Conventional Filtration Systems Research Articles

Insights into polystyrene nanoplastics adsorption mechanisms onto quartz sand used in drinking water treatment plants

The widespread production and use of plastics with poor recycling practices have resulted in higher discharge of plastic waste into the aquatic systems. Nanoplastics (NPLs) resulting from the fragmentation of microplastics, are considered as the most hazardous fraction. Adsorption to mineral surfaces is considered as one of the most important processes controlling the fate and transport of nanomaterials both in the natural environment and conventional filtration systems. However, adsorption mechanisms, influencing physicochemical parameters, and adsorption capacities of different porous media are still poorly known. In this study, the adsorption process of polystyrene (PS) NPLs to quartz sand, used as a filter medium in the drinking water treatment plant in Geneva (Switzerland), is investigated. Contrasting conditions are considered: ultrapure water and Geneva Lake water. Results indicate that PS NPLs dispersed in ultrapure water are adsorbed to the sand surface mainly due to the electrostatic interactions and adsorption capacity of the sand grains varies from 0.05 ± 0.01 mg g−1 to 0.10 ± 0.02 mg g−1 for PS NPLs concentrations comprised between 10 and 50 mg L−1. The adsorption process is successfully described by Langmuir isotherm, therefore indicating the formation of a monolayer on the sand grain surfaces. SEM micrography confirms PS NPLs monolayer formation and image analysis indicates a maximum surface coverage ranging from 9 to 12 %. Adsorption mechanisms of PS NPLs are significantly modified under environmental conditions (i.e., pH, ionic composition, presence of DOM). The adsorption capacity of sand grains for the removal of PS NPLs increased and varies from 0.05 ± 0.01 mg g−1 to 0.7 ± 0.2 mg g−1 for PS NPLs concentrations ranging from 10 to 50 mg L−1. Increased adsorption capacity is due to heteroaggregation and cation bridging processes. SEM micrography shows aggregates attached to smooth sand surfaces and deposited in the vicinity of surface irregularities.

Evaluation of the aluminum migration from metallic seals to coffee beverage after using a high-pressure coffee pod machine

The availability of aluminum during coffee drink preparation using a coffee pod machine was evaluated, through its determination in capsule seals, ground coffee, and coffee drink. The coffee drink preparation through a conventional filtration system and coffee pod machines was compared, having an increase around 13 % on aluminum concentration when the coffee was prepared with a coffee pod machine (459 ± 9 μg L−1) against the conventional filtration system (408 ± 6 μg L−1). The highest aluminum concentration (approximately 80 %) was found in the capsule seals, and 6 mg kg−1 incorporated into the ground coffee during coffee drink preparation. An aluminum concentration of 0.46 mg kg−1 was leached to the coffee drink, indicating its strong absorption by the ground coffee. This concentration represented only 0.15 % of that range recommended by the European Food Safety Authority (EFSA), indicating a safe consumption of espresso coffee (5 cups/day). However, the reuse of ground coffee is of great concern, once approximately 3.5 times higher aluminum content was found in this sample.

Conventional filtration system for seawater pretreatment at the Beni Saf desalination plant using conventional sand filters: a comparison with Filtralite pure and clay filters

Conventional filtration system for seawater pretreatment at the Beni Saf desalination plant using conventional sand filters: a comparison with Filtralite pure and clay filters

