Effluent Medium Research Articles

Life cycle assessment of lipid production from Pavlova gyrans: Influence of the culture medium composition

Microalgae have been increasingly recognized as an alternative source of lipids, especially polyunsaturated fatty acids (PUFA) such as omega 3 and 6, being essential to carefully assess their life cycle environmental impacts. Hence, this work aims to carry out a life cycle assessment (LCA) of lipid production from the microalga Pavlova gyrans grown in different culture media and nutrient concentrations, on a “cradle-to-gate” approach. For the life cycle inventory, primary data obtained from laboratory experiments was used for the foreground processes, complemented with secondary data from LCA databases and literature for the background processes. The functional unit chosen is 1 g of lipids extracted. For the environmental impact assessment, the ReCiPe 2016 method was used, evaluating 18 midpoint indicators from an egalitarian perspective. An uncertainty estimate was performed using experimental results and the ANOVA statistical test. Results show that the organic fertilizer medium has an overall environmental impact around 1.28 to 2 times lower than the aquaculture effluent medium. Energy is the process hotspot, contributing more than 95%, on average, to the overall potential environmental impact. Alternative renewable energy scenarios were therefore evaluated. Results show that, compared to the electricity mix, renewable energies led to significant reductions in 13 environmental impact categories, such as global warming potential, which decreased by around 70 and 90% respectively for solar and wind energy, but to significant increases in 5 impact categories, such as terrestrial ecotoxicity, which increased by around 231 and 184%, and the mineral resources scarcity, which increased by around 114 and 302% respectively for solar and wind energy. The results of this study can provide valuable information to guide research and development efforts towards more sustainable processes for obtaining lipids from microalgae.

Gut microbiota modulatory capacity of fermented ketchup in a validated in vitro model of the colon

This study aimed to evaluate the effects of fermented beetroot ketchup enriched with Lactobacillus johnsonii K4 and non-fermented beetroot ketchup on pooled fecal microbiota from healthy adults in in vitro colon model. The research focused on how these products influenced the composition and functionality of the gut microbiota, as well as metabolite production, using the validated dynamic in vitro colon model, TNO Intestinal Model (TIM-2). After an initial starvation phase, a single 60 g dose of predigested and freeze-dried ketchup was introduced into the model. The potential probiotic strain Lactobacillus johnsonii K4 was added over three days. A carbohydrate mixture of standard ileal effluent medium (SIEM) served as the control. Our analysis identified 21 bacterial taxa that were significantly modulated (q-value < 0.2) when comparing ketchup samples to control samples. Notably, the ketchup samples led to an increase in butyrate-producing taxa, including Faecalibacterium, Blautia, Ruminococcaceae, Ruminiclostridium 6, and Anaerostipes. Conversely, there was a reduction in potentially pathogenic genera Desulfovibrio and Escherichia-Shigella. Distinct profiles of short-chain fatty acids (SCFA) were observed among the fermented ketchup, non-fermented ketchup, and control samples. Non-fermented ketchup resulted in higher proportions of acetate, propionate, and butyrate compared to the other interventions. This may be related to the fermentation with lactic acid bacteria in fermented samples with lower levels of substrate for SCFAs production. However, fermented ketchup sample has higher relative abundance of beneficial bacteria like Lactobacillus, Weissella and Dorea in gut microbiota. These findings suggest that beetroot ketchup, can positively influence gut microbiota composition and function, highlighting its potential benefits for human health.

Augmented Catalytic Performance of PVA- Assisted Fe2O3 Nano Catalyst for Water Treatment Synthesized via Green Route

Abstract Metal oxides (MO) are widely preferred for removing various effluents from water and air; however due to poor utilization of visible light, the application of MO nanoparticles for water treatments is hindered. This work reports the synthesis of ring-structured PVA-assisted Fe2O3 (P-Fe2O3) nanocomposite through a green route synthesis, for the elimination of methylene blue via sunlight triggered photocatalyst. FTIR spectroscopy confirmed the presence of desired functional groups in novel ring-structured Fe2O3 and PVA-assisted Fe2O3 (P-Fe2O3) nanocomposite. The crystallinity of Fe2O3 was also studied through XRD. Surface topography of Fe2O3 was examined through FE-SEM, that reveals a central hole with extended surface area of Fe2O3. UV-vis-spectroscopy is used to evaluate photocatalytic efficiency which shows, pristine Fe2O3 exhibited 37% degradation in stipulated time intervals of 30~120 mins. The photocatalytic efficiency of augmented P-Fe2O3 nanocomposite expelled 82% of the methylene blue in span of just 02 hours. The stability of the developed nanocomposite in the effluent medium was investigated through FTIR by observing the change in carboxyl adsorption band produced during degradation of PVA, that manifests the fact that no degradation was witnessed for PVA even after 120 min, that makes P-Fe2O3 a promising material for the degradation of AZO dyes.

