RESUMO
Consideration is now being given to the use of metal coagulants to remove turbidity from drinking water and wastewater. Concerns about the long-term impact of non-biodegradable sludge on human health and the potential contamination of aquatic systems are gaining popularity. Recently, alternative biocoagulants have been suggested to address these concerns. In this study, using a 1 M sodium chloride (NaCl) solution, the active coagulating agent was extracted from Pinus halepensis Mill. Seed, and used for the first time to remove Congo red dye, the influence of numerous factors on dye removal was evaluated in order to make comparisons with conventional coagulants. The application of biocoagulant was shown to be very successful, with coagulant dosages ranging from 3 to 12 mL L-1 achieving up to 80% dye removal and yielding 28 mL L-1 of sludge. It was also found that biocoagulant is extremely pH sensitive with an optimum operating pH of 3. Ferric chloride, on the other hand, achieved similar removal rate with higher sludge production (46 mL L-1) under the same conditions. A Fourier Transform Infrared Spectroscopy and proximate composition analysis were undertaken to determine qualitatively the potential active coagulant ingredient in the seeds and suggested the involvement of proteins in the coagulation-flocculation mechanism. The evaluation criteria of the Support vector machine_Gray wolf optimizer model in terms of statistical coefficients and errors reveals quite interesting results and demonstrates the performance of the model, with statistical coefficients close to 1 (R = 0.9998, R2 = 0.9995 and R2 adj = 0.9995) and minimal statistical errors (RMSE = 0.5813, MSE = 0.3379, EPM = 0 0.9808, ESP = 0.9677 and MAE = 0.2382). The study findings demonstrate that Pinus halepensis Mill. Seed extract might be a novel, environmentally friendly, and easily available coagulant for water and wastewater treatment.
Assuntos
Pinus , Purificação da Água , Humanos , Vermelho Congo/análise , Esgotos/química , Pinus/química , Águas Residuárias , Floculação , Sementes/química , Purificação da Água/métodos , Cloreto de SódioRESUMO
This work reports a combined coagulation-electrocoagulation process using a biocoagulant from the Opuntia ficus-indica for treatment of cheese whey wastewater. The process parameters as pH, biocoagulant dosage, and current density were evaluated from the chemometric tools. A Box-Behnken design was used, having as responses the removal percentages of turbidity and chemical oxygen demand (COD). The results showed that for the studied variable ranges, linear models were obtained and the pH was parameter more significant for treatment proposed. The pH showed synergic effect with the investigated parameters, while the biocoagulant dosage and density current showed antagonistic effects. The desirability function was used to optimization of process, and suggested values were pH 10.0, biocoagulant dosage of 4.4 g L-1, and current density of 31.5 mA cm-2, which showed removals of turbidity and COD of 98.9 and 83.8%, respectively.
Assuntos
Queijo , Opuntia , Poluentes Químicos da Água , Águas Residuárias , Eliminação de Resíduos Líquidos/métodos , Soro do Leite/química , Monitoramento Ambiental , Eletrocoagulação/métodos , Análise da Demanda Biológica de Oxigênio , Resíduos Industriais/análiseRESUMO
This study proposes a unique way of preparation of biocoagulant from Moringa oleifera defatted seed press cake. The press cake used in this study is a waste material produced as a by-product during cold press oil making from Moring oleifera seeds. The prepared Moringa oleifera seed defatted press cake based biocoagulant was found more effective than presently used metallic and polymer-based coagulants and flocculants for removal of fine particles of colloidal size from the effluent generated in the process of coal beneficiation. The detailed characterization of Moringa oleifera defatted seed press cake and the prepared biocoagulant for Particle size, Field Emission Scanning Electron Microscopy, Energy Dispersive X-Ray analysis, Zeta Potential, Fourier-transform Infrared Spectroscopy, etc. was done. The biocoagulant has been found effective in 97.4% total suspended solids removal and 97.48% turbidity removal from coal beneficiation plant effluent. The biocoagulant has been found to work satisfactorily under high fluxes of turbidity and total suspended solids with high removal of fine particles. The age of biocoagulant had negligible effect on fine particle removal efficiency (97.4% for fresh to 95% for 3-week-old biocoagulant). Field Emission Scanning Electron Microscopy analysis reveals considerable increase in flocs size from 198 nm to a 20 µ size well-developed flocs. The biocoagulant has proved as an efficient substitute of the metallic and polymer-based coagulants for the efficient treatment of coal beneficiation plant effluent.
