Laboratory-scale Trials Research Articles

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Abstract Polycultural aquaculture typically utilises a mix of low trophic level species to increase yield above that which can be obtained from a single species. Low trophic level species are not widely accepted for consumption within Australia, so this study focussed on two species that have market acceptance, the yabby (Cherax destructor) and the silver perch (Bidyanus bidyanus). Laboratory scale trials examined the effect of each species on the growth and survival of the other species as well as the role of shelter for crayfish in this system over a 13.5 week period. Neither species negatively impacted the growth of the other, however, survival was negatively impacted. Shelter enhanced crayfish survival, although fish survival was impacted in those treatments. A higher total biomass was harvested from polyculture treatments than monoculture treatments. The positive results warrant further investigation at the scale of mesocosm, prior to large-scale pond trials.

Conversion of Entire Dusts and Sludges Generated During Manufacture of Stainless Steels into Value Added Products

During manufacture of stainless steel, for each ton of product, nearly 50 kg of dusts from electric arc furnace (EAF), argon-oxygen decarburizing converter (AOD), grinding shop & rolling mills are generated. In addition, nearly 25 kg of filter cake is produced from pickling lines sludge. These contain valuable as well as hazardous metals and their gainful utilization/disposal has been subject of intense research. Wide varieties of technologies have been developed and some of them have been successfully used on industrial scale. The technologies developed are of two types. One way is to recover metals present in the dust and sludge and the other is to immobilize their hazardous components followed by their utilization as ceramic material or landfill. Such processes include direct injection of dust in the metal bath of EAF, injection in a coke bed reactor, pelletizing with coal or coke fines and reducing them in a rotary kiln/rotary health furnace to obtain hot DRI/HBI or briquetting of dust followed by smelting in submerged arc furnace (SAF). The conversion of entire dusts and sludge by SAF is energy intensive. While there is increasing focus on utilization of dusts and sludge by internal or external processing, a significant amount of generated dusts and sludge still find their way to land fill. Recognizing that the composition of dusts/sludges emanating from EAF, AOD, rolling mills and pickling lines differ vastly, study was undertaken for a more efficient and cost effective approach for recycling them for metal recovery. Since AOD dust contains high percentage of lime, its utilization in SAF entails addition of quartz and high energy consumption. This paper describes lab scale trials in induction furnace with AOD dust briquettes containing different proportion of carbonaceous reductant. These trials indicated that very good recovery of metallic elements is possible by use of AOD dust briquettes containing high carbon in EAF. On the other hand, briquetting of zinc rich EAF dust, followed by charging it in SAF, enriched zinc oxide powder and master alloy containing valuable metals were obtained as useful products. The paper describes combining AOD dust, mill scale, grinding dust and low sulfur filter cake in one stream and clubbing EAF dust which is rich in zinc with high sulfur filter cake. The former category was briquetted with carbonaceous reductant and recycled in large scale plant trials in a 50 ton EAF and the latter was briquetted and smelted in SAF to produce master alloy and enriched zinc oxide powder. In this manner, the entire quantity of dusts and sludges could be profitably utilized along with conservation of valuable metallic elements.

Monoethanolamine Degradation during Pilot-Scale Post-combustion Capture of CO2 from a Brown Coal-Fired Power Station

The use of aqueous amines, such as monoethanolamine (MEA, 2-aminoethanol), for post-combustion capture (PCC) of CO2 from fossil-fuel-fired power station flue gases leads to undesirable reactions with oxygen, SOx, and NOx. This study has used a gas chromatography with mass spectrometry detection (GC–MS) method to measure the changes in concentrations of organic compounds in samples of a 30% (w/w) aqueous MEA absorbent obtained from CSIRO’s PCC pilot plant operating at AGL’s Loy Yang brown coal-fired power station in Latrobe Valley, Victoria, Australia. This aqueous MEA absorbent was previously used for more than 700 h of PCC, and the collected samples represent a further 834 h of PCC operation. These data provide a new perspective on the close, interdependent relationships between corrosion and amine degradation reactions. Other important outcomes include confirmation that (a) organic degradation products identified during laboratory-scale trials were also produced during pilot-scale PCC and (b) N-(2-hydro...

