Improvement of the coagulation/flocculation process using a combination ofMoringa oleiferaLam with anionic polymer in water treatment

Abstract

The objective of this study is to investigate the impacts of anionic polymer as a flocculant aid on the coagulation/flocculation performance with a saline solution of Moringa oleifera as a coagulant to provide larger flocs and decrease the time sedimentation. For the tests, raw water was used from Pirapó River Basin (Maringá, Paraná, Brazil). Optimization of coagulation/flocculation tests was initially performed in a jar-test with a dosage of M. oleifera Lam (crude extract--MO, oil-extracted with ethanol--MO (et) and hexane--MO (hex) 1% m/v) as the coagulant that ranged from 10 to 60 mg L(-1) and of the anionic polymer 0.1% as a flocculant aid with a dosage that ranged from 0 to 0.4 mg L(-1). The parameters analysed were colour, turbidity and compounds with absorption in UV254nm. In view of the statistical analysis results, MO (hex) with a dosage of 30 mg L(-1) was chosen as a coagulant for the next tests of coagulation/flocculation. When anionic polymer was used alone (0.0 mg L(-1) of MO (hex)), parameters were not removed and there was no generation of heavy flocs as compared with the combination of MO (hex) with the anionic polymer. Statistical analysis showed that MO (hex) obtained the highest removals of the parameters analysed in lower dosages and no significant increase in parameters removal was observed when the polymer dosage was increased. The efficacy of the coagulant +/- anionic polymer was optimal when 30mg L(-1) of MO (hex) was used as a coagulant and 0.1 mg L(-1) of the anionic polymer was used as a flocculant aid, decreasing the time sedimentation from 1 h to 15 min.

Combined water treatment with extract of natural Moringa oleifera Lam and synthetic coagulant

“…Floc size is a crucial parameter in water treatment processes (Bongiovani et al, 2014). It is also known that large flocs tend to present better removal efficiencies (Wang et al, 2009).…”

“…The sludge produced during the coagulation process is innocuous because all MO byproducts are organic, non-toxic and biodegradable (Ndabigengesere et al, 1995). Furthermore, MO seeds also have antimicrobial activity (Joshua and Vasu, 2013 Aiming to improve the efficiency in coagulation/flocculation processes with MO, several researchers have studied its association with synthetic coagulants, such as aluminum sulfate, ferric chloride, PAC and anionic polymers (Awad et al, 2013;Bongiovani et al, 2014;David et al, 2016;Freitas et al, 2016;Ghebremichael et al, 2009;Valverde et al, 2013;. However, there is still a shortage of comprehensive studies comparing the efficiency of coagulant associations (Yin, 2010).…”

Trihalomethanes minimization in drinking water by coagulation/flocculation/sedimentation with natural coagulant Moringa oleifera Lam and activated carbon filtration

“…Subsequently, the solution was stirred for 30 min and filtered under vacuum on a qualitative membrane, resulting a solution of 10 g/L concentration (1 %) . The dosage used was 30 mg/L, as obtained by Carvalho Bongiovani et al…”

“…Afterwards, this mixture was vacuum filtered on a qualitative membrane, obtaining a solution of 10 g/L (1 %) of MO seeds . The saline solution dosage used was 50 mg/L …”

TRATAMIENTO DE AGUAS RESIDUALES DE UNA CENTRAL DE SACRIFICIO: USO DEL POLVO DE LA SEMILLA DE LA M. oleífera COMO COAGULANTE NATURAL

“…al., (1995) [22] verificaron con medidas del potencial Zeta que los mecanismos de coagulación más probables con la utilización de las semillas de M. Oleífera son los de adsorción -neutralización de cargas y adsorción y formación de puentes (Carvalho Bongiovany, M; et al) [23], pudiendo incluso ocurrir de forma simultánea. Esto corrobora los resultados del presente estudio.…”