Wet Filtration Research Articles

Woven filter media used in wet filtration processes: investigation of pore size distribution, air and water permeability and finding correlations between them

Currently, methods for evaluating the performance of woven filter media used for filtration processes are mainly reduced to air permeability and filtration resistance. However, filtration processes are not limited to dry filtration only. Moreover, critical performance-related factors such as the pore size distribution and liquid permeability are studied but often omitted and ignored in the characterization process. The present study aims to investigate and analyze three characteristics, namely air and liquid permeability and pore size distribution, and to examine correlations between the studied characteristics. The results of the present study show that correlations between the studied characteristics do exist. Polynomial and exponential functions could describe the correlation between the mean flow pore diameter and permeability. At the same time, the dependency between air and water permeability is characterized by a logarithmic function. Consequently, the characterization and selection of filter cloths should be done by analyzing several different parameters simultaneously. These correlations could become the basis of a system of media indexing in the future.

DEM filtration modelling for granular materials: Comparative analysis of dry and wet approaches

AbstractA detailed study comparing two – dry and wet – numerical approaches to model filtration processes at stake in actual granular filters is presented using the discrete element method (DEM). In the first approach, the migration of fines is provided by gravitational forces, while in the second, hydrodynamic forces induce their movement. Numerical filtration tests were performed on granular filters involving materials with different gradings and porosities. The study demonstrated that the wet filtration approach generates higher tortuosity due to the possibility for fines to deviate from direct paths towards more open sideways. It leads to a lower coefficient of retention for the filter than if it were characterised using a dry filtration approach. However, the intensity of this feature greatly depends on the grading and the porosity of the granular filter. Finally, an enhanced dry filtration model designated as the “equivalent cyclic wet filtration model” is presented, which better mimics the results obtained through the preferable wet filtration model compared to the original dry filtration model. This new model constitutes a valuable alternative tool for studies of filtration properties in granular materials.

Assessment of microplastic abundance in Central Java coastal waters: a study of Sendang Sikucing, Karangjahe, and Caruban Beaches

Marine pollution caused by plastic waste is a problem that occurs in many places. Plastic waste is a type of waste that is difficult to decompose, requiring a very long time to decompose. Plastic degrades into smaller particles known as microplastics, which can accumulate in seawater. Microplastics can transfer to humans and are carcinogenic. This study is a preliminary investigation of microplastic pollution in beach waters surrounded by industrial activities, tourism and fishing activities. From the analysis of microplastics from the three locations above, it can be seen that the abundance of microplastics in the area is dangerous or still at the normal threshold. Determination of the research location using purposive sampling method. Identification of microplastic particles in water samples using wet filtration to obtain microplastic samples < 5 mm using a 5 mm and 0.3 mm stainless steel mesh filter that is stacked. The abundance of microplastics in the waters of Sendang Sikucing Beach was 0.01863 particles/m³, Karang Jahe Beach was 0.26315 particles/m³, and Caruban Beach was 0.05022 particles/m³. The types of microplastics found in both waters are the same, namely fragments, fibers and films.

Perbanyakan Mikoriza Indigenus Taman Nasional Gunung Ciremai dengan Berbagai Tanaman Inang

This study aimed to determine the effectiveness of the use of host plants in an effort to multiply mycorrhizal propagules indigenous to Gunung Ciremai National Park. The experimental method used a factorial complete randomized design with 2 factors. The first factor was the location of the source of inoculum by 3 levels: mixed forests, shrubs, and pine stands. The second factor was 4 types of host plant many as 4 levels: corn (Zea mays), sorghum (Sorghum bicolor. (L.) Moench), centro beans (Centrosema pubescens), and ruji beans (Pueraria javanica). Each treatment was repeated five times, so there were 60 experimental units. The spores were isolated by wet filtration and decantation methods adapted from Gerdemann and Nicolson (1963), followed by the modified sugar centrifugation method from Jenkins (1964). The observed parameter was the number of mycorrhizal spores. The data obtained were analyzed by a variance test (F test). To evaluate the treatment's effect and compare the selected treatments, Duncan's follow-up test was used at the level of 5%. The combination of the location of the shrub inoculum and the centro bean host plant showed the largest spore population, which was 222.60 per 50 g soil sample. Trapping techniques using host plants of corn, sorghum, centro beans, and ruji beans showed suboptimal results. The most common genera were Glomus (80%; 4 species), Gigaspora (10%, 1 species), and Acaulospora (10%, 1 species). Glomus was evenly found in all trapping results.&#x0D; &#x0D; Keywords: Acaulospora, Glomus, mycorrhiza, propagules, spores