Celebrating 40 years anaerobic sludge bed reactors for industrial wastewater treatment

In the last 40 years, anaerobic sludge bed reactor technology evolved from localized lab-scale trials to worldwide successful implementations at a variety of industries. High-rate sludge bed reactors are characterized by a very small foot print and high applicable volumetric loading rates. Best performances are obtained when the sludge bed consists of highly active and well settleable granular sludge. Sludge granulation provides a rich microbial diversity, high biomass concentration, high solids retention time, good settling characteristics, reduction in both the operation costs and reactor volume, and high tolerance to inhibitors and temperature changes. However, sludge granulation cannot be guaranteed on every type of industrial wastewater. Especially in the last two decades, various types of high-rate anaerobic reactor configurations have been developed that are less dependent on the presence of granular sludge, and many of them are currently successfully applied for the treatment of various kinds of industrial wastewaters worldwide. This study discusses the evolution of anaerobic sludge bed technology for the treatment of industrial wastewaters in the last four decades, focusing on granular sludge bed systems.

Evaluation of Novel Inoculation Strategies for Solid State Anaerobic Digestion of Yam Peelings in Low-Tech Digesters

The operation of household scale anaerobic digesters is typically based on diluted animal dung, requiring stabled livestock and adequate water availability. This excludes many rural households in low-income countries from the benefits of a domestic biogas digester. Solid state anaerobic digestion (SSAD) can be operated with low process water demands, but the technology involves operational challenges, as e.g., risk of process acidification or low degradation rates. This study aimed at developing simple methods to perform SSAD of yam peelings in low-tech applications by testing different inoculation strategies and evaluating the necessity of dung addition as a supportive biomass. In initial lab scale trials 143 ± 4 mL CH4/g VS (volatile solids) were obtained from a mixture of yam peelings and dung digested in a multi-layer-inoculated batch reactor. In a consecutive incubation cycle in which adapted inoculum was applied, bottom inoculated digesters loaded without dung reached a yield of 140 ± 16 mL CH4/g VS. This indicates that SSAD of yam peelings is possible with simple inoculation methods and dung addition is unnecessary after microbial adaptation. A comparison with a conventional fixed dome digester indicated that SSAD can reduce process water demand and the digester volume necessary to supply a given biogas demand.

Development of Anaerobic High-Rate Reactors, Focusing on Sludge Bed Technology.

In the last 40 years, anaerobic sludge bed reactor technology has evolved from localized laboratory-scale trials to worldwide successful implementations in a variety of industries. High-rate sludge bed reactors are characterized by a very small footprint and high applicable volumetric loading rates. Best performances are obtained when the sludge bed consists of highly active and well settleable granular sludge. Sludge granulation provides a rich microbial diversity, high biomass concentration, high solids retention time, good settling characteristics, reduction in both operation costs and reactor volume, and high tolerance to inhibitors and temperature changes. However, sludge granulation cannot be guaranteed on every type of industrial wastewater. Especially in the last two decades, various types of high-rate anaerobic reactor configurations have been developed that are less dependent on the presence of granular sludge, and many of them are currently successfully used for the treatment of various kinds of industrial wastewaters worldwide. This study discusses the evolution of anaerobic sludge bed technology for the treatment of industrial wastewaters in the last four decades, focusing on granular sludge bed systems.

Mild Process for Dehydrated Food-grade Crude Papain Powder from Papaya Fresh Pulp: Lab-scale and Pilot Plant Experiments