Promoting Magnusiomyces spicifer AW2 Cell-Bound Lipase Production by Co-culturing with Staphylococcus hominis AUP19 and Its Application in Solvent-Free Biodiesel Synthesis.

Yeast-bacterium interaction has recently been investigated to benefit the production of cell-bound lipases (CBLs). Staphylococcus hominis AUP19 supported the growth of Magnusiomyces spicifer AW2 in a palm oil mill effluent (POME) medium to produce CBLs through a bioremediation approach, including oil and grease (O&G) and chemical oxygen demand (COD) removals. This research used the yeast-bacterium co-culture to optimize CBLs and cell biomass (CBM) productions through bioremediation using the statistical Plackett-Burman design and response surface methodology-central composite design. The CBLs were finally applied in biodiesel synthesis. The CBM of 13.8g/L with CBLs activity at 3391 U/L was achieved after incubation at room temperature (RT,30 ± 2°C) for 140h in 50% POME medium, pH 7.0, containing 1.23% (w/v) ammonium sulfate. Bacterium promoted yeast growth to achieve bioremediation with 87.9% O&G removal and 84.5% COD removal. Time course study showed that the CBLs activity was highest at 24h cultivation (4103 U/L) and retained 80% and 60% of activities at 4°C and RT after 5weeks of storage. The CBLs application successfully yielded 77.3% biodiesel from oleic acid (esterification) and 86.4% biodiesel from palm oil (transesterification) within 72h in solvent-free systems. This study highlights that yeast-bacterium co-culture and POME should receive more attention for potential low-cost CBLs production through bioremediation, i.e., O&G and COD removals, while the CBLs as biocatalysts are promising for significant contribution to an effective strategy for economic green biodiesel production.

2'-Fucosyllactose inhibits proliferation of Clostridioides difficile ATCC 43599 in the CDi-screen, an in vitro model simulating Clostridioides difficile infection.

Clostridioides difficile is a Gram-positive anaerobic bacterium that can produce the toxins TcdA and/or TcdB and is considered an opportunistic pathogen. C. difficile is mainly transmitted as endospores, which germinate to produce the pathogenic vegetative cells under suitable conditions in the gut. To efficiently screen novel therapeutic- interventions against the proliferation of C. difficile within a complex microbial community, platforms are needed that facilitate parallel experimentation. In order to allow for screening of novel interventions a medium-to-high throughput in vitro system is desirable. To this end, we have developed the 96-well CDi-screen platform that employs an adapted simulated ileal effluent medium (CDi-SIEM) and allows for culturing of pathogenic C. difficile. C. difficile strain ATCC 43599 was inoculated in the form of vegetative cells and spores into the CDi-screen in the presence and absence of a cultured fecal microbiota and incubated for 48h. To demonstrate its utility, we investigated the effect of the human milk oligosaccharide 2'-Fucosyllactose (2'-FL) at 4 and 8 mg/mL on C. difficile outgrowth and toxin production in the CDi-screen. The test conditions were sampled after 24 and 48 hours. C. difficile -specific primers were used to monitor C. difficile growth via qPCR and barcoded 16S rRNA gene amplicon sequencing facilitated the in-depth analysis of gut microbial community dynamics. C. difficile ATCC 43599 proliferated in CDi-SIEM, both when inoculated as spores and as vegetative cells. The strain reached cell numbers expressed as C. difficile genome equivalents of up to 10 8 cells per mL after 24h of incubation. 2'-FL significantly inhibited the outgrowth of the ATTC 43599 strain within a complex human gut microbial community in the CDi-screen. In addition, a dose-dependent modulation of the gut microbial community composition by 2'-FL supplementation was detected, with a significant increase in the relative abundance of the genus Blautia in the presence of 2'-FL. The CDi-screen is suitable for studying C. difficile proliferation in a complex gut ecosystem and for screening for anti-pathogenic interventions that target C. difficile directly and/or indirectly through interactions with the gut microbiota. Different doses of compounds such as in this study the dose of the human milk oligosaccharide 2'-FL can be screened for efficacy in the inhibition of C. difficile proliferation.

