Packing Media Research Articles

Langual

LANGUAL, a computer-based food-description language, uses standardized vocabulary to describe specific characteristics of foods and food products. Each food product in a database is described by a set of descriptors from the following factors: product type; food source; part of plant or animal; physical state, shape, or form; extent of heat treatment; cooking method; treatment applied; preservation method; packing medium; container or wrapping; food contact surface; consumer group/dietary use/label claim; geographic places and regions; and adjunct characteristics. The purpose of LANGUAL is to allow rapid, accurate retrieval of food names from food-related databases relative to descriptive terms for these factors. The major advantages of LANGUAL are the speed and specificity of the retrievals and the flexibility of the system relative to change and updating.

生物ろ過による池水浄化に関する実験的検討

Two laboratory-scale biological filter treatment systems packed with ceramics media and plastic media and control system withuot biological filter process were operated to treat polluted pond water. Three algal culture tanks with sufficient nutrient and light for growth were used as polluted ponds. A portion of water from the algal culture tank was withdrawn and treated through the biological filter process. The effluent was recirculated into the algal culture tank. Treatment performance of biological filter system was compared based on water quality of three algal culture tanks. The range of circulation ratio (feeding rate to biological filter process divided by the volume of the algal culture tank) was varied from 1.5 d-1 to 0.1 d-1. Growth of algae was depressed and sedimentation rates of suspended solids increased in the tank with biological filter process even if the circulation ratio was low (i.e., 0.1 d-1). There was no difference between water quality and algal composition in the two tanks with two different packing media. The biological filter process could increase the transparency of polluted pond water and the diversity of algal species compared to the control tank.

Changes in tomato pulp quality caused by lactic acid bacteria

SummaryThe most important changes in physicochemical and sensory parameters taking place in tomato pulp (i.e. crushed, diced or chopped tomatoes with about 30% tomato juice as packing medium) were studied after inoculation with lactic acid bacteria (Lactobacillus plantarum). Microbial growth could be detected after 12h of storage at 30°C whilst only 6 h were necessary for the chemical and sensory variations. Multiple regression analysis and principal component analyses were performed to ascertain interdependence between sensory and chemical parameters as well as the contribution of each chemical to sensory variable. Off‐taste threshold ranges based on the content of some chemical parameters were calculated with the aim of replacing the limits of acceptability which are often empirically formulated in commercial contracts.

Upflow Anaerobic Filtration of a Sugar Containing Wastewater

Pretreatment of a sugar containing wastewater from a date processing plant was tested for COD removal in an anaerobic pilot filter over a period of eight months. The filter was operated in the upflow mode and randomly packed with a plastic pipe carrier material. Initial start and restart after a 6-week break, steady state performance on seven different COD load levels ranging from 1.6 to 25 kg COD/m3·d, and filter behavior during reactor acidification were observed. In all examined experimental cases, the anaerobic filter rapidly adapted (5-7 days) to new operating conditions, thus indicating its high process flexibility. Below COD loads of 20 kg COD/m3·d, a COD removal of 90% or more was achieved. The specific CH4 gas production was measured at 0.40 - 0.53 m3 CH4/kg COD removed, and the specific sludge production was quantified at 0.1 kg paniculate COD/kg COD removed throughout the experimental periods. Biomass distribution revealed that 60% was attached to the packing media and 40% was suspended in the pore space. Based on COD profiles along the filter height, conclusions on the reactor flow pattern could be drawn. With the help of a simple reactor model, the experimental results could be used to simulate other process conditions for design considerations.

Composition of Commercial Tomato Pulp and Its Relationship to Some Typical Sensory Characteristics

The physical and chemical properties of tomato pulp (i.e., crushed, diced, or chopped tomatoes with about 30–40% tomato juice as packing medium) as well as the contribution of many analytical parameters (including those indicative of degradation reactions) to the sensory attributes of acidity, natural taste, color, and viscosity were evaluated. Linear correlations (P ≤ 0.05) were found between the sensory attributes and some physical and chemical parameters. Principal components analysis, a multivariate technique particularly useful when many variables are involved, made it possible to create a model to determine to what extent the different parameters contribute to basic sensory properties.

