Food Industry Wastewater Research Articles

Water recovery by treatment of food industry wastewater using membrane processes

ABSTRACT This work presents a proposal for the recovery of water through the treatment of food industry wastewater using membrane processes. Three wastewater streams from the different manufacturing steps were identified as possible sources of water recovery: (1) wastewater from the washing of ionic exchange resins and (2) wastewater from the concentration stage of animal proteins (type 1 and 2). The wastewater streams were treated as effluent mixtures; each one with different level of pollution. The principal characteristics of the effluent mixtures were identified as high conductivity and the presence of organic matter. Under these conditions, ultrafiltration and reverse osmosis were carried out for the treatment of wastewater. The ultrafiltration process was tested at an industrial-level plant and the reverse osmosis process was applied at a pilot-plant level. The results showed the feasibility of the proposed treatment for water recovery. The data demonstrates an efficiency greater than 95% in all the quality parameters and therefore, a high quality in the recovered water was obtained by membrane processes. According to the chemical composition of wastewater, the reversible fouling was linked to salts and protein retention, promoting the formation of a cake layer as reversible resistance; whereas, irreversible fouling was minimum during wastewater treatment.

Development of a new PET flow reactor applied to food dyes removal with advanced oxidative processes

Scientists have been exploring new sustainable alternatives in effluent treatment due to the growing concern with highly stable organic pollutants. In this work, a photocatalytic flow reactor was developed from Poli Ethylene Terephthalate (PET) bottles in order to optimise photocatalysis of two synthetic dyes commonly found in food industry wastewater. Four different photo-oxidative systems were tested within 360 min under UV-C radiation. The best results were obtained in a UV-C/H2O2/TiO2 system due to the synergic effect of the oxidizing agents. The influence of the oxidizing agent’s amounts was investigated in a 2² experimental planning and 99.25% of dyes degradation could be reached in 180 min. A kinetic study was carried out with these results and the kinetic rate for the global reaction was estimated at 0.016 min−1 and half-life reaction time at 43.32 min applying the pseudo-first-order kinetic model. Acute toxicity assays revealed the IC50 increased 165.8% after the treatment indicating the by-products were less toxic than the parental compounds. TOC and COD were evaluated as water quality parameters and decreased from 40.50 and 103.4 mg L−1 to 8.25 and 15.0 mg L−1 after the photocatalytic process, respectively. Cost analysis of the construction and operation expenses and removal efficiency presented the developed PET flow reactor as a feasible alternative to the treatment of synthetic organic dyes.

Electroflocculation for the treatment of wastewater from dairy food industry: scale-up of a laboratory reactor to full-scale plant

The aim of this work was to evaluate the scale-up of a laboratory reactor to full-scale plant for the electroflocculation of dairy food industry wastewater. The structural, operational and financial feasibilities were evaluated in reactors with either aluminum or iron electrodes. The laboratory reactor contained a beaker of 500.0 mL, two metal electrodes (thickness: 0.10 cm, length: 15.0 cm, width: 7.0 cm, distance between electrodes: 2.0 cm, total area for two electrodes in the laboratory reactor: 210.0 cm2), power source and magnetic stirring. The employed operational parameters included operation time of 1.0 h, applied potential intensity of 5.0 V, and electric currents of 0.94 A for aluminum electrodes and 0.71 A for iron electrodes. The scale-up was evaluated considering 110 m3 generated wastewater per day in a dairy food industry. The total applied electric power, electrode consumption, and final temperature after 1 h operation were 64.89 kWh, 1220 g m−3, and 32.19 °C using aluminum electrodes, whereas these values were 30.01 kWh, 1483 g m−3, and 25.64 °C using iron electrodes. Effective structural and operational costs higher than 65.0% in relation to the total costs of operation of the system were associated with the mass consumption of either aluminum or iron electrodes. In general, the scale-up of the laboratory reactor to full-scale plant was structurally, operationally and economically viable compared to the conventional wastewater treatment systems.

