Utilização de processos industriais no desenvolvimento de coagulante orgânico à base de moringa oleifera para área de saneamento

Abstract

Coagulation and flocculation processes are the main processes in water treatment and are responsible for removing more than 90% of contaminants present in raw water. However, the most used chemical coagulating agent, aluminum sulfate, ends up generating residues that harm the environment and there is also research that links aluminum intake with neurological diseases. Organic coagulating agents that generate biodegradable waste and do not cause damage to health are becoming increasingly necessary. The seed of the Moringa oleifera plant has in its composition two proteins the thermosensitive lectin (WSMoL) and the thermotolerant lectin (SSMoL) with coagulant properties capable of being used in the treatment of raw water. However, its use as a coagulant in water treatment processes is limited due to other organic substances present in the seed, such as lipids and other proteins, which can increase the residual nitrogen in the water under treatment by interacting negatively in other treatment processes, increasing the color, odor and taste of the water, in addition to being able to generate carcinogenic compounds such as trihalomethanes when in contact with chlorine and its derivatives. This research developed 6 coagulating agents in dry extract, MB0, MD1, MDM2, MDM3, MDMX4 and MDC5 that went through different industrial processes, such as extraction, thermal dehydration processes and Maillard reaction and mixing with guar and xanthan gum. And with the aim of extracting and denaturing organic compounds present in Moringa oleifera seed, without the lectin SSMoL losing its function. The coagulants were tested in Jar Test coagulation tests that demonstrated that the SSMoL lectin, in addition to being more efficient than WSMoL, does not denature in a thermal process up to 120 ° C for 6 hours. Losing coagulant function at temperatures above 150 ° C. The statistical analysis showed that the coagulant developed MDMX4 that went through the stages of lipid extraction, Maillard reaction and mixture with guar and xanthan gum obtained the best results in the removal of turbidity and organic matter obtained by spectrometry UV 254 nm. The analysis of the proximate composition of the MDMX4 coagulant showed a removal of oil content above 25% and protein denaturation above 75% in relation to crude seeds. In the alternative boiling water treatment, the MDM2 coagulant, which only wentthrough the extraction and dehydration stage without reaching a Maillard reaction, showed the best result in reducing organic matter analyzed by spectrometry UV 254 nm. The analyzes of ammoniacal nitrogen showed results <0.10 mg N-NH3 / L in the water treatments by mechanical agitation using MDMX4 and by boiling using MDM2. Indicating the possibility of these coagulating agents to be used in the treatment of water without causing them to interfere with other treatment processes.