Food Processing Industry Wastewater Research Articles

Evaluation of Efficiently Removing Secondary Effluent Organic Matters (EfOM) by Al-Based Coagulant for Wastewater Recycling: A Case Study with an Industrial-Scale Food-Processing Wastewater Treatment Plant.

The reuse of wastewater has been identified as an important initiative for the sustainable development of the environment; thus, the removal of secondary effluent organic matter (EfOM) to ensure the safety of reused wastewater is the key step and a subject of extensive research. In this study, Al2(SO4)3 and anionic polyacrylamide were selected as coagulant and flocculant, respectively, for the treatment of secondary effluent from a food-processing industry wastewater treatment plant to meet the standard regulatory specifications for water reuse. In this process, the removal efficiencies of chemical oxygen demand (COD), components with UV254, and specific ultraviolet absorbance (SUVA) were 44.61%, 25.13%, and 9.13%, respectively, with an associated reduction in chroma and turbidity. The fluorescence intensities (Fmax) of two humic-like components were reduced during coagulation, and microbial humic-like components of EfOM had a better removal efficiency because of a higher Log Km value of 4.12. Fourier transform infrared spectroscopy showed that Al2(SO4)3 could remove the protein fraction of the soluble microbial products (SMP) of EfOM by forming a loose SMP protein complex with enhanced hydrophobicity. Furthermore, flocculation reduced the aromaticity of secondary effluent. The cost of the proposed secondary effluent treatment was 0.034 CNY t-1 %COD-1. These results demonstrate that the process is efficient and economically viable for EfOM removal to realize food-processing wastewater reuse.

Aqueous Two-Phase Systems Based on Cationic and Anionic Surfactants Mixture for Rapid Extraction and Colorimetric Determination of Synthetic Food Dyes.

In this study, aqueous two-phase systems (ATPSs) containing a cationic and anionic surfactants mixture were used for the preconcentration of the synthetic food dyes Allura Red AC, Azorubine, Sunset Yellow, Tartrazine, and Fast Green FCF. A rapid, simple, low cost, affordable, and environmentally friendly methodology based on microextraction in ATPSs, followed by spectrophotometric/colorimetric determination of the dyes, is proposed. The ATPSs are formed in mixtures of benzethonium chloride (BztCl) and sodium N-lauroylsarcosinate (NaLS) or sodium dihexylsulfosuccinate (NaDHSS) under the molar ratio close to equimolar at the total surfactant concentration of 0.01-0.20 M. The density, viscosity, polarity, and water content in the surfactant-rich phases at an equimolar ratio BztCl:NaA were determined. The effects of pH, total surfactant concentration, dye concentration, and time of extraction/centrifugation were investigated, and the optimum conditions for the quantitative extraction of dyes were established. The smartphone-based colorimetric determination was employed directly in the extract without separating the aqueous phase. The analytical performance (calibration linearity, precision, limits of detection and quantification, reproducibility, and preconcentration factor) and comparison of the spectrophotometric and smartphone-based colorimetric determination of dyes were evaluated. The method was applied to the determination of dyes in food samples and food-processing industrial wastewater.

New kinetic models for predicting the removal of oil and grease from food-processing industry wastewater

Biochemical accumulation rate of Serratia marcescens SA30 to remove the oil and grease (O&G) contaminant from a wastewater can be described using the kinetic models of packed-bed column reactor (PBCR) treatment system. The aim of this study was to develop the linear and logarithmic equations for predicting the efficiency of O&G removal from food-processing industry wastewater. The results showed that the performance of PBCR treatment process can achieve nearly 100% efficiency when the PBCR experiments were run using the initial O&G concentrations of 26.9 and 33.5 g L−1 with a volumetric flow rate of 0.18 L h−1. The applicability of the linear and logarithmic equations represented a quick and reliable method to monitor the trend of O&G removal by the PBCR treatment process contributes to strengthening the future biotechnological methods of treating oil-contaminated wastewater in the tropical environment.

