Cartridge Filters Research Articles

Challenges in using 0.45 µm filters to assess potentially bioavailable trace elements in the dissolved fraction of river and peat bog waters of the Boreal Zone

Passing through a 0.45 µm filter can significantly alter the concentrations of dissolved trace elements (TEs) in organic-rich waters of the Boreal Zone. However, little evidence has been provided about the impacts of filtration on the size distribution of dissolved TEs. This limitation hinders our comprehension of how filtration affects the assessment of the potentially bioavailable forms of dissolved TEs (i.e. ions and small molecules). Using AF4-UV-ICP-MS, this study systematically investigates such artefacts and their influence on the concentrations of dissolved, primarily ionic, and colloid-associated TEs in river waters and peat bog waters of the Boreal Zone. In river waters (circumneutral pH), membrane filtration had a significant impact on TEs that are associated with inorganic colloids such as Al, Mn, Fe, As, the rare earth elements, Pb, and Th. Approximately 20–80 % of primarily ionic TEs (< 0.5 kDa) and 100 % of large inorganic (ca. 40–300 nm) TEs were excluded from the filtrates under clogged conditions. In contrast, little impact of filtration was observed for bog waters (pH 4). Similarly, cartridge filtration of river waters also led to a decrease in concentrations and size distributions of dissolved TEs. However, cartridge filtration demonstrated a higher efficiency in allowing the passage of ions and excluding colloids than membrane filtration. On average, the ratio of the dissolved concentrations between a cartridge and a membrane filtrate was 1.0 ± 0.2. For primarily ionic species, the average ratio was 1.4 ± 0.4, while for colloidal species, it was 0.4 ± 0.1. Therefore, despite having similar dissolved concentrations, filtration methods with the same nominal pore size can yield different concentrations of bioavailable forms of TEs. These findings may be important for studies of the environmental relevance of dissolved TEs in surface waters of the Boreal Zone, and organic-rich waters elsewhere.

Computational Fluid Dynamics Analysing of Preferential Flow in Gas Mask Filter Cartridge

In various hazardous locations, gas mask filters are essential to protect from airborne pollutants and harmful gases. However, under certain conditions, such as the weather or climate in some locations can affect gas mask filtration. Based on a previous study, the existing geometry of the gas mask filter cartridge unit been analyse for its preferential flow within the gas mask domain, which resulted in a significant pressure drop and heat concentration in the filter, affecting the filtration. However, another study suggested designing the main sieve passageway of the filter to help in resolving the pressure drop and create much well distribution of flow within the cartridge. In this study, three geometries with re-design of the main sieve passageway of the filter were made and simulated to determine the preferential flow using the computational fluid dynamics (CFD) method. Two filter concentrations (300 ppm, and 1000 ppm) and constant humidity ratios of at 80 % were simulated. The presence of the dead zone was examined using the computational fluid dynamics (CFD) method, which was controlled by the Navier-Stokes equation and continuity based on several flow parameters. Based on the result occupied can be concluded, the second geometry had a much better velocity contour distribution around 40% than the other geometry, maintaining the overall minimum velocity area even though the formation of the dead zone area for the second geometry was 10% higher at the lower part of the filter than for the third geometry. The abilities of the second geometry to perform well even in the presence of higher concentrations brought to the honeycomb-based design as the main sieve passageway actually improve the velocity distribution and then minimizing formation of “dead zone”. Concluding justified that the proposed geometry met the prediction of improving the pressure drop and create quite well distribution of flow in the filter. prediction of improving the pressure drop and create quite much well distribution of flow in the filter.

