Start-up adjustment of a plug-flow digester for cassava wastewater (manipueira) treatment (original) (raw)
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Cassava wastewater (manipueira) treatment using a two-phase anaerobic biodigestor
Ciência e Tecnologia de Alimentos, 2000
A two-phase anaerobic biodigestor was employed in order to analyze methane production with different manipueira organic loading rates. The acidogenic phase was carried out in a batch process whereas the methanogenic in an up-flow anaerobic fixed bed reactor with continuous feeding. The organic loading rates varied from 0.33 up to 8.48g of Chemical Demand Oxygen (COD)/L.day. The highest content of methane, 80.9%, was obtained with organic loading rate of 0.33g and the lowest, 56.8%, with 8.48gCOD/L.d. The highest reduction of COD, 88.89%, was obtained with organic loading rate of 2.25g and the lowest, 54.95%, with 8.48gCOD/L.d. From these data it was possible to realize that anaerobic biodigestion can be managed in at least two ways, i.e., for energy production (methane) or for organic loading reduction. The organic loading rate should be calculated as part of the purpose of the treatment to be accomplished.
Optimization of Anaerobic Treatment of Cassava Processing Wastewater
Engenharia Agrícola, 2017
The main contribution of this research is to optimize the operating conditions of an anaerobic reactor applied to the treatment of wastewater from cassava starch production. A 20-L anaerobic reactor was used, operating in a batch system, with temperature control. Temperature and inoculum total volatile solids (TVSi) were controlled for evaluation of effects on the removals of chemical oxygen demand (COD) and reactor total volatile solids (TVSr) by means of a Central Composite Rotational Design (CCRD). Twelve trials were analyzed simultaneously by the desirable function approach. The higher COD removal (96.82%) was obtained at 42 °C and 12.0% TVSi. The largest TVSr removal (69.31%) was registered at 45 °C and 10.0% TVSi. Equations representative of the process were obtained from the responses of variables, being statistically significant at a 90% confidence level. Based on the desirability function approach, we can conclude that an optimal operational condition for the anaerobic reactor is at 39.7 °C and 10.8% TVSi. The estimated COD and TVSr removal efficiencies under these operating conditions were 90.45% and 63.12%, respectively.
Performance of an Anaerobic Baffled Reactor (ABR) in treatment of cassava wastewater
Brazilian Journal of Microbiology, 2009
The performance of an anaerobic baffled reactor (ABR) was evaluated in the treatment of cassava wastewater, a pollutant residue. An ABR divided in four equal volume compartments (total volume 4L) and operated at 35ºC was used in cassava wastewater treatment. Feed tank chemical oxygen demand (COD) was varied from 2000 to 7000 mg L -1 and it was evaluated the most appropriated hydraulic retention time (HRT) for the best performance on COD removal. The ABR was evaluated by analysis of COD (colorimetric method), pH, turbidity, total and volatile solids, alkalinity and acidity. Principal component analysis (PCA) was carried to better understand data obtained. The system showed buffering ability as acidity decreased along compartments while alkalinity and pH values were increased. There was particulate material retention and COD removal varied from 83 to 92% for HRT of 3.5 days.
Engenharia Agrícola, 2013
The use of anaerobic reactors with media support in the treatment of wastewater from the cassava starch industry has emerged as a viable option because it allows the application of high organic loads and a significant reduction of the HDT needed for the treatment. This research aimed at studying the process of biodigestion in two anaerobic reactors with bamboo support, in the treatment of effluent of cassava starch, by evaluating their performance. The two reactors used present the following diameter: length ratio, 1:6 and 1:3. The organic loads applied to the systems were 0.519, 1.156, 1.471, 3.049, 4.347, 4.708 and 5.601g.L-1.d-1. Regarding the efficiency of removal of COD, TS and TVS, no statistically significant differences were obtained between the reactors. The two systems evaluated showed a stable behavior with respect to the VA/TA (volatile acidity/total alkalinity) for all submitted loads. The reactors tended to the maintenance of biogas production as a function of consumed...