Assuntos
Moringa oleifera , Purificação da Água , Carvão Mineral , Extratos Vegetais , SementesRESUMO
Cationic polypeptide proteins found in the seeds of the tropical plant Moringa oleifera have coagulation efficiencies similar to aluminum and ferric sulfates without their recalcitrant nature. Although these proteins possess great potential to augment or replace traditional coagulants in water treatment, harvesting active protein from seeds is laborious and not cost-effective. Here, we describe an alternative method to express and secrete active M. oleifera coagulant protein (MO) in Bacillus subtilis. A plasmid library containing the MO gene and 173 different types of secretory signal peptides was created and cloned into B. subtilis strain RIK1285. Fourteen of 440 clones screened were capable of secreting MO with yields ranging from 55 to 122 mg/L of growth medium. The coagulant activity of the highest MO secreting clone was evaluated when grown on Luria broth, and cell-free medium from the culture was shown to reduce turbidity in a buffered kaolin suspension by approximately 90% compared with controls without the MO gene. The clone was also capable of secreting active MO when grown on a defined synthetic wastewater supplemented with 0.5% tryptone. Cell-free medium from the strain harboring the MO gene demonstrated more than a 2-fold reduction in turbidity compared with controls. Additionally, no significant amount of MO was observed without the addition of the synthetic wastewater, suggesting that it served as a source of nutrients for the effective expression and translocation of MO into the medium.
Assuntos
Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Moringa oleifera/química , Proteínas de Plantas/biossíntese , Sementes/química , Coagulantes/metabolismo , Floculação , Microbiologia Industrial , Extratos Vegetais/metabolismo , Águas Residuárias/química , Purificação da Água/métodosRESUMO
The consumption of unsafe water in rural areas is a real public health problem in developing countries. This situation mainly affects children under five years of age and causes several deaths and many cases of malnutrition every year. The objective of this study was to evaluate and optimize the capacity of four local plant extracts in the potabilization of unsafe water. Thus, Moringa oleifera and Boscia senegalensis seeds, or Aloe vera and Opuntia ficus-indica mucilages were prepared in a solution and applied during a jar test as biocoagulants and bioflocculants on three raw water samples of 82.3 NTU, 549.8 NTU and 796.9 NTU. After treatment results showed that 0.9 g/L of Moringa biocoagulant or 1 g/L of Boscia biocoagulant applied with 0.4 mL of Aloe vera bioflocculant or 0.6 mL of Opuntia ficus-indica bioflocculant reduced the turbidity of each water sample to values less than 5 NTU after only 15 min of decanting. Moreover, the sanitary quality of the water treated by these different extracts showed a perfect conformity of the physicochemical and microbiological parameters with the standards of acceptability in drinking water decreed by the World Health Organization. Thus, the application of these local plant extracts has made it possible to considerably improve the quality of unsafe water in record time. Their popularization could be an alternative in the fight against malnutrition related to the consumption of unsafe water, especially in rural areas.
