Starch Industry Wastewater Research Articles

Mixed (organic and inorganic) contaminants removal ability of water fern biomass-based biochar on starch industry wastewater

Mixed (organic and inorganic) contaminants removal ability of water fern biomass-based biochar on starch industry wastewater

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.

Biopesticide production using Bacillus thuringiensis kurstaki by valorization of starch industry wastewater and effluent from aerobic, anaerobic digestion

Unconventional alternatives such as aerobic and anaerobic effluent from starch industry contain essential nutrients for Btk active ingredient synthesis. Effluent from starch industry is rich in carbon and nitrogen and can replace expensive feedstock used during the fermentation process. The main objective of this study was to achieve a biopesticide formulation from starch industry wastewater (SIW) with high entomotoxicity (UI/ml) of larvae comparable to Foray 76B, which is a commercial biopesticide. Bacillus thuringiensis var kurstaki HD1 (Btk) strain was cultivated and sub-cultured to aerobic, anaerobic digested effluent and SIW. Pre-treatment was carried on these different substrates to enhance the residual carbon required for Btk growth and delta endotoxin synthesis. After 48 hours of fermentation, cells count and delta-endotoxin were determined. A biopesticide formulation containing fermented broth and adjuvants was fed to larvae to determine larvae mortality. Btk cell growth and sporulation profile in SIW media displayed a high total cell count and viable spores compared to btk growth in anaerobic or aerobic media after 48h fermentation. The maximum endotoxin concentration in the SIW medium was 435μg/mL, whereas, in anaerobic and aerobic effluent, the maximum concentrations were at 161 μg/mL and 136 μg/mL, respectively. When acidic treatment was performed at pH 2 for these substrates, entomotoxicity obtained from aerobic and anaerobic biopesticide formulations displayed significantly higher entomoxicity than the untreated ones. The entomotoxicity of SIW treated at pH 2 was equivalent to the standard Foray 76B which is 20,000 IU/μL. Anaerobic and aerobic effluent did not contain enough total organic carbon to augment Btk growth and entomotoxicity. Substrates pre-treated at pH 2 provided significant organic matter for Btk growth and resulted in larval mortality equivalent to the com ercial biopesticide Foray 76B.

Production of Bacillus thuringiensis based biopesticide formulation using starch industry wastewater (SIW) as substrate: A techno-economic evaluation

In this study, cost simulation was made to produce Bacillus thuriengiensis based biopesticide formulation using starch industry wastewater (SIW) as substrate. The results obtained at pilot plant (2000L capacity fermenter) were used for cost simulation of the process. The unit production cost for annual production of 5 million L of formulated biopesticide (20.2 Billion International Units (BIU)/L) was estimated to be $ 2.54/L, which is competitive to chemical pesticides. The techno-economic evaluation revealed that the profitability of the biopesticide manufacturing process was sensitive to the plant capacity and selling price of the biopesticide. The manufacturer should target 5 million L annual plant capacity and selling price of $ 15/L for payback period to be less than 5 years. The process serves many advantages (1) alternate disposal or bio-valorisation of industry wastewater and (2) use of industry wastewater as inexpensive carbon source reducing cost of raw materials for fermentation.

Hydrolytic pre-treatment methods for enhanced biobutanol production from agro-industrial wastes

Brewery industry liquid waste (BLW), brewery spent grain (BSG), apple pomace solid wastes (APS), apple pomace ultrafiltration sludge (APUS) and starch industry wastewater (SIW) have been considered as substrates to produce biobutanol. Efficiency of hydrolysis techniques tested to produce fermentable sugars depended on nature of agro-industrial wastes and process conditions. Acid-catalysed hydrolysis of BLW and BSG gave a total reducing sugar yield of 0.433 g/g and 0.468 g/g respectively. Reducing sugar yield from microwave assisted hydrothermal method was 0.404 g/g from APS and 0.631 g/g from APUS, and, 0.359 g/g from microwave assisted acid-catalysed SIW dry mass. Parameter optimization (time, pH and substrate concentration) for acid-catalysed BLW hydrolysate utilization using central composite model technique produced 307.9 g/kg glucose with generation of inhibitors (5-hydroxymethyl furfural (20 g/kg), furfural (1.6 g/kg), levulinic acid (9.3 g/kg) and total phenolic compound (0.567 g/kg)). 10.62 g/L of acetone-butanol-ethanol was produced by subsequent clostridial fermentation of the substrate.

