Filter Aid Research Articles

Dewatering of Sewage Sludge with Coal as a Conditioner Using Thermal Compression

Thermal compression is effective for solid-liquid separation of various materials. In this paper, thermal compression was applied on the dewatering of sewage sludge with coal as a filter aid. Experiments with 0.25-1 mm coal particles (0.2 kg coal/kg dry sludge solid) obtained cakes of solid content over 49%. Higher dosage of coal generated cakes with lower moisture content. The combustion behavior of the sludge cake was studied using TG/DTG analysis. The results showed that a total weight loss of 65.1% occurred from 25 °C to 800 °C, including two major weight loss stages corresponding to loss of moisture and volatile materials respectively.

Study on the Property of Silica Minerals Supported NanoTiO<sub>2</sub>

In the study, porous amorphous silica minerals including Porous Silicon (PS), Diatomite Filter Aid (DFA) and Opal (Op) were chosen as carriers or supports to prepare TiO2/PS, TiO2/DFA and TiO2/Op composites by chemical co-precipitation method. The compound materials were characterized by SEM, TEM, and the photo-catalytic property of the prepared composites was investigated by degradation of Rhodamine B (RhB). Characterization showed that nanoTiO2 was coated on the surface of porous amorphous silica minerals. The crystal form of TiO2 was mainly anatase, and the size of which was nanoscale. Through comparative analysis, the photo-catalytic efficiency of TiO2/PS composite was the best, followed by TiO2/ DFA, and then TiO2/Op.

Scaling up the chemical treatment of spent oil-in-water emulsions from a non-ferrous metal-processing plant

The treatment of spent oil-in-water emulsion (SOWE) from a non-ferrous metal-processing plant by using aluminum sulfate and hydrated lime was studied to determine the purification efficiency, to optimize the operating conditions and to scale up the treatment process. The purification efficiency was estimated by comparing the compositions of the SOWE and the processed wastewater. The treatment efficiency does not depend on the type of mineral oil and filter aid. The optimum doses of aluminum sulfate and hydrated lime must be experimentally determined for each batch of SOWEs, but the results obtained at laboratory level are applicable at pilot level. The processed wastewater and the filter cake from the process can be safely disposed into public sewage systems and at municipal waste landfills, respectively. The purification efficiency was higher than 98% with respect to total suspended solids, chemical oxygen demand and oil and grease, and was comparable to the known treatment processes based on coagulation/flocculation followed by sedimentation.

メンブレンフィルターを用いた植物病原菌検出における濾過補助剤の目詰まり改善効果

メンブレンフィルターを用いた植物病原菌検出における濾過補助剤の目詰まり改善効果

Comparison methods for microstructure analysis on highly porous extrudates based on diatomite filter aids

The origin of the hysteresis, obtained from mercury porosimetry analyses of diatomite filter aids DFA powders and DFA-kaolin based extrudates for fluidized bed applications, is used for fundamental description of the porous network. Pore sizes calculated from the depressurization step, corrected with contact angle of 101.4° and with Kloubek semi-empirical equations, were compared to pores size evaluated with a conventional contact angle of 140.0°. Interestingly same behaviour is observed for DFA powders and extrudates: a hysteresis is observed at 800°C, while no mercury is removed during the extrusion step for samples heat treated at 1300°C. These results indicate that the pore structure for extrudates is mainly dominated by the structure of DFA in comparison to the interconnected pores coming from the removal of the organic binders. The presence of contact angle hysteresis was observed by comparing Kloubek and Washburn equations. Similar mesopore size distributions were obtained with using Barret–Joyner–Halenda model and Kloubek equations. This work allows confirming the interest of using Kloubek equations on the whole range of pore size distribution (from the macro- to the mesopores) for siliceous based materials, composed of low cristobalite, quartz and mullite. In case of multi-cycle studies, because of the overestimated pore sizes determined by Washburn equations during extrusion step, Kloubek equations seem to give a better description of the microstructure.

Recovery of used frying sunflower oil with sugar cane industry waste and hot water.