Abstract 3858: Peristalsis-like mechanical stimuli in the intestinal milieu promotes colorectal cancer invasion through GABAergic signaling changes in an organ-on-chip platform

Abstract Mechanical forces in the tumor microenvironmental milieu are often understudied due to a lack of relevant preclinical model systems. Here we describe a microfluidic organ-on-chip platform that incorporates tissue-tissue interfaces and physical forces to aid in the examination of colorectal cancer (CRC) progression. A major advantage of this model is the ability to mimic peristalsis, a physiological process occurring in the gut. Live-cell imaging with a 3D printed organ-on-chip cradle was used to quantify the number of CRC cells that have invaded from the epithelial channel into the vascular channel over time. We determined that peristalsis-like motions in our organ-on-chip model enhanced the invasion capacity of CRC cells, mimicking intravasation. We subsequently examined the effluent media in stretched compared to non-stretched conditions using mass spectrometry based metabolomics and discovered an increase in the secretion of gamma-aminobutyric acid (GABA) by CRC cells, implicating peristalsis-mediated tumor cell invasion with neurotransmitter release. Inhibitors targeting the GABA-A receptor reversed the observed tumor cell invasion phenotype when cells were subjected to peristalsis-like motions. Interestingly, even in the absence of peristalsis, tumor cell invasion was promoted when GABA agonists were introduced into the organ-on-chip system. This work reveals important interactions between CRC cells and their microenvironment, and that disrupting GABAergic signaling might be an approach to prevent or delay cancer progression. Citation Format: Carly Strelez, Sujatha Chilakala, Kimya Ghaffarian, Ah Young Yoon, Jonathan Katz, Shannon M. Mumenthaler. Peristalsis-like mechanical stimuli in the intestinal milieu promotes colorectal cancer invasion through GABAergic signaling changes in an organ-on-chip platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3858.

Pyrolysis Processing of PFAS-Impacted Biosolids, a Pilot Study

Concentrations of per- and poly-fluoroalkyl substances (PFAS) present in wastewater treatment biosolids is a growing concern. Pyrolysis is a thermal treatment technology for biosolids that can produce a useful biochar product with reduced levels of PFAS and other contaminants. In August 2020, a limited-scope study investigated target PFAS removal of a commercial pyrolysis system processing biosolids with analysis of 41 target PFAS compounds in biosolids and biochar performed by two independent laboratories. The concentrations of 21 detected target compounds in the input biosolids ranged between approximately 2 µg/kg and 85 µg/kg. No PFAS compounds were detected in the biochar. The PFAS concentrations in the biochar were assumed to equal the compounds’ minimum detection limits (MDLs). The pyrolysis system’s target PFAS removal efficiencies (REs) were estimated to range between >81.3% and >99.9% (mean = >97.4%) with the lowest REs being associated with the lowest detected PFAS concentrations and the highest MDLs. No information on non-target PFAS compounds in influent or effluent media or products of incomplete combustion were considered. Select gaseous emissions were measured by Fourier transform infrared spectroscopy and gas chromatography time-of-flight mass spectrometry to provide additional information on air emissions after process controls. This limited-scope study indicated that additional research to further understand this process is warranted. Implications Statement Development of alternative approaches to manage PFAS-impacted biosolids is of emerging international importance. A commercially operating biosolids pyrolysis process was shown to lower target PFAS levels in produced biochar. Additional research is warranted to understand all potential PFAS transformation emission routes and optimal air pollution emissions control strategies for this technology class.

