Yeast Industry Wastewater Research Articles

Simultaneous biomethane optimization and wastewater treatment using isolated acclimatized bacterial strains in baker yeast effluent

The Baker yeast industry wastewater is a substantial environmental concern because of industrial contamination, representing a large reservoir of untapped resources. Anaerobic digestion (AD), a multi-stage biological process, can promote sustainability by producing methane (CH4) from baker’s yeast effluent. This manuscript presents a novel method for isolating bacterial strains from animal remnants and effluent produced during baker's yeast manufacturing. The method is intended to preferentially discover bacterial strains that not only can survive but also show increased growth and metabolic activity in particular environmental circumstances. The bacterial consortia, which was kept separate, not only reduced the incubation duration by five days but also decreased BOD and COD levels by 45% and 51.3%, respectively. Additionally, it increased the purity of methane to 73%. This technique proposes a hopeful method for treating industrial effluents with high levels of COD and BOD, which is in line with the objective of achieving zero discharge and promoting water recycling. AD as compared to membrane filtration, coagulation, electrocoagulation, ozonation, aerobic digestion is feasible and economical process. Sustainability is ensured by production of methane and wastewater treatment.

Single-stage biopolymer production with yeast industry wastewater: effect of SRT and OLR on biopolymer production yield

Single-stage biopolymer production with yeast industry wastewater: effect of SRT and OLR on biopolymer production yield

Yeast industry wastewater treatment with microbial fuel cells: Effect of electrode materials and reactor configurations

Simultaneous pollutant removal and electricity production using microbial fuel cells is a promising environmental sustainable technology that contributes to the circular economy. Numerous studies have been conducted previously using exogenously adding easily degradable sugars for electricity generation in microbial fuel cells (MFCs). However, in real-world applications involving wastewater, the performance of the process varies according on the source, the microorganisms presented and the electrodes employed. The simultaneous treatment of baker's yeast industrial effluents and electricity generation is investigated in various MFCs using titanium and graphite electrodes. Reduced chemical oxygen demand (COD) is reported to be between 73% and 92% depending on the MFC configuration and electrodes employed. The two-chamber MFC with titanium electrodes and inoculum sludge from upflow anaerobic sludge blanket reactors (UASB) perform better, reaching 51.02 mW/m2 and 12.74 μA/cm2 power and current densities, respectively.

Extraction of polyhydroxyalkanoate from activated sludge using supercritical carbon dioxide process and biopolymer characterization

Polyhydroxyalkanoates (PHA) are biodegradable polymers and have the potential to substitute with fossil-fuel based polymers since they have similar properties. Many studies on the production of PHA have been conducted, but the extraction/purification processes have received less attention. Mostly, solvent extraction has been studied, and the effect of different solvent types on the separation processes have been investigated. A better extraction method for PHA makes it a feasible alternative to fossil-fuel based polymers. In this study, a new protocol for the extraction of PHA from activated sludge by supercritical carbon dioxide disruption (sCO2) and biopolymer recovery from disrupted cells were proposed. Extraction experiments were carried out with sCO2 at different pressures, temperatures, times, biomass amounts, and modifier volumes. The operation yield was expressed based on the polyhydroxybutyrate (PHB) release efficiency. The biomass for the extraction experiments was obtained from a PHA production reactor where activated sludge was fed with anaerobically pretreated yeast industry wastewater. 80 % PHB releasing efficiency was achieved by disturbing 2 g of biomass at a density of 57 g/L (biomass/volume) with sCO2 at 200 bar pressure for 15 min at 40 °C. The PHB purity and molecular weight (Mv) of biopolymers were 80 % and 0.27•106 respectively. The use of methanol as a modifier during the sCO2 disruption increased the Mv to 0.37•106. Characterization studies by Fourier transform infrared spectroscopy (FTIR) and thermal degradation analysis (TGA) demonstrated that the biopolymer recovered with this extraction protocol was comparable to commercial PHB. As a clear advantage over the other extraction protocols; operationally fast and simple extraction procedure was achieved.

Butanol Production by Clostridium acetobutylicum NCIMB 13357 Utilizing Yeast Industry Wastewater as a Fermentation Medium

Increasing fuel costs and global environmental concerns have aggravated the search for renewable energy. Significant progress for biofuels production by microorganisms using many types of industrial and agricultural wastes has been achieved. Yeast Industry Wastewater (YIW) is one of the cost-effective and nutrients rich media that is produced in large quantities in Jordan. This study aims to investigate the ability of Clostridium. acetobutylicum NCIMB 13357 to utilize YIW to produce butanol. As a result, C. acetobutylicum was able to grow and metabolize in agar plates continuing undiluted YIW. Shake cultures of YIW supplied with glucose and ammonium acetate resulted in the production of 11.73 g L-1 of butanol. Butanol production was enhanced in column bioreactor as the total carbohydrates were consumed. Nevertheless, immobilization of C. acetobutylicum in sodium alginates slightly enhanced the production of butanol to reach 12.47 g L-1 under batch fermentation, whereas under continuous operation the maximum production of butanol recorded 18.35 g L-1 and 34.85 g L-1 for total solvents after 96 h of fermentation. Consequently, YIW is a promising media for butanol production with additional benefits of its use with regard to environmental and economic aspects.