Diffusion and reaction within porous packing media: A phenomenological model

A phenomenological model has been developed to describe biomass distribution and substrate depletion in porous diatomaceous earth (DE) pellets colonized by Pseudomonas aeruginosa. The essential features of the model are diffusion, attachment and detachment to/from pore walls of the biomass, diffusion of substrate within the pellet, and external mass transfer of both substrate and biomass in the bulk fluid of a packed bed containing the pellets. A bench-scale reactor filled with DE pellets was inoculated with P. aeruginosa and operated in plug flow without recycle using a feed containing glucose as the limiting nutrient. Steady-state effluent glucose concentrations were measured at various residence times, and biomass distribution within the pellet was measured at the lowest residence time. In the model, microorganism/substrate kinetics and mass transfer characteristics were predicted from the literature. Only the attachment and detachment parameters were treated as unknowns, and were determined by fitting biomass distribution data within the pellets to the mathematical model. The rate-limiting step in substrate conversion was determined to be internal mass transfer resistance; external mass transfer resistance and microbial kinetic limitations were found to be nearly negligible. Only the outer 5% of the pellets contributed to substrate conversion.

Quality evaluation of tomato pulp

The physicochemical properties of tomato pulp (i.e. crushed, diced or chopped tomatoes with about 30% tomato juice as packing medium) and the contribution of various analytical parameters to some sensory attributes were evaluated. In addition, discriminant analysis was used to obtained a sensory classification model based solely on physical and chemical parameters.

Use of ultrafiltration for preparing improved tomato pulp

SummaryThe characteristics of high‐quality tomato pulp (commercial def.: crushed or diced tomatoes with about 30% tomato juice as packing medium) canned with tomato juice pulp enriched by ultrafiltration as packing medium were compared with those covered with conventional vacuum‐concentrated juice.Both hot‐ and cold‐break products were prepared and those containing 20% serum‐reduced packing juice proved to be the best, showing no signs of syneresis on storage and with improvements in sensory properties, colour and non‐enzymatic browning; some volatile components were reduced.

Dry‐packed capillary columns for micro HPLC

AbstractA dry‐packing method has been developed which enables the preparation of packed capillary columns for micro HPLC from 250 μm i.d. tubing and 5 μm packing materials. Pressurized gases, such as hydrogen and argon, were used to transport the packing media, and ethanol or methanol were used as discharge agents. By changing the gas pressure, the packing density could be easily adjusted. It was found that, within experimental limits, the higher the packing density, the greater the column efficiency. Comparison between dry‐ and slurrypacked columns showed that the former had greatly improved stability; the efficiency of dry‐packed columns was about the same as, or even better than, that obtained by slurry‐packing.

Short-cut method for predicting the productivity of affinity chromatography

A method was developed for predicting the productivity P (amount of the target protein recovered per unit volume per unit time) of affinity chromatography (AFC) and similar chromatographic operations. The constant-pattern approach was employed for describing the breakthrough curve. It was found that P increases with increasing u at low u regions and there is a maximum in the P-u curve. The u value that gives the maximum P ( u M) was derived as a function of the number of transfer units, n. The experimental breakthrough curves for several different packing media systems such as 40- and 10-μm porous particles, 2.5-μm non-porous particles and surface-derivatized membrane media were measured, from which the n values were determined. The u M values were then calculated using the n values. It is suggested that the present method is useful for the rapid survey of the operating conditions in scaling-up AFC and similar chromatographic operations.