Aerobic-pond Palm Oil Mill Effluent (POME) utilization as growth medium of Scenedesmus obliquus for lipid production

The purpose of this research is to know the growth rate and biomass production of Scenedesmus obliquus in palm oil mill effluent (POME) medium taken from aerobic pond and to know the lipid concentration produced by S. obliquus. In this research, S. obliquus was cultured in various POME concentration, those were 20, 60, 80, 90, 95, and 100% v/v, while the concentration of inoculum was 30% v/v, and fatty acid content was analysed by gas chromatography. The results revealed that growth rate was decrease with the increasing concentration of POME (0.3545, 0.1792, 0.1566, 0.1268, 0.1158, and 0.1008/day), dry biomass weight was increase with the increasing concentration of POME (0.40, 1.20, 1.30, 1.77, 2.28, and 2.45 g/L), and lipid content also tended to increase with the increasing concentration of POME (13.10%, 36.59%, 36.65%, 50.37%, 60.40%, and 64.98%). Oleic acid and behenic acid were the dominant fatty acid content in S. obliquus lipid cultured in 100% concentration POME media. It is concluded that aerobic-pond POME can be utilized as growth medium for S. obliquus with a high lipid content.

The potential use of purple nonsulfur bacteria to simultaneously treat chicken slaughterhouse wastewater and obtain valuable plant growth promoting effluent and their biomass for agricultural application

Abstract Treatment of wastewater with purple nonsulfur bacteria (PNSB) simultaneously produces the biomass of plant growth promoting bacteria (PGPB) and the effluent containing plant growth promoting substances (PGPS). Among 46 PNSB strains isolated from chicken slaughterhouse wastewater (CSW) treatment unit, only four strains grew well in non-sterile effluent of the anaerobic digester (CSW-Di), under both microaerobic light and aerobic dark conditions. However, only strains WS308 and WS502 were selected as inoculants for subsequent experiments since they released high levels of 5-aminolevulinic acid (ALA) into the digester effluent medium under both incubating conditions. Based on 16S rRNA genes analysis, the strains WS308 and WS502 were identified as Rhodopseudomonas faecalis and Rhodopseudomonas palustris, respectively. The central composite design (CCD) experiments were conducted by using a mixed culture of the two strains (1:1) treating the non-sterile CSW-Di (soluble chemical oxygen demand, sCOD 736 mg/L) under 72-hr microaerobic light condition. The optimal conditions on the multivariate regression were found at the inoculum size (X1) of 3.63% (roughly 106 cells/mL), initial pH (X2) of 6.9 and light intensity (X3) of 3731 lux. At this condition, sCOD removal was predicted at 85.3%, while the verification test result favorably achieved 88.1% removal. ALA concentration in CSW-Di of the verification set was found at 0.13 mg/L. All trace elements detected in CSW-Di effluent were much lower than recommended maximum concentrations for irrigation water. Treating wastewater with potent PNSB strains could produce effluent containing PGPS, such as ALA, and also the biomass as PGPB for organic agricultural applications.

WAT-on-a-chip integrating human mature white adipocytes for mechanistic research and pharmaceutical applications

Obesity and its numerous adverse health consequences have taken on global, pandemic proportions. White adipose tissue (WAT) – a key contributor in many metabolic diseases – contributes about one fourth of a healthy human’s body mass. Despite its significance, many WAT-related pathophysiogical mechanisms in humans are still not understood, largely due to the reliance on non-human animal models. In recent years, Organ-on-a-chip (OoC) platforms have developed into promising alternatives for animal models; these systems integrate engineered human tissues into physiological microenvironment supplied by a vasculature-like microfluidic perfusion. Here, we report the development of a novel OoC that integrates functional mature human white adipocytes. The WAT-on-a-chip is a multilayer device that features tissue chambers tailored specifically for the maintenance of 3D tissues based on human primary adipocytes, with supporting nourishment provided through perfused media channels. The platform’s capability to maintain long-term viability and functionality of white adipocytes was confirmed by real-time monitoring of fatty acid uptake, by quantification of metabolite release into the effluent media as well as by an intact responsiveness to a therapeutic compound. The novel system provides a promising tool for wide-ranging applications in mechanistic research of WAT-related biology, in studying of pathophysiological mechanisms in obesity and diabetes, and in R&D of pharmaceutical industry.