Effect of horizontal cartridges on the uniformity of flow field distribution inside a cartridge filter

Cartridge filters are widely utilized in industrial dust removal due to their advantages of high dust removal efficiency, compact size relative to bag filters, and the capacity to reuse collected dust. However, the conventional upright installation of the cartridges' front row directly faces the air inlet, which is directly impacted by the high-velocity dirt airflow and is often broken. This setup also disrupts airflow distribution, leading to uneven mass flow distribution and localized high velocity. To address these challenges, this study proposes horizontally installing the cartridges, by utilizing the bottom cone to buffer the airflow. This not only resolves issues of localized cartridge breakage but also promotes uniform airflow distribution, thereby prolonging filter service life. Computational Fluid Dynamics (CFD) is employed to simulate the changes in the flow field within the physical model, using finite element iterative calculations. This approach reduces experimental costs while providing precise data. Therefore, numerical simulation is used to verify the effectiveness of horizontal cartridges in improving the uniformity of the flow field distribution in the cartridge filter. The results showed that the horizontal cartridge filter improved the mass flow distribution uniformity by 54.9%, the peak velocity difference was reduced by 69.63%, and the maximum velocity was reduced by 68.42% compared to the upright cartridge filter. Horizontal cartridges have a more uniform flow field distribution, effectively avoiding problems such as abrasion and rupture of the filter media caused by excessive local air velocity.

Long-Term Monitoring of Microplastics in a German Municipal Wastewater Treatment Plant

Wastewater treatment plants (WWTPs) have been identified as important point sources for microplastics (MPs) in the environment; monitoring MP emissions in the WWTP effluent is therefore essential for contamination control. The aim of this study is to acquire a large number of samples (320) over a period of two years and three months to determine the temporal variations in microplastic contamination in the outlet of the municipal WWTP Landau-Mörlheim. The effluent of the third cleaning stage is sampled with a 10 µm filter cartridge, processed in the laboratory using a hydrogen peroxide treatment, and MPs are then detected by fluorescence staining. The results show high temporal variations in the microplastic concentrations in the effluent of the WWTP. This indicates that high numbers of samples are necessary to obtain a representative assessment of the microplastic emissions; single samples are not representative. The average microplastic concentration in the effluent was 27.8 ± 29.8 MP/L, ranging from 0.6 MP/L to 194.0 MP/L. This leads to a yearly emission of 1.5 × 1011 MP for the WWTP Landau-Mörlheim, corresponding to an emission of 2.8 × 106 MP/inhabitant and year. Statistically significant seasonal variations could not be observed, although there is a trend towards lower MP concentrations in summer. Further, no correlations with other wastewater or weather parameters could be found.

Application of Mill Scale Waste for Geoecological Protection of Aquatic Medium

The potential for use of mill scale (metallurgical production waste) as an affordable sorption-filtration material for aqueous medium protection from phosphates and heavy metals is considered. The results of X-ray phase studies of mill scale prototypes, as well as extraction of dissolved components from them into bidistilled water at long-term contact, which revealed insignificant emission of harmful substances indicating safety of the mill scale application as a sorbent, are given. It is proposed to use industrial cartridges (filter cartridges) loaded from rolled scale to purify large volumes of surface wastewater in real conditions.

Screening the Performance of a Reverse Osmosis Pilot-Scale Process That Treats Blended Feedwater Containing a Nanofiltration Concentrate and Brackish Groundwater.

A two-stage pilot plant study has been completed that evaluated the performance of a reverse osmosis (RO) membrane process for the treatment of feedwater that consisted of a blend of a nanofiltration (NF) concentrate and brackish groundwater. Membrane performance was assessed by monitoring the process operation, collecting water quality data, and documenting the blended feedwater's impact on fouling due to microbiological or organic means, plugging, and scaling, or their combination. Fluorescence and biological activity reaction tests were used to identify the types of organics and microorganisms present in the blended feedwater. Additionally, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to analyze suspended matter that collected on the surfaces of cartridge filters used in the pilot's pretreatment system. SEM and EDS were also used to evaluate solids collected on the surfaces of 0.45 µm silver filter pads after filtering known volumes of NF concentrate and RO feedwater blends. Water quality analyses confirmed that the blended feedwater contained little to no dissolved oxygen, and a significant amount of particulate matter was absent from the blended feedwater as defined by silt density index and turbidity measurements. However, water quality results suggested that the presence of sulfate, sulfide, iron, anaerobic bacteria, and humic acid organics likely contributed to the formation of pyrite observed on some of the membrane surfaces autopsied at the conclusion of pilot operations. It was determined that first-stage membrane productivity was impacted by the location of cartridge filter pretreatment; however, second-stage productivity was maintained with no observed flux decline during the entire pilot operation's timeline. Study results indicated that the operation of an RO process treating a blend of an NF concentrate and brackish groundwater could maintain a sustainable and productive operation that provided a practical minimum liquid discharge process operation for the NF concentrate, while the dilution of RO feedwater salinity would lower overall production costs.

