Kinerja Filter Portabel Tepat Guna dalam Mereduksi Kekeruhan Air Banjir untuk Sanitasi atau MCK

During flood people had difficulties in obtaining clean water for sanitation (toilet). There was plenty of flood water but highly turbid. The water filter required electricity but its power outaged during flood. Filters usually used energy from electricity or gravity. This study evaluated the performance of a new handy-manually operated flood water portable filter. The standard of Permenkes No. 32/2017 was used as a reference. The flood water filter was pressurized by 0.025 kgf/cm2 and 0.051 kgf/cm2 and used local media: gravel, silica sand, anthracite, sponge. The results showed that pressure 0.025 kgf/cm2 was able to reduce turbidity from 220 NTU to 20.17 NTU with efficiency 90.83%. At 0.051 kgf/cm2 the filter was able to reduce turbidity from 220 NTU to 29.67 NTU with efficiency 86.52%. The pressure variation significantly affects the filtrate quality. The filter with pressure 0.025 kgf/cm2 could be applied for optimal filtration and produced 100-150 liters before clogging. This filter still needs to be studied related to physical strength, type and composition of media, portability and volume of water produced. This flood water filter will be an alternative solution for areas that often flood but no electricity or the power outage during flood.

Removal of antibiotic resistance genes in secondary effluent by slow filtration-NF process

In this study, the combined process of slow filtration and low pressure nanofiltration (NF) has been used to deeply remove the antibiotic resistance genes (ARGs) in a secondary effluent, and the mechanism of ARGs removal has been subsequently explored. It is observed that the optimal filtration rate for the slow filtration without biofilm, slow filtration with the aerobic heterotrophic biofilm, slow filtration with the nitrification biofilm and slow filtration with the denitrification biofilm to remove tet A, tet W, sul I, sul II and DOC is 20 cm/h, and the slow filtration with the aerobic heterotrophic biofilm exhibits the highest removal amount. The slow filtration with biofilms removes a high extent of free ARGs. As compared with the direct NF of the secondary effluent and the slow filtration without biofilm-NF, the slow filtration with the aerobic heterotrophic biofilm-NF combined process exhibits the best ARGs removal effect. The microbial population structure and the high filtration rate in the aerobic heterotrophic biofilmand promote the removal of ARGs. Strengthening the removal of 16S rDNA, intI 1 and DOC can improve the ARGs removal effect of the combined process. Overall, the slow filtration-NF combined process is a better process for removing ARGs.

On biological flow networks: Antagonism between hydrodynamic and metabolic stimuli as driver of topological transitions.

A plethora of computational models have been developed in recent decades to account for the morphogenesis of complex biological fluid networks, such as capillary beds. Contemporary adaptation models are based on optimization schemes where networks react and adapt toward given flow patterns. Doing so, a system reduces dissipation and network volume, thereby altering its final form. Yet, recent numeric studies on network morphogenesis, incorporating uptake of metabolites by the embedding tissue, have indicated the conventional approach to be insufficient. Here, we systematically study a hybrid-model which combines the network adaptation schemes intended to generate space-filling perfusion as well as optimal filtration of metabolites. As a result, we find hydrodynamic stimuli (wall-shear stress) and filtration based stimuli (uptake of metabolites) to be antagonistic as hydrodynamically optimized systems have suboptimal uptake qualities and vice versa. We show that a switch between different optimization regimes is typically accompanied with a complex transition between topologically redundant meshes and spanning trees. Depending on the metabolite demand and uptake capabilities of the adaptating networks, we are further able to demonstrate the existence of nullity re-entrant behavior and the development of compromised phenotypes such as dangling non-perfused vessels and bottlenecks.

External heat-exchange in a quasi-bidisperse granular fluidized bed

This paper presents the results of an experimental study of the external heat-exchange with a tube bundle in a bidisperse fluidized bed with marked bimodality of particle size distribution. The dependence of the maximum heat-transfer coefficient on the rate of air filtration was determined. The influence of the mass fraction of large particles on the heat-transfer coefficient in a mixture has been established. An interpolation dependence for calculating the optimal filtration rate of the investigated mixtures has been obtained. It is recommended to use the average surface diameter of the polydisperse particles mixture as the equivalent diameter when calculating the heat-exchange. A method for calculating the maximum heat-transfer coefficient and the