Electrocoagulation process using aluminum electrodes for treatment of baker's yeast industry wastewater

Background and Aims: Severe contamination with organic compounds and very high color is characteristic of yeast industry wastewater. Discharging this wastewater into the environment has adverse effects on the environment. The present study was conducted to determine the efficiency of the electrocoagulation (EC) using aluminum electrodes for the removal of color, turbidity, and chemical oxygen demand (COD) from the baker's yeast industry wastewater. Materials and Methods: In this experimental study, the effect of current densities (60, 80, 100, and 120 A/m2) and reaction times (15, 30, 45, and 60 min) using aluminum electrode was investigated on removal efficiencies of COD, color, and turbidity. The pilot consisted of a reactor with a useful volume of 2.5 l of epoxy glass, a direct current power supply, and aluminum electrodes of 8 cm × 8 cm in diameter. Results: The highest removal efficiencies were obtained to be 83% for COD, 93% for color, and 96% for turbidity at density of 80 A/m2 and 45-min contact time (pH = 7). Under these conditions, the power and electrode consumption was 16.89 kWh and 94.3 g/m3, respectively, and the treatment cost of wastewater was estimated to be 1.5 $ per each cubic meter. Conclusion: The results showed that EC process using aluminum electrode is an appropriate and effective method for removing color, turbidity, and COD from baking industry wastewater.

Continuous cultivation strategy for yeast industrial wastewater-based polyhydroxyalkanoate production

Polyhydroxyalkanoates (PHAs) present an eco-friendly alternative for conventional plastics. Industrial wastewater from the food industry is a copious source of organic carbon that can be recovered in the form of PHA. However, the wastewater composition varies considerably among the different industries demanding for an industry-specific investigation of the PHA production process. Wastewater from the yeast industry, besides its high concentration in organic carbon, also contains a high ammonium concentration which might decrease the PHA production. Thus, this study aims to investigate PHA production using yeast industry wastewater via an enriched mixed microbial culture (MMC). A less explored cultivation strategy, i.e., continuous cultivation for PHA production was evaluated and compared to the widely used batch cultivation. PHA accumulating MMC was enriched using a sequencing batch reactor (SBR) operated under aerobic dynamic feeding. An MMC dominated by the Thauera species was successfully enriched in the SBR. Experimental results showed that ammonium is indeed required for PHA accumulation and the complete absence of ammonium negatively affects the accumulation process. Using wastewater, batch and continuous feeding strategies, respectively, yielded the PHA accumulation of 72 % and 65 % per dry cell weight. Despite the slightly lower PHA accumulation with continuous cultivation, four times more biomass growth was produced. Consequently, higher theoretical PHA production (270 t/year) can be expected using continuous cultivation in half of the reactor volume (45m3). Therefore, this study asserts the viability of continuous cultivation as a feasible investigatory tool and PHA production strategy.

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.

Pre-treatment of Yeast Production Wastewater and Hydrogen Production Based on MF-CSTR Process

Wastewater produced during the yeast production has high COD concentration, chroma and turbidity and it is difficult to dissolve the water, which has constrained the development of yeast industry. This thesis researched the process of pretreatment of wastewater from yeast production wastewater. Membrane filtering was introduced to hold back the yeast existed in the wastewater. The filtered water was sent to produce hydrogen in anaerobic environment, while the residue was sent to extract protein. The filtering process utilized the PVDF membrane with an aperture of 0.2μm can hold back the yeast sufficiently. According to the transmembrane pressure, 10days worked as a period to clean the membrane at the aeration of 0.15m3•h-1. The cost as well as the profit is compared, which showed that for a yeast factory which had a daily wastewater production of 1 000m3, the profit could be as high as 1 090 yuan•d-1. Intermittent shake flask tests were conducted to study the difference of hydrogen production between direct anaerobic digestion and anaerobic digestion after filtration. When influent pH was 5.00, the hydrogen percentage of filtered group was 49.69%, which exceeded the group without filtration by 20.34%. The HRT and OLR were tested for CSTR to get the highest hydrogen production through anaerobic fermentation of the filtered yeast industry wastewater. Results showed that, when HRT was 8h and OLR was 24kgCOD•m-3•d-1, the system can get the highest biohydrogen production rate at 13.2L•d-1. This test suggested that MF-CSTR pretreatment process can simultaneously treat yeast industry wastewater effectively and realize resource recovery from yeast protein and energy recovery and utilization from hydrogen, which provides the theoretical foundation for the treatment and resource utilization from yeast industry wastewater.

