Potato Processing Wastewater Research Articles

Biotransformation of starch-based wastewater into bioplastics: Optimization of poly(3-hydroxybutyrate) production by Cupriavidus necator DSM 545 using potato wastewater hydrolysate

Biodegradable biopolymers, such as polyhydroxyalkanoates (PHAs), have emerged as an alternative to petrochemical-based plastics. The present work explores the production of PHAs based on the biotransformation of potato processing wastewater and addresses two different strategies for PHA recovery. To this end, culture conditions for PHA synthesis by Cupriavidus necator DSM 545 were optimized on a laboratory scale using a response surface methodology-based experimental design. Optimal conditions rendered a PHB, poly(3-hydroxybutyrate), accumulation of 83.74 ± 2.37 % (5.1 ± 0.2 gL−1), a 1.4-fold increase compared to the initial conditions. Moreover, polymer extraction with non-halogenated agent improved PHB recovery compared to chloroform method (PHB yield up to 78.78 ± 0.57 %), while maintaining PHB purity. (99.83 ± 4.95 %). Overall, the present work demonstrated the potential valorization of starch-based wastewater by biotransformation into PHBs, a high value-added product, and showed that recovery approaches more eco-friendly than the traditional treatments could be applied to PHB recovery to some extent.

Application of Microbial Fuel Cell Technology in Potato Processing Industry

The potato processing industry is among the biggest water-consuming industries, using an average of 17 L of water per 1 kg of processed product. Taking into account that the potato is the fourth-most-important non-cereal food crop with a global production of 376 million tons a year, this branch is a large wastewater producer. Potato-processing wastewater is highly loaded and thus difficult to treat through conventional methods, especially when a low energetic input for environmental benignancy is required. In this review, it was shown that microbial fuel cells (MFCs) are an excellent technology for sustainable potato wastewater treatment. MFCs allow for potato wastewater COD removal with efficiencies as high as 99%, which is accompanied by electricity production that may reach 3.7 W/m2. Thus, the recently published research reviewed in this paper indicates that simultaneous power production and removal of chemical oxygen demand make MFCs superior to conventional treatment methods. Encouraging results and the unique advantages of MFC technology, like significant water and energy use reduction, give a promising perspective on potato-processing wastewater treatments.

Aqueous phase reforming of starch wastewater over Pt and Pt-based bimetallic catalysts for green hydrogen production

This work analyses the application of aqueous phase reforming (APR) for green hydrogen production from starch industry wastewater. This work reports for the first time on the direct conversion of a high molecular weight biomass polymer contained in wastewater in contrast to low molecular weight substrates mainly reported in the literature. The potential of this type of feedstock was evaluated by varying the starch source (rice, potato, sweet potato and cassava) and the type of catalyst (carbon supported Pt, PtRu, PtPd, PtRe and PtRh catalysts). In APR experiments at 220 °C with synthetic wastewater, PtRu/C and Pt/C catalysts achieved the highest H2 yield values, around 51 mmol H2 per g of organic carbon in the initial wastewater, close to 2.6 times higher than that reported in the literature of brewery wastewater, a promising substrate. The lack of free aldehyde or keto groups due to glycosidic bonds between glucose units in starch results in higher conversion to gas and H2 production compared to APR of glucose. This fact shows that APR has more feedstock flexibility than that previously reported for light compounds. In the experiments with real wastewaters, the organic matter removal was influenced largely by the starch source: the best APR performance (28.5 mmol H2 gTOCi−1) was obtained for rice processing wastewater, which is characterized by the highest starch concentration and the lowest protein content. Poor performance was observed in the APR of potato processing wastewater, probably due to catalyst deactivation caused by protein fraction.

Integration of Ultra- and Nanofiltration for Potato Processing Water (PPW) Treatment in a Circular Water Recovery System.