Bioflocculant production using palm oil mill and sago mill effluent as a fermentation feedstock: Characterization and mechanism of flocculation

This study was conducted to examine the production of bioflocculants using agricultural wastewater as a fermentation feedstock under different temperatures and incubation times. The mechanism of flocculation was studied to gain a detailed understanding of the flocculation activity. The highest bioflocculant yield (2.03 g/L) at a temperature of 40 °C was produced in a palm oil mill effluent medium (BioF-POME). Bioflocculant produced from a fermented SME medium (BioF-SME) showed the highest activity. The flocculation tests for colour and turbidity removal from lake water indicated that BioF-SME and BioF-POME performed comparably to commercial alum. Analyses of the bioflocculants using liquid chromatography-mass spectrometry (LC-MS) found that the bioflocculants contained xylose and glucose. The mechanism study showed that flocculation occurred through charge neutralization and interparticle bridging between the bioflocculant polymer and the particles in the lake water. Thus, agricultural wastewater can be used as a fermentation feedstock for high-quality bioflocculants.

Cultivation of Chlorella pyrenoidosa as a raw material for the production of biofuels in palm oil mill effluent medium with the addition of urea and triple super phosphate

Background: The utilization of microalgae as a renewable energy is an important aspect in solving shortage of future oil reserve in 15 years. One of the renewable energy sources is microalgae biodiesel. Palm oil mill effluent (POME) is a wastewater that has a high content of organic materials. These organic materials can be used as growth nutrients for microalgae. Chlorella pyrenoidosa is one of the most potential microalgae used as a raw material for the production of biodiesel since it contains lipids (8%-35%). Methods: Chlorella pyrenoidosa was cultured on the POME medium with concentrations of 0%, 25%, 50%, 75%, and 100%v with addition of synthetic nutrients (urea: TSP) at the ratios of 2:1 ; 1:2 ; 0.5:1 in a 500 mL Erlenmeyer flask, at pH 6-8, aeration using aquarium pumps, and using LED lights (3000 lux). Results: It was revealed that at POME concentration of 25% and with addition of urea: TSP at a ratio of 2:1, the optimum specific growth rate (0.306/day) with the highest number of cells was 3.530 × 107 cells/mL and the highest lipid content was 36% of its dry weight. The removal efficiency of POME could be obtained from the removal efficiency of chemical oxygen demand (COD), total nitrogen, and orthophosphate (P-PO4 ), which was 70, 90.42, and 81.12%, respectively. Conclusion: According to the results, under appropriate culture conditions, C. pyrenoidosa can produce lipids with good use of nutrients contained in the POME medium.

Growth Kinetics for Microalgae Grown in Palm Oil Mill Effluent (POME) medium at various CO2 Levels

This paper sought to find the growth kinetic data of maximum specific growth rate (μmax) and substrate saturation constant (KS) for a microalgal reaction system over various dissolved CO2 levels (0.04, 0.1, 0.3, 0.5, 0.8, 1.0, 5.0, 10.0% v/v) at a constant sparging rate of 1.2 vvm, by using logistic model and Monod kinetics. The reaction system consisted of microalgae growing in palm oil mill effluent (POME) medium in 1 L flask with constant light illumination and sparged with the specified CO2 gas mixture. It is found from the experimental works that the values of μmax and KS to be at 0.04958 h-1 and 0.03523% (v/v) respectively. The results also showed that utilizing CO2 levels (v/v) in the sparging gas mixture more than 1% (v/v) would not improve microalgae growth significantly as expressed in the values of specific growth rate µ. These data and information are critically important for bioreactor scaling up purposes, especially bioreactor system dedicated for microalgae products and CO2 sequestration.

Longitudinal Monitoring of Biofilm Formation via Robust Surface-Enhanced Raman Scattering Quantification of Pseudomonas aeruginosa-Produced Metabolites.

Detection of bacterial metabolites at low concentrations in fluids with complex background allows for applications ranging from detecting biomarkers of respiratory infections to identifying contaminated medical instruments. Surface-enhanced Raman scattering (SERS) spectroscopy, when utilizing plasmonic nanogaps, has the relatively unique capacity to reach trace molecular detection limits in a label-free format, yet large-area device fabrication incorporating nanogaps with this level of performance has proven difficult. Here, we demonstrate the advantages of using chemical assembly to fabricate SERS surfaces with controlled nanometer gap spacings between plasmonic nanospheres. Control of nanogap spacings via the length of the chemical crosslinker provides uniform SERS signals, exhibiting detection of pyocyanin, a secondary metabolite of Pseudomonas aeruginosa, in aqueous media at concentration of 100 pg·mL-1. When using machine learning algorithms to analyze the SERS data of the conditioned medium from a bacterial culture, having a more complex background, we achieve 1 ng·mL-1 limit of detection of pyocyanin and robust quantification of concentration spanning 5 orders of magnitude. Nanogaps are also incorporated in an in-line microfluidic device, enabling longitudinal monitoring of P. aeruginosa biofilm formation via rapid pyocyanin detection in a medium effluent as early as 3 h after inoculation and quantification in under 9 h. Surface-attached bacteria exposed to a bactericidal antibiotic were differentially less susceptible after 10 h of growth, indicating that these devices may be useful for early intervention of bacterial infections.