Development of pilot scale nanofiltration system for yeast industry wastewater treatment

The treatment of the yeast industry wastewater was investigated by nanofiltration (NF) membrane process on a pilot scale. Two wastewaters were used as feed: (i) dilute wastewater with COD 2000 mg/L and (ii) concentrate wastewater with COD 8000 mg/L. The permeate flux, COD retention, color and electrical conductivity (EC) removal were evaluated in relation to trans-membrane pressure and long-term filtration. A linear growth in permeate flux was found with increasing in trans-membrane pressure for wastewaters. In addition, the COD retention, color and EC removal increased with trans-membrane pressure enhancement. The results obtained from the long-term nanofiltration of dilute wastewater indicated that the permeate flux decreased from 2300 L/day to 1250 L/day and COD retention increased from 86% to 92%. The quality of the permeate in term of COD is lower than the discharge standard in river (200 mg/L). Thus, this process is useful for treatment of wastewaters produced by yeast industry.

The Use of Fenton?s System in the Yeast Industry Wastewater Treatment

The paper presents the results of the research conducted with the use of hydrogen peroxide and iron (II) sulfate or chloride in the chemical pretreatment of Saccharomyces cerevisae yeast industry wastewater. It was found that the use of Fenton's system permitted a high reduction of sugar-like substances and total decolorizing of non-sugar compounds. The level of COD reduction depended on the amount and mutual proportions of COD:Fe(II):H2O2, as well as a type of the applied salt Fe(II). For iron concentrations: 1000-4000 mg l-1 with molar excess [H2O2]:[Fe(II)] – 2-14:1 and reaction pH – 3.1-3.4, very high reproducibility of results and the COD reduction exceeding 75 % were obtained. For this range of the reagent concentrations, the distribution of COD reduction values correlated with the equation: COD = − Ax4 + Bx3 − Cx2 + Dx − E (where: x = [H2O2]:[Fe(II)]). Additional neutralization with the use of lime milk made the secondary reduction of CODr(CaO) value possible, which resulted in the reduction of the total CODT above 90 %. The method enabled us to consider the possibility of the preliminary chemical elimination of the wastewater load, which might increase the effectiveness of working wastewater treatment plants, especially in cases of continuous and occasional overloads above the level assumed by the project.

Characterization of sulfate-reducing bacteria in yeast industry waste by microcalorimetry and PCR amplification

Sulfate-reducing bacteria (SRB) were isolated from anaerobic sludge of yeast factory wastewater treatment plant by cultivation on Postgate C medium. Microcalorimetry was used to monitor the anaerobic digestion processes and to measure the growth rates of sulfate-reducing bacteria. The maximum growth rates determined by microcalorimetry and ATP analysis were different— μ max(d Q/d t) = 0.165 ± 0.008 h −1 and μ max(N ATP) = 0.207 ± 0.013 h −1. Experiments on the cultivation of SRB from yeast industry wastewater treatment plant in batch culture showed that during the first 20 h the concentration of sulfate decreased from 78.3 mM down to 62.2 mM while the increase of sulfide production was negligible. Perceptible amount of sulfide (7.82 mM) appeared on the 33.5 h of fermentation together with a peak on the power–time curve and considerable increase in the cell count (1.26 × 10 9). First steps of sulfate metabolism (activation of sulfate by ATP sulfurylase, production of H 2) are accompanied by endothermic heat effects, therefore the values of thermal power remain moderate until the evolution of sulfide starts. The influence of green microalgae Chlorococcum sp. (preparation Biotreat 100) on the growth characteristics of microorganisms was also studied. Identification of one SRB strain was started by sequencing of PCR-amplified 16S rRNA gene. Two sets of primers were used for PCR amplification, both specific for domain Bacteria but giving different gene fragments. PCR-products were purified with JETQUICK kit according to the manufacturer instructions.

Concentrated wastewater treatment studies using an anaerobic hybrid reactor

The treatment performance of an anaerobic hybrid reactor was investigated for different types of concentrated wastewater using a laboratory scale model reactor. Its performance was first examined using synthetic wastewater at different hydraulic retention times (0.5, 1 and 2 days) and organic loading rates (1–10 kg chemical oxygen demand (COD) m −3 per day) over 2 years. COD removal efficiencies ranging from 77 to 90% were achieved. Baker's yeast and meat processing industry wastewater was fed to the model reactor, consecutively. HRT and OLR values were 2 days—9.0 kg COD m −3 per day and 2 days—1.0 kg COD m −3 per day, and about 78 and 75% COD removal efficiency was obtained for yeast and meat industry wastewater, respectively. The methane content of the biogas produced was about 58, 58, and 70% for synthetic, yeast industry and meat processing wastewater, respectively. The organic matter removal efficiency of the reactor indicated that this type of reactor is suitable for treatment of high strength effluent.