기후변화 대응을 위한 수처리 여과시스템 선정 방안 연구

The problem of water shortages and water related disasters caused by climate change has increased the seriousness of water problems and the importance of water treatment technology capable of securing clean water is expanding. In this study, we analyzed not only the water pollutant generated by the filtration system technology of various water treatment technologies but also the indirect greenhouse gas emissions generation, and analyzed the influence on the environment. The subjects of study are Fabric Filter, Reverse Osmosis System and Pressurized Microfiltration Device which are widely used for water treatment and we analyzed the impact on the environment using the Life Cycle Assessment (LCA) method using the electricity amount necessary for use, the water purification efficiency, the throughput per ton and the cost. The amount of greenhouse gas generated when the Pressurized Microfiltration Device operates for 1 year is 2.15E+04 kg CO₂-eq., Fabric Filter is 3.29E+04 kg CO₂-eq., and Reverse Osmosis System is 1.68E+05 kg CO₂-eq. As a result of analyzing the amount of greenhouse gas generated at the time of purifying 1 ton of the Pressurized Microfiltration Device and the conventional filtration system, the Pressurized Microfiltration Device was 20.5 g CO₂-eq., Fabric Filter was 34.7 g CO₂-eq., and Reverse Osmosis System was 191.7 g CO₂-eq. The amount of greenhouse gas generated was calculated to be 41.0% less than that of the Fabric Filter by the Pressurized Microfiltration Device and 89.3% less than the Reverse Osmosis System. From the viewpoint of climate change, it is necessary to select a filtration system that takes climate change into account, not from the viewpoint of water quality removal efficiency and economic efficiency according to future water treatment applications, and it is necessary to select a water treatment filtration system more researches and improvements will be made for.

Conventional Water Filter (Sand and Gravel) for Ablution Water Treatment, Reuse Potential, and Its Water Savings

<p>Ablution process consumes a huge amount of water especially in mosques for cleaning certain part of the body before performing prayers. The high volume of ablution water produced in mosques and its low strength in quality makes it a feasible option to be reused. This paper introduced an assessment of conventional filtration (sand and gravel) in treating ablution water for reuse purposes and its water savings potential in mosques. The treatment system has assessed its capability for reuse and its water savings potential. A pilot scale of filtration system was developed and was run with the ablution water from the Parit Raja mosque and the Pintas Puding mosque. The samples were taken during Friday noon prayer between January to March 2013. The efficiency of the conventional filtration system was tested for the effluent quality of NH<sub>3</sub>, TSS, COD, and BOD. The case study of water savings estimation for the proposed system was undertaken at Pintas Puding mosque. It was determined based on the quantity of ablution water, water consumption, water demand, and water bills record. The results deduced that the conventional sand filtration can improve the water quality parameters; 0.60-0.05mg/L reduction of nitrogen ammonia (NH<sub>3</sub>), 6.0-1.53mg/L of suspended solids (TSS), 3.12-0.15mg/L of chemical oxygen demand (COD), and 27.67-4.16mg/L of biochemical oxygen demand (BOD). The treatment system was projected to save water consumption by 41.73% and RM180.16 of water saving per month. Water consumption was estimated to be further reduced to 50.83% if reused activities such as irrigation and toilet flushing were applied. Hence, annual water savings could reach up to RM2161.92 per year. With the current instability of water resources, the implementation of the conventional filtration system for ablution water in the mosques provides water security and water resources conservation option for the country.</p>

Comparison of Filtration System and a Honeycomb Denuder-Based System for Sampling PM2.5 in Tianjin, China

To evaluate sampling artifacts of PM_2.5 with conventional filtration system (FS), a contrastive study between the FS and a honeycomb denuder system (HDS) in measuring atmospheric concentrations of PM2.5 and its main water-soluble ions (Cl^-, NO_3^-, SO_4^(2-) and NH_4^+) was conducted at a urban site in Tianjin, China in both summer and winter. In this study, we confirmed the optimum concentration of absorbents of Na_2CO_3 and citric acid for HDS were 3% and 6% in summer experiments and 4% and 5% in winter experiments. Daily mean concentrations of Cl^- obtained by HDS were higher than those by FS both in summer and winter. In contrast, the HDS gave lower daily mean SO_4^( 2-) concentrations than FS in both summer and winter. For NO_3^- and NH_4^+, concentrations obtained by HDS were lower than those obtained by FS in winter. However, the HDS gave larger values of NO_3^- and NH_4^+ than FS in summer. The different results of different ions were in response to the concentrations of interfering gases in ambient air and chemical characteristics of ionic species. In addition, the concentrations of PM_2.5 obtained by HDS were higher than those obtained by FS in summer, while virtually no significant difference between HDS and FS in winter. Our study points out that investigating optimum concentrations of coating solutions before denuder system sampling is necessary. Moreover, it is essential to make careful evaluation and modification when applying FS in highly polluted Environment, especially for PM_2.5 ions determining.