Lactate-Induced Glucose Output Is Unchanged by Metformin at a Therapeutic Concentration - A Mass Spectrometry Imaging Study of the Perfused Rat Liver.

Metformin is the first line drug for type 2 diabetes but its molecular mechanisms remain unclear. Here, we have studied the acute effect of a therapeutically relevant intrahepatic concentration of metformin on glucose production from lactate. We selected the perfused rat liver as experimental system since it enables the complete control of drug dosage. We used MALDI (matrix-assisted laser desorption/ionization) mass spectrometry imaging to estimate the concentration of metformin in the livers and we measured the concentration of glucose in the effluent medium under basal conditions and following lactate addition. MALDI mass spectra of thin-sections of freeze-clamped rat liver perfused with metformin showed a peak at 130.16 m/z which was unambiguously assigned to metformin. The mass spectrometric detection limit was at a tissue concentration of about 250 nM, and uptake of metformin from the perfusion medium to the liver occurred with a Km of 0.44 mM. Metformin was evenly distributed in the liver irrespective of its concentration in the perfusion medium and the duration of a perfusion. At a parenchymal concentration of 30 μM, metformin did not induce any significant suppression of the basal or lactate-induced glucose release from the liver. These results show that matrix-assisted laser desorption/ionization mass spectrometry imaging can be applied to estimate the tissue concentration and distribution of metformin in a therapeutically relevant micromolar concentration range. Our findings challenge the view that metformin causes an inhibition of glucose release from the liver by an acute inhibition of mitochondrial glycerol 3-phosphate dehydrogenase (EC 1.1.5.3).

Prebiotic effect of predigested mango peel on gut microbiota assessed in a dynamic in vitro model of the human colon (TIM-2)

Mango (Mangifera indica L.) peel (MP), is a by-product from the industrial processing to obtain juices and concentrates, and is rich in polyphenols and dietary fiber (DF). DF content of dried MP is about 40%. The aim of this study was to determine the prebiotic potential of this by-product submitting predigested mango (‘Ataulfo’) peel to a dynamic in vitro model of the human colon. Dried MPs were predigested following an enzymatic treatment and separating digestion products and undigested material by diafiltration. The predigested samples were fermented in a validated in vitro model of the colon (TIM-2) using human fecal microbiota and sampled after 0, 24, 48 and 72h. A carbohydrate mixture of standard ileal effluent medium (SIEM) was used as control. Production of short chain fatty acids (SCFA), branched chain fatty acids (BCFA) and ammonia profiles were determined in both lumen and dialysates. Microbiota composition was determined by sequencing 16S rRNA gene V3–V4 region. Principal component (PC) analysis of fermentation metabolites and relative abundance of genera was carried out. Fermentation of MP resulted in SCFA concentrations resembling those found in the SIEM experiments, with a 56:19:24 molar ratio for acetic, propionic and butyric acids, respectively. BCFA and ammonia were produced in similar concentrations in both samples. About 80 bacterial genera were identified after fermentation of MP, with an 83% relative abundance of Bifidobacterium at 24h. Three PC were identified; PC1 was influenced by a high Bifidobacterium abundance and low metabolites production. PC2 resulted in a decrease of other genera and an increase of metabolites studied. The relative abundance at 72h in MP was distributed over 4 genera Bifidobacterium, Lactobacillus, Dorea, and Lactococcus. Our results suggest MP as a potential prebiotic ingredient.