The article analyzes integrated ultrafiltration (UF) and nanofiltration (NF) processes for potato processing wastewater treatment for the purpose of which a laboratory filtration system for flat sheet membranes with the effective surface area of 1.4 × 10-2 m2 (UF: polysulfone, cut-off: 10,000 Da; NF: polypiperazine amide, cut-off: 150-300 Da) was used. As part of the study, the effect of the transmembrane pressure of UF (0.2 MPa and 0.4 MPa) and NF (1.0 MPa and 1.8 MPa) on the permeate flux and rejection coefficient was investigated and the impact of sewage preparation methods on the degree of pollution reduction was determined. Moreover, a method for a fouling layer removal from the UF membranes is also proposed. The results of the analyses conducted by the authors show that the pretreatment stage offers additional advantages to TSS and turbidity removal. In both cases (0.2 and 0.4 MPa), UF used after the pretreatment process resulted in a 97-99% reduction in these impurities. The analysis of the determined rejection coefficients shows that the use of NaOH and H2O2 for the regeneration of the UF membrane has a positive effect on filtration efficiency. Regarding NF, the rejection coefficients for most tested parameters were higher for the 1.8 MPa process compared to 1.0 MPa, and approximately 80% of water was recovered.

Hybrid Anaerobic Membrane Bioreactor System for Treatment and Reuse of Potato Processing Wastewater

Hybrid Anaerobic Membrane Bioreactor System for Treatment and Reuse of Potato Processing Wastewater

Single-Chamber Microbial Fuel Cell with Multiple Plates of Bamboo Charcoal Anode: Performance Evaluation

In this study, three single-chamber microbial fuel cells (MFCs), each having Pt-coated carbon cloth as a cathode and four bamboo charcoal (BC) plates as an anode, were run in a fed-batch mode, individually and in series. Simulated potato-processing wastewater was used as a substrate for supporting the growth of a mixed bacterial culture. The maximum power output increased from 0.386 mW with one MFC to 1.047 mW with three MFCs connected in series. The maximum power density, however, decreased from 576 mW/m2 (normalized to the cathode area) with one MFC to 520 mW/m2 with three MFCs in series. The experimental results showed that power can be increased by connecting the MFCs in series; however, choosing low resistance BC is crucial for increasing power density.

Potato Processing Wastewater Treatment Using a Combined Process of Chemical Coagulation and Membrane Filtration

AbstractThe potato‐processing wastewater (PPW) treatment method employe a combined process of chemical coagulation/flocculation and membrane filtration. Four different inorganic coagulants are used: polyaluminium chloride, alum, iron(III) chloride and iron(II) sulphate. The results show that the inorganic coagulants enhanced both chemical oxygen demand (COD) with turbidity removal at 1 g/L of concentration. Iron(III) chloride is the most efficient for COD and turbidity removal efficiencies of 54% and 88%, respectively. At pH=6, COD and turbidity elimination performances are enhanced to 67% and 96%, respectively. The findings suggest that coagulation plays a key role in the removal of COD and turbidity of PPW, but water quality is again improved by a second stage of treatment. The utilisation of ultrafiltration (UP150) at 1 bar of transmembrane pressure (TMP) has highly improved water quality. At the end of this research, a comparative study is conducted between the combined process: coagulation/flocculation‐membrane filtration and direct filtration of raw PPW. The results demonstrate that the primary stage of treatment is necessary to prevent early membrane fouling and provided high permeate flux. Even though, the most used treatments rely on combined coagulation/flocculation and membrane filtration systems, very few research articles are reported for PPW treatment.

COD reduction of potato processing wastewater using natural and commercial adsorbents

COD reduction of potato processing wastewater using natural and commercial adsorbents

Comparison of thermophilic and mesophilic anaerobic treatment for potato processing wastewater using a contact reactor

In this study, different organic loading rates (OLRs) ranging from 1.1 to 5.0 kg COD/m3·day were used to assess the performance of an anaerobic reactor at the optimum mesophilic (35°C) and thermophilic (55°C) temperatures. The methane gas production rate of the thermophilic treatment was higher than that of the mesophilic treatment. The efficiency of chemical oxygen demand (COD) removal was observed to range from 89.12 to 93.20% following the thermophilic anaerobic treatment and from 76.36 to 92.62% following the mesophilic treatment. The average VFA (volatile fatty acid)/alkalinity ratio of the effluent was 0.3 under both thermophilic and mesophilic conditions for all the OLR applications. The HPr/HAc (propionic acid/acetic acid) ratio was calculated as 0.16 and 1.3 for the mesophilic and thermophilic treatments, respectively. For the mesophilic treatment, the average methane gas production was found to be 0.394 m3 CH4/kg CODremoved while it was 0.42 m3 CH4/kg CODremoved for the thermophilic experiment. However, the sludge settleability of the mesophilic treatment was better than that of the thermophilic treatment.

