Priscila Ferri Coldebella

Improvement of the coagulation/flocculation process using a combination of Moringa oleifera Lam with anionic polymer in water treatment

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 30 mg 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.

Water treatment with exceptional virus inactivation using activated carbon modified with silver (Ag) and copper oxide (CuO) nanoparticles

ABSTRACT Continuous flow experiments (450 mL min−1) were performed in household filter in order to investigate the removal and/or inactivation of T4 bacteriophage, using granular activated carbon (GAC) modified with silver and/or copper oxide nanoparticles at different concentrations. GAC and modified GAC were characterized by X-ray diffractometry, specific surface area, pore size and volume, pore average diameter, scanning electron microscopy, transmission electron microscopy, zeta potential and atomic absorption spectroscopy. The antiviral activity of the produced porous media was evaluated by passing suspensions of T4 bacteriophage (∼105 UFP/mL) through filters. The filtered water was analyzed for the presence of the bacteriophage and the release of silver and copper oxide. The porous media containing silver and copper oxide nanoparticles showed high inactivation capacity, even reaching reductions higher than 3 log. GAC6 (GAC/Ag0.5%Cu1.0%) was effective in the bacteriophage inactivation, reaching 5.53 log reduction. The levels of silver and copper released in filtered water were below the recommended limits (100 ppb for silver and 1000 ppb for copper) in drinking water. From this study, it is possible to conclude that activated carbon modified with silver and copper oxide nanoparticles can be used as a filter for virus removal in the treatment of drinking water.

Removal of Anabaena flos-aquae in water treatment process using Moringa oleifera and assessment of fatty acid profile of generated sludge

ABSTRACT This study aimed to evaluate the efficiency of the coagulation/flocculation/dissolved air flotation (C/F/DAF) process using the coagulant Moringa oleifera (MO) seed powder, and to analyse the profile of fatty acids present in the generated sludge after treatment. For the tests, deionized water artificially contaminated with cell cultures of Anabaena flos-aquae was used, with a cell density in the order of 104 cells mL–1. C/F/DAF tests were conducted using ‘Flotest’ equipment. For fatty acid profile analyses, a gas chromatograph equipped with a flame ionization detector was used. It was seen that the optimal dosage (100 mg L–1) of MO used in the C/F/DAF process was efficient at removing nearly all A. flos-aquae cells (96.4%). The sludge obtained after treatment contained oleic acid (61.7%) and palmitic acid (10.8%). Thus, a water treatment process using C/F/DAF linked to integral MO powder seed was found to be efficient in removing cells of cyanobacteria, and produced a sludge rich in oleic acid that is a precursor favourable for obtaining quality biodiesel, thus becoming an alternative application for the recycling of such biomass.

Evaluation of protein extraction methods to obtain protein concentrate from cassava leaf

The cassava leaf, waste generated in the harvest of the roots, is characterized by high content of protein, vitamins and minerals; however, its use is limited due to the high fiber content and antinutritional substances, which can be removed by obtaining protein concentrates. In this context, the objective of this study was to evaluate protein extraction processes, aiming the use of cassava leaves (Manihot esculenta Crantz) as an alternative protein. Four methods were tested: 1) Coagulation of Proteins by Lowering the Temperature, 2) Extraction by Isoelectric Precipitation, 3) Solubilization of Proteins and 4) Fermentation of Filter Leaf Juice. To obtain the concentrates, the use of fresh or dried leaves and extraction in one or two steps were also evaluated. The solubilization of proteins (method 3) showed a higher extraction yield; however, with concentrate of low quality. The fermentation of the juice (method 4) produced concentrates with higher quality and lower costs and the isoelectric precipitation (method 2) promoted the obtention of concentrates in less time, both with good prospects for use. The use of two extraction steps was not advantageous to the process and there was no difference between the use of fresh or dried leaf, and the use of fresh leaves is presented as a good option for the simplicity of the method.

Moringa oleifera Lam. and Its Potential Association with Aluminium Sulphate in the Process of Coagulation/Flocculation and Sedimentation of Surface Water

The present study aims to optimize the operational conditions in surface water coagulation/flocculation and sedimentation step, besides evaluating the association between seeds of Moringa oleifera Lam. (M. oleifera) and the synthetic coagulant aluminium sulphate for surface water treatment. The assays were performed in Jar Test using surface water from Pirapo River basin, Maringa, PR. It was observed that the operational conditions affect the coagulation/flocculation and sedimentation process efficiency. Optimal operational conditions for coagulants association are as follows: rapid mixing velocity (RMV) of 105 rpm, rapid mixing times (RMT) of 1 min, slow mixing velocity (SMV) of 30 rpm, slow mixing times (SMT) of 15 min, and sedimentation time (ST) of 15 min; this enables an improvement in the process, contributing to a reduction in synthetic coagulant aluminium sulphate demand of up to 30%, combined with an increase in M. oleifera dosage, not affecting the coagulation/flocculation and sedimentation process efficiency, considering the water pH range between 7 and 9.