Influence of temperature on mixed microbial culture polyhydroxyalkanoate production while treating a starch industry wastewater

The influence of temperature on the production of enrichment biomass and polyhydroxyalkanoates by activated sludge was evaluated within a practical case study. Two laboratory-scale sequencing batch reactors (SBRs) were operated in parallel over 131days to treat a wastewater from a potato-starch modification facility, and produce surplus activated sludge biomass with PHA accumulation potential. The SBRs were operated similarly but at different temperatures (15 and 25°C). Temperature did not influence wastewater treatment performance (average 97% COD removal).Replicate PHA accumulation experiments were conducted on the SBR surplus biomass at 15, 20, 25 and 30°C. Surplus biomass accumulated PHA with acetic acid to between 60 and 65%, gPHA/gVSS for all temperatures tested and with estimated Arrhenius temperature coefficients (θ) of 1.048 for the PHA production, and 1.062 for the COD consumption specific rates. The MMC PHA production process was adaptable within a common range anticipated for seasonal fluctuation of temperature for the influent wastewater and PHA production feedstocks without loss of performance. This outcome suggests a broad range in the practical feasibility and reliability with MMC method and process implementations. PHA production was predicted to be more efficient at lower temperatures. Strategies can be engineered in the bioprocess design and operations to accommodate for temperature shifts in practical applications of PHA production as a route to resource recovery from organic waste management services.

Pilot-scale biopesticide production by Bacillus thuringiensis subsp. kurstaki using starch industry wastewater as raw material

ABSTRACTPilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (KLa) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material.

Kinetic and equilibrium studies of fluoride adsorption by a carbonaceous material from pyrolysis of waste sludge

The efficiency of the adsorption for fluoride by sludge from the treatment of starch industry wastewater was investigated. Batch experiments were conducted in order to determine the parameters that affect the adsorption process. The activation for waste sludge and specific surface area and porosity effects in enhancing the pyrolysis conditions were determined. The adsorption parameters of initial fluoride concentration, pH and adsorbent dosage were investigated with carbonaceous material. As a result of pyrolysis of samples treated with ZnCl2 1196 m2/g, the specific surface area was reached. Correlation coefficient of 0.99 and 12.75 mg/g adsorption capacity and adsorption isotherm model were revealed as convenient. Experimental results show that the adsorption of fluoride waste sludge will be effective in many ways in which the adsorbent is applied.

Microflora from leaf debris is suitable for treatment of starch industry wastewater

Biological treatment of industrial waste is a widely practiced technique that generates comparatively less environmentally hazardous waste than other chemical treatment processes. Wet milling of maize generates huge amount of wastewater (5 m3/ton) of low pH with organic matter and nutrients. Anaerobic methanogenic and aerobic bacteria are mostly highly sensitive to low pH. The treatment of wastewater causes huge cost of chemical neutralization or hydraulic recirculation for maintaining neutral pH. In the present study, different microbial consortia isolated from cow dung, active sludge from an anaerobic reactor for treatment of industrial wastewater, and leaf debris from benthic soil were screened for tolerance against low pH and for potential of chemical oxygen demand (COD) removal in order to find out an alternative microbial population for industrial water treatment at low pH. The most effective consortia found from leaf debris were further investigated for optimal operation. The microscopic analysis of leaf debris sludge showed abundance of Gram‐negative methanococci, which was found tolerant to low pH in plate culture method. On further investigation for COD removal from starch industry effluent, they were found to be most effective at pH 5 with highest COD removal rate of 70% and lowest biomass generation of 81%. Hence, it was concluded that the low pH‐tolerant methanogen bacteria, enriched from leaf debris sludge, is highly beneficial for anaerobic treatment of wastewater from several industries including corn starch industry by reducing cost of operation for neutralization to neutral pH and through reducing excess waste sludge production by the treatment system.