High Carbon Load in Food Processing Industrial Wastewater is a Driver for Metabolic Competition in Aerobic Granular Sludge

Aerobic granular sludge (AGS) processes are among the most robust wastewater treatments. One of their greatest advantages is related to the granules multi-layered structure, which creates a protective barrier against organic shock loads and variable wastewater composition, particularly attractive for the treatment of industrial wastewater. However, when treating a wastewater with variable and complex composition, the difficulty in identifying factors that most affect a specific biological process increases. In this study, the effect of organic loading rate (OLR), namely carbon content, on nitrification in an AGS process treating fish canning wastewater was investigated. Besides process performance, also biomass structural changes, and microbial community composition were analysed. Reactor operation lasted for 107 days and was divided in three phases during which different OLR and C/N ratios were applied. A higher OLR was applied during the first two phases (ca. 1.1 and 1.5 kg COD m−3 day−1, respectively) compared to the third phase (between 0.12 and 0.78 kg COD m−3 day−1) and the C/N ratios also varied (ca. 4.4, 7.8, and 2.9, respectively). Throughout the operation, COD concentration in the outlet was lower than 100 mg O2 L−1. Nitrification was inhibited during the second phase and recovered afterwards. Principal component analysis (PCA) of quantitative image analysis (QIA) and performance data allowed to distinguish process changes over the three operational phases. During the first two phases, the decrease in the biomass robustness occurred, but recovered during the last phase, indicating that the high content of organic matter had possibly an effect on the aerobic granules structural characteristics. The composition of the AGS microbiome did not change substantially after the end of the higher OLR periods. The main microbial diversity shifts were mostly associated to adaptation to higher or lower carbon availability. Bacteria and inferred enzymes associated to nitrogen and phosphorous removal were identified. Chryseobacterium, a bacterium with high metabolic versatility, was able to adapt to the organic shock load, becoming dominant over operation. Despite the variable composition of the fish canning wastewater, carbon was identified as the main driver for nitrification inhibition, while promoting changes in the physical characteristics and on the microbial community of granules.

Conversion of Food Processing Waste to Bioenergy: Bangladesh Perspective

Microbial fuel cell (MFC) is an attractive renewable and sustainable technology to meet up the drastic energy crisis of the world through waste water treatment. This Bioelectrochemical system (BES) converts biomass spontaneously into electricity by the metabolic activity of microorganisms. Food processing industry generally discharges large volume of wastewater, which creates adverse financial and ecological impacts to the industry and environment. In this present contribution, electricity production from food processing industry wastewater that serves as substrates in MFCs was investigated. Dual chambered mediator-less MFC was designed and fabricated using locally available materials. Performance of the MFC was evaluated by measuring potential parameters, such as current generation, current density, change in pH, and change in chemical oxygen demand at different operating conditions. Polarization experiments were conducted to find the maximum power density. Current generation increased with increasing sludge loading, and maximum results were recorded as 90 µA with 9 g of sludge and optimum pH value 8 in the anode chamber. This study documented a maximum power density of 7.42 mW/m 2 with the corresponding current density of 25 mA/m 2 . Citation: Amin, M. S. A., Talukder, M. J., Raju, R. R., and Khan, M. M. R. (2019). Conversion of Food Processing Waste to Bioenergy: Bangladesh Perspective. Trends in Renewable Energy, 5(1), 1-11. DOI: 10.17737/tre.2019.5.1.0080

Microalgal bioremediation of food-processing industrial wastewater under mixotrophic conditions: Kinetics and scale-up approach

The Chlorella microalgae were mixotrophically cultivated in an unsterilized and unfiltered raw food-processing industrial wastewater. Both inorganic carbon (CO2-air) and organic carbon (wastewater) were provided simultaneously for microalgae growth. The aim of the study is to find out the utilization rates of total organic carbon (TOC) and chemical oxygen demand (COD) under mixotrophic conditions for a given waste water. About 90% reduction in TOC and COD were obtained for all dilutions of wastewater. Over 60% of nitrate and 40% of phosphate were consumed by microalgae from concentrated raw wastewater. This study shows that microalgae can use both organic and inorganic sources of carbon in more or less quantity under mixotrophic conditions. The growth of microalgae in food-processing industrial wastewater with all studied dilution factors, viz. zero (raw), 1.6 (dilution A), and 5 (dilution B) suggests that the freshwater requirement could be reduced substantially (20%–60%). The degradation kinetics also suggests that the microalgae cultivation on a high COD wastewater is feasible and scalable. Open image in new window

Homogeneous sonophotolysis of food processing industry wastewater: Study of synergistic effects, mineralization and toxicity removal