Mechanistic Modeling of Solids Separation in Solid/Liquid Hydrocyclones

Summary Hydrocyclones have been used for many years for removing solids from continuous liquid media in the mineral, chemical, petroleum, and environmental industries, among others. In oilfield applications, the solid/liquid hydrocyclone (SLHC) has emerged as a sound technological and economical alternative to conventional filtration systems where space, efficiency, reliability, and continuous operations are critical. The SLHC is particularly attractive in offshore, subsea water-injection applications and in other oilfield operations. Early and effective removal of solids in pipelines and process equipment help prevent erosion and premature failures that are costly and pose serious health, safety, or environmental hazards. To date, hydrocyclone design has relied primarily on empirical experience and, most recently, costly and lengthy computational fluid dynamic (CFD) simulations. The main objective of this work is the development of a mechanistic model for practical, yet reliable, SLHC design. The proposed model is capable of describing the hydrodynamic-flow phenomena inside the hydrocyclone, enabling the prediction of continuous-phase-swirl intensity and the velocity profile used in determining particle trajectories, and hence, the grade separation efficiency curves. The model is validated against oilfield experimental data run under a wide range of conditions and equipment configurations. Model agreement with global and grade separation efficiency data are 94.7% and 88.2%, respectively.

Effect of coagulation and flocculation conditions on water quality in an immersed ultrafiltration process

The removal of natural organic matter under variable coagulation and flocculation pretreatment conditions was evaluated for three surface waters in an immersed ultrafiltration (UF) process. Coagulation with alum, flocculation and UF treatment were conducted in a bench‐scale test apparatus designed to simulate pilot‐ and full‐scale water treatment systems. Variable coagulation and flocculation operating conditions were investigated, including coagulant dose, hydraulic retention time (HRT) and mixing intensity (e.g. velocity gradient). Treatment performance was evaluated by measuring specific water quality parameters in the permeate stream, including dissolved organic carbon (DOC), UV254 and true colour. Coagulant dose was found to be the most important variable for treatment performance with regard to permeate water quality, with significantly lower alum dosages required to achieve enhanced coagulation water quality targets than conventional filtration systems. Experiments conducted to evaluate variable flocculation stage HRT and applied velocity gradient demonstrated that traditional set points for these operating variables, applied in conventional filtration systems, may not be required in UF systems. In particular, optimized UF permeate water quality was found with reduced flocculation retention times (e.g. <10 minutes) and mixing intensities (e.g. < 100 s−1). The impact of intermittent air scour, or air sparging, operations in the UF process tank during operation was also evaluated. The use of air scour, tested as an intermittent operation at an applied velocity gradient of 50 s−1 was found to significantly reduce DOC concentrations and UV254 measurements in the UF permeate stream when compared with UF operations without air scour.

Application of ultrafiltration to improve the extraction of antibiotics

The production of antibiotics typically consists of fermentation, removal of biomass, solvent extraction, and crystallization. Vacuum rotary filtration or other conventional filtration systems and microfiltration are used to remove the biomass, but the biomass removal step fails to remove macromolecules including polysaccharides and proteins which may act as emulsifiers causing emulsion in the subsequent solvent extraction process, and reducing the process efficiency and product quality. In this work, an attempt was made to remove these “emulsifiers” before solvent extraction using ultrafiltration (UF). Bench and pilot scale spiral wound membrane modules with the MWCO of 5, 20 and 50 kDa were tested to treat benzylpenicillin (Pen G) broth following microbe removal. The UF permeates were subsequently fed to solvent extraction (acidic extraction at pH 2.0). The experimental results showed that UF could significantly improve the extraction operation in terms of phase separation, elimination of the need for any de-emulsifier or wet agent, and increase extraction recovery and product quality. Similar improvements from UF were observed in the extractions of erythromycin and medmycin (alkaline extraction at pH 10.0 and 8.7, respectively). The experimental results show that UF is an alternative to the use of de-emulsifier or other wet agent to obtain good phase separation even by gravity without centrifugal extractor in solvent extractions of Pen G, erythromycin and medmycin. The mechanisms of the improvement of extraction were discussed based on the experimental results on characterizing the feed and permeate solutions of UF. And it was concluded that there existed bioemulsifiers in antibiotic fermentation broth and UF could successfully remove them and hence could improve the extraction operation.