Size effects of potato waste on its treatment by microbial fuel cell

ABSTRACTThe performance of microbial fuel cell (MFC) in treating potato cubes with different sizes (the edge size of 3, 5 and 7 mm) was investigated. Current density was found lower as the size of potato cubes increased, even if the differences in their removal were less apparent. At the end of MFC operation for 81 days, both total and soluble chemical oxygen demand reached nearly identical values, irrespective of the potato sizes; and citrate and isobutyrate were two major organic acids remaining in the solutions. Bacterial community analysis using polymerase chain reaction, denaturing gradient gel electrophoresis and sequencing indicated that bacterial species on the anode and in the anodic solution were similar and did not change obviously with potato sizes, and that, in similarity with previous studies on potato-processing wastewater treatment, Proteobacteria and Firmicutes were two dominating phyla. Geobacter was found richer on the anode than in the anodic solutions.

English

An evaluation of a laboratory-scale aerobic method for the treatment of potato-processing wastewater at 37°C was investigated. Composite samples were collected to establish batch variations. The wastewater was characterized for Chemical Oxygen Demand (COD), Permanganate Value (PV), Total Solids (TS), phosphates and pH over a period of 6 months. Wastewater with an average of 6.8 g COD/l, high concentration of total solids (up to 6725 mg/l), and low pH was subjected to active sludge treatment in a Continuously Stirred Tank Reactor (CSTR) with Organic Loading Rates (OLRs) gradually increased from 3.4 to 12.1 g COD/litre/day. Stepwise increase in OLR reduced average COD reduction from 86% at 3.4 g COD/litre/day to 76% at 12.1 g COD/litre/day. High rates of treatment efficiency (TE) were recorded at low OLRs (<6.8 g COD/litre day) with a notable pH of the effluent increasing from 4 to neutral values. TS reduction was achieved at 57% at HRT of 2 d. This study indicated that biological methods can be used for treatment of potato-processing wastewater in order to reduce the organic load and other pollutants acceptable levels for municipal discharge. Key words: Potato wastewater, biotreatment, mesophilic, continuous stirred tank reactor (CSTR), activated sludge.

Utilisation of potato processing wastewater for microbial lipids and γ-linolenic acid production by oleaginous fungi.

Microbial lipids are considered as the starting material for production of second-generation biofuels and their polyunsaturated fatty acids are rich sources of neutraceuticals. Exploring cheap feedstock for producing microbial lipids is necessary. The present study examined the potential of microbial lipids and γ-linolenic acid (GLA) production by two oleaginous fungi, Aspergillus flavus I16-3 and Mucor rouxii, with potato processing wastewater as a low-cost or no-cost nutrient source. Biochemistry and physiology of two oleaginous fungi, A. flavus I16-3 and M. rouxii, on lipid accumulation showed the two fungi grew well and efficiently utilised the starch in wastewater. On average (P < 0.05), 2.8 and 3.6 g L(-1) of lipids were produced by A. flavus I16-3 and M. rouxii, respectively, with maximum GLA yields of 60 and 100 mg L(-1) . Addition of nutrients to raw wastewater significantly improved (P < 0.05) the lipid and GLA yields; 3.5 and 4.2 g L(-1) of lipids, and 100 and 140 mg L(-1) of GLA were produced by A. flavus I16-3 and M. rouxii, respectively. In addition, the wastewater was efficiently treated, with soluble chemical oxygen demand, total soluble nitrogen and total soluble phosphorus removals up to 60% and 90%, 100% and 98%, and 92% and 81% by A. flavus I16-3 and M. rouxii, respectively. This study demonstrated an alternative approach to valorise potato processing wastewater to produce microbial lipids and GLA (nutraceuticals).

The effect of shock loading on the performance of a thermophilic anaerobic contact reactor at constant organic loading rate.