Toxicity assessment on combined biological treatment of pharmaceutical industry effluents

This paper describes the wastewater characterization and aerobic/anaerobic treatability (oxygen uptake rate and biogas production measurement) of chemical-synthesis based pharmaceutical industry effluents in a nearby baker's yeast industry treatment plant. Preliminary experiments by the industry had indicated strong anaerobic toxicity. On the other hand, aerobic treatability was also uncertain due to complexity and unknown composition of the wastewater. The work in this study has indicated that the effluents of the pharmaceutical industry can be treated without toxicity in the aerobic stage of the treatment plant. Methanogenic activity tests with anaerobic sludge from the anaerobic treatment stage of the wastewater treatment plant and acetate as substrate have confirmed the strong toxicity, while showing that 30 min aeration or coagulation with an alum dose of 300 mg/l is sufficient for reducing the toxicity almost completely. Powdered activated carbon, lime and ferric chloride (100-1,000 mg/l) had no effect on reduction of the toxicity. Consequently, the pharmaceutical industry was recommended to treat its effluents in the anaerobic stage of the nearby baker's yeast industry wastewater treatment plan at which there will be no VOC emission and toxicity problem, provided that pretreatment is done.

Chemical changes of yeast industry wastewater during infiltration in Ruseifa area, Jordan

Water quality changes taking place during the infiltration process of treated wastewater produced by the Yeast Industrial Company, Jordan, are discussed. It was found that the COD, NH4 + and PO4 3- contents decreased with depth. More than 80% of NH4 + and about 95% of PO4 3 and COD were removed at a depth of 70 cm in the soil profile. However, the electrical conductivity (EC) of the infiltrated water, which was extracted from different depths, increased gradually due to the dissolutional processes of soluble minerals within the soil profile. Furthermore, the probable effect of the irrigation return flows of the treated wastewater used in irrigation on the groundwater resources of the area are discussed. Generally, it was found that land application of this sort of wastewater is an efficient method of further treatment taking into consideration the negligible effects of the wastewater on the groundwater resources in the area.

Common anaerobic treatability of pharmaceutical and yeast industry wastewater

The purpose of this study is to demonstrate the feasibility of anaerobic treatment of pharmaceutical and baker's yeast industry effluents in a joint treatment system. Anaerobic treatability studies have been performed in a lab-scale upflow anaerobic sludge blanket reactor (UASBR). The experimental study has been carried out for 333 days. The influent COD's during the experimental study were about 10,000 mg/l. Pharmaceutical wastewater has a 5% of inhibition on the COD removals at the dilution rate of 1/100 or more in the joint anaerobic treatment with baker's yeast industry effluents. Maximum inhibition of 10% on the average was observed when the system was characterized with acclimation periods. The study has shown that, following the solvent extraction with pre-aeration process, a common anaerobic treatment can be applied to baker's yeast industry wastewater and to pharmaceutical industry effluents.

Common anaerobic treatability of pharmaceutical and yeast industry wastewater

The purpose of this study is to demonstrate the feasibility of anaerobic treatment of pharmaceutical and baker's yeast industry effluents in a joint treatment system. Anaerobic treatability studies have been performed in a lab-scale upflow anaerobic sludge blanket reactor (UASBR). The experimental study has been carried out for 333 days. The influent COD's during the experimental study were about 10,000 mg/1. Pharmaceutical wastewater has a 5% of inhibition on the COD removals at the dilution rate of 1/100 or more in the joint anaerobic treatment with baker's yeast industry effluents. Maximum inhibition of 10% on the average was observed when the system was characterized with acclimation periods. The study has shown that, following the solvent extraction with pre-aeration process, a common anaerobic treatment can be applied to baker's yeast industry wastewater and to pharmaceutical industry effluents.

Pretreatment of Yeast Industry Wastewater in an Aerated Balancing Tank and Its Effect on the Municipal Treatment Plant Performance

Organic shook loads from a yeast plant caused severe operational problems and unacceptable effluent qualities at the chemical/biological wastewater treatment plant serving the City of Oslo. to alleviate these problems a pretreatment concept for the yeast wastewater, based on an aerated balancing tank without following solids separation, was proposed. Laboratory tests with aeration of yeast wastewater at hydraulic residence times of 0.5 to 2.3 days showed 25 to 67% removal of soluble COD. Jar-tests indicated that with proper balancing, yeast wastewater aerated for at least 0.8 days would have a very limited influence on the pre-precipitation process at the municipal treatment plant. Based on this information, a full-scale aerated balancing tank was constructed. After pretreatment of the yeast wastewater was introduced, data from the municipal treatment plant show very low and stable effluent concentrations.