It is important to update work procedures in the preventive aspects and occupational diseases of wastewater treatment plants. The objective of the research was to identify levels of exposure to hazardous products by the tasks performed in wastewater treatment plants in order to update work procedures in the preventive aspects and occupational diseases of wastewater treatment plants, and reduce health risks and negative impacts on the environment. One of the operating processes in the treatment of domestic wastewater is coagulation, where aluminum sulfate is generally used with very efficient results, but it generates health and environmental risks; Therefore, the coagulating power of Opuntia ficus-indica clouded and Caesalpinia spinosa gum was evaluated against the conventional coagulant Aluminum Sulfate to remove turbidity from water samples of the UASB effluent from the Septic Tank of the Wastewater Research Center (CITRAR) - UNI. The tests were done by jar test for the coagulation, flocculation and sedimentation process, in six equal doses for each coagulant. The results of coagulant removal efficiency were 59.42 % when using a dose of 40 mg/L of Opuntia ficus-indica, 55.78 % with a dose of 110 mg/L of Caesalpinia spinosa and 91.60 % with a dose of 70 mg/L of Aluminum Sulfate. The results indicate that natural coagulants offer considerable percentages of turbidity improvement in the treatment of urban effluents; therefore, replacing the use of aluminum sulfate with natural coagulants reduces negative impacts and prevents damage to health, providing safety to workers and the environment.