The main goal of the current investigation was to use sugar cane bagasse ash (SCBA) and to compare its adsorption efficiency with Magnesol XL as synthetic adsorbents to regenerate the quality of used frying sunflower oil. In addition, to evaluate the effect of water washing process on the quality of used frying oil and the treated oil. The metal patterns of sugar cane bagasse ash and Magnesol XL were determined. Some physical and chemical properties of unused, used frying and used-treated sunflower oil were determined. Sunflower oil sample was heated at 180°C + 5°C, then frozen French fries potato were fried every 30min. during a continuous period of 20h. Oil samples were taken every 4h. The filter aids were added individually to the used frying oil at levels 1, 2 and 3% (w / v), then mechanically stirred for 60min at 105°C. The results indicate that all the filter aids under study were characterized by high levels of Si and variable levels of other minerals. The highest level of Si was recorded for sugar cane bagasse ash (SCBA) was 76.79 wt. %. Frying process caused significant (P ≤ 0.05) increases in physico-chemical properties of sunflower oil. The treatments of used frying sunflower oil with different levels of sugar cane bagasse ash and Magnesol XL caused significant (P ≤ 0.05) increase in the quality of treated oil, however the soap content of treated oil was increased, therefore, the effect of water washing process on the quality of used frying and used-treated sunflower oil was evaluated. The values of soap and Total polar compounds after water treatment were about 4.62 and 7.27 times as low as that for sunflower oil treated with 3% sugar cane bagasse ash (SCBA). The results of the present study indicate that filtration treatment with different levels of sugar cane bagasse ash( SCBA) regenerated the quality of used sunflower oil and possess higher adsorbing effects than the synthetic filter aid ( Magnesol XL ) in removing oil oxidation products. The current study also recommends using hot water treatment for improving the quality of used frying oil.

Simultaneous Filtration and Stabilization of the Beer: Potential for Oxidized High-Density Polyethylene (OxPE) to Be Used as Filter Aid

For decades, kieselguhr has been the most common filter aid for beer filtration. However, costs for disposal are severely increasing and brewers today are concerned about replacing kieselguhr filtration by a greener technology. Filtration trials were carried out with the regenerable filter aid oxidized high-density polyethylene (OxPE) on a pilot-scale candle filter using green lager beer from settling tanks. OxPE has an average particle size distribution of 37 μm and its outer surface presents nodular structures. The porosity of the OxPE media is 0.6 compared with 0.85 for kieselguhr. OxPE retains a good amount of haze and yeast cells without clogging; however, the expected clarity was reached only when using Brewtan. The use of polyvinyl-polypyrrolidone (PVPP) mixed with the OxPE filter aid (25/75%) showed the best results for filtration because of the shape of PVPP particles and their slight compressibility. Regeneration is one of the most important steps to achieve because the filter aid has to be reused as many times as possible while keeping its properties of retention toward haze and yeast cells. OxPE proved to have very good resistance to aggressive regeneration conditions, and filtration trials carried out after such an operation confirmed this.

Filter-Based Pathogen Enrichment Technology for Detection of Multiple Viable Foodborne Pathogens in 1 Day

Conventional foodborne pathogen assays currently used in the food industry often require long culture enrichments to increase pathogen levels so they can be detected. Even using sensitive real-time PCR assays, culture enrichment at least overnight is necessary especially for detection of pathogens with slow growth rates such as Listeria monocytogenes. To eliminate this cumbersome enrichment step and detect minute amounts of pathogens within 1 day, filter-based pathogen enrichment technology was developed utilizing a unique combination of glass fiber depth filter and porous filter aid materials to efficiently separate pathogens from food homogenates and avoid filter clogging by food particles. After pathogen immobilization in depth filters, only viable pathogens were selectively collected in a small volume of growth medium via microbial multiplication and migration; nonviable pathogens remained inside the filters. By assaying viable pathogens using real-time PCRs, multiple species of foodborne pathogens were detected, including L. monocytogenes, Salmonella enterica, and Escherichia coli O157:H7, at around 1 CFU/ml or 1 CFU/g in various food samples. This filter-based pathogen enrichment technology is a unique bacterial enrichment alternative to the conventional culture enrichment step and can significantly shorten the time necessary to obtain assay results.