Strategies for the Controlled Integration of Food SMEs’ Highly Polluted Effluents into Urban Sanitation Systems

The artisan production of canned tuna is characterized by generating effluents with high organic and saline loads, which complicates their suitable treatment. The main objective of the LIFE VERTALIM project is to demonstrate the efficiency of a holistic solution (including technical, legislative, social, and environmental aspects) for the controlled integration of food industry wastewater from small and medium enterprises (SMEs) in the urban sanitation system with the compliance of all stakeholders. This work shows the viability of the implementation of low-cost innovative solutions, through the clean and eco-efficient production and wastewater pretreatment for fish canneries. This solution allows on average a reduction of 30% of the wastewater discharges to the environment and a reduction of food losses of up to 0.1%. Moreover, there is a reduction of between 40% and 90% related to high organic load. These results allow the canneries to dispose their pretreated effluents to the urban sanitation system, avoiding the high costs of an industrial wastewater treatment plant (WWTP) to discharge to the river. A better physical-chemical quality in the river waters as a well as the marine water surrounding the urban WWTP have been achieved.

Trichosporon fermentans biomass flocculation from soybean oil refinery wastewater using bioflocculant produced from Paecilomyces sp. M2-1.

The soybean oil refinery (SOR) wastewater contains a high concentration of chemical oxygen demand (COD) and lipid, so the direct emissions of SOR wastewater will result in environmental pollution and waste of resources. Oleaginous yeast Trichosporon fermentans can consume organic materials in SOR wastewater to synthesize microbial oil, which achieves the purpose of SOR wastewater resource utilization. The effective harvesting technology of oleaginous yeasts can improve the utilization efficiency. In this study, Paecilomyces sp. M2-1 with high flocculating activity was isolated. The flocculants produced by M2-1 (MBF2-1) include 75% (w/w) polysaccharides, rely on cations, and display the flocculation percentage of above 77% in the range of pH2-11. Especially under alkaline conditions, the flocculation percentage can be kept above 97%. The results of scanning electron microscope observation and zeta potential measurements suggested that the bridging, net trapping, and sweeping were the main flocculation mechanism of MBF2-1. MBF2-1 could flocculate T. fermentans that was used to reduce the organic matter in SOR wastewater and to produce microbial oil. Under the optimum conditions, the flocculation percentage of MBF2-1 against T. fermentans from SOR wastewater can reach 95%. Fatty acid content percent in microbial oil from T. fermentans was not almost affected by flocculation of MBF2-1. Moreover, MBF2-1 can further remove 55% and 53% of COD and oil content in the fermented SOR wastewater, respectively. The properties and high flocculating percentage displayed by MBF2-1 indicated its potential application prospect in oleaginous yeast harvest and food industry wastewater treatment.

Odour nuisance assessment of the food industry wastewater treatment plant

Odour nuisance generated by food industry objects is a significant problem, the result of which is often numerous complaints from local residents about the quality of air. Apart from the production process, this problem often concerns industrial wastewater treatment processes, which contribute to a large extent to the emissions of odorants from the sulphur group, including hydrogen sulphide and mercaptans. In order to estimate the odorous air quality around these types of objects, the modelling of dispersion of pollutants: odours or odorants is often used. The paper presents the results of tests on odour emission as well as hydrogen sulphide and mercaptans emission as compounds typical for waste gases from the sewage treatment process from the food industry. In order to estimate the range of odour impact, model calculations using the Polish reference model for the aforementioned substances were made. The values of annual average concentrations and frequency of odour detection thresholds for odorants and odour concentration of 1 ouE/m3 for odours as a mixture in a computational grid of 1400 m x 1400 m with a step of 50 m were calculated. The results showed the highest range of odour impact of mercaptans, whose value of the average annual concentration exceeded the odour detection threshold up to 700 m in the east and west direction from the emission source.

