"Mejoramiento de la calidad de agua para uso y consumo humano a nivel domiciliar mediante la remoción de hierro en la Comunidad Monte Rey ubicada en Cariari de Pococí"

Proyecto de Graduación (Licenciatura en Ingeniería Ambiental) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería Ambiental, 2014.

The Community of Monte Rey is a small settlement where there are 29 plots. At least half of the plots presented serious problems with drinking water for the presence of soluble iron, which has led to the rejection of water for human consumption and the progressive deterioration of the sanitary fittings and plumbing, the metallic taste of the water, turbidity and colour. Each plot has an excavated well without coating, generally with a minimum of 4 m and a maximum of 15 m depth The physico-chemical and microbiological quality of the water taken from a kitchen faucet for each plot connected to each well was determined for a total of household nine samples, in order to know the original quality of the water that the inhabitants are consuming and propose an alternative to level based on that diagnostic. The preliminary diagnostics demonstrated that four samples exceeded the maximum levels admissible for iron (1,39; 1,20; 1,00; 0,80 mg/L) and one sample for manganese (0,60 mg/L), and eight samples reached a turbidity of higher than 1 NTU. In addition, one sample had a significant measurement of chloride (26, 30 mg/L). According to the analysis of organophosphorus, carbamates, organochlorines and paraquat, pesticides were not detected in any sample.Furthermore, on a bacteriological level, one sample was considered potable. After the analysis, it was designed and built a home filtration system to remove iron. Finally, the inflow and outflow of the implemented filtration system was evaluated to check the efficiency of the proposed treatment. The purification system implemented was made of two pretreatment units: tank 1(diffuser system) and tank 2 (sedimentation tank); two secondary treatment units: tank 3 (rapid filter) and tank 4 (slow sand filtration) ; and one storage unit of filtrated water. An evaluation system implemented in December 2013, which consisted in taking two samples (input and output) of the prototype, the values reported in the input of the system were: iron 1,39 mg/L, 48 NTU turbidity and manganese 0,17 mg/L; in the output, iron 0,39 mg/L, 16,38 NTU turbidity and manganese 0,16 mg/L. The iron removal efficiency was of 71% during a week since the system operates, results slightly exceeding the value set by the existing standard (0,3 mg/L).However further iron analysis of the water out of the filtration system is recommended to achieve values under the established norm. Part of this study is not to evaluate the prototype as such, but it gets a benefit for its construction, which is experiencing for the first time at a property in the area of Cariari (Pococi, Limon), the decrease of iron to the output of the installed model. In view of the lack of budget at the end of the period in which the project was planing, not continued further testing in the laboratory and not hydraulic character assessments. Technical and complete filtration system evaluation can be proposed by other students who wish to know the variables and behaviour of household filters. For the evaluation of the efficiency of the system, both in the iron removal properties hydraulic homemade filters over time, it is recommended to carry out another investigation of monitoring the quality of water after each component of the filtration system and study in more detail the behaviour of physical and chemical processes that occur.

Instituto Tecnológico de Costa Rica, Escuela de Ingeniería Ambiental.