The mineralization of industrial wastewater coming from food industry using an emerging homogeneous sonophotolytic oxidation process was evaluated as an alternative to or a rapid pretreatment step for conventional anaerobic digestion with the aim of considerably reducing the total treatment time. At the selected operation conditions ([H2O2]=11,750ppm, pH=8, amplitude=50%, pulse length (cycles)=1), 60% of TOC is removed after 60min and 98% after 180min when treating an industrial effluent with 2114ppm of total organic carbon (TOC). This process removed completely the toxicity generated during storing or due to intermediate compounds.An important synergistic effect between sonolysis and photolysis (H2O2/UV) was observed. Thus the sonophotolysis (ultrasound/H2O2/UV) technique significantly increases TOC removal when compared with each individual process.Finally, a preliminary economical analysis confirms that the sono-photolysis with H2O2 and pretreated water is a profitable system when compared with the same process without using ultrasound waves and with no pretreatment.

Effect of Process Parameters on Greenhouse Gas Generation by Wastewater Treatment Plants

The effect of key process parameters on greenhouse gas (GHG) emission by wastewater treatment plants was evaluated, and the governing parameters that exhibited major effects on the overall on- and off-site GHG emissions were identified. This evaluation used aerobic, anaerobic, and hybrid anaerobic/aerobic treatment systems with food processing industry wastewater. The operating temperature of anaerobic sludge digester was identified to have the highest effect on GHG generation in the aerobic treatment system. The total GHG emissions of 2694 kg CO2e/d were increased by 72.5% with the increase of anaerobic sludge digester temperature from 20 to 40 degrees C. The operating temperature of the anaerobic reactor was the dominant controlling parameter in the anaerobic and hybrid treatment systems. Raising the anaerobic reactor's temperature from 25 to 40 degrees C increased the total GHG emissions from 5822 and 6617 kg CO2e/d by 105.6 and 96.5% in the anaerobic and hybrid treatment systems, respectively.

Influence of wastewater characteristics on methane potential in food-processing industry wastewaters

In this study, we identified the influence of wastewater characteristics on the theoretical and practical methane potential using different food industrial wastewaters as substrates. Ten composite wastewater samples from five industries were investigated. The ultimate practical methane yields ( B o) were compared to the theoretical methane yields ( B o,th) in order to evaluate the biodegradability of the tested wastewaters and the influence of their physico-chemical characteristics. The analytical method applied to quantify the wastewaters’ organic content proved to influence the estimation of their theoretical yields. The substrate:inoculum ratio as well as the dilution factor of the wastewaters influenced the ultimate practical methane yields differently in each of the wastewaters assessed. Substrate chemical oxygen demand (COD) concentrations did not present any influence on ultimate practical methane yields; on the other hand, it was found that they were affected positively by concentrations of total inorganic carbon when wastewaters were 25% and 50% diluted and affected negatively by concentrations of total acetate when wastewaters were undiluted. Carbohydrate and protein concentrations affected negatively the maximum achieved practical methane yields.

Biotechnological conversion of agro-industrial wastewaters into biodegradable plastic, poly β-hydroxybutyrate

Waste activated sludge generated from a combined dairy and food processing industry wastewater treatment plant was evaluated for its potential to produce biodegradable plastic, poly β-hydroxybutyric acid (PHB). Deproteinized jowar grain-based distillery spentwash yielded 42.3% PHB production (w/w), followed by filtered rice grain-based distillery spentwash (40% PHB) when used as substrates. Addition of di-ammonium hydrogen phosphate (DAHP) resulted in an increase in PHB production to 67% when raw rice grain-based spentwash was used. Same wastewater, after removal of suspended solids by filtration and with DAHP supplementation resulted in lower PHB production (57.9%). However, supplementing other wastes with DAHP led to a substantial decrease in PHB content in comparison to what was observed in the absence of DAHP.

Electrochemical Treatment Applied to Food-Processing Industrial Wastewater

The removal of organic pollutants from food-industry wastewater by an aluminum electrocoagulation process was evaluated using a pilot batch reactor coupled to a rotating electrode. Under optimal conditions of pH 4, 18.2 A m-2 current density, and 150 rpm electrode rotational velocity, the electrochemical method yields a very effective reduction of all organic pollutants. Treatment reduced chemical oxygen demand (COD) by 88%, biochemical oxygen demand (BOD5) by 52%, total solids by 82%, and total coliforms by 93%. The effect on the species formed of reducing the pH of the aqueous solution with sulfuric acid was determined. The wastewater quality was monitored using UV−vis spectrometry and cyclic voltammetry in order to characterize initial and final pollutant levels. Finally, the morphology and elemental composition of the resulting sludge was characterized using scanning electron microscopy (SEM) and energy-dispersion spectroscopy (EDS).