Edit Propagation via Edge-Aware Filtering

This paper presents a novel framework for efficiently propagating the stroke-based user edits to the regions with similar colors and locations in high resolution images and videos. Our framework is based on the key observation that the edit propagation intrinsically can also be achieved by utilizing recently proposed edge-preserving filters. Therefore, instead of adopting the traditional global optimization which may involve a time-consuming solution, our algorithm propagates edits with the aid of the edge-preserve filters. Such a propagation scheme has low computational complexity and supports multiple kinds of strokes for more flexible user interactions. Further, our method can be easily and efficiently implemented in GPU. The experimental results demonstrate the efficiency and user-friendliness of our approach.

Application and Mechanism Study of a Novel Copolymer for Filter Aids on Wet-Process Phosphoric Acid

A novel copolymer PADA which has two functions of flocculation and surface activity was synthesized in aqueous solution. The copolymer was applied to filtration aiding on wet-process phosphoric acid (WPA). The results show that PADA can increase the filtration rate of the phosphoric acid slurry and decrease the moisture of the filter cake. The mechanism of filtration aiding was studied. PADA neutralizes the surface potential of the phosphogypsum and makes the microcrystal particles flocculate to conglobation, which indicate that electrostatic neutralization and flocculation might be the action modes in the process of filtration aiding. The shortest flocculation time and largest average diameter of floccules can be obtained with the addition of 10 ppm PADA. The average pore size and porosity of the filter cake are enlarged by 0.22 μm and 15.38% respectively with the addition of PADA. The surface contact angle of the phosphogypsum is increased by 3.4° with PADA presence.

Environmental and depositional characteristics of diatomite deposit, Alayunt Neogene Basin (Kutahya), West Anatolia, Turkey

This paper describes the geological-depositional and environmental characteristics of diatomite. The diatomite deposit is situated in the southern part of the Alayunt (Kutahya) Basin. Samples of 18 diatomites and 12 host rocks were collected from four sedimentary profiles in the spring season. Basement rocks are Paleozoic-aged metamorphic rocks (schist, phyllite, quartzite, etc.) and Mesozoic-aged ophiolitic and complex rocks. Host rocks are rhyodacitic–rhyolitic tuffite, volcanic glass. Diatomite is composed of Upper Miocene–Upper Pliocene-aged diatom species. Diatomite shows layer morphology and lies on volcanic glass layer. XRD characteristic peaks of diatomite show that it comprises dominantly of Opal-A silica, whereas volcanic glass has Opal-CT constituent. SEM and NPM photomicrographs indicate that diatomites are dominantly composed of benthic freshwater diatom species, such as Pinnularia microstauron, Pinnularia lundii, Pinnulariasubrostrata, Pinnularia brevicostata, Pinnularia tenuis, Pinnularia sp., Navicula eligensis, Fragilaria construens, Mastogloia braunii Grunow, Melosira varians Agardh, Surirellacapronii Brebisson, Cymbella lanceoloata, Amphora venata, Gomphonema germainii, Gomphonema angustatum and Rhapalodia gibba. These species are general indicators of shallow paleolake environment and cool climate conditions. Due to the fluvial currents and climatic conditions; lake water levels, temperature and nutrient content fluctuated through the time. Chemical data obtained from 18 diatomite samples show that while silica is the bodybuilding material for diatomite (over 89 % SiO2), Al, Mg and Fe contents of diatomite samples might be derived from clastic materials. The concentration of Al, Mg and Fe decreases toward the lake center. Diatom genera, sedimentary profile sections and mineralogic data suggest that diatomite deposited in lacustrine-type freshwater shallow lake is associated with Upper Miocene-aged extension tectonics. Physical and filtration tests along with environmental characteristics of diatomite suggest that calcined diatomite can be used for waste treatment processes in the filter aid industry.