Assuntos
Aloe , Países em Desenvolvimento , Desnutrição , Extratos Vegetais , Purificação da Água , Extratos Vegetais/química , Humanos , Aloe/química , Purificação da Água/métodos , Moringa oleifera/química , Abastecimento de Água , Opuntia/química , Água Potável/química , Moringa/químicaRESUMO
Natural coagulants derived from by-products have gained popularity as sustainable alternatives to inorganic coagulants in water/wastewater treatment due to their abundant availability, biodegradability, low cost, easy disposal and low sludge volumes. In this study, the mucilage obtained from the peel of Opuntia ficus-indica fruit was evaluated as a biocoagulant for treating synthetic turbid water and compared with a traditional chemical coagulant (FeCl3). The effects of coagulant dosage and pH on the turbidity and color-removal efficiency of synthetic turbid water were analyzed. To estimate the coagulation mechanism, the flocs produced under optimal values were characterized structurally (FTIR and zeta potential) and morphologically (SEM). The optimal condition for the removal of turbidity and color was a coagulant dose of 12 mg/L at pH 13. For the optimal values, the biocoagulant and the FeCl3 presented a maximum removal of 82.7 ± 3.28% and 94.63 ± 0.98% for turbidity and 71.82 ± 2.72% and 79.94 ± 1.77% for color, respectively. The structure and morphology of the flocs revealed that the coagulation mechanism of the mucilage was adsorption and bridging, whereas that of FeCl3 was charge neutralization. The results obtained showed that the mucilage could be used as an alternative coagulant to replace FeCl3.
RESUMO
The nontoxicity, worldwide availability and low production cost of cuttlefish bone products qualify them an excellent biocoagulant to treat food industry wastewater. In this study, cuttlefish bone liquid waste from the deproteinization step was used as a biocoagulant to treat food industry wastewater. This work concerns a waste that has never before been investigated. The objectives of this work were: the recovery of waste resulting from cuttlefish bone deproteinization, the replacementof chemical coagulants with natural ones to preserve the environment, and the enhancement ofthe value of fishery byproducts. A quantitative characterization of the industrial effluents of a Moroccan food processing plant was performed. The physicochemical properties of the raw cuttlefish bone powder and the deproteinization liquid extract were determined using specific analysis techniques: SEM/EDX, FTIR, XRD and 1H-NMR. The protein content of the deproteinization liquid was determined by OPA fluorescent assay. The zeta potential of the liquid extract was also determined. The obtained analytical results showed that the deproteinization liquid waste contained an adequate amount of soluble chitin fractions that could be used in food wastewater treatment. The effects of the coagulant dose and pH on the food industrial effluents were studied to confirm the effectiveness of the deproteinization liquid extract. Under optimal conditions, the coagulant showed satisfactory results. Process optimization was performed using the Box-Behnken design and response surface methodology. Thus, the optimal removal efficiencies predicted using this model for turbidity (99.68%), BOD5 (97.76%), and COD (82.92%) were obtained at a dosage of 8 mL biocoagulant in 0.5 L of food processing wastewater at an alkaline pH of 11.
RESUMO
In this study, a biocoagulant synthesized from the association of iron oxide (Fe3O4) nanoparticles and Moringa oleifera Lam (MO) extract was tested in different concentrations for the removal of the apparent colour and dye concentration (reactive black 5) of synthetic textile wastewater. Coagulation/flocculation process was performed and followed by magnetic sedimentation in Jar-Test equipment, the operational parameters studied were sedimentation time and biocoagulant dosage. The efficiency of the C/F/S process was determined by analysing the apparent colour and RB5 concentration, and removals of 93.7% apparent colour and 96.2% RB5 concentration were observed after 20 min of magnetic sedimentation. Reuse tests were performed, which indicated that the biocoagulant and the resulting sludge from the process could be used again for synthesis and used for three consecutive cycles without drastically reducing efficiency (69% for colour removal and 70% for dye concentration). All analyses were conducted considering 95% confidence level. Thus, the proposed biocoagulant demonstrated high potential for the removal of the evaluated parameters in the treatment of textile wastewater due to its high efficiency, simple and fast preparation, and its environmentally friendly qualities.