Long-Term Performance Evaluation and Fouling Characterization of a Full-Scale Brackish Water Reverse Osmosis Desalination Plant

Water scarcity in Tunisia’s semi-arid regions necessitates advanced brackish water desalination solutions. This study evaluates the long-term performance and fouling characteristics of the largest brackish water reverse osmosis desalination plant in southern Tunisia over a period of 5026 days. The plant employs two-stage spiral-wound membrane elements to treat groundwater with a salinity of 3.2 g L−1. The pre-treatment process includes oxidation, sand filtration, and cartridge filtration, along with polyphosphonate antiscalant dosing. Membrane performance was assessed through the analysis of operational data, standardization of permeate flow (Qps) and salt passage (SPs), and the calculation of water (A), solute (B), and ionic (Bj) permeability coefficients. Over the operational period, there was an increase in operating pressure, pressure drop, and permeate conductivity, accompanied by a gradual increase in SPs as well as in the solute B and ionic Bj permeability coefficients. The average B increased by 82%, reflecting a decrease in solute rejection over time. Additionally, the ionic permeability coefficients for both SO42− and Cl− ions increased, with Cl− showing an 88% increase and SO42− showing an 87% increase. The produced water’s salinity increased by 67%, indicating a significant loss of membrane performance. To identify the cause of these problems, membrane characterization was analyzed using visual inspection, X-ray fluorescence (XRF), and Fourier transform infrared spectroscopy (FTIR). The characterization revealed the complex nature of the foulants, with a predominant presence of calcium sulfate, along with minor quantities of calcite, dolomite, and silica. The extent of CaSO4 deposition suggests poor antiscaling efficiency, highlighting the critical importance of selecting an effective antiscalant to mitigate membrane fouling.

Technical solution for purifying emissions of climate-active gases

The rising demand for food products and subsequent increase in agricultural production leads to heightened quantities of waste and by-products, particularly within the livestock industry. Traditional methods of livestock by-product disposal encompass intensive processing, including biodestruction processes. However, these processes tend to generate significant emissions of climate-active gases such as carbon dioxide, methane, nitrous oxide, and ammonia. To mitigate environmental impacts, it is proposed to integrate an advanced gas-air emission purification system into the existing livestock by-product processing lines. (Research purpose) The objective is to develop a system for purifying emissions of climate-active gases, particularly ammonia, produced during the intensive biotechnological processing of livestock by-products. (Materials and methods) Based on the properties of the primary pollutants, possible methods for their removal from emissions were determined. Such methods include dry, wet, condensation, and biological treatment. The biopurification method was selected for its efficacy and optimal performance. (Results and discussion) As a technical solution, a sequential gas-air emission purification process was developed using biofilters equipped with a polymer carrier and organic substrates as fillers. The system is equipped with digital sensors for monitoring and controlling the operational workflow. A special feature of the proposed system design is the use of replaceable filter cartridges and an active irrigation system. (Conclusions) The research helped to identify main types, parameters and methods for purifying emissions of climate-active gases with a focus on ammonia. Emission purification with a digital workflow control system is carried out sequentially in a shell-and-tube condenser and a biofilter. The specific cooling surface is 1.09∙10–3 square meters per 1 cubic meter, the specifi c refrigerant consumption is 0.7 liters per 1 cubic meter. Optimal biofilter performance was attained at the temperature of 30 degrees Celsius, with 45-55 percent humidity, active acidity of 8-8.4 units, and residence time of 15-30 seconds in the filter layer. These conditions ensure a high degree of ammonia purification and long-term biofilter operation.