Sequential Treatment of Food Industry Wastewater by Electro-Fenton and Electrocoagulation Processes

Sequential Treatment of Food Industry Wastewater by Electro-Fenton and Electrocoagulation Processes

Enhanced alure-type biological system (E-ATBS) for carbon, nitrogen and phosphorus removal from slaughterhouse wastewater: A case study

Slaughterhouse wastewater is one of the most harmful agriculture and food industrial wastewaters. The emissions of not fully treated slaughtering wastewater would cause eutrophication of surface water and pollution of groundwater. This study investigated the nutrient removal performance for the enhanced alure-type biological system (E-ATBS) in the full-scale application. During the whole study period, COD, TN and TP removal efficiencies were higher than 97.1%, 90.8% and 90.1%, respectively. The effluent concentrations were lower than the newest effluent standard in China to avoid the discharged water pollution. Partial denitrification (PD)-ANAMMOX was considered as the main approach for anaerobic NH4+-N removal, which helped to guarantee the efficient N removal in the full-scale E-ATBS. Denitrifying P removal and aerobic P uptake ensured the efficient and stable P removal. E-ATBS is a promising technology especially for wastewater treatment in food processing facilities and should be widely popularized.

Evaluation of a magnetic coagulant based on Fe3O4 nanoparticles and Moringa oleifera extract on tartrazine removal: coagulation-adsorption and kinetics studies

ABSTRACTThe lack of data regarding the mechanisms at work in the coagulation processes of different substances using magnetic coagulants makes it difficult to understand the phenomena involved and, consequently, makes it difficult to elucidate the mechanisms involved in the coagulation process. Thus, the present study aimed at evaluating the performance of a magnetic coagulant composed of iron oxide (Fe3O4) functionalised with Moringa oleifera (MO) salt extract in the treatment of a synthetic food industry wastewater simulated by the addition of dye to distilled water. From the data obtained in the coagulation/flocculation assays followed by magnetic sedimentation, the different mechanisms involved were evaluated for their fit to pseudo-first order, pseudo-second order, Langmuir and Freundlich theoretical models. The adjustments to the models were evaluated from the kinetic data and indicated that at pH 3 the best fit was to the pseudo-second order model, whereas for pH 6 and 9 the best fit was for the pseudo-first order model. The isothermal data were adjusted to the Langmuir model, suggesting adsorption of a monolayer, characterising chemical processes with selective adsorption. In relation to the mechanisms involved in the process, it is suggested that the neutralisation of charges was the predominant mechanism in the removal of tartrazine at pH 3, whereas at the other pH values evaluated the mechanism that prevailed was monolayer adsorption. Thus, the proposed magnetic coagulant was found to be an efficient alternative material for tartrazine removal, allowing easy separation in the sedimentation stage while also being compatible with environmental issues.

A novel Serratia sp. ZS6 isolate derived from petroleum sludge secretes biosurfactant and lipase in medium with olive oil as sole carbon source

Biosurfactants emulsify lipids, facilitating their exposure to microorganisms in water. Secretion of biosurfactant together with lipase can enhance oil assimilation by microorganisms. In this study, we show the analysis of the biosurfactant and lipase producing microbe originating from oil-sludge. The enrichment of the biosurfactant-producing ZS6 strain from the mixed culture of sludge-derived microbes in medium with olive oil as sole carbon source was monitored using the modified T-RFLP (or mT-RFLP) methodology. Phylogenetic tree analysis based on 16S rDNA sequences suggested that ZS6 belonged to a member of Serratia sp. Serratia sp. ZS6 secreted both a serrawettin-type biosurfactant and lipase in medium with olive oil as sole carbon source. By using an in-gel lipase assay followed by LC–MS/MS analysis, we identified the amino acid sequences of the ZS6 lipase, which belonged to the lipase subfamily III of the family I. Its lipolytic activity was found to be enhanced by salinity, calcium, and methanol. Together, we show that the novel isolate Serratia sp. ZS6 secretes both biosurfactant and lipase which makes it useful for applications such as in food industry wastewater treatment and biodiesel production.