Innovative belt filter press takes the hard work out of sludge dewatering

Small to medium sized operations often produce wastewater with highly variable quality, which presents a number of problems to conventional filtration systems. V-Fold™, a redesigned belt filter press, on the other hand, offers continuous dewatering regardless of slurry flow rate or compostion, and with minimal operator intervention. Paul Day, founder of Dayco Pty Ltd, Australia, explains.

Avaliação da determinação da fibra em detergente neutro e da fibra em detergente ácido pelo sistema ANKOM

O objetivo do trabalho foi comparar os valores de fibra em detergente neutro (FDN) e os de fibra em detergente ácido (FDA) obtidos com o equipamento ANKOM e pelo método convencional (Van Soest). No primeiro ensaio foram analisados cinco materiais diferentes (cana-de-açúcar, capim-braquiária, silagem de milho, polpa cítrica e fezes bovina) e testados quatro tipos de saquinhos para filtragem de amostra. O delineamento experimental foi em blocos casualizados, em um fatorial 5x4 (cinco materiais diferentes e quatro tipos de saquinhos de filtragem), com três repetições. As médias obtidas foram comparadas àquelas obtidas com método convencional. No segundo ensaio procurou-se avaliar o efeito da quantidade de amostra por saquinho (0,5; 0,8 e 1,0 g) sobre os teores de FDN e FDA em três tipos de alimentos, utilizando o ANKOM. Neste ensaio, o delineamento experimental foi em blocos casualizados em esquema fatorial 3x3 (três alimentos x três quantidades), com três repetições. Os tipos de saquinhos de filtragem utilizados não influenciaram os teores de FDN nos diferentes alimentos, com exceção das fezes, cujos saquinhos de náilon resultaram em concentrações de FDN inferiores. Não houve diferença entre os valores de FDN e FDA, obtidos pelo equipamento ANKOM ou pelo convencional, para os alimentos estudados, com exceção da polpa cítrica, cujo valor médio de FDA pelo ANKOM foi inferior àquele obtido pelo método convencional. A quantidade não exerceu efeito sobre a concentração de FDN dos alimentos analisados no equipamento ANKOM.

A FEASIBILITY STUDY OF USING HEMATITE TO REMOVE DISSOLVED ORGANIC CARBON IN WATER TREATMENT

An experimental investigation of using hematite to remove natural organic substances from water was carried out. Hematite sols (iron oxide, α-Fe2O3) prepared in the laboratory were found to form flocs with natural organic substances. Jar tests revealed that when a 85 mg/L hematite concentration (as Fe) was used, natural organic substances in the form of fulvic acid (4 mg/L) were totally removed. Direct filtration experiments using hematite were effective in removing dissolved organic carbon (DOC) from water; however the large hematite-organic flocs clogged the filter and reduced the filter run. A conventional filtration system, which included flocculation and sedimentation prior to filtration, was found to be very effective at removing total DOC from water. An 86 mg/L hematite concentration (as Fe) was found to effectively remove 4 mg/L of fulvic acid from Milli-Q water. A residual iron concentration in the final effluent from the filtration unit was well below the allowable Australian drinking water guideline. Further research is warranted to optimize hematite concentration, pH, and ionic strength for application of this process in conventional water treatment plants.

An integrated approach to dissolved air flotation

DAFRapide techniques utilising reduced flocculation times, of the order of 5 minutes, together with flotation loading rates of up to 40 m/h, can be incorporated with conventional filtration systems operating at up to 20 m/h. Product quality of typically < 1 NTU and < 0.1 NTU after flotation and filtration respectively can be achieved.

Demonstration of a KIER-Type CYBAGFILTER system at the clinker calcination process

A high performance KIER-type CYBAGFILTER that combines a fabric filtration and centrifugal dust removal technology was developed to enhance the performance of conventional filtration systems. Based on the performance evaluation results obtained from a pilot-scale test and fluid dynamic computer simulation, a test CYBAGFILTER of 18,000 m3/hr capacity was installed in the clinker calcination process of Ssangyong Cement Co. located at Yongwol, Korea. Membrane filters for surface filtration were applied and evaluated. After 12-month operation, the mean pressure drop was maintained at 70–80 mmH2O, the collection efficiency was more than 99.8%, and the outlet dust concentration was less than 5 mg/Sm3. With an operating pressure drop of 100 mmH2O, the cleaning interval was much longer than that of conventional ones, promising the prolongation of filter life.