Hydraulic Design of the Bleeding Chamber for the Steam Turbine

Hydraulic Design of the Bleeding Chamber for the Steam Turbine Hydraulic loss coefficients in the turbine flow discharge section were calculated on the basis of experimental determination of pressure losses in the turbine section designed for the heating bleeding in the steam turbine. It has been established that these loss coefficients are affected by the number of outlet branches, the diameters of outlet branches, a value of throat cross-section (narrow), radial cone cross-section through which the steam enters the bleeding section, and a relative flow of effluent medium (up to 35 %). The investigation was carried out using the aerodynamic test bench. The bleeding chamber was designed with the axial symmetry and had a large volume peculiar for the turbines with large uncontrolled steam bleedings. Consideration was given to the operation of the options of bleeding channels that have radial cone elements and also the options that have no radial cone. The technique was given that allows us to calculate pressure losses in the region between the flow passage of real steam turbine and the bleeding branches. This technique was developed based on the experimental investigation of bleeding channel carried out using the stationary aerodynamic test bench. It has been established that the use of two outlet branches instead of one results in a more substantial decrease of losses in the diffuser bleeding channel in comparison with the approach when the area of one outlet branch is increased two times.

A cost effective cultivation medium for biocalcification of Bacillus pasteurii KCTC 3558 and its effect on cement cubes properties

Application of carbonate precipitation induced by Bacillus pasteurii for improving some properties of cement has been reported. However, it is not yet successful in commercial scale due to the high cost of cultivation medium. This is the first report on the application of effluent from chicken manure bio-gas plant, a high protein content agricultural waste, as an alternative growth medium for carbonate precipitation by B. pasteurii KCTC3558. Urease activity of B. pasteurii KCTC3558 cultured in chicken manure effluent medium and other three standard media were examined using phenate method. The highest urease production was achieved in chicken manure effluent medium (16.756Umg−1 protein). Cost per liter of chicken manure effluent medium is up to 88.2% lower than other standard media. The most effective cultivation media was selected for carbonate precipitation study in cement cubes. Water absorption, voids, apparent density and compressive strength of cement cubes were measured according to the ASTM standard. The correlation between the increasing density and compressive strength of bacterial added cement cube was evident. The density of bacterial cement cube is 5.1% higher than control while the compressive strength of cement mixed with bacterial cells in chicken manure effluent medium increases up to 30.2% compared with control. SEM and XRD analysis also found the crystalline phase of calcium carbonate within bacterial cement which confirmed that the increasing density and compressive strength were resulted from bacterial carbonate precipitation. This study indicated that the effluent from chicken manure bio-gas plant could be used as an alternative cost effective culture medium for cultivation and biocalcification of B. pasteurii KCTC3558 in cement.

Nephelometric approach to study coagulation–flocculation of brewery effluent medium using Detarium microcarpum seed powder by response surface methodology

The coagulation–flocculation performance of Detarium microcarpum seed powder (DMSP) varying effluent pH, coagulant dosage and settling time in the removal of suspended solid particles from brewery effluent (BE) at room temperature has been investigated. A laboratory bench-scale jar test was employed for the experiments. Such Coag–flocculation parameters as coagulation rate constant and coagulation half-time were determined. Statistical parameters such as coefficient of determination, R2, sum of squares due to error, SSE, and the root mean square error, RMSE, were used to evaluate the adequacy of the process. The optimum pH was observed at 4.0, while 100.0mg/L DMSP delivered optimum suspended solid particle removal. Suspended solid particle removal concentration from the initial concentration of 728.3mg/L was recorded between 699.66 and 113.85mg/L for the various dosages and pH studied, while the coagulation half-time, τ1/2,ranged from 1.46 to 109.6min for various dosages and pH studied. The use of DMSP exhibited an excellent potential for treatment of brewery effluent.

PERTUMBUHAN CHROOCOCCUS DISPERSUS DALAM MEDIA LIMBAH CAIR PABRIK MINYAK KELAPA SAWIT

Research on the effect of palm oil mill effluent medium on Chroococcus dispersus growth had been done. The research was an experimental study with complete random design with 8 treatment (sediment and anaerob wastewater with concentration 25%, 50%, 75% and 100%). The growth curve was made based on the value of optical density (OD) measured at a wavelength of 680 nm. Chroococcus dispersus best growth seen at sediment wastewater medium with concentration of 100% and at anaerob wastewater medium with concentration of 75%.