The influences of organic loading disturbances on the process performance of a thermophilic anaerobic contact reactor treating potato-processing wastewater were investigated. For this purpose, while the reactor was operated at steady state conditions with organic loading rate of 5.5 kg COD/m3 · day, an instant acetate concentration increase (1 g/L) was introduced to the reactor. During the shock loading test of acetate, it was observed that the overall process performance was adversely affected by all the shock loading, however, the system reached steady state conditions less than 24 hours of operation indicating that thermophilic anaerobic contact reactor is resistant to shock loading and be capable of returning its normal conditions within a short time period.

Potato Starch Processing Wastewater Physical Property Estimation Based on Material Properties

In order to meet the demand of wastewater physical properties in low temperature, vacuum evaporation equipment design for potato starch processing wastewater treatment, the way is used to collect physical properties data and listed in table, then equations have been gotten from curve fit way with multi parameters calculation expression of potato processing wastewater, multi parameters mainly about: the density, viscosity, thermal conductivity and heat enthalpy, boiling point, heat capacity and engineering calculation formula of concentration with temperature. From then on, physical properties data of potato starch processing wastewater can be easy to get from the formula, just input the temperature and the concentration into these calculation formulas, it is the foundation for design and calculation of process devices.

Microbial lipid production from potato processing wastewater using oleaginous filamentous fungi Aspergillus oryzae

Use of potato processing wastewater for microbial lipid production by oleaginous filamentous fungus Aspergillus oryzae was studied with the purpose of recycling potato processing wastewater for biodiesel production. The wastewater contained high concentrations of solids, starch and nutrients. Sterilization of the potato processing wastewater resulted in a thick gelatinized medium, causing the fungi to grow slow. In order to overcome this problem, the wastewater was diluted with tap water at three dilution ratios (25%, 50% and 75% before fermentation). Dilution of the wastewater not only enhanced lipid production, starch utilization and amylase secretion but also COD and nutrient removal. The dilution ratio of 25% was found to be optimum for lipid production and the maximum lipid concentration obtained was 3.5 g/L. Lipid accumulation was influenced by amylase secretion, and the amylase activity was up to 53.5 IU/mL at 25% dilution. The results show that phosphate limitation may be the mechanism to stimulate the lipid accumulation. In addition to lipid production, removals of COD, total soluble nitrogen and total soluble phosphorus up to 91%, 98% and 97% were achieved, respectively. Microbial lipids of A. oryzae contained major fatty acids such as palmitic acid (11.6%), palmitolic acid (15.6%), stearic acid (19.3%), oleic acid (30.3%), linolenic acid (5.5%) and linoleic acid (6.5%) suggesting that the lipids be suitable for second generation biodiesel production.

Applicability of industrial wastewater as carbon source for denitrification of a sludge dewatering liquor

The applicability of four industrial waste streams from potato processing, canola processing and oil refining, biodiesel production (glycerol), and glycol as substitutes to methanol and ethanol in denitrification of anaerobically digested sludge dewatering liquor (centrate) was evaluated in bench-scale sequencing batch reactors. It was found that glycerol was the best substitute with the specific denitrification rate (SDNR) of 13 mg NO 3-N/(g VSS·h) followed by potato processing wastewater at 12 mg NO 3-N/(g VSS·h ). Both substrates produced faster SDNR than methanol's 10 mg NO 3-N/(g VSS·h ); however, they were inferior to ethanol's 17 mg NO 3-N/(g VSS·h ). Glycol had SDNR of 8 mg NO 3-N/(g VSS·h ) and demonstrated a very fast acclimation rate, i.e. the response in increased denitrification rate was visible in three days following glycol addition. Canola processing and oil refining wastewater was considered an inappropriate carbon source due to a low SDNR of 5 mg NO 3-N/(g VSS·h ) and apparent inhibitory effect on nitrification.