A Standardized Treatment Model for Head Loss of Farmland Filters Based on Interaction Factors

A head loss model for pressureless mesh filters used in farmland irrigation was developed by integrating the four basic test factors: irrigation flow, filter cartridge speed, self-cleaning flow, and initial sand content. The model’s coefficient of determination was found to be 98.61%. Among the basic factors, the total irrigation flow accounted for only 17.20% of the relatively small self-cleaning flow. The contribution of initial sand content was found to be the smallest, with a coefficient of only 0.0166. Furthermore, the contribution rate of the flow term was significantly higher than that of the initial sand content, with a value of 159.73%. In terms of quadratic interaction, the difference between the interaction term of flushing flow and filter cartridge speed, and the interaction term of filter cartridge speed and self-cleaning flow was 38.42%. On the other hand, the difference within this level for the interaction term between initial sand content and filter cartridge speed, as well as the interaction term between irrigation flow and self-cleaning flow, was 2.82%. Finally, through joint optimization of the response surface and model, the optimal values for the irrigation flow rate, filter cartridge speed, self-cleaning flow rate, and initial sand content were determined to be 121.687 m3·h−1, 1.331 r·min−1, 19.980 m3·h−1, and 0.261 g·L−1; the measured minimum head loss was found to be 21.671 kPa. These research findings can serve as a reference for enhancing the design of farmland filters and optimizing irrigation systems.

The pressure drop of fibrous surface filters for gas Filtration: Modeling and experimental studies

Surface filters are extensively utilized for the control of particulate matter and air pollution, and predicting the pressure drop can offer theoretical guidance in the selection of operational parameters for fibrous surface filters. However, there is presently a dearth of efficient and user-friendly methods for predicting the pressure drop. This paper focuses on the accurate and convenient prediction of the pressure drop of fibrous surface filters for gas filtration. Firstly, an analytical model for pressure drop, including the blocked fiber layer and the dust cake, was developed by considering the characteristics of the filter media, dust properties, and loading conditions. The model was validated through laboratory experiments, and the relative error between the model values and experimental data remains within a 15% error. Furthermore, based on the model, the quantitative analysis of the relationship between the pressure drop of the fiber layer and the pressure drop of the dust cake, and the filtration parameter importance were conducted. The influence of filtration parameters on the pressure drop follows the order of filtration velocity, dust concentration, and dust particle size, which provides guidance for choosing the gas filtration operating conditions in the efficient and low-resistance operation of surface filters. Additionally, the model was validated through field test data collected with large-scale cartridge filters in bulk grain loading. The predicted values fit well with the field test results. Overall, this study provides a promising tool for predicting the pressure drop of fibrous surface filters.

STRATEGI PEMBERDAYAAN EKONOMI MELALUI INOVASI TEKNOLOGI AIR BERSIH: STUDI KASUS PENERAPAN REVERSE OSMOSIS DAN PERINTISAN BISNIS

The helplessness of coastal communities in processing salt and brackish water into drinking water is a great irony of modern society, in the midst of technological advances and the industrial era 4.0. The problem in the coastal areas of Sungai Kakap subdistrict, Kubu Raya district, is the lack of availability of clean water and the absence of clean water infrastructure. Peat groundwater in coastal deltas cannot support the use of groundwater sources due to high levels of acid and organic substances. This can trigger problems of poor community sanitation and cause the community's inability to optimize the potential of villages that have abundant natural resources. This activity aims to empower and increase community participation in designing and processing brackish/salt water into drinking water using Reverse Osmosis (RO) technology to meet the need for hygienic ready-to-drink water. Small scale water treatment system design using ultrafiltration (UF) and reverse osmosis (RO) membranes. The raw water used comes from river surface water in coastal areas. The small-scale water treatment design consists of two FRP tubes containing filter media, three filter cartridges, and UF and RO membranes. Two thrust pumps, with a minimum pressure specification of 40 m, are used to provide pressure that exceeds osmosis pressure so that raw water can be filtered through the RO membrane. The results of the activity show that the implementation of the RO system has succeeded in increasing the availability of clean water in Sungai Itik Village, which previously experienced challenges in providing adequate water supply. In addition, the integration of local business startups with RO technology opens up new opportunities for local residents to participate in the local economy and increase family income. Key factors supporting the success of this economic empowerment strategy were identified, including active community involvement in planning and implementation, collaboration between local government and local stakeholders, and adoption of new technologies and skills by local communities. This activity provides an important contribution in understanding the role of clean water technology innovation as a catalyst for local economic transformation in coastal areas. The practical implications of these findings can help decision makers in designing sustainable and effective policies to improve the welfare of coastal communities through sustainable economic empowerment. The use of this technology can help increase the availability of clean water in areas that previously experienced difficulties in this regard.