In-plant real-time manufacturing water content characterisation

To trial the concept of in-plant real-time manufacturing water content characterisation, a commercial optical system for measuring light absorption and backscatter intensity was used with samples of food industry wastewater, and the results compared with conventional laboratory based water analysis. It is shown that the instrumentation is capable of coping with the range of turbidities presented by the wastewater and that there is some correlation between the absorption and backscatter measurements with the conventional parameters COD and TSS. It is suggested that combining backscatter and absorption data may provide an optical fingerprint of effluent that can be used as a management parameter, for example to identify unexpected contamination events. Potential uses of the instrumentation are discussed, including to provide rapid feedback on effects of system changes on effluent production, and in a feedback control loop to allow reuse of water without compromising product safety.

A comparative study of electrocoagulation and electro-Fenton for food industry wastewater treatment: Multiple response optimization and cost analysis

ABSTRACTIn this study, response surface methodology was applied for food wastewater by electrocoagulation (EC) and electro-Fenton (EF) processes. The optimum conditions for the chemical oxygen demand (COD) removal were found to be 21.36 min, pH 10 and 86 mA/cm2 in EC, whereas 27.11 min, pH 2.38, 86 mA/cm2 and H2O2/COD:2 in EF process. COD removal efficiencies were determined to be 29.4% for EC and 59.1% for EF processes and higher than 99% total suspended solids removal efficiencies were achieved. It can be concluded that high COD removal was obtained (4998 mg/L COD removal by EC and 10,047 mg/L COD removal by EF).

Biodiesel production from algae grown on food industry wastewater.

Algae have an ample potential to produce biodiesel from spent wash of food industry. In addition, it is cheaper and presents an environment friendly way to handle food industry wastewater. This study was conducted to optimize the growth of microalgal strains and to assess biodiesel production potential of algae using untreated food industry wastewater as a source of nutrients. The food industry wastewater was collected and analyzed for its physicochemical characteristics. Different dilutions (10, 20, 40, 80, and 100%) of this wastewater were made with distilled water, and growth of two microalgal strains (Cladophora sp. and Spyrogyra sp.) was recorded. Each type of wastewater was inoculated with microalgae, and biomass was harvested after 7days. The growth of both strains was also evaluated at varying temperatures, pH and light periods to optimize the algal growth for enhanced biodiesel production. After optimization, biodiesel production by Spyrogyra sp. was recorded in real food industry wastewater. The algal biomass increased with increasing level of food industry wastewater and was at maximum with 100% wastewater. Moreover, statistically similar results were found with algal growth on 100% wastewater and also on Bristol's media. The Cladophora sp. produced higher biomass than Spyrogyra sp. while growing on food industry wastewater. The optimal growth of both microalgal strains was observed at temperature 30°C, pH: 8, light 24h. Cladophora sp. was further evaluated for biodiesel production while growing on 100% wastewater and found that this strain produced high level of oil and biodiesel. Algae have an ample potential to produce biodiesel from spent wash of food industry. In addition, it is cheaper and presents an environment friendly way to handle food industry wastewater.

Problems with Fat, Oil, and Grease (FOG) in Food Industry Wastewaters and Recovered FOG Recycling Methods Using Anaerobic Co-Digestion: A Short Review

Food production industry is the main producer of wastewaters with high fat, oil, and grease (FOG) content. FOG waste can be recovered from the wastewater stream by using physicochemical methods and reused considering their high methane potential. Popular method of FOG reuse is anaerobic co-digestion (AcoD) with wastewater treatment sludge and scum from the primary wastewater sedimentation tanks. This short review focuses on understanding the efficiency of FOG reuse possibilities by AcoD and takes a closer look at problems connected to degradation issues, gives an understanding on microbial changes during FOG degradation, and reviews enzymes involved in the degradation process.