Air stripping VOCs from groundwater: Process design considerations

AbstractConsiderations for evaluating and designing the air stripping process are presented by case study. The case study involves the design of an air stripping process to remediate groundwater contaminated with volatile organic compounds (VOCs) at a National Priorities List site in Tacoma, WA. Design objectives included developing a tower with minimum volume and energy requirements while complying with discharge air and water quality standards. A two‐phase resistance model using Onda correlations to determine liquid‐ and gas‐phase resistance model using Onda correlations to determine liquid‐ and gas‐phase mass transfer coefficients was used to assist in the evaluation and design.Considerations for applying the two‐phase resistance model to air stripping tower design are presented. The ability of the model to simulate process performance is demonstrated by comparison with actual data for 11 priority pollutant list VOCs evaluated during an onsite pilot study. Design procedures with which to develop a tower with minimum volume and energy requirements are described. Other considerations involving the evaluation of VOC emissions and the precipitation and buildup of inorganic constituents within the internal packing media are described.

Improvement of the anaerobic digestion of diluted whey in a fluidized bed by nutrient additions

Abstract Anaerobic digestion of diluted whey was performed in two different fluidteed bed pilot reactors of 40 1 and 250 1 respective volume. Different operating conditions were tested. Without nutrient addition there is a maximum COD removal rate which is directly proportional to the packing medium volume. The corresponding specific maximum COD removal rate is of about 6 kg COD degraded. m‐3 packed bed volume. d‐3. Suitable nutrient additions, consisting mainly of iron, nickel and cobalt salts and of dried yeasts, allow a dramatic increase of this maximum rate up to about 40 kg COD degraded m‐3 packed volume. day‐1. This increase of COD removal rate is mainly due to higher biomass accumulation inside the reactor.

Pretreatment of Poultry Processing Wastewater in a Pilot-Scale Anaerobic Filter

Wastewater from a typical poultry processing plant in the southeastern U.S.A. was treated on site with a pilot-scale anaerobic packed-bed reactor. The reactor had a working volume of 3.2 m3, was filled with 15-cm diameter polyethylene random-pack media, and was operated at 35°C with a retention time of 21 hours and at a loading rate of 2.8 kgCOD/m3d−1. Under these conditions, treatment efficiencies were sufficient to meet typical surcharge-free municipal discharge requirements, with effluent soluble COD of 440 mg/L, soluble BOD5 of 190 mg/L, fats, oil and grease (FOG) of 10 mg/L, and total suspended solids of 140 mg/L. Results from pilot operation are compared to those of previous laboratory-scale studies, where similar results were obtained with less than half of the hydraulic retention time. Differences in treatment on pilot vs. laboratory scale were largely due to differences in wastewater variability and reactor operation. Recommendations for future studies to reduce the costs of treatment, including emphasis on types of low-cost packing, amounts of packing media, and heating requirements are presented.

Response of Easter Lily Bulbs to Peat Moisture Content and the Use of Peat or of Polyethylene-lined Cases during Handling and Vernalization

Lining of shipping cases with low-density polyethylene (PE) greatly reduced moisture loss from packing media and bulbs of Lilium longjlorum Thunb. `Nellie White' during shipping, handling, and case vernalization (CV). Three years of studies showed that use of PE liners accelerated floral sprout emergence above the growing medium, floral bud initiation, and flowering date. Effects of case lining became more pronounced as the initial water content of the spagnum peat packing was lowered. Case lining sometimes increased apical meristem diameters measured immediately after vernalization, or 2 or 4 weeks after bulb planting, but flower bud number was never significantly increased. Root growth during the first 4 weeks after planting was not affected by case lining. Bulb scale and basal plate water contents at planting were greater in lined than nonlined cases and when packed in peat of relatively high moisture content. Handling and vernalization of bulbs in PE-lined cases without a packing medium resulted in similar bulb forcing characteristics as in bulbs held in PE-lined cases packed with sphagnum peat.