ВЛИЯНИЕ ОБРАБОТКИ СЕМЯН РАЗНЫМИ ДОЗАМИ ГЕТЕРОАУКСИНА НА РОСТОВЫЕ ПАРАМЕТРЫ ДВУХ СОРТОВ ФАСОЛИ

Priming of seeds in auxin solution is a model of the action of auxin-producing bacteria on plant growth. The aim of the study was to identify auxin concentrations that stimulate and inhibit the growth of seedlings of two varieties of beans. Seeds were soaked for 3 hours in tenfold dilutions of heteroauxin 0,00001–100 mg/l, germinated on wet filters in the dark, growth parameters (germination energy, germination, length of axial organs of the seedling, number and length of lateral and accessory roots, root and shoot weight) were measured on the 7th day. For the Ufa variety, an increase in all growth indicators by 25-36% relative to the control occurred only at a dose of 0,001 mg/l, while the shoot/root ratio of 1.8 was as in the control. Changing this dose by an order of magnitude led to a neutral or negative effect on all growth indicators. For the Elsa variety, the growth of the length of the main root on the gradient of hormone concentrations was characterized by a two-vertex graph with a maximum value of an increase in root length by 23% to the control at a dose of 0,1 mg/l hormone. At the same time, the shoot/root ratio is 1,0. According to other indicators, no stimulating effect was found. The presence of one or more pessimums of the values of the growth indicators of seedlings on the concentration curve indicates that in both varieties the range of stimulating concentration of exogenous auxin is very narrow. Therefore, to stimulate growth, it is necessary to use precision and individual concentrations of exogenous hormone for each variety.

Observation of Arbuscular Mycorrhizal Fungi (AMF) Spores in Organic and Conventional Coffee Farms

In this study, AMF colonization in the soil of coffee farms adopting organic and conventional agricultural practices was observed in two different sites. Variation of AMF types, density, and inoculation in the coffee roots was observed throughout the wet filtration method. Although we found the infection of the root in coffee roots from both organic and conventional farming systems, in the organic farming system, we found higher variation in AMF types than in the conventional farming system. Sustainable land management is crucial to maintain the existence of soil microorganisms that are important for plant growth.

Development of Lignin-Containing Cellulose Nanofibrils Coated Paper-Based Filters for Effective Oil-Water Separation.

New methods of oil-water separation are needed as industrialization has increased the prevalence of oil-water mixtures on Earth. As an abundant and renewable resource with high oxygen and grease barrier properties, mechanically refined cellulose nanofibrils (CNFs) may have promising applications for oil-water separations. The unbleached form of these nanofibrils, lignin-containing CNFs (LCNFs), have also been found to display extraordinary barrier properties and are more environmentally friendly and cost-effective than CNFs. Herein, both wet and dry LCNF-modified filter papers have been developed by coating commercial filter paper with an LCNF suspension utilizing vacuum filtration. The LCNF-modified filters were tested for effectiveness in separating oil-water emulsions, and a positive relationship was discovered between a filter's LCNF coat weight and its oil collection capabilities. The filtration time was also analyzed for various coat weights, revealing a trend of high flux for low LCNF coat weights giving-way-to predictions of a coat weight upper limit. Additionally, it was found that wet filters tend to have higher flux values and oil separation efficiency values than dry filters of the same LCNF coat weight. Results confirm that the addition of LCNF to commercial filter papers has the potential to be used in oil-water separation.