Agro-industrial wastes as feedstock for sustainable bio-production of butanol by Clostridium beijerinckii

Three different inexpensive, abundant agro-industrial wastes: suspended brewery liquid waste (BLW), starch industry wastewater (SIW) and apple pomace ultra-filtration sludge (APUS) have been explored for biobutanol production. Physicochemical analysis of biomass for carbohydrate and nutrient pool, acid hydrolysis, fermentation of raw extracts and hydrolysates by Clostridium beijerinckii NRRL B-466 for ABE production and glucose supplementation to increase butanol production have been studied. The efficiency of the microorganism to produce butanol and other metabolites was explored via carbon balance. Inhibitory effects were minimized by dilution and detoxification method. Pretreated diluted extracts having reducing sugar content of 30g/L gave optimum butanol production of 4.68g/L, 1.4g/L and 1.8g/L from SIWH, APUSH and BLWH, respectively, as compared to 5.1g/L obtained from control. Reducing sugar concentration in each diluted extract was increased to 60g/L by 3% (w/v) glucose supplement and the butanol production was increased to 11.04g/L (0.27g/g), 9.3g/L (0.24g/g) and 8.06g/L (0.25), respectively. For SIWH, the maximum yield of butanol (0.27g/g) and acetone–butanol–ethanol (ABE) (0.46g/g) was obtained. Thus, production of butanol, with 3% glucose supplement demonstrated that these inexpensive agro-industrial wastes could have important implications in stimulating energy-economics.

Corrosion and stability study of Bacillus thuringiensis var. kurstaki starch industry wastewater-derived biopesticide formulation

Biopesticides are usually sprayed on forests by using planes made up of aluminum alloy. Bioval derived from starch industry wastewater (SIW) in suspension form was developed as stable anticorrosive biopesticide formulation. In this context, various anticorrosion agents such as activated charcoal, glycerin, ethylene glycol, phytic acid, castor oil and potassium silicate were tested as anticorrosive agents. There was no corrosion found in Bioval formulation where potassium silicate (0.5% w/v) was added and compared with Foray 76 B, as an industrial standard, when stored over 6 months. In relation to other parameters, the anticorrosion formulation of Bioval+buffer+KSi reported excellent zeta potential (−33.19 ± 4 mV) and the viscosity (319.13 ± 32 mPa.s) proving it's stability over 6 months, compared to the standard biopesticide Foray 76 B (−36.62 ± 4 mV potential zeta, pH 4.14 ± 0.1 and 206 ± 21 mPa.s viscosity). Metal analysis of the different biopesticides showed that Bioval+buffer+KSi has no corrosion (5.11 ± 0.5 mg kg−1 of Al and 13.53 ± 1.5 mg kg−1 of Fe) on the aluminum alloy due to the contribution of sodium acetate buffer at pH 5. The bioassays reported excellent results for Bioval+Buffer+KSi (2.95 ± 0.3 × 109 CFU mL−1 spores and 26.6 ± 2.7 × 109 IU L−1 Tx) compared with initial Bioval (2.46 ± 0.3 × 109 CFU mL−1 spores and 23.09 ± 3 × 109 IU L−1 Tx) and Foray 76 B (2.3 ± 0.2 × 109 CFU mL−1 spores and 19.950 ± 2.1 UI L−1 Tx) which was due to the break-up of the external chitinous membrane due to abrasive action of potassium silicate after ingestion by insects. The contribution of sodium acetate buffer and potassium silicate (0.5% and at pH = 5) as anticorrosion agent in the Bioval allowed production of an efficient biopesticide with a reduced viscosity and favorable pH as compared to Foray 76 B which enhanced the entomotoxic potential against spruce budworm (SB) larvae (Lepidoptera: Choristoneura fumiferana).

