and boost its natural recovery. The objective of this preliminary study was to develop a cheap and accessible alternativeto improve the water quality of rivers and lakes by using low-cost waste materials. Experiments were conducted to observe the decrease of organic matter of biofilms supported in coconut fibers and in P.U spongesthrough time. Both biofilms presented high degradation efficiencies and at low contact times.The biofilm in coconut fiber showed a higher average organic matter degradation rate, but the biofilm in P.U sponges showed a higher decrease of coloration and odor. A structure was created to simulate the condition of a river and both materials were placed into it in order to analyze their efficiency. The results showed considerable decrease in nutrients, organic matter, suspended solids, turbidity and coloration. Considering the system had a relatively high flow rate, thus not allowing the water to have contact with the structure for a long time, these results establish that the structure could be applied in a real effluent to improve the water quality.However, further research is needed to analyze the effects of more variables and establish some strategies of how this should be applied in a real waterbody.

Water quality monitoring of rural reservoirs is essential to detect the effects of diffuse pollution sources such as agricultural activities on the water quality. This paper describes a preliminary study that uses a multiparameter probe and total phosphorus analysis to characterize and compare two reservoirs in Pindorama/SP surrounded by active plantations, noting that one of them has its surface filled with floating macrophytes. The reservoirs’ areas were characterized, and analysis of physicochemical parameters were made in strategic sampling points. Elevated total phosphorus concentrations were detected in both reservoirs, being hypothesized that the source of this nutrient is the runoff of agricultural byproducts from the surroundings. The reservoir filled with macrophytes had greater phosphorus concentration and was characterized as in a eutrophic state, thus explaining the overpopulation of macrophytes as they can be a consequence of the eutrophication process. Lower levels of phosphorus in the other reservoir may be explained by its morphological characteristics and the presence of a more consolidated riparian forest. To reduce the environmental impacts of the contamination in both reservoirs, it was proposed that practices for adequate soil management in the surroundings, for increasing the reservoirs’ water circulation, and for sustainably retaining the contamination sources, could be implemented to control the effects of eutrophication.