Jose Crispiniano Feitosa Filho,Tarlei Ariel Botrel,Antonio Pires de Camargo,Jose Maria Pinto,Cassiana Felipe de Sousa, Universidade Federal da Paraiba, Solos e Engenharia Rural, feitosafilho@ig.com.br
ABSTRACT:
This work had the purpose to evaluate the efficiency of artificial aeration processes done isolated and/or together with chlorination and pH control, followed by filtration for treatment of Fe++ and Mn++ ions excess in irrigation water. At aeration system it was used a Venturi injector to capture atmospheric air injecting it into the water. In this process it was used a system of perforated PVC pipes to put the air captured by the injector into the water. The water was stored in two reservoirs made of polyester reinforced with glass fiber with capacity of 5000 l each one. The water samples were obtained at interval of times equal to 0; 30; 60; 90 and 120 minutes and sent to laboratory. It was determined Fe++, total iron, Mn++ and total manganese concentrations. At field, it was determined oxygen values of the water, water temperature, ambient temperature, electric conductivity and pH of the water. The chlorination was made using sodium hypochlorite (NaOCl) and the pH control using sulfuric acid. At filtration process were used two sand filters, one filter of disks and one screen filter (200 mesh). The aeration done with pH control of the water was more efficient for treatment of iron than manganese. At chlorination and in the treatment using sulfuric acid for pH control there was an increase on the electric conductivity of the water. The aeration system using Venturi injector and perforated PVC pipes was highly efficient about of proposed objectives.
KEYWORDS: emitter clogging, aeration, pH control, filtration, microirrigation.