Removal of Non-Steroidal Anti-Inflammatory Drugs from Drinking Water Sources by GO-SWCNT Buckypapers.

Pharmaceutical products such as antibiotics, analgesics, steroids, and non-steroidal anti-inflammatory drugs (NSAIDs) are new emerging pollutants, often present in wastewater, potentially able to contaminate drinking water resources. Adsorption is considered the cheapest and most effective technique for the removal of pollutants from water, and, recently, membranes obtained by wet filtration method of SWCNT aqueous solutions (SWCNT buckypapers, SWCNT BPs) have been proposed as self-standing porous adsorbents. In this paper, the ability of graphene oxide/single-walled carbon nanotube composite membranes (GO-SWCNT BPs) to remove some important NSAIDs, namely Diclofenac, Ketoprofen, and Naproxen, was investigated at different pH conditions (pH 4, 6, and 8), graphene oxide amount (0, 20, 40, 60, and 75 wt.%), and initial NSAIDs concentration (1, 10, and 50 ppm). For the same experimental conditions, the adsorption capacities were found to strongly depend on the graphene oxide content. The best results were obtained for 75 wt.% graphene oxide with an adsorption capacity of 118 ± 2 mg g-1 for Diclofenac, 116 ± 2 mg g-1 for Ketoprofen, and 126 ± 3 mg g-1 for Naproxen at pH 4. Overall, the reported data suggest that GO-SWCNT BPs can represent a promising tool for a cheap and fast removal of NSAIDs from drinking water resources, with easy recovery and reusability features.

Diversity of Arbuscular Mycorrhizal Fungi of Kalappia celebica: An endemic and endangered plant species in Sulawesi, Indonesia

Abstract. Husna, Tuheteru FD, Albasri, Arif A, Basrudin, Nurdin WR, Arman E, Agustin DI, Saribadu J, Rahmat, Dermawansyah A, Daliana, Lody LP, Deri AS, Safitri I. 2022. Diversity of Arbuscular Mycorrhizal Fungi of Kalappia celebica.): An endemic and endangered plant species in Sulawesi, Indonesia. Biodiversitas 23: 5290-5297. Arbuscular Mycorrhizal Fungi (AMF) are a group of fungi belonging to Phylum Glomeromycota. AMF has a symbiotic relationship with higher plants, including endangered species in various climatic regions and land types. Research on AMF diversity related to endemic and endangered tree species in the tropics is still limited. This study aimed to examine the diversity of AMF in the natural habitat of Kalappia celebica Kosterm. (kalapi) in Southeast Sulawesi Province, Indonesia. Samples of soil and roots of K. celebica were collected from six natural habitat locations, i.e., Konawe District (Anggatoa and Abuki Villages), East Kolaka District (Lalingato and Anggaloosi Villages) and Kolaka District (Lalonaha and Lapao Pao Villages). The AMF spores were isolated by using the pouring method, followed by wet filtration. AMF identification was carried out by observing the morphology of AMF spores. A total of eight AMF species belonging to three genera Viz. Glomus, Funneliformis and Rhizophagus were isolated. Among the species identified, five species belong to genus Glomus, two species belong to the genus Funneliformis and one species belongs to the genus Rhizophagus. Glomus sp.1 and 2 and F. mosseae had the highest spore density, relative density and frequency, and importance index values. The AMF highest spore density was obtained in Anggaloosi Village of East Kolaka District. Soil properties such as organic C, total N and clay were positively correlated with spore density and negatively correlated with AMF colonization. The Simpson’s Index ranged from 0.42 ± 0.117 to 0.86 ± 0.068. The range of Shannon-Wiener Index was 0.12 ± 0.208 to 0.99 ± 0.198, while the Evenness Index ranged from 0.17 ± 0.189 to 0.75 ± 0.106. These findings indicated that K. celebica species are rich in AMF diversity. These symbiont fungi are key components of the ecosystem. Further research is needed to develop their use as promoters of plant establishment in conservation and restoration of those sites.