Enhancement of ethanol production from potato-processing wastewater by engineering Escherichia coli using Vitreoscilla haemoglobin

Ethanologenic Escherichia coli strain FBR5 was transformed with the Vitreoscilla haemoglobin (VHb) gene (vgb) in two constructs (resulting in strains TS3 and TS4). Strains FBR5, TS3 and TS4 were grown at two scales in LB medium supplemented with potato-processing wastewater hydrolysate. Aeration was varied by changes in the medium volume to flask volume ratio. Parameters measured included culture pH, cell growth, VHb levels and ethanol production. VHb expression in strains TS3 and TS4 was consistently correlated with increases in ethanol production (5-18%) under conditions of low aeration, but rarely did this occur with normal aeration. The increase in ethanol yields under low aeration conditions was the result of enhancement of ethanol produced per unit of biomass rather than enhancement of growth. 'VHb technology' may be a useful adjunct in the production of biofuels from food-processing wastewater. Genetic engineering using Vitreoscilla haemoglobin (VHb) has been shown previously to increase ethanol production by Escherichia coli from fermentation of the sugars in corn fibre hydrolysate. The study reported here demonstrates a similar VHb enhancement of ethanol production by fermentation of the glucose from potato waste water hydrolysate and thus extends the list of sugar containing waste products from which ethanol production may be enhanced by this strategy.

Two-stage foam separation technology for recovering potato protein from potato processing wastewater using the column with the spiral internal component

For recovering potato protein from potato processing wastewater, the effects of temperature, pH, volumetric airflow rate, liquid loading volume and sparging time on the foam separation performances were investigated using the column with the spiral internal component (SIC). A two-stage foam separation technology was designed to improve both the enrichment ratio and recovery percentage of potato protein. The results showed that the SIC and specially the increase of temperature were effective for improving the enrichment ratio of potato protein. A best enrichment ratio of potato protein of 4.69 was obtained under the optimal conditions of temperature 45°C, pH 7, volumetric airflow rate 100mL/min, liquid loading volume 300mL and sparging time 90min. The total recovery percentage of potato protein was as high as 73.4% by using the two-stage foam separation technology. So the two-stage technology was effective for the protein recovery from potato processing wastewater.

Screening of Industrial Wastewaters as Feedstock for the Microbial Production of Oils for Biodiesel Production and High-Quality Pigments

The production of biodiesel has notably increased over the past decade. Currently, plant oil is the main feedstock for biodiesel production, but, due to concerns related to the competition with food production, alternative oil feedstocks have to be found. Oleaginous yeasts are known to produce high amounts of lipids, but no integrated process from microbial fermentation to final biodiesel production has reached commercial realization yet due to economic constraints. Therefore, growth and lipid production of red yeastRhodotorula glutiniswas tested on low-cost substrates, namely, wastewaters from potato, fruit juice, and lettuce processing. Additionally, the production of carotenoids as high-value by-products was examined. All evaluated wastewaters met the general criteria for microbial lipid production. However, no significant increase in lipid content was observed, probably due to lack of available carbon in wastewaters from fruit juice and lettuce processing, and excess of available nitrogen in potato processing wastewater, respectively. During growth on wastewaters from fruit juice and lettuce processing the carotenoid content increased significantly in the first 48 hours. The relations between carbon content, nitrogen content, and carotenoid production need to be further assessed. For economic viability, lipid and carotenoid production needs to be increased significantly. The screening of feedstocks should be extended to other wastewaters.

Kinetic studies on the anaerobic degradation of soluble and particulate matter in potato wastewater

The anaerobic degradation of particulate-containing potato processing wastewater using a mixed culture from an industrial anaerobic wastewater treatment plant as inoculum was characterised and modelled. Anaerobic digestion is being increasingly used for wastewater treatment, particularly those which contain high levels of biodegradable matter such as potato processing effluents. A major prerequisite for its proper modelling is a reliable wastewater characterisation with a proper discrimination of the chemical oxygen demand (COD) fractions. These wastewaters contain both soluble (S) and particulate (X) organic load that are assimilated by microorganisms at different rates. Furthermore, these wastewaters generally contain both solid (XI) and soluble (SI) inert to anaerobic degradation fractions. In this work, a procedure to determine the COD fractions of potato wastewater is developed. For the wastewater studied, the initial fraction of inert particulate organic matter ( x X I ) was negligible, while the initial fraction of inert soluble organic matter ( x S I ) was 20.94% ± 1.65. A model with first-order serial-parallel reactions system was developed for biodegradable fractions. This model has demonstrated its capability to predict the behaviour of the system and can be used for further research work or more complex reactor design.