Introduction
Since the LACQUASE project has its scope focused on the improvement of water quality in Brazil and countries with similar water and sanitary structures, a study was carried out on the current legislation regarding the water treatment process. We aim to adapt our project to meet the quality standards, resolutions and environmental guidelines imposed.
The company Sabesp is a Brazilian company that holds the concession of public basic sanitation services in the State of São Paulo, being responsible for the treatment of water in the city of Lorena. In this sense, the company informed us about the criteria and emission parameters of the treated effluents and we had access to the resolutions CONAMA n°357 and Portaria de consolidação n°5 anexo 20.
Analyzing the resolutions:
CONAMA is the National Council for the Environment, and the Resolution No. 357 dictates water quality rules and specifies the maximum composition of certain organic and inorganic compounds that may be present in each type of water. One of main articles from the resolution is the follows:
Art. 14. Class 1 fresh water shall observe the following conditions and standards:
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I - water quality conditions:
- non-verification of chronic toxic effects to organisms, according to the criteria established by the competent environmental body or, in its absence, by a renowned national or international institutions, by a standardized ecotoxicological test or other recognized methodology.
- floating materials, including non-natural foams: virtually absent;
- oils and greases: virtually absent;
- substances that communicate taste or odor: virtually absent;
- dyes from anthropic sources: virtually absent;
- objectionable solid waste: virtually absent;
- thermotolerant coliforms: for the use of primary contact recreation should be obeyed the standards set in the CONAMA Resolution No. 274 of 2000. For other uses, a limit of 200 thermotolerant coliforms per 100 milliliters should not be exceeded 80% or more, of at least 6 samples, collected during a period of one year, bimonthly. The E. Coli can be determined in place of the thermotolerant coliform parameter of according to limits established by the competent environmental agency;
- BOD 5 days at 20 ° C to 3 mg / L of oxygen;
- OD, in any sample, of not less than 6 mg / L O2;
- turbidity up to 40 nephelometric turbidity units (UNT);
- true color: natural color level of the body of water in mg Pt / L; and pH: 6.0 to 9.0.