Electrochemical treatment of biodigester effluent of maize-based starch industry: COD and color removal

Electrochemical (EC) treatment of biodigester effluent (BDE) of maize (corn)-based starch industry wastewater was investigated. Four aluminum plate electrodes were employed in a 1.5 dm3 electrolytic batch reactor. Experiments were performed in the pH range of 4–10 using current density (CD) in the range of 51–255 A/m2 (1–5 A). The distance between each of the aluminum electrodes was fixed at 15 mm. At pH 9 and at a CD of 153 A/m2 for an operation time of 100 min, maximum chemical oxygen demand reduction of 84.13% and color reduction of 94.89% were achieved using the EC process. The power (energy) requirement and electrode loss were calculated at varying pH. The settling and filterability characteristics of electro-coagulated sludge were studied at different pH. It was demonstrated that EC treatment is an effective treatment method to treat BDE from maize-based starch industry.

Anaerobic reactors with biofilter and different diameter-length ratios in cassava starch industry wastewater treatment

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 COD for the last three organic loads applied, indicating an ability to withstand higher organic loads.

Optimisation of spray drying by response surface methodology for the production of Sinorhizobium meliloti powder formulation by using starch industry wastewater

A spray-drying process was optimised by response surface methodology for the development of a powder formulation of Sinorhizobium meliloti (produced in starch industry wastewater). The process parameters comprised drying temperature, air drying rate, spray pressure and feed sample rate. Cheese whey powder, sorbitol and sucrose were added at 10, 1 and 1% w/v, respectively before drying. Responses studied comprised cell viability, moisture and outlet temperature. Under the optimal conditions (maximum desirability = 0.81), the formulation showed cell viability of 6.8 × 109 CFU g−1, moisture of 11.4% and outlet temperature of 42 °C. During 4 months of refrigerated storage, viability was maintained at >109 CFU g−1. Analysis of inoculated alfalfa plants showed that powder formulation induced similar shoot yield on dry basis (144.6 mg) (p = 0.23) and nodulation index (15.2) (p = 0.18) compared to fresh cells cultured in standard media (shoot yield and nodulation index were 131 and 14 mg, respectively). Micrographs showed that cells were embedded in the mixture of additives (whey–sucrose–sorbitol) which acted as a matrix.

Energy balance and greenhouse gas emissions of biodiesel production from oil derived from wastewater and wastewater sludge

It has been recognized that oils derived from microorganism and wastewater sludge are comparable replacements of traditional biodiesel production feedstock, which is energy intensive and costly. Energy balance and greenhouse gas (GHG) emissions are essential factors to assess the feasibility of the production. This study evaluated the energy balance and GHG emissions of biodiesel production from microbial and wastewater sludge oil. The results show that energy balance and GHG emissions of biodiesel produced from microbial oil are significantly impacted by the cultivation methods and carbon source. For phototrophic microorganism (microalgae), open pond system gives 3.6 GJ higher energy gain than photo bioreactor system in per tonne biodiesel produced. For heterotrophic microorganisms, the energy balance depends on the type of carbon source. Three carbon sources including starch, cellulose, and starch industry wastewater (SIW) used in this study showed that utilization of SIW as carbon source provided the most favorable energy balance. When oil extracted from municipal sludge is used for biodiesel production, the energy gain is up to 29.7 GJ per tonne biodiesel produced, which is higher than the energy gain per tonne of biodiesel produced from SIW cultivated microbes. GHG emissions study shows that biodiesel production from microbes or sludge oil is a net carbon dioxide capture process except when starch is used as raw material for microbial oil production, and the highest capture is around 40 tonnes carbon dioxide per tonne of biodiesel produced.