Development, confirmation, and application of a seeded Escherichia coli process control organism to validate Salmonella enterica serovar Typhi environmental surveillance methods.

Salmonella enterica serovar Typhi (S. Typhi) is the causative agent of Typhoid fever. Blood culture is the gold standard for clinical diagnosis, but this is often difficult to employ in resource limited settings. Environmental surveillance of waste-impacted waters is a promising supplement to clinical surveillance, however validating methods is challenging in regions where S. Typhi concentrations are low. To evaluate existing S. Typhi environmental surveillance methods, a novel process control organism (PCO) was created as a biosafe surrogate. Using a previous described qPCR assay, a modified PCR amplicon for the staG gene was cloned into E. coli. We developed a target region that was recognized by the Typhoid primers in addition to a non-coding internal probe sequence. A multiplex qPCR reaction was developed that differentiates between the typhoid and control targets, with no cross-reactivity or inhibition of the two probes. The PCO was shown to mimic S. Typhi in lab-based experiments with concentration methods using primary wastewater: filter cartridge, recirculating Moore swabs, membrane filtration, and differential centrifugation. Across all methods, the PCO seeded at 10 CFU/mL and 100 CFU/mL was detected in 100% of replicates. The PCO is detected at similar quantification cycle (Cq) values across all methods at 10 CFU/mL (Average = 32.4, STDEV = 1.62). The PCO was also seeded into wastewater at collection sites in Vellore (India) and Blantyre (Malawi) where S. Typhi is endemic. All methods tested in both countries were positive for the seeded PCO. The PCO is an effective way to validate performance of environmental surveillance methods targeting S. Typhi in surface water.

Ultrafiltration of anaerobically digested sludge centrate as key process for a further nitrogen recovery process

In a wastewater treatment plant, the centrate generated in the dehydration process of the anaerobically digested sludge has a high potential for nutrients recovery because of its high nutrients concentration (specifically nitrogen and phosphorous). However, the high organic matter and solids content may make difficult its management. Membrane fouling is the most significant challenge limiting the application of membrane techniques for wastewater treatment. Results in this article highlight the potential of conventional filtration followed by ultrafiltration as pretreatment for further nutrients recovery using emerging membrane technologies (as membrane contactor, membrane distillation or forward osmosis). Thus, a conventional filtration (with 1, 5 and 60 μm filters) followed by an ultrafiltration process were tested. The UF membranes studied were two PES membranes (5 kDa and 0.01 μm) and one PVDF membranes (100 kDa). Results demonstrated that a conventional filtration with a cartridge filter of 60 μm and a subsequent UF process with a 0.01 μm RAY100 membrane (Orelis, France) achieved the best results in terms of the maximum organic matter (66% COD removal) and solids (over 97% suspended solids removal) separation, hardly varying nutrients concentration (13% NH4+ removal). Concerning membrane fouling, FESEM-EDX confirmed salt precipitation on the membrane surface, which has to be controlled to avoid loss of performance.

Research on Online Monitoring Technology and Filtration Process of Inclusions in Aluminum Melt.