05/02386 Production of biodegradable plastics from activated sludge generated from a food processing industrial wastewater treatment plant

05/02386 Production of biodegradable plastics from activated sludge generated from a food processing industrial wastewater treatment plant

Organic matter characteristics of food processing industry wastewaters affecting their C and N mineralization in soil incubation

This study aimed at determining food processing wastewater composition factors that regulate their carbon and nitrogen mineralization when added to soil. Twenty three different wastewaters from various food processing industries were characterized by C and N concentrations, liquid and solid physical separation and acid solubility. They were also incubated in a calcareous soil during six months at 28 °C. The C and N concentrations were low but covered a wide range. Carbon and nitrogen were variously distributed in the liquid and solid fractions and much C was present in the acid-soluble fraction in which C to N ratios were low. The C and N mineralization measured during soil incubation covered a wide range of decomposition pathways. Carbon mineralization was linked significantly ( p = 0.05) with the C to N ratio of the acid soluble fraction and C present in the liquid fraction. N mineralization was significantly correlated ( p = 0.05) with the organic C to organic N ratio and the C to N ratio of the acid soluble fraction. Multiple factor analysis and clustering also enabled defining clusters which partially overlap the various origins of the wastewaters.

Production of biodegradable plastics from activated sludge generated from a food processing industrial wastewater treatment plant

Most of the excess sludge from a wastewater treatment plant (60%) is disposed by landfill. As a resource utilization of excess sludge, the production of biodegradable plastics using the sludge has been proposed. Storage polymers in bacterial cells can be extracted and used as biodegradable plastics. However, widespread applications have been limited by high production cost. In the present study, activated sludge bacteria in a conventional wastewater treatment system were induced, by controlling the carbon: nitrogen ratio to accumulate storage polymers. Polymer yield increased to a maximum 33% of biomass (w/w) when the C/N ratio was increased from 24 to 144, where as specific growth yield decreased with increasing C/N ratio. The conditions which are required for the maximum polymer accumulation were optimized and are discussed.

Process using DO and ORP signals for biological nitrification and denitrification : validation of a food-processing industry wastewater treatment plant on boosting with pure oxygen

The simultaneous removal of carbonaceous and nitrogenous pollution by the activated sludge process is becoming common in industrial and municipal wastewater treatment plants. An oxygenation monitoring process has been developed, which is based on the dynamic analysis of ORP and DO signals and allows the detection of specific characteristic points at the end of the biological nitrification and denitrification. The aim of this study is to validate this process in a food-processing industry WWTP (slaughterhouse) having large variations of carbonaceous and nitrogenous loads. In order to treat during the peak period, pure oxygen is used. The first part of the study provides a precise diagnosis of the WWTP operation by the analysis of the ORP and DO signals. It is particularly easy to estimate the level of nitrogen treatment actually achieved and the oxygen requirements, and to detect the over- or under-oxygenated phases. Thanks to the monitoring process, the aerobic period of each cycle is reduced to the optimal duration, providing a reduction of 30% on the energy consumption compared to a traditional schedule. We have demonstrated that the use of pure oxygen associated with the existing air system is particularly relevant for the peak period. The revamping of an existing plant to simultaneously treat the carbon and the ammonia in the same basin is now technically feasible.

Oxidation of p-hydroxybenzoic acid by Fenton's reagent

Fenton's reagent has been shown to be a feasible technique to treat phenolic-type compounds present in a variety of food processing industry wastewaters. A model compound, p-hydroxybenzoic acid was oxidised by continuously pumping two solutions of ferrous iron and hydrogen peroxide. Typical operating variables like reagent feeding concentrations and flowrate, temperature and pH were studied. A mechanism of reactions based on the classical Fenton's chemistry was assumed, and computed concentration profiles of the parent compound, ferrous ion and dihydroxybenzene were compared to experimental results. The model qualitatively predicted the influence of several operating variables, however, calculated results suggested the presence of parallel routes of substrate elimination and/or a initiating rate constant with a higher value. The low efficiency of a well-known hydroxyl radical scavenger ( tert-butyl alcohol) also supports the contribution of oxidising species different from the hydroxyl radical to substrate removal. Further evidence of the presence of reactions different from the hydroxyl radical oxidation was observed from comparison of the simultaneous Fenton's or UV/H 2O 2 oxidations of p-hydroxybenzoic acid, tyrosol and p-coumaric acid.