Diversity of Arbuscular Mycorrhizal Fungi of Kalappia celebica: An endemic and endangered plant species in Sulawesi, Indonesia

Abstract. Husna, Tuheteru FD, Albasri, Arif A, Basrudin, Nurdin WR, Arman E, Agustin DI, Saribadu J, Rahmat, Dermawansyah A, Daliana, Lody LP, Deri AS, Safitri I. 2022. Diversity of Arbuscular Mycorrhizal Fungi of Kalappia celebica.): An endemic and endangered plant species in Sulawesi, Indonesia. Biodiversitas 23: 5290-5297. Arbuscular Mycorrhizal Fungi (AMF) are a group of fungi belonging to Phylum Glomeromycota. AMF has a symbiotic relationship with higher plants, including endangered species in various climatic regions and land types. Research on AMF diversity related to endemic and endangered tree species in the tropics is still limited. This study aimed to examine the diversity of AMF in the natural habitat of Kalappia celebica Kosterm. (kalapi) in Southeast Sulawesi Province, Indonesia. Samples of soil and roots of K. celebica were collected from six natural habitat locations, i.e., Konawe District (Anggatoa and Abuki Villages), East Kolaka District (Lalingato and Anggaloosi Villages) and Kolaka District (Lalonaha and Lapao Pao Villages). The AMF spores were isolated by using the pouring method, followed by wet filtration. AMF identification was carried out by observing the morphology of AMF spores. A total of eight AMF species belonging to three genera Viz. Glomus, Funneliformis and Rhizophagus were isolated. Among the species identified, five species belong to genus Glomus, two species belong to the genus Funneliformis and one species belongs to the genus Rhizophagus. Glomus sp.1 and 2 and F. mosseae had the highest spore density, relative density and frequency, and importance index values. The AMF highest spore density was obtained in Anggaloosi Village of East Kolaka District. Soil properties such as organic C, total N and clay were positively correlated with spore density and negatively correlated with AMF colonization. The Simpson’s Index ranged from 0.42 ± 0.117 to 0.86 ± 0.068. The range of Shannon-Wiener Index was 0.12 ± 0.208 to 0.99 ± 0.198, while the Evenness Index ranged from 0.17 ± 0.189 to 0.75 ± 0.106. These findings indicated that K. celebica species are rich in AMF diversity. These symbiont fungi are key components of the ecosystem. Further research is needed to develop their use as promoters of plant establishment in conservation and restoration of those sites.

Investigate the Water Activity of Different Solutions According to Solute Concentration for Preparing Wet Filtration Solution

According to the World Health Organization (WHO), air pollution ranks 6th among the leading causes of death globally. The wet porous membrane filter has been widely used in dust removal, VOCs, and acid gas absorption. The wet filtration solutions need to ensure a low water activity that limits the release of moisture into the air, inhibits microbial growth, and can absorb dangerous gases. This study investigated the water activity of NaCl, NaNO3, K2CO3, KCl, K2SO4, Mg(NO3)2, MgCl2, and CaCl2 solutions at different concentrations to saturation at 25 °C. NaCl and NaOH solutions are not only investigated at different concentrations but also investigated the effect of temperature in the range of 0-40 °C. Some solution formulas are suggested that ensures the following properties: low water activity, antifungal, antibacterial and acid gas absorption.&#x0D; &#x0D; &#x0D;

Experimental Investigation on the Retention of Soluble Particles by Pool Scrubbing