Improving Field Performance of Southern Pine Seedlings by Treating with Fungicides before Storage

Abstract Field survival of longleaf, shortleaf, slash, and loblolly pine seedlings that had benomyl incorporated into the packing medium was markedly improved over that of clay-slurry controls. The more difficult to store seedlings of longleaf and shortleaf pine had greater magnitudes of response than more easily stored loblolly and slash pines. The decrease in seedling survival with storage time is related to a rapid increase in pathogenic microorganisms in cold storage. Although Benlate® ¹ 50WP is now registered for this use, the most effective fungicide dosage rates for routine use with different southern pine species must still be determined. South. J. Appl. For. 12(4):281-285.

FDA's Factored Food Vocabulary for food product description

The Food and Drug Administration's Factored Food Vocabulary (FFV) uses standardized language to describe characteristics of food products that are important for food safety and nutritional quality. Each food product is described by a set of descriptors from the following factors: product type; food source; part of plant or animal; physical state, shape, or form; degree of preparation; cooking method; treatment applied; preservation method; packing medium; container or wrapping; food contact surface; and user group. The purpose of the vocabulary is to facilitate retrieval of food composition, food consumption, food contamination, and other food-related data relative to these factors. The major advantages of this system are flexibility with specificity, enhanced searchability with economy, and ease of change and updating. J Am Diet Assoc 88:336, 1988.

Anaerobic fluidized-bed treatment of hazardous wastes.

The anaerobic attached film process consists of a columnar reactor containing a packing medium that serves as an attachment surface for the retention of anaerobic microorganisms that metabolize the organic constituents of a waste. The wastewater is usually applied in an upflow mode in order to submerge completely the unit and maintain an anaerobic environment (21). Anaerobic reactors have been operated in both the packed-bed and the expanded-bed modes. When operated in the expanded-bed or fluidized-bed mode, effluent recycle is often practiced to fluidize the bed and thereby establish close to completely mixed-flow conditions. Although the kinetics of substrate removal are generally lower in this type of reactor than in a “once-flow-through” reactor, dilution of the incoming waste can often enhance treatment by reducing inhibition. Dilution of the concentration of degradable inhibitory compounds in the feed, and the prevention of pH depression by suppressing the rapid buildup of volatile fatty acids at the inlet sections of the reactor, are two advantages attributed to effluent recycle (4). In addition, recycle minimizes problems with bed-plugging, leads to improved flow distribution, and allows for the entrapment of small particles within the bed, thus enhancing their degradation. Fluidization also reduces the thickness of the hydrodynamic boundary layer, thus decreasing resistance to mass transport.

Separation of oil from oil-in-water mixture by glass fiber beds.

Separation of oil droplets in oil-in-water mixture was studied by using a glass fiber bed coalescer. Fuel oil (B-type) was used as the oil phase and was dispersed in water at a concentration of 1000 ppm. Glass fibers of 5.3 μm and 19μm diameter were used as packing media. The relationship between the pressure drop across the bed and the oil holdup in the bed at steady state was examined under several experimental conditions and a correlated equation for the relationship was presented. The equation could predict not only the pressure drop at steady state but also those at unsteady states. A new correlation equation for separation efficiency of oil droplets was proposed.

Contact oxidation process followed by activated carbon adsorption for textile wastewater treatment

AbstractA pilot plant study and a full scale plant study were conducted to determine the feasibility of using contact oxidation followed by activated carbon adsorption process in textile wastewater treatment, and to determine the effects of types of packing media in the contact oxidation tank and types of aeration process on the treatment performance. Results indicated that contact oxidation followed by activated carbon adsorption process was effective in removing organics and color from textile wastewaters. Types of packing media and types of aeration processes had little effect on the treatment performance. The pilot plant performance was found to perform slightly better than the performance of the full scale plant.

Production of uniform packing blocks using bag filters

The authors describe a method for intensifying the heat transfer and hydraulic conductivity and, consequently, the overall energy efficiency of a petroleum extraction column by the implementation of bag filters as the packing medium. Diagrams and schematics of the proposed column are presented and test results are cited indicating the high efficiency of the crosscurrent packing design for a wide range of vapor and liquid feeds.