Proteases are protein digesting biocatalysts long time used in the food industry. Although many authors reported the crystallization of papain and chymopapain from papaya latex, the powder of crude papain had the largest application as food supplements due to its highly positive effect on the degradation of casein and whey proteins from cow's milk in the stomach of infants. As the industrial preparative procedures have not been extensively applied, this study aims at producing dehydrated crude papain from fresh papaya pulp, planning lab-scale trials, followed by process development toward the pilot industrial-scale. In the lab-scale experiments, the enzyme activity (EA), expressed as protease unit (PU) /g, were evaluated on pulp and papain standard before and after a 2 h thermal treatment at 70 °C, 90 °C, and 120 °C, and the thermal behavior was monitored by means of differential scanning calorimeter (DSC). The process development toward the pilot-scaling optimized: the homogenization of the fresh pulp, followed by its filtration at high pressure (HP) in order to obtain the vegetation water and the pre-dehydrated pulp which was then oven dried varying the time-temperature conditions (4 h-80 °C; 2 h-120 °C; 30 min-150 °C). Proceeding at higher temperatures for a shorter time allowed obtaining commodity-related and technologically valid products. In the final pilot-scale step, filtration was done with vertical HP filter press, and final dehydration was performed with 2-step turbo-drying: the first aimed to concentrate with 2 min air flow (500 m 3 /h) at 200 °C, the second aimed to dry with 10 min air flow (500 m 3 /h) at 120 °C. The resulting dehydrated pulp was grinded with ball-mill to obtain a stable powder. Starting from 90±2 % pulp moisture, the two turbo-drying steps lowered the water content from 75±4 % to 50±2 % and from 50±2 % to 8±1 %, respectively. The enzyme release from the final powder highlighted an EA of the food-grade crude papain powder extract of 28 PU/g. The thermal steps provided with turbo-driers permitted to maintain a fraction of sugars and pectin acting as a protective structure, so increasing the digestion effects provided by papain. Vegetation waters were ultra-filtered allowing at obtaining a concentrated pectin suspension and rich in nutrient waters which can be reused along the food chain. Further efforts should be made to implement this procedure as potential alternative for the dehydrated crude papain production, deepening the impact of process variables on this matter.

Suitable technological conditions for enzymatic hydrolysis of waste paper by Novozymes® enzymes NS50013 and NS50010.

Waste paper belongs to a group of quantitatively the most produced waste types. Enzymatic hydrolysis is becoming a suitable way to treat this type of waste and at the same time, to produce a valuable liquid biofuel, because reducing sugars solutions that are formed during the process of saccharification can be a precursor for following or simultaneous fermentation. If it will be possible to make the enzymatic hydrolysis of the waste paper economically viable, it could serve as one of the new ways to lower the dependence of the transport sector on oil in the future. Only several studies comparing the enzymatic hydrolysis of different waste papers were performed in the past; they are summarized in this manuscript. In our experimental trials, suitable technological conditions for waste paper enzymatic hydrolysis using enzymes from Novozymes® biomass kit: enzymes NS50013 and NS50010 were investigated. The following enzymatic hydrolysis parameters in laboratory scale trials were verified on high cellulose content substrates-filter paper and cellulose pulp: type of buffer, pH, temperature, concentration of the substrate, loading of the enzyme and rate of stirring.

Combined seawater toilet flushing and urine separation for economic phosphorus recovery and nitrogen removal: a laboratory-scale trial

Freshwater toilet flushing consumes 20-35% of typical household water demand. Seawater toilet flushing, as practised by Hong Kong since 1958, provides an alternative water source. To maximise the benefits of this unique dual water supply, urine separation could be combined to allow low-cost struvite production and subsequent urine nitrification - in-sewer denitrification. This paper reports on a laboratory-scale study of seawater urine phosphate recovery (SUPR) and seawater-urine nitrification. A laboratory-scale SUPR reactor was run under three phases with hydraulic retention time between 1.5 and 6 h, achieving 91-96% phosphorus recovery. A urine nitrification sequencing batch reactor (UNSBR) was also run for a period of over 650 days, averaging 90% ammonia removal and loading of up to 750 mg-N/L.d. Careful control of the SUPR phosphate removal was found necessary for operation of the downstream UNSBR, and system integration considerations are discussed.