Abstract In the late stage of a severe loss-of-coolant accident, the pressure in the containment building of a nuclear power plant could rise beyond the design limits and thus endanger its structural integrity. Therefore, to avoid pressure failure, it may be necessary to perform controlled venting of the containment. During the event of an accident, a large amount of fission and activation products are released into the containment as airborne particles (aerosols). These particles are filtered during the venting process, usually with the help of wet filters, in order to keep risks to the surrounding environment to a minimum. Consequently, the knowledge of the retention processes in a water reservoir (pool scrubbing) is of central importance for such filtered containment venting systems and for reactor concepts in which water reservoirs are used for pressure reduction (e.g., condensation chamber of a boiling water reactor (BWR)). Investigations on pool scrubbing are carried out in the severe accident aerosol behavior (SAAB) test facility at the Juelich Research Center in the framework of a national project (“severe accident aerosol behavior-II”). SAAB is a unique large-scale facility with the ability to perform a great variation of experiments using various measurement tools. The influence of numerous parameters, such as the height of the water pool, solubility of aerosols and concentration on the retention capacity, is investigated by means of separate effect studies on both insoluble and soluble particles. This technical brief gives a detailed overview over the facility and includes example results of the first test series with soluble particles including cesium iodine (CsI).

Numerical simulation of gas holdup in nocoalescence media of industrial-scale bubble column

A bubble column is an industrial-scale wet filtration facility that contains non-coalescence media. To overcome the experimental challenges, numerical simulation was employed to investigate the influence of various factors on the whole gas holdup εt. These include the bubble diameter ds, initial liquid height Hs, column diameter, Dc, the number of bubbling orifices N, and the configuration of bubbling orifices. Two magnitudes of the superficial gas velocity UG, were selected to represent the homogeneous and heterogeneous flow regimes, respectively. The relationship between εt and ds changed within different ds ranges. The proportion of the developing region in the total liquid height is an important factor that influences εt. For an “industrial-scale” column, εt increased with N when N < 49, but becomes insensitive to N when N > 49. The configuration of bubbling orifices significantly influences εt when N > 49. The results of this study show the need to optimize the bubble column and improve the operating performance of filtered containment venting systems.

Simple Incinerator Model with Wet Coconut Filters for Mask Waste Treatment in Banjarbaru, South Kalimantan

Aim: Based on data from the 2019 Population Census, the population of Banjarbaru City is 262,719 people; if as many as 50% of the people of Banjarbaru City use masks, approximately 135,200 masks are generated per day, or 4,056,000 masks waste per month. To analyze the effect of the incinerator on CO, CO2 and NO2 exhaust gases of mask waste before using wet coconut fiber and after using wet coconut fiber.Methodology: This research method uses the experimental method. The experimental design in this study is a pre-experimental design by providing treatment and measuring the results of the treatment carried out pretest and post-test. The research was conducted at the Mustika Graha Asri Housing Complex RT 11 RW 01 Loktabat Utara Banjarbaru, South Kalimantan, in April 2022.Findings: From the results of statistical data processing using the paired t-test method, CO exhaust gas was obtained with a significance value of 0.853 (p &gt; 0.05), CO2 with a significance value of 0.002 (p &lt; 0.05) and NO2 with a significance value of 0.801 (p &gt; 0.05). The exhaust gas that has a significant difference before and after using the wet coconut fiber filter is CO2 exhaust gas, while there is no significant difference between CO gas and NO2 exhaust gas. Many shortcomings still need to be addressed so that the combustion process in this simple incinerator is more optimal.Implications/Novel Contribution: The present study advances knowledge by comprehensively summarizing mask waste treatment using wet coconut filters. Additionally, this research offers useful information on the entire installation procedure and necessary tools.

Development of robust models for rapid classification of microplastic polymer types based on near infrared hyperspectral images.

Hyperspectral data in the near infrared range were examined for nine common types of plastic particles of 1 mm and 100-500 μm sizes on dry and wet glass fiber filters. Weaker peak intensities were detected for small particles compared to large particles, and the reflectances were weaker at longer wavelengths when the particles were measured on a wet filter. These phenomena are explainable due to the effect of the correlation between the particle size and the absorption of infrared light by water. We constructed robust classification models that are capable of classifying polymer types, regardless of particle size or filter conditions (wet vs. dry), based on hyperspectral data for small particles measured on wet filters. Using the models, we also successfully classified the polymer type of polystyrene beads covered with microalgae, which simulates the natural conditions of microplastics in the ocean. This study suggests that hyperspectral imaging techniques with appropriate classification models allow the identification of microplastics without the time- and labor-consuming procedures of drying samples and removing biofilms, thus enabling more rapid analyses.