Bio-hydrogen production from waste materials: A review

When hydrogen burns in air, it produces nothing but water vapour. It is therefore the cleanest possible, totally non-polluting fuel. This fact has led some people to propose an energy economy based entirely on hydrogen, in which hydrogen would replace gasoline, oil, natural gas, coal, and nuclear power. Hydrogen is a clean energy source. Therefore, in recent years, demand on hydrogen production has increased considerably. Electrolysis of water, steam reforming of hydrocarbons and auto-thermal processes are well-known methods for hydrogen gas production, but not cost-effective due to high energy requirements. As compare to chemical methods, biological production of hydrogen gas has significant advantages such as bio-photolysis of water by algae, dark and photo-fermentation of organic materials, usually carbohydrates by bacteria. New approach for bio-hydrogen production is dark and photo-fermentation process but with some major problems like dark and photo-fermentative hydrogen production is the raw material cost. By using suitable bio-process technologies hydrogen can be produced through carbohydrate rich, nitrogen deficient solid wastes such as cellulose and starch containing agricultural and food industry wastes and some food industry wastewaters such as cheese whey, olive mill and baker's yeast industry wastewaters. Utilization of aforementioned wastes for hydrogen production provides inexpensive energy generation with simultaneous waste treatment. This review article summarizes bio-hydrogen production from some waste materials with recent developments and relative advantages.

Microbial Communities in Sand Bioreactors Treating High Salt Content Food Industry Wastewater

Microbial Communities in Sand Bioreactors Treating High Salt Content Food Industry Wastewater

Morphological features of thermophilic activated sludge treating food industry wastewater in MBR

Microscopic examination of the activated sludge and morphological characterization of the flocs provides detailed information about the treatment process. The aim of this study is to investigate the morphological parameters of flocs obtained from a thermophilic jet loop membrane bioreactor (JLMBR) in different sludge retention times (SRTs), considering EPS and SMP concentration, hydrophobicity, zeta potential. The results showed that irregularity decreased with the increasing SRT. The compactness value was calculated to be less than 1 for all SRTs. However, the sludge had a more compact structure when the SRT increased. Zeta potential increased whereas hydrophobicity and floc size reduced, with increasing SRT. Furthermore, 2-D porosity calculated using the hole ratio was higher at greater SRTs. Hence, there was a significant correlation between the results obtained using the imaging technique and operation conditions of thermophilic JLMBR.

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Treatment of Sea Food Industry Wastewater Using Zinc Oxide Nano Catalyst Based Photo Oxidation Process

In this present study, Response surface methodology (RSM) coupled with three factor and three level BBD design was employed to optimize the process variables such as catalyst dose, pH, radiation on COD and BOD removal from sea food industry wastewater. A mathematical model and ANOVA was developed to correlate the influencing parameter on the pollutant removal and used to predict the treatment efficiency. Operating conditions was found to be as follows: Catalyst dose of 55 mg/100ml, radiation time of 60min and pHof 4. Under this conditions 91 % of BOD removal and 93% of COD removal was achieved.

Assessment of Groundwater Quality in Areas Irrigated with Food Industry Wastewater: a Case of Wastewater Utilisation from Sugar and Yeast Factories

This work presents the outcomes from two independent studies evaluating the chemical quality of groundwater in agricultural areas irrigated with wastewater from sugar and yeast industries. The evaluation was determined using chemical parameters representing typical contaminants of sugar industry wastewater (SIWW) and yeast industry wastewater (YIWW), and characterising the content of organic matter (BOD5), nutrients (NH4-N, NO3-N, TN and TP) and salts (Cl, SO4, Na and K). The studies reveal that food industry wastewater constitutes a valuable water-nutrient-rich medium that can be reused in agricultural applications as an alternative water resource for irrigation and nutrients for fertilisation. Furthermore, the reuse facilitates the sustainable discharge of wastewater through a soil-aquifer zone to the natural environment. This does not affect chemical quality of groundwater, which was comparable in areas irrigated and non-irrigated with SIWW and YIWW. Although some parameters (NO3-N, NH4-N, SO4, Cl and Na) displayed higher concentrations in groundwater from the fields irrigated with wastewater, these contents were within recommended health-based guideline limits defined in either the groundwater quality standards or the drinking water quality norms. Only the contents of K revealed an exclusive groundwater impact from wastewater irrigation. This was confirmed in statistical tests employing the Ward’s hierarchical clustering method, which exposed excessive amounts of K introduced into groundwater through irrigation with both SIWW and YIWW. However, this parameter is not considered to pose any health risk to humans or the environment, and its content is not restricted by quality guideline values for either groundwater or drinking water.