Online monitoring and real-time feedback on inclusions in molten metal are essential for metal quality control. However, existing methods for detecting aluminum melt inclusions face challenges, including interference, prolonged processing times, and latency. This paper presents the design and development of an online monitoring system for molten metal inclusions. Initially, the system facilitates real-time adjustment of signal acquisition parameters through a multiplexer. Subsequently, it employs a detection algorithm capable of swiftly extracting pulse peaks, with this task integrated into our proprietary host computer software to ensure timely detection and data visualization. Ultimately, we developed a monitoring device integrated with this online monitoring system, enabling the online monitoring of the aluminum alloy filtration process. Our findings indicate that the system can accurately measure the size and concentration of inclusions during the filtration process in real time, offering enhanced detection speed and stability compared to the industrial LiMCA CM (liquid metal cleanliness analyzer continuous monitoring) standard. Furthermore, our evaluation of the filtration process demonstrates that the effectiveness of filtration significantly improves with the increase in inclusion sizes, and the synergistic effect of combining CFF (ceramic foam filter) and MCF (metallics cartridge filter) filtration methods exceeds the performance of the CFF method alone. This system thus provides valuable technical support for optimizing filtration processes and controlling inclusion quality.

Research and application of bag filter system for railway ballast bed coal suction vehicles: An optimization and application study.

The current bag filter system used by railway ballast bed coal suction vehicles for cleaning coal dust from railway tunnels has low operational efficiency and generates significant volumes of dust. This paper describes a simulation test unit designed to enhance the dust removal performance in railway tunnels. The flow field inside the simulation test unit is investigated under different operating conditions through numerical simulations, and the variations in air volume and working resistance, total dust collection efficiency, and optimal operating parameters of a pulse cleaning system are identified through a series of experiments. The numerical results show that the pulse cleaning system does not significantly affect the uniformity of the flow field distribution at the bottom of the filter cartridge during the process of operation. The experimental research indicates that the simulation test unit satisfies the design requirements, achieving an average total dust removal efficiency of 99.93%. A field application shows that the total dust mass concentration at the operator position can be reduced from 335.8 mg∙m-3 to 4.2 mg∙m-3, effectively improving the operating environment within the tunnel.

The relationship between the resistance characteristics and structural parameters of the elongated filter cartridge in the dust collector

Due to the advantages of a large filtration area, elongated filter cartridges are gradually replacing filter bags in dust collectors. However, the production standards for these filter cartridges lack clarity in determining various parameters. Therefore, this paper combines experimental validation with computational fluid dynamics simulations to analyze the resistance characteristics of elongated filter cartridges, aiming to establish recommended parameter combinations for their optimal design. Single factor analysis and Response Surface Methodology (RSM) are employed for parameter optimization. The study establishes a quadratic regression model to predict resistance based on various filter cartridge parameters. Single factor analysis indicates that the optimal combination of length and pleat number is approximately diagonally distributed. The RSM ranks the factors' impacts on resistance as follows: length (L) > pleat number (N) ≈ pleat length (Pl) > filtering velocity (vf) > outer radius (R). The optimal parameter combination under global optimization is: N = 43, Pl=23 mm, R = 76 mm, L = 2 m. Additionally, the study analyzes the distribution of normal and tangential velocities of airflow on the filter medium surface to understand their impact on filter lifespan. Results indicate that tangential velocity has a significant impact on filter wear, and locations with higher tangential velocity are situated in the bottom region of the fold at the outlet.

The influence of nozzle height on the cleaning performance of inner cone double-layer filter cartridges with different cone radius through the distributional characterization of peak static pressure

The inner cone double-layer filter cartridges have the capability to guide the flow, which can optimize the airflow distribution inside the cartridge and reduce the cartridge's incomplete cleaning. However, the selection of different cone radius and nozzle heights can affect the cartridge's cleaning performance. More thorough investigations of the static pressure distribution properties within double-layer cartridges are required to improve their design and optimization. The results show that double-layer cartridges' peak static pressure at different nozzle heights has a similar distribution law. Peak static pressure increases progressively with cartridge height in the middle and lower sections (OM3-OM5, IM2-IM5), with the lower section having a larger peak static pressure. The cleaning performance of cartridges with a cone radius of R ≥ 80 mm is little impacted by the nozzle height. The stability of the cartridge's cleaning performance improves and then deteriorates as the cone radius increases, with the best cleaning effect and stability reached at R = 80 mm. In practical applications, double-layer filter cartridges with larger cone radius should be considered.