Biopreservation of fresh-cut melon using the strain Pseudomonas graminis CPA-7

The use of biopreservation is a promising technique to ensure microbial safety of fresh-cut produce. The objective of this work was to test the effectiveness of the strain CPA-7 of Pseudomonas graminis against a cocktail of Salmonella spp. and Listeria monocytogenes on fresh-cut melon, and evaluate its effect on its quality during shelf-life when tested in conditions simulating commercial application.Fresh-cut melon was artificially inoculated with Salmonella spp. and L. monocytogenes and with or without the biopreservative strain at different concentrations and stored at 20, 10 and 5°C. Moreover, the effect of the strain was tested in conditions simulating commercial application. Fresh-cut melon was packaged using passive modified atmosphere (MAP) and AIR conditions and stored at 5 and 10°C. Quality of fresh-cut melon was evaluated in CPA-7 treated and untreated samples. At laboratory scale trials, P. graminis reduced Salmonella and L. monocytogenes growth on fresh-cut melon stored at 5, 10 and 20°C. Effectiveness depended on their concentration and on storage temperature. At low pathogen concentration and 20°C, L. monocytogenes growth was reduced between 2.1 and 5.3logcfu g−1 units after 2 days of storage and Salmonella growth between 2.0 and 7.3logcfu g−1 depending on CPA-7 dose. At 10°C, similar reductions of pathogens were observed after 5 days of storage. In studies simulating commercial conditions, packaging atmosphere and temperature influenced P. graminis effectiveness, with better results in samples packaged under AIR conditions and 10°C. Reduction of pathogen growth was <1-log unit in fresh-cut melon stored in MAP whilst it was >4-log units in AIR. Soluble solids content, titratable acidity, pH and firmness of fresh-cut melon were not significantly different in CPA-7 treated and untreated (control) melon. In general, lightness, chroma and hue values of fresh-cut melon stored in AIR decreased faster in CPA-7 samples than on control ones. At 5°C, CPA-7 treated melon was visually scored lower than untreated melon. P. graminis has demonstrated promising results at 10°C, which is a temperature more compromised for safety. Nevertheless more detailed studies on the modified atmosphere are required because AIR packaging is not recommended due to the rapid loss of quality.

The acceleration of pork curing by power ultrasound: A pilot-scale production

Abstract Power ultrasound (US) has been proven to accelerate mass transfer in meat demonstrating a potential to reduce processing times. However, there is a lack of pilot-scale studies which assess the potential scale up of the technology and also possible detrimental effects on meat quality. The aim of this study was to optimise pilot-scale US pork curing to reduce processing time by assessing various US intensities (0, 10.7, 17.1 and 25.4 W cm− 2) and treatment times (2, 4 or 6 h). Three US treatments (2 h; 10.7, 17.1 or 25.4 W cm− 2) which resulted in equal NaCl content (2.25%) as the control (4 h; 0 W cm− 2) were assessed for changes in quality (colour, texture, cook loss, expressible moisture), sensory attributes, oxidative stability and microbial status. Hue angle, a* values (redness) and lipid oxidation increased over storage (p Industrial relevance Curing of meat is generally characterised as a slow process. Processing times have been reduced through injection and tumbling but these processes may reduce product quality if used excessively. US has been shown to accelerate mass transfer of brine into meat during lab-scale trials but no studies have assessed the feasibility of an US probe system on ham curing at pilot-scale. This study achieved up to a 50% reduction in processing times with no adverse effects on quality in the production of premium wet-cured cooked hams. Therefore, potential could exist for the use of US in the processing of other cured meat products within the meat curing industry.

Effects of Ozone Gas Exposure on Toxigenic Fungi Species from Fusarium, Aspergillus, and Penicillium Genera

The antifungal properties of ozone (O3) gas exposure towards toxigenic fungi were evaluated in laboratory-scale treatments trials. O3 gas was utilized at a concentration of 60 μmol/mol at different times of exposure, which efficiently inhibited the fungi colonies growth, especially F. graminearum and P. citrinum. At the concentration applied, O3 gas exposure was able to inhibit conidia germination, caused hyphae morphological alterations that led to hyphae death and ROS production of all fungi tested. O3 action can be related to cell metabolism alterations, leading to apoptosis and oxidative stress, showing to be effective on controlling toxigenic fungal development which is one of the main problems regarding food contamination.