Prediction of residual saturation and pressure drop during coalescence filtration using dynamic pore network model

Microstructure optimization of mist and dust filter media used in many applications including respirators, lubricated machining, compressors and engine crankcases is increasingly becoming reliant on computational simulations of dry and wet filtration processes. Computational fluid dynamics (CFD) based full-morphology simulations with advanced interface capturing techniques offer unique advantages in enabling accurate characterization of the pore-scale transport processes, yet demand substantial computational effort especially for fine filters. In this work, a dynamic pore network modeling (DPNM) framework is developed and evaluated for the prediction of residual saturation and pressure drop during mist filtration, and applied to an oil-air system. Two nonwoven filters (stainless steel and polyester) with different fibre diameters and packing densities are considered. The pore network is extracted using a watershed-based algorithm, from realistic virtual filter geometries (Abishek et al., 2017), and validated for macroscopic properties such as packing density. The validity of the steady PNM model is assessed by comparison of the dry (air) pressure drop against CFD and experimental data in the literature. The validity of the DPNM model is assessed by comparison of multiphase pressure drops and residual saturation against micro-CT and gravimetric experiments carried out in this work, as well as pore-scale CFD simulations using the volume-of-fluid model. It is found that the dynamic pore network model is able to successfully predict the critical properties of the filtration process such as saturation (local and total) and pressure drop to within 15% of experiment and CFD. Considering that the overall computational cost of DPNM is about 2–3 orders of magnitude lower than fully resolved CFD, DPNM stands as a potential tool for the early-stage design and optimization of mist filtration media.

Lead Distribution in Ground-Level Atmospheric Aerosol of Zaporizhia City

The results of long-term observations on the geochemical peculiarities of technogenic lead distribution in atmospheric aerosol of Zaporizhia, as well as in soils, bottom sediments, suspended matter from Dnipro river and substance from wet gas filters of open-hearth furnaces PJSC Zaporizhstal are presented. The actual material was obtained on the basis of comprehensive field monitoring during 2015-2019. Simultaneous involvement of data on hydrometeorological conditions (seasonality, precipitation, wind speeds, directions and duration) in the study area provided a integral approach to the processing and generalization of research results. A number of peculiarities of sedimentary substance distribution in air, interrelations of its anthropogenic and natural components are defined. Correlations were revealed between lead concentrations changes and aeolian mineral component distribution, seasonality, and a number of other factors. The highest concentration of lead was found in solid aerosol particles accumulated by the sedimentary trap at the monitoring site. It was revealed that the average concentration of investigated element in river suspension of Dnipro exceeds significantly background values, and for soils exceeds more than 3.5 times the permissible norms. At the same time, the fixed form of lead in atmospheric aerosol, in contrast to other environmental objects, loses its domination, giving the way to easily soluble forms, so the evidence of environmental hazard. Monitoring of seasonal patterns of the element distribution in the city air showed excess concentrations in the cold period of the year, which, according to the authors, is due to both meteorological conditions and redistribution of natural and anthropogenic factors that serve the driving force in processes of arriving and conversion of lead in atmosphere during different seasons of the year.