カビペレットを活用した生デンプン含有食品工場排水の処理特性

Treatabilities of food-processing industrial wastewater containing raw starch were experimentally investigated in batch and continuous cultures with Aspergillus niger pellets.In batch culture using wastewater of 10, 000 mg-TOC/l containing in raw starch of 25 g/l, the removal efficiencies of starch and TOC reached 90% and 44% for 10 days, respectively. An important information from practical point of view was that starch granules were rapidly incorporated into the pellet inside with growth of pellets. It can be assumed that high removal efficiency of starch is closely related to this incorporation.In continuous culture using wastewater of 1, 000 mg-TOC/l containing raw starch of 1.25 g/l and soluble starch of 1.25 g/l, the removal efficiency of starch was held at over 77% during experimental period of 28 days by replacing the grown pellets with new ones.By use of multi-stage reactor with fungal and activated sludge processes, the removal efficiencies of total sugar and TOC in the food-processing industrial wastewater containing raw starch were held at 100%and over 86%, respectively. This result clearly shows that the actual industrial wastewater can be effectively treated in multi-stage process with Aspergillus niger pellets and activated sludge.

Cost-Effective Pre-Treatment of Food-Processing Industrial Wastewater

Performance of laboratory-scale aerobic and anaerobic systems treating food-processing wastewater was investigated. The results obtained showed that BOD and COD of wastewater discharged from a potato-chips factory can be reduced by 86% and 82% using UASB reactor at an organic loading rate (OLR) of 2.9 kg BOD/m3·d and a hydraulic retention time (HRT) of 18 hr. Corresponding results for an activated sludge system, operated at an OLR of 8.9 kg BOD/m3·d with a HRT of 6hr were 86% and 84%, respectively. Treatment of confectionery wastewater using UASB at a HRT of 12hr and an OLR of 4.4 kg BOD/m3.d gave satisfactory results. COD and BOD removals were 92.4% and 91.5%, respectively. The use of completely activated sludge system at a HRT of 6 hr and ORL of 8.4 kg BOD/m3.d gave lower results as compared to UASB reactor. However, characteristics of the effluents produced using the two systems were in agreement with the standards regulating discharge of industrial wastewater into the sewerage system. Based on the technical and economic evaluation of the results, engineering designs were made for the selected systems.

Cost-effective pre-treatment of food-processing industrial wastewater

Performance of laboratory-scale aerobic and anaerobic systems treating food-processing wastewater was investigated. The results obtained showed that BOD and COD of wastewater discharged from a potato-chips factory can be reduced by 86% and 82% using UASB reactor at an organic loading rate (OLR) of 2.9 kg BOD/m3d and a hydraulic retention time (HRT) of 18 hr. Corresponding results for an activated sludge system, operated at an OLR of 8.9 kg BOD/m3-d with a HRT of 6hr were 86% and 84%, respectively.Treatment of confectionery wastewater using UASB at a HRT of 12hr and an OLR of 4.4 kg BOD/m3.d gave satisfactory results. COD and BOD removals were 92.4% and 91.5%, respectively. The use of completely activated sludge system at a HRT of 6 hr and ORL of 8.4 kg BOD/m3.d gave lower results as compared to UASB reactor. However, characteristics of the effluents produced using, the two systems were in agreement with the standards regulating discharge of industrial wastewater into the sewerage system. Based on the technical and economic evaluation of the results, engineering designs were made for the selected systems.

Anaerobic fluidized beds: ten years of industrial experience

The Anaflux process, an upflow anaerobic fluidized bed reactor using a mineral bacterial support, has been employed industrially for ten years treating a variety of food-processing and paper industry wastewaters. This paper describes five aspects of the design and operation of the anaerobic fluidized bed which have proven, from industrial experience, to be essential. The optimization of these factors enables a stable functioning of the process and allows the application of high loading rates. Included are the results of a semi-industrial pilot study, treating wine distillation wastewaters, which demonstrate the present capabilities (OLR=70 kg COD/m3·d) of this type of reactor.