A Model for Optimal Treatment of Cassava Wastewater Using Anaerobic Baffled Reactor
NIGERIAN JOURNAL OF TECHNOLOGICAL DEVELOPMENT, 2021
The major components of the effluents from cassava processing industries are cyanide and starch. However it is suspected that cyanide inhibits the treatment of cassava wastewater. The experimental data were successfully fitted to a polynomial model which was used to optimize the treatment processes at a laboratory scale. The Monod and Michealis-menten models for cassava wastewater treatment was successfully calibrated and validated in an ABR system. For Michealis-Menten model, the maximum substrate utilization rate is estimated in the range: 2866.88 to 1432.84 mgl-1 and for Monod's model, it is estimated in the range: 493 to 1242 mgl-1, which is more realistic, hence validating the empirical model as more accurate than the former, which is theoretical. The result revealed that the inhibitor constant decreased from 9.9989 to 1.6101mgl-1 as the number of baffles increased from 3 to 10. To reach a maximum COD removal efficiency of 99%, it was found that the aspect ratio of 10, 20 baffles, cyanide inhibition constant of 30 mg/l and influent flow rate of 0.8 l/min, are the required optimum operating conditions of the anaerobic baffled reactors.
Mathematical Modelling of Cassava Wastewater Treatment Using Anaerobic Baffled Reactor
The performance of an anaerobic baffled reactor (ABR) was evaluated in the treatment of cassava wastewater as a pollutant residue. An ABR divided in four equal volume compartments (total volume 4L) and operated at 35°C was used in cassava wastewater treatment. Feed tank chemical oxygen demand (COD) was varied from 2000 to 7000mg L -1 . The objective of the study was to formulate an improved mathematical model to describe cassava wastewater treatment without taking into account its inhibition characteristic. In the study, Kincannon-Stover model constants µ max and K s , were found to be 0.8803mg/L. d and 0.2113COD/m 3 . day respectively and Monod Model constants µ max and K s , were found to be 100mg/L. d and 98mgCOD respectively. The coefficient of determinations (R 2 ) of Kincannon-Stover and Monod Models were evaluated as 0.634 and 0.986. This showed that the Monod model is a more applicable model for describing the kinetics of the organic removal in anaerobic baffled reactor for treating cassava wastewater.
Anaerobic biodegradation of cassava wastewater under different temperatures and inoculums
Comunicata Scientiae
The production of starch generates, as a by-product, the cassava wastewater (manipueira), which can be treated by anaerobic digestion to provide biogas and minimize its polluting potential. The most commonly utilized biomass in the anaerobic digestion is the anaerobic sludge. The literature presents, as an alternative to sludge, bovine manure and ruminal fluids, being scarce the studies with the cassava wastewater. This research evaluated the influence of temperature on the microbial ability of cattle and goat rumen in anaerobically biodegrading the manipueira in substitution to the anaerobic sludge. The cattle and goat rumen specific methanogenic activities (SMA) were compared with that of the anaerobic sludge. Subsequently, by using the inoculum which had the best SMA results, cassava wastewater biodegradability tests were performed, investigating the kinetics of the organic matter removal and methane production at 32 ° C and 39 ° C. The bovine rumen presented better results in th...
2019
The absence of wastewater treatment facilities in small-scale cassava agroindustry results in the disposal of toxic effluent that causes environmental problems to host communities. A pilot multi-compartment reactor packed with graded earthen materials with continuous aeration and anaerobic degradation was evaluated for the treatment of cassava mill wastewater. The results suggest that continuous aeration and biodegradation of the effluent reduced Hydrogen Cyanide by 84%, BOD (72%), COD (69%) and Turbidity (41%). A slightly acidic pH of 5.0 was obtained for the final effluent. The results suggest an efficient and promising technique that combines physical and nature-based processes in degrading key pollutants from cassava effluent. Despite having some pollutants with final values above permissible limits, the system can be optimized to enhance performance. The treatment technique is adjudged sustainable with low technical operating demands and can be used for on-site wastewater treat...