Analysis of infrared optical polishing effluents and reduction of COD and TSS levels by ultrafiltration and coagulation/flocculation

Samples of polishing effluent produced during infrared optics manufacture were analyzed. Their particle size, composition, Zeta potential, chemical oxygen demand (COD), total suspended solids (TSS), and settleable solids were determined. Feasibility of treatment methods such as ultrafiltration (UF) and coagulation/flocculation was investigated to reduce both COD and TSS. It was found that effluents consisted of a suspension of micro- and nanoparticles. Effluent particle size distribution reflected the removal rate of the originating polishing process. Their composition was primarily germanium and other polished substrates as well as polishing abrasives. The effluent Zeta potential was highly negative and prevented particle settling. COD of all specimens was very high, which prevented sewage discharge. Laboratory-scale trials using UF showed substantial COD abatement of up to 74.1%. TSS was reduced to zero after UF. Comparable coagulation/flocculation COD abatement was demonstrated for the highest COD sample.

Enzymatic hydrolysis of pretreated waste paper – Source of raw material for production of liquid biofuels

Enzymatic hydrolysis of waste paper is becoming a perspective way to obtain raw material for production of liquid biofuels. Reducing sugars solutions that arise from the process of saccharification are a precursors for following or simultaneous fermentation to ethanol. Different types of waste paper were evaluated, in terms of composition and usability, in order to select the appropriate type of the waste paper for the enzymatic hydrolysis process. Novozymes® enzymes NS50013 and NS50010 were used in a laboratory scale trials. Technological conditions, which seem to be the most suitable for hydrolysis after testing on cellulose pulp and filter paper, were applied to hydrolysis of widely available waste papers - offset paper, cardboard, recycled paper in two qualities, matte MYsol offset paper and for comparison again on model materials. The highest yields were achieved for the cardboard, which was further tested using various pretreatment combinations in purpose of increasing the hydrolysis yields.

Mill case, simulation, and laboratory plant study of black liquor spill effects on a multiple stage biological treatment plant

In this study, the impact of black liquor shocks on multiple stage biological treatment plant was studied. The tests were carried out in a lab scale plant and using a mathematical simulation model. The results showed good relation to a parallel situation at the Gruvön Mill. The MultiBio concept is persistent to short-term black liquor spills due to the design where the black liquor is diluted between every compartment. According to the lab scale trials, short-term shocks (5 and 10 h) of black liquor addition reduce bio activity in the first part of the MultiBio plant. Oxygen uptake rate and chemical oxygen demand (COD) degradation decreased during high concentrations of black liquor and increased when the black liquor concentration declined. Protozoas disappeared from compartments exposed to high concentrations of black liquor. A long-term trial encompassing 24 h of black liquor addition inhibited the COD reduction in the whole plant for several weeks.

Effect of unmalted oats (Avena sativa L.) on the quality of high-gravity mashes and worts without or with exogenous enzyme addition

Barley malt is the preferred brewing material these days because of its high extract content and high enzyme activities. However, when substituting malted barley with oats to create a unique beer flavor and aroma, endogenous malt enzymes become the limiting factor. Therefore, the objectives of this study were to evaluate the effect of 10–40 % unmalted oats on the quality of high-gravity mashes/worts and to investigate the limitations of endogenous malt enzymes as well as the benefits of the application of industrial enzymes. The enzyme mix Ondea® Pro was found to be particularly suitable for mashing with unmalted oats and was therefore used in the present rheological tests and laboratory-scale mashing trials. In order to gain detailed information about the biochemical processes occurring during mashing, the quality of mashes was comprehensively analyzed after each mash rest using standard methods described by Mitteleuropaische Brautechnische Analysenkommission and Lab-on-a-Chip capillary electrophoresis. Mashing with up to 40 % oats resulted in increased mash consistencies, color/pH (20 °C) values, β-glucan concentrations, wort viscosities 12.0 %, and filtration times as well as decreased FAN and extract contents. The application of Ondea® Pro enormously increased the color of worts despite lower pH values but considerably improved the quality and processability of 30 or 40 % oat-containing mashes/worts. However, the substitution of up to 20 % barley malt with unmalted oats can easily be realized without the addition of exogenous enzymes.