Filtration of machining Fluids by Microfiltration Membranes. 4th Report. Cross-Flow Microfiltration of Grinding Fluids Using Swirling Flows.

Recent developments in the precision grinding technology of advanced ceramics have been remarkable. However, ceramic swarf floating in grinding fluids causes scratches on the ground surface, deteriorating the surface finish. Ceramic swarf is extremely fine hard nomagnetic substance and this shape is relatively particulate with low specific gravity. Therefore, the removal of ceramic swarf by the conventional filtration system becomes very difficult. In this report, the experimental and theoretical analyses of the cross-flow microfiltration of grinding fluids were examined and the influence of swirling flow of suspension on the membrane permeation flux was clarified. A swirling flow type inlet was set on the front edge of a cross-flow microfiltration apparatus. Cross flow microfiitration of grinding fluids was carried out using a cellulose-type membrane for microfiltration, with a pore diameter of 1μm. The influences of Reynolds number, feed concentration on the membrane Permeation flux and the solute rejection, respectively were examined. A filtration model based on the lateral migration theory was applied to calculate the time-decline curve of the membrane Permeation flux. The calculated results agreed qualitatively with the experimental results and the adequacy of this model was confirmed.

Cross-Flow Filtration of Machining Fluids by Microfiltration Membranes : Influence of Chip Size on Permeation Flux

Recent developments in the precision grinding technology of advanced ceramics have been remarkable. However, ceramic chips floating in grinding fluids cause scratches on the surface being ground, deteriorating the surface finish. Ceramic chips are extremely hard, fine, nonmagnetic substances and their shape is relatively particulate with low specific gravity. Therefore, the removal of these chips by the conventional filtration system becomes very difficult. In this study, the experimental and theoretical analyses of the cross-flow microfiltration of grinding fluids were examined and the effect of the turbulence promoter on the permeation flux was clarified. The effects of the blockage ratio of the turbulence promoter and feed concentration on the permeation flux and solute rejection, respectively, were examined. A filtration model based on the lateral migration theory was proposed. The calculated results agree qualitatively with the experimental results and the adequacy of this model was confirmed.

The treatment of groundwater containing hydrogen sulfide using microfiltration

Conventional treatment of groundwater that contains gaseous hydrogen sulfide (H 2S) has normally utilized air stripping as a means to remove this undesirable contaminant. The use of this treatment technique has several disadvantages which include noxious off-gas discharge, high finished water turbidity levels, increased copper corrosion, and deposition of elemental sulfur in the distribution system. Conventional filtration processes have not been historically applied to treatment of this type of water because of the difficulty in coagulating elemental sulfur. Microfiltration can be used as part of a treatment approach to satisfy the filtration and turbidity removal requirements for this type of groundwater. Microporus membranes range from 0.1 to 1.0 micron in pore size and have a level of retention significantly higher than conventional filtration systems (10 to 100 times) [1]. The mechanism of particle retention using microfiltration is physical instead of a physio-chemical separation as with media filters and therefore, coagulation of the particles is not required. In addition to H 2S removal, typical air stripping processes do not remove disinfection by-product (DBP) precursors that may be in the groundwater. The use of a coagulant prior to the filter can be used to reduce DBP precursor material and further improve the finished water quality. Microfiltration has been evaluated for reducing H 2S from groundwater for the City of Oviedo, Florida. Chlorine oxidation followed by microfiltration successfully removed the H 2S by first oxidizing it to elemental sulfur and then removing by filtration. The advantages of this process include lower finished water turbidity levels to improve disinfection efficiencies, elimination of noxious off-gasses, and reduction of sulfur from entering and settling in the distribution system. In addition, a coagulant was added to evaluate to removal of DBP processors to maximize the benefits from providing particle removal with the microfiltration process.