Mineralogical study and properties of natural and flux calcined porcelanite from Gafsa-Metlaoui basin compared to diatomaceous filtration aids

The purification of melting sulfur by Tunisian Chemical Group factories was performed with filtration by siliceous earth filters such as French clarcel, Algerian kieselguhr, Spanish perlite and Spanish diatomite, i.e. calcined diatomites which have biogenic origin, except for perlite, which is volcanic glass. The porcelanite rocks of the Ypresian phosphatic series from the Gafsa-Metlaoui basin also have a biogenic origin and are formed in Si-rich depositional environment, at low diagenetic conditions. This work examines the thermal treatment of these porcelanite rocks to obtain calcined siliceous material with physical–chemical characteristics comparable to the diatomaceous earth filters. The porcelanite samples used in this work come from the Mides CPG trench, where the Ypresian porcelanite beds are 10m thick. The flux calcined porcelanite was obtained by heating the raw samples at 400, 800 and 1000°C with 5% Na2CO3 flux. The raw porcelanites from the Gafsa-Metlaoui basin had high SiO2 content, similar to the usual filtration aids. The natural porcelanite is dominated by opal-CT and minor clay minerals (smectite, palygorskite and sepiolite), hydroxylapatite, quartz, calcite and hematite. During heating up to 800°C, the opal-CT progressively turned into opal-C. After 1000°C, the calcined porcelanite samples had similar properties as the calcined industrial products derived from the Spanish and French diatomite raw materials. Hence, the short range ordering of opal CT increased significantly as cristobalite-like structure formed. The thermal treatment of porcelanite rocks up to 800°C decreased the specific surface area and increased the permeability coefficient of the calcined porcelanite samples to values comparable to calcined industrial filtration aids.

New Filtration Systems for Extra-Virgin Olive Oil: Effect on Antioxidant Compounds, Oxidative Stability, and Physicochemical and Sensory Properties

The purpose of this work was to evaluate some new filtration systems in relation to the quality of extra-virgin olive oil (EVOO). Filtration processes were undertaken using a polypropylene filter bag and two different inert gas flows as filter aids (argon and nitrogen). Qualitative and quantitative variations of the glyceride composition, antioxidant and pro-oxidant compounds, and water content were correlated with the oxidative stability to establish the effect on EVOO shelf life. The influence on physicochemical and sensorial properties was also evaluated. After filtration, the oxidative stability was reduced. The behavior of the polyphenols and water content on the filtration process could explain the lowest oxidative stability of filtered EVOO. Moreover, the results of the sensorial analysis confirmed that filtration using inert gases did not decrease the intensity of the main positive sensory attributes. The results could help olive-oil producers to improve EVOO quality and establish optimal storage conditions.

Consecutive Proteolytic Digestion in an Enzyme Reactor Increases Depth of Proteomic and Phosphoproteomic Analysis

Analytical advantages of using multiple enzymes for sample digestion (MED), primarily an increase of sequence coverage, have been reported in several studies. However, this approach is only rarely used, mainly because it requires additional sample and mass spectrometric measurement time. We have previously described Filter Aided Sample Preparation (FASP), a type of proteomic reactor, in which samples dissolved in sodium dodecyl sulfate (SDS) are digested in an ultrafiltration unit. In FASP, such as in any other preparation protocol, a portion of sample remains after digestion and peptide elution. Making use of this fact, we here develop a protocol enabling consecutive digestion of the sample with two or three enzymes. By use of the FASP method, peptides are liberated after each digestion step and remaining material is subsequently cleaved with the next proteinase. We observed excellent performance of the ultrafiltration devices in this mode, allowing efficient separation of orthogonal populations of peptides, resulting in an increase in the numbers of identified peptides and proteins. At the low microgram level, we found that the consecutive use of endoproteinases LysC and trypsin enabled identification of up to 40% more proteins and phosphorylation sites in comparison to the commonly used one-step tryptic digestion. MED-FASP offers efficient exploration of previously unused sample material, increasing depth of proteomic analyses and sequence coverage.

Granulometric distribution of natural and flux calcined chert from Ypresian phosphatic series of Gafsa-Metlaoui basin compared to diatomite filter aid

The cherty rocks of the Chouabine Formation of the Gafsa-Metlaoui basin (south-western Tunisia), that is composed by biogenic silica, are treated using thermal treatment at 1000°C with flux calcination method in order to prepare a specific filter aids of melting sulfur filter used for the production of sulfuric acid. This work presents the effect of heating on the granulometry of chert. The mineralogical composition of natural starting chert is composed by opal CT (cristobalite/tridymite) and by the mineral mixture of quartz, smectite clay minerals, palygorskite-sepiolite fibrous clay minerals, calcite and hematite. After thermal treatment, at 1000°C, the crystallinity of chert increases significantly and the opal-CT, transforms mostly to opal-C. The comparison of infrared spectra of untreated and treated cherts shows systematic variation of the wavenumber and the intensity of the absorption bands, due to the apparition of 619, 795, 1094 and 1202 cm−1 absorption bands of cristobalite in the infrared spectrum of chert treated sample, which is similar to diatomite. Granulometric analysis show that the natural untreated chert sample displays unimodal distribution, whereas the treated chert sample display bimodal distribution, as same as diatomite. Thus, a new mode appears systematically, between 0.1 μn and 1 μm, for all thermal treated samples with alkaline flux as observed for diatomite.

Membrane Processes in Biorefineries: From Feedstock Preparation to Downstream Processing

1. IntroductionThe third and latest wave of biotechnology is the so called „white biotechnology“ aiming to replace the C2/C3 chemistry based on oil and gas by biological processes. The backbone of biotechnology is the conversion by fermentation which is widely established in the production of antibiotics, enzymes, bioethanol and organic acids. In the past, fermentation processes had to partly compete with chemical conversion but the foreseeable shortage of raw materials for chemical conversion has revived the interest in fermentation in recent years. Since the 1970’s, cross-flow membrane processes have established themselves in the downstream processing of fermentation products for recovery and purification. It is expected that this role will extend into the new concept of biorefineries. The first part of this presentation will provide an overview of the existing potential and future opportunities of membrane processes within the concept of biorefineries in general and the second part provides an application study for a wheat-based biorefinery in details. 2. Membrane processes in biorefineriesThe aim of biorefineries is the full utilisation of feedstock to simultaneously produce e.g. food, biofuels and biochemicals. The integrated production of biomaterials can be based on e.g. sugar, starch and cellulose-based feedstock and as such extend current sugar, starch and pulp factories. Membrane processes have been identified as a key separation technology due to their high selectivity and low energy consumption. The initial step in the concept of biorefineries is conversion of the feedstock, e.g. cellulosic or starch-based materials, into sugars. The sugar stream might be polished by micro-filtration (MF) or ultrafiltration (UF) and concentrated by reverse osmosis (RO) before fermentation. During the fermentation step, the fermentation products can be continuously removed by using either MF/UF or pervaporation (PV) in a side stream or submerged in the fermenter to avoid product inhibitions. In the downstream process after the fermenter, membrane processes can be used for the polishing and concentration of the fermentation products, e.g. biofuels/biochemicals. 3. Application study: Membrane processes in a wheat-based biorefinery The presentation will provide an overview of membrane applications in a wheat-biorefinery focused on four applications with reference to the four key production steps: starch extraction, starch conversion to sweetener, fermentation and downstream processing. The first step in wheat-based biorefineries is extraction of the starch from the wheat. For this the wheat flour is mixed with water and then separated by a 3-phase decanter resulting in an A-starch fraction, a gluten and B-starch fraction, and a fraction consisting of solubles and pentosanes. In order to optimise the water consumption it is possible to apply UF for concentrating the solubles and pentosanes and recovering water for recycling in the process. The overall water balance for the starch extraction can be improved by using this concept. An important step in the subsequent conversion of starch to sweeteners is the removal of the mud fraction after liquification and saccarfication. A combination of UF with a decanter can be used as an alternative to rotary vacuum filters achieving higher purities and a mud fraction which is not contaminated with filter aid kieselguhr and can therefore be added directly in the bioethanol production. Hence, the closed process avoids potentially hazardous filter aids and results in a value-added by-product. Continuous fermentation is an important feature in the concept of biorefineries. MF/UF, either submerged or as side-stream, can be applied to recover the active principles directly from the fermentation broth. In this way, the production can be moved from batch to continuous thus preventing product inhibitions. This concept is valid for bioethanol as such but also other biochemicals such as organic acids or bioplastics. Evaporation is often used in the downstream processing as a stand-alone unit or in combination with RO for concentration of the fermentation products. The resulting evaporator condensate from the concentration can be polished by RO resulting in a permeate stream which can be recycled in the process thus improving the water balance of the process. Pilot and/or production results will be presented for all four focus applications. 4. Conclusions and outlookThis paper demonstrates the great potential of membrane processes in the concept of biorefineries and thus in solving the energy and environmental problems of the future. (Less)

GHGT-9 Polymeric Filtration Aids: “Two Decades of Lab and Plant Observations – the Rest of the World”

Abstract Many Phosphoric Acid plants use a Polymeric Filtration Aid for increased production and recovery. This paper presents laboratory filtration data, comparing conditions at various di-hydrate acid plants around the world. Results from the latest AMCC Filter Aid technology to enhance vacuum filters is compared for plants in Brazil, Canada, China, Mexico, Morocco, and the USA.

Using speciation diagrams to improve synthesis of magnetic nanosorbents for environmental applications

This work addresses environmental applications of magnetic nanoparticles. We highlight the chemical design of filtration aids based on magnetic nanoferrites coated with specific ligands potentially used in magnetic separation of pollutants from water. From electrochemical measurements, we determined the concentration of the surface sites in function of pH for the precursor magnetic nanoparticles. Then, coupling the speciation diagrams of the precursor nanoferrite particle surface with that of the specific ligand, it was possible to provide a theoretical prediction of the optimal pH for particle surface-ligand complexation, leading to advances in nanosorbents developing.

On the Particles Size Distributions of Diatomaceous Earth and Perlite Granulations

When filtering products with a high level of non-soluble solids and containing filtration-inhibiting substances, a variety of different filter aids can be used. Among others, kieselguhr and perlite are possible materials for this purpose. The selection of the granulation that should be applied depends on the filtered liquid medium and the desired retention level. While perlite is most commonly used for rough filtration, kieselguhr is also suitable for more subtile filtration. In the paper, particle size distributions of three kieselguhr granulations and a perlite granulation are analysed. Particle sizes are measured by the morphometric method, commonly used in the microbiology. Basic statistic parameters are calculated for all considered samples and compared. The applicability of hyperbolic and log-hyperbolic functions, in describing the particles size distributions of these granulations is verified. Depending on the imposed filtration requirements, this approach enables simple modelling and composition of a wide variety of different granulations characterised by appropriate particle size distributions from a few available granulations.

Activities, Kinetics and Emission Spectra of Bacterial Luciferase‐Fluorescent Protein Fusion Enzymes

A new approach to alter bacterial bioluminescence color was developed by fusing Vibrio harveyi luciferase with the coral Discosoma sp. fluorescent protein mOrange, a homolog of the Aequorea green fluorescent protein. Attachment of mOrange to the N- or C-terminus of luciferase α or β subunit, via a 5 or 10 residue linker, produced fully active fusion enzymes. However, only the fusion of mOrange to the N-terminus of luciferase α produced a new 560 nm emission. The differences in emission color by two such fusion enzymes from that of the wild-type luciferase (λ(max) 490 nm) were evident by eye or photographically with the aid of cut-off optical filters. In nonturnover reactions, light decay rates of fusion enzyme remained the same when monitored as the full-spectrum light or at 480 nm (from the luciferase emitter) or 570 nm (from mOrange). No 560 nm emission component was observed with a mixture of luciferase and free mOrange. These findings support that the 560 nm emission by the fusion enzyme was due to bioluminescence resonance energy transfer from luciferase to mOrange. We believe that the same approach could also alter the bacterial bioluminescence color by covalent attachment of other suitable fluorescent proteins or chromophores to luciferase.