A Comparison of White Nigerian and Red Italian Sorghum (Sorghum Bicolor) as Brewing Adjuncts Based on Optimized Enzyme Additions

Sorghum has been used for thousands of years in human food products. In Western countries, however, it is primarily used as bird and animal feed, although there is considerable interest in its use as gluten-free alternative to wheat, barley, and rye. The aim of this study was to compare the mashing performance of white Nigerian and red Italian sorghum based on optimized enzyme additions. For this purpose, both sorghum types were fully characterized using standard methods, Lab-on-a-Chip capillary electrophoresis, and scanning electron microscopy. The application of exogenous enzymes was optimized by monitoring changes in mash consistency during mashing using a Physica MCR rheometer. Furthermore, laboratory-scale mashing trials were carried out to compare the quality of worts produced with up to 40% white or red sorghum and optimized enzyme levels. Both sorghum types are characterized by higher starch and lower protein/β-glucan contents in comparison to barley malt. The addition of protease/β-glucanase as recommended had no significant effect on mash consistency and wort quality. Besides, 50% of the recommended heat-stable α-amylase dose was sufficient for 40% sorghum adjunct. Worts produced with 40% white or red sorghum had significantly lower TSN/FAN contents and viscosities than the reference wort (100% barley malt). However, white sorghum provided significantly more TSN/FAN compared to red sorghum. Its use as a substitute for barley malt also resulted in significantly higher extract contents.

Mould Powder Development for Continuous Casting of Steel

Mould powders significantly determine the stability of the continuous casting process of steel at all casting speeds. The main functions of mould powders are to provide strand lubrication and to control the mould heat transfer in the horizontal direction between the steel shell and the copper mould. The composition, properties and operational performance of mould powders were investigated in detail with a focus on high-speed thin slab casting and conventional slab casting. Various advanced characterisation methods were applied, completed with experiments at laboratory scale and full-scale plant trials. It was found that melting of mould powder at the meniscus and crystallisation of the slag film are key processes during continuous casting. Both powder melting and slag crystallisation are primarily based on the composition of the mould powder and the mould slag. Additionally, the operational parameters during continuous casting will affect these processes as well. Results of the work are used for a further and more fundamental understanding of the mould powder functions and to guide mould powder design for various steel grades.

Effects of low-pressure homogenisation pre-treatment of cheesemilk on the ripening of Cheddar cheese

Homogenisation of milk breaks the protective fat globule membrane, allowing access of indigenous lipoprotein lipase and hydrolysis of free fatty acids (FFA) from triglycerides. The use of homogenisation in cheesemaking is limited due to the deleterious impact on cheese quality. The objective was to investigate the effects of a pre-processing routine (homogenisation of raw milk, incubation and pasteurisation) on the resultant cheese. Pilot- and laboratory-scale Cheddar cheeses were produced where raw bovine milk was homogenised at various pressures (0, 5 and 10 MPa in the pilot-scale and 0, 5, 10, 15, 20 and 25 MPa in the laboratory-scale trial), incubated at 37 °C for 1 h and batch-pasteurised at 63 °C for 30 min. A control milk was not homogenised. Acid degree value increased with increasing homogenisation pressure. Moisture and salt contents were higher in cheeses made with milk homogenised at 5 and 10 MPa, as was pH. The cheese made from milk homogenised at 10 MPa contained the highest level of FFA initially and throughout ripening. Breakdown of αs1-casein was more extensive in cheese made from non-homogenised milks and breakdown of β-casein was more extensive in homogenised milk cheeses. The use of low-pressure homogenisation in a controlled pre-processing routine may be suitable for cheesemaking; however, further investigation into the effects of the pre-treatment and effects on cheese microstructure and sensory properties is warranted.

Effects of highly absorbing pigments on near infrared cured polyester/melamine coil coatings

In order to expand available colour range for an industrial coil coating line a range of 25μm polyester melamine coatings were applied to galvanised steel substrate and rapidly cured using near infrared (NIR) radiative curing. The purpose was to improve understanding of this relatively new curing technology and identify any problems associated with differing absorption of a range of coloured coatings. It has been suggested that in order to increase efficiency of NIR cure, NIR absorbers should be added to the coating formulation. UV/Vis/NIR spectroscopy was used to deduce the parts that coating and substrate absorption play in topcoat cure and lab scale trials were run on coatings throughout the colour range with their heating profiles and surface finish being recorded and assessed. The results showed that in this particular application having a coating that absorbs too strongly in the NIR region can actually result in solvent boil defects due to cross linking and film formation occurring prior to solvent removal.