Mathematical relationships between spore concentrations, delta-endotoxin levels, and entomotoxicity of Bacillus thuringiensis preparations produced in different fermentation media

Mathematic relationships between spore concentrations, delta-endotoxin concentrations and entomotoxicity (Tx) of Bacillus thuringiensis var. kurstaki HD-1 (Btk HD-1) preparations produced in six different media were analysed. The relationship between delta-endotoxin and spore concentration and SpTx-spore (specific Tx per 1000 spore) and spore concentration produced in the different media (starch industry wastewater (SIW) with total solids (TS) concentration of 15g/L, SIW with TS of 30g/L, SIW supplemented with 0.2% (w/v) colloidal chitin, SIW supplemented with 1.25% (w/v) cornstarch and 0.2% (v/v) Tween 80, secondary sludge, and semi-synthetic medium) strictly followed the Power law. Tx and delta endotoxin concentration followed the exponential relation whereas a definite relation between Tx and spore concentration could not be established. Spore and delta-endotoxin produced at the early time (12h) during fermentation might be more toxic than those produced during latter period of fermentation irrespective of media used. Tx and delta-endotoxin concentration exhibited a semi-log linear relationship. Based on these findings, delta-endotoxin concentration can be determined rapidly to monitor the progress of the biopesticide production process.

Flux Improvement during Cross-flow Microfiltration of Wheat Starch Suspension using Turbulence Promoter

The objective of this study was to investigate the effects of the process variables (transmembrane pressure, flow rate, and concentration) on the permeate flux during the microfiltration of model starch suspensions, and to determine the conditions under which the use of Kenics statics mixer as a turbulence promoter is justified. A response surface methodology was used to examine the influence of the selected operating conditions on starch suspension microfiltration using a single channel ceramic membrane with 200 nm pore size. The experimental results clearly show that the improved performance of starch suspension cross-flow microfiltration can be obtained by using a Kenics static mixer, especially at lower flow rates. Compared to the operation without the turbulence promoter, the average permeate flux improvement during the filtration period ranged from 30% to 230%. As a result of the statistical analysis, the optimal conditions for starch suspension microfiltration were determined and applied to microfiltration of starch industry wastewater.

Efficient and simple method for determination of suspendibility of bio-inoculant suspensions

This study assessed the utilization of viscosity and zeta potential as a novel method to evaluate suspendibility of formulation of Sinorhizobium meliloti grown in starch industry wastewater for use as bio-inoculants. For this objective, sorbitol was used as a suspending agent at concentrations of 0 to 10% w/v. Model, based on multiple linear regression (with pH as dependant variable, and zeta potential, average particle size and sorbitol concentration as independent variables) demonstrated an important relation which was significant (p<0.001, R2=0.98). Sigmoid regression revealed a significant relation between zeta potential and suspendibility with p value=0.007 and R-squared=0.86, and between viscosity and suspendibility (p value<0.0001 and R squared=0.9823). Thus, these direct correlations established the lowering of measurement time from 12h to 5min.

Large-scale magnetic separation of Solanum tuberosum lectin from potato starch industry waste water

Large-scale magnetic separation of Solanum tuberosum lectin from potato starch industry waste water

Reduction of solid content in starch industry wastewater by microfiltration

AbstractWastewater obtained in the production process of wheat starch and vital wheat gluten was treated by microfiltration through a ceramic tubular membrane with 200 nm pore sizes. The consumption of process water would thus be reduced, the starch would be recovered to a greater extent and the wastewater problem would consequently be solved. Reduction of the occurrence of polarization layer on the membrane and the constant wastewater permeate flux through the membrane was maintained by inserting of the mixer Kenics inside the membrane tube. The maximum value of the permeate flux (24 L m−2 h−1) without the use of a static mixer was achieved at 3 × 10−5 Pa and at a flow rate of 150 L/h, for wastewater samples initially allowed to settle for 4 h prior microfiltration. Under the very same conditions of the working parameters, the use of a static mixer enables a flux that is up to two or three times more intensive compared to the values obtained without using a mixer. Microfiltration reduces the wastewater dry matter from 11 000 to 4000 mg/L, lessens the chemical oxygen demand by 74%, i.e. from 21 000 to 5100 mgO2/L and significantly decreases the values of the suspended matter, namely from 9000 to 300 mg/L.