Cacto mandacaru (Cereus jamacaru): coagulante como auxiliar no tratamento de água

Abstract

Water is highly important for both life and ecosystem, being an abundant source on the planet. To make it drinkable for society, the solution is a water treatment, where the main function is to remove the present impurities. Among the main stages of this process, we can name the coagulation, flocculation, decanting, filtration and disinfection. During the coagulation stage, a product known as coagulant is used, which makes the present particles in the water to agglomerate, and usually the aluminium sulfate is applied. However, due to problems pointed out in studies, it is necessary to find substitutes or an auxiliary in order to avoid the problems. Although, this study aimed to apply the Cereus jamacaru cactus as an auxiliary and substitute to the aluminium sulfate, analysing the results and verifying which showed better efficiency. Initially, the raw water was collected in the CODAU that is captured in the Uberaba River, and the acid, basic and saline extracts were prepared with the addition of the cactus and then with aluminum sulphate. Physicochemical analysis of both raw water and water with coagulants was performed, and the analysis of alkalinity, pH, turbidity, apparent colour, dissolved oxygen, electrical conductivity and temperature. From the results obtained with the extracts in addition to the cactus, it was observed that the acid solution showed better results with a dosage of 34mL, managing to reduce turbidity by 89.7%, while basic and saline showed a turbidity reduction of 62.15% and 60.27%, respectively. With the extracts in conjunction with aluminum sulphate and cactus, the results were also more efficient with the acid-extracting solution. This one showed turbidity removal of 88.2%, while with the basic and saline extracts, the reduction was 51.2% and 50.53% respectively. The turbidity removal applying only aluminum sulphate was 72.48%. Therefore, it was possible to conclude that the application of acid extraction solution as a coagulant in water treatment showed better results in reducing turbidity, both in the presence of cactus alone and when in aid of aluminum sulphate, but some studies are necessary for the results found to fit within the established parameters.