OTIMIZAÇÃO DAS CONDIÇÕES DE OPERAÇÃO NO PROCESSO DE CLARIFICAÇÃO DE ÁGUA SUPERFICIAL POR MEIO DA ASSOCIAÇÃO DOS COAGULANTES Moringa oleifera Lam E CLORETO FÉRRICO

RESUMO: Informacoes sobre as condicoes de operacao no processo de clarificacao ainda sao escassas na literatura, principalmente relacionadas aos efeitos do uso de coagulantes quimicos em conjunto com a Moringa oleifera Lam (MO). Assim, esse estudo propoe otimizar as condicoes de operacao do processo de coagulacao/floculacao e sedimentacao, por meio de ensaios em Jar Test realizados com a alteracao das velocidades de mistura rapida (VMR) e lenta (VML), tempos de mistura (TMR e TML) e sedimentacao (TS), para a associacao do coagulante MO e cloreto ferrico. Utilizou-se agua superficial proveniente da bacia do rio Pirapo, Maringa, PR, com turbidez inicial de 72,9 NTU e as dosagens de coagulantes adicionadas nos ensaios foram de 10 mg.L -1 e 50 mg.L -1 para o cloreto ferrico e MO, respectivamente. Para a avaliacao da remocao dos parâmetros de qualidade utilizou-se delineamento fatorial 27x4, sendo vinte e sete variacoes quanto a velocidade de mistura (VMR e VML) e tempos de mistura (TMR e TML); e quatro tempos de sedimentacao (TS). Verificou-se que os parâmetros de mistura afetam a eficiencia de remocao dos parâmetros de qualidade. Por meio da aplicacao do teste Tukey, as condicoes de operacao foram: 100 rpm (VMR), 3 min (TMR), 30 rpm (VML) e 15 min (TML), com eficiencias de remocao de 89,7%, 90,8% e 73,5% para os parâmetros cor aparente, turbidez e compostos com absorcao em UV 254nm , respectivamente. Palavras chaves: Clarificacao da agua. Moringa oleifera Lam. Cloreto ferrico.

Adsorption of naturals hormones estrone, 17β-estradiol, and estriol by rice husk: monocomponent and multicomponent kinetics and equilibrium

ABSTRACT In the present study, the use of the rice husk biomass as an alternative biosorbent for treating the estrone, 17 β-estradiol, and estriol hormones in monocomponent and multicomponent systems was investigated. The high-performance liquid chromatography technique (HPLC-UV) was applied in order to quantify the hormones, validating this method according to ANVISA and INMETRO. The biosorbent presented functional groups typical of cellulose, hemicellulose, lignin, and proteins, with an amorphous, fibrous, and porous surface. The best performance was obtained with a neutral pH and at room temperature (25C). The equilibrium times in batch systems were 60  min for the estrone, and 120 min for 17 βestradiol and estriol. The monocomponent kinetics of adsorption of estrone and estriol were adequately described by the pseudo-first-order model, whereas for the 17 β estradiol both pseudo-first-order and pseudo-second-order models well described the experimental data. For the multicomponent system, the kinetics of adsorption was appropriately represented by the pseudo-first-order model, demonstrating that the number of active sites was the limiting factor of the process. The monocomponent adsorption isotherms were adequately fitted by the Langmuir model, reaching adsorption capacities of 2.698, 1.649, and 0.979 mg g−1 for the estrone, 17 βestradiol, and estriol hormones, respectively. The ternary isotherm models did not represent the experimental data, indicating that there was no competition among the hormones. The reactions presented favourable and spontaneous characteristics. The rice husk biomass showed a great potential as an adsorbent when treating effluents contaminated with hormones. GRAPHICAL ABSTRACT

Coagulation/flocculation/flotation/nanofiltration processes using Moringa Oleifera as coagulant of Eutrophized river

This study investigated the efficiency of Moringa oleifera (MO) seeds as natural coagulant in coagulation/flocculation/dissolved air flotation (C/F/DAF), followed by nanofiltration (NF) for Microcystis protocystis and microcystin-LR removal. The methodology adopted in this work was performed in two steps: 1) coagulation/flocculation/dissolved air flotation (C/F/DAF) process using the MO extracted in saline solution of potassium chloride (KCl-1M) and sodium chloride (NaCl-1M) in optimum dosage 50 mg·L -1 ; 2) nanofiltration process using NF90 and NF270 membrane provided Dow Chemical Company®. A working pressure of 8 bar was applied. In all samples were analyzed color, turbidity, pH, cyanobacterial cells count and microcystin concentration. The use of MO seeds as natural coagulant, obtained satisfactory results in the M. protocystis, color and turbidity removal. NF was able to completely remove cyanobacterial cells and microcystins (100 %) from M. protocystis (always under the quantification limit). Therefore, C/F/DAF+NF sequence is a safe barrier against M. protocystis and microcystins in drinking water.