Assuntos
Moringa oleifera , Poluentes Químicos da Água , Purificação da Água , Floculação , Fenômenos Magnéticos , NaftalenossulfonatosRESUMO
Tannin extracts from the bark of Acacia mearnsii and wood of Schinopsis balansae, commonly known as Quebracho, were employed. These were modified at laboratory sale via the Mannich aminomethylation with formaldehyde and dimethylamine hydrochloride. Some reaction conditions were varied, namely the formaldehyde dosage and reaction time, while keeping the Mannich solution activation time constant, and their influence on the shear viscosity of the created bio-coagulants was evaluated. The effect of the final pH of the products on their shear viscosity was also analyzed. Up-scaling of the Mannich reaction for tannin from South Africa was performed and the procedure developed at 1-L scale was reproducible in upscaled conditions. One example of a modified South Africa tannin and the modified Quebracho tannin was subsequently selected for the treatment of an industrial wastewater and tested for color and turbidity reduction in jar tests. The effluent treatment was carried out in a single and dual system with cationic synthetic flocculation agents of different charge degree. Good turbidity and decoloration results (93 and 89% reduction, respectively) were obtained with the simultaneous introduction of a cationic, 40% charged polyacrylamide, with minimal dosage (5 ppm) of the latter additive. The tannin-based coagulant from Acacia mearnsii was successfully applied in dual system with cationic polyacrylamide flocculant for industrial wastewater treatment at pilot plant scale. It was shown to satisfactorily treat the water and generate less sludge.
Assuntos
Taninos/química , Águas Residuárias , Purificação da Água , Floculação , África do SulRESUMO
A new commercial cationic polyelectrolyte chitosan (CM), obtained from the waste of mushroom production, was examined using models of water and wastewater namely kaolin and palm oil mill effluent (pome). As it is biocompatible, widely available, and economically feasible, chitosan mushroom has high potential to be a suitable replacement for alum. Also, it can be a promising alternative to chitosan obtained traditionally from Crustaceans due to its higher zeta potential and homogeneity based on the raw material required for its production. A wide range of coagulant dose (5-60 mg l-1) and wastewater pH (2-12) were taken into account to find the optimal conditions of coagulation. The optimal doses are 10 and 20 mg l-1 at best pH (11 and 3) when treated with kaolin and palm oil mill effluent, respectively, while 1200 mg l-1 of alum was not enough to reach the efficiency of chitosan mushroom. On the other hand, the optimum dose of chitosan mushroom (20 mg l-1) at pH 3 of pome produced (75, 73, and 98%) removal of chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS), respectively. The significant potential of chitosan mushroom was proved by zeta potential measurement. Indeed, it possesses the highest zeta potential (+70 mV) as compared to the traditional chitosan produced from crustaceans. In short, chitosan mushroom as a biocoagulant is eco-friendly and it enhances water quality that meets the requirements of environmental conservatives.
Assuntos
Agaricales/química , Quitosana/química , Polieletrólitos/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Quitosana/isolamento & purificação , Floculação , Polieletrólitos/isolamento & purificaçãoRESUMO
Aims@#Providing safe drinking water is an ongoing global concern. Coagulation is an essential process in water treatment. However, most of the coagulants are chemical in nature and have negative impacts on human health and the environment. This study investigated the production of myco-coagulant in solid-state fermentation using a fungal strain. @*Methodology and results@#A scale-up was performed using the tray method to investigate the influence of substrate thickness (from 2-30 mm) on myco-coagulant production. The results revealed that the turbidity removal efficiency of myco-coagulant in kaolin suspension was found to be increasing with the increase in thickness of the coco peat substrate. However, the myco-coagulant extracted from the media with a thickness of 30 mm was able to remove the highest turbidity by 96%. Three different subculturing methods for mycelium inoculation were evaluated. The surface inoculation approach produced better results than other inoculation processes. The effect of initial turbidity values (50-300 NTU) on turbidity removal was studied too. The myco-coagulant was found to be the most suitable for high-turbidity water (300 NTU) with turbidity removal of 52%. Subculturing of fungus from solid-state to solid-state was also studied, which showed that the strategy was just as effective as an inoculum-based subculture. @*Conclusion, significance and impact of study@#Excellent bio-coagulation activity has been shown for the myco-coagulant that was isolated from the fungus strain. Subculturing using existing substrates will be more economical than subculturing using fresh inoculum. This strategy saves time, labour and cost of the coagulant production.