The effect of pleat ratio on the effective filtration area of the large-diameter pleated filter cartridge

To solve the problem of point source dust in industrial production, we employed a large-diameter pleated filter cartridge (fold ratio α values of 1.23, 1.47, 1.7, and 1.8). However, its complex pleated structure affects the stable operation state of the dust collector. The experimental results show that with the gradual increase of the fold ratio of the filter, the filter cleaning efficiency ε increases at first and then decreases, and an α value of 1.47 shows the best results. The average effective filtration area Ae ¯ increases with increasing fold ratio over the same run time. The higher the dust concentration, the lower is the Ae ¯ ; the ratio of the average effective filtration area to the theoretical filtration area β ¯ decreased from 80.2% (α = 1.8) and 80% (α = 1.47) to 77% (α = 1.7).

Amino acids profile of Two Chinese nuts (Juglans sigillata and Castanea mollissima ) in local markets of Kurdistan region/Iraq using HPLC

Aim: current study was aimed to study the amino acid contents of two Chinese nuts, walnuts (Juglans sigillata Dode.) and chestnuts (Castanea mollissima Blume.) from the local market of the Kurdistan region / Iraq. Methodology: Walnut fruits (Juglans sigillata) and chestnut fruits (Castanea mollissima) were collected from local market in the Kurdistan region / Iraq, samples were collected, dried and ground. one milgram of each sample was weighed, then dissolved in 10 ml High Performance Liquid Chromatography (HPLC) methanol, the sample was shaken and agitated in an ultrasonic bath for 10 minutes , then concentrated by evaporating the solvent with a stream of liquid N2 until it reached 1 ml, filtrated the liquid sample on deposable sep-pak cartridge filter ( supleco Co, Ltd),then 20 ml were injected on HPLC column . Results: firstly current study can identified thirteen amino acids from chestnuts but there are only eight amino acids were identified from walnuts. Secondly, there are big different between them in the percentage of amino acids where valine is appear in the highest percentage which record 69.43 %, while it recorded 6.32% in chestnut fruit , While threonine showed the highest percentage in chestnuts arrived to 54.09% compared to only 3.72% in walnuts fruits.

Analysis of the dust cleaning performance of a branch-type nozzle.

To solve the problem of uneven dust cleaning in filter cartridges, a simple and easy-to-install "branch-type" nozzle structure was designed to improve cleaning efficiency. In this study, numerical simulations, range analysis methods, orthogonal experimental design, back-blowing experiments, and powder cleaning experiments were conducted. By choosing the back-blowing uniformity as the evaluation index for cleaning performance, with the flow distribution coefficient A, length of branch pipe B, and outlet diameter of main pipe C as the factors, and ignoring the interaction between factors, an orthogonal experiment was designed to simulate the fluid flow field of nine different nozzle structures installed in the back-blowing model. The results were analyzed using range analysis methods, and the optimal nozzle structure parameter combination was determined to be A = 50%/40%/10%, B = 70 mm, and C = 18 mm. Based on the back-blowing experiment, the accuracy of the simulation results was verified, and the back-blowing uniformity was improved by 50.12%. In the powder cleaning experiment, a new method of measuring the mass of dust shaken off by a single pulse of cleaning to calculate the residual dust on the filter cartridge, rather than removing the filter cartridge and weighing it, was found to reduce experimental errors and make the conclusions more solid and convincing. The results showed that the "branch-type" nozzle increases the cleaning efficiency by 37.6% compared with no nozzle installed, proving that the "branch-type" nozzle can reduce the number of reverse cleaning required and extend the cleaning interval, thus optimizing the cleaning performance of the dust collector.