The Indigenous endomycorrhizal fungi at salak (Salacca zalacca) plantations in Bali, Indonesia and their colonization of the roots

Abstract. Rai IN, Suada IK, Proborini M, Wiraatmaja IW, Semenov M, Krasnov G. 2019. Indigenous endomycorrhizal fungi at salak (Salacca zalacca) plantations in Bali, Indonesia and their colonization of the roots. Biodiversitas 20: 2410-2416. Cultivation of snake fruit, commonly known as salak usually done organically on dry land with limited fertilizer in Bali. This research aimed to observe and to identify the indigenous endomycorrhizal fungi on salak roots. The exploration was carried out by collecting soil and root samples in salak producing areas in Bali, i.e. Bebandem and Selat of Karangasem Regency, Payangan of Gianyar, and Pupuan of Tabanan Regency. At each location, 9 random samples were taken, resulting in a total of 36 samples. Spore extraction was carried out using a wet filtration technique followed by centrifugation according to the method by Brunndrett et al. (2009). Morphological identification was carried out at the genus and species level using the Manual for Identification of Mycorrhiza Fungi for identifying Vesicular-Arbuscular-Mycorrhiza (VAM) fungi (Schenk and Perez, 1990), while molecular identification was carried out according to Tedersoo et al. (2014). The percentage of root infections was carried out using the coloring method with trypan blue. The results showed there were only two genera of endomycorrhizae (Glomus and Entrophospora) identified at the locations of study sites. The results also showed that samples from Bebandem and Selat regions had 3 Glomus species, Payangan had 3 Glomus species and 1 Entrophospora species, while in Pupuan had only 2 Glomus species. Identification results based on morphological characters showed that all species in the genus Glomus consisted of 3 species, namely Glomus sp-1, Glomus sp-2, and Glomus sp-3, while one species in the genus Entrophospora was Entrophospora sp. Genetic identification results based on the nucleotide arrangement showed that Glomus sp-1 concluded as Glomus cubence, Glomus sp-2 concluded as Glomus custos, and Glomus sp-3 concluded as Glomus indicum, while Entrophospora species concluded as Entrophospora_sp_SH197095.06FU. The average of root colonization/ infection was very high, reaching 93.33% in Bebandem and Selat, 95.00% in Pupuan, and 100% in Payangan. The very high root infection rates indicated that the indigenous endomycorrhiza found in these areas was very adaptive in salak plantation, so there is an opportunity to be developed as biofertilizers.

Sampling efficiencies of two modified viable cascade impactors

ABSTRACTPrevention of airborne contagious diseases depends on successful characterization of aerosols in the environment. The use of cascade impactors to characterize ambient aerosols is one of the most commonly used methods, providing data on both particle size and concentration. In this study, the use of a cascade impactor recently described in the literature using 8 mL of liquid in Petri dishes (CI-L) was compared with a new method that uses wet membrane filters on top of wax filled Petri dishes (CI-WWMF). Sampling efficiencies of the cascade impactors were evaluated using 0.5, 1, 3, and 5 μm polystyrene latex (PSL) microspheres and aerosol consisting of single spores of Bacillus atrophaeus var. globigii (BG). The sampling efficiency of the CI-L was 6%, 11%, 17%, 21%, and 58% for 0.5, 1, 3, 5 μm PSL microspheres and BG spores, respectively. Higher overall sampling efficiencies of 71%, 91%, 60%, 64%, and 104% were observed for the same size and type of particles for the CI-WWMF. This study indicates tha...

PRELIMINARY ANALYSES ON AN ALGAE-BASED WATER SCRUBBER FOR SYNGAS CLEANSING

Common issues of the gasification systems relate to filtering apparatus. Dry filtering processes are simple and reliable. However, the filtering material defines the maximum and minimum temperature at which the filter can operate properly. In addition, dry filtration is not effective on light tar compounds (i.e. benzene and toluene) or ammonia compounds. On the other hand, despite being very efficient, wet filters drop the gas temperature below the line of condensation of tar, ammonia and steam. The resulting condensate is normally disposed at a high cost on account of the high amount of hydrocarbons it contains. This work investigates the effects of a specific micro-algae growth on the waste-water from a syngas water scrubber. The results demonstrated the capability of the algal growth in the tar-contaminated water in which a certain amount of contaminants have been dissolved. Quantitative analyses of the compounds outlined the effect of algal growth on the reduction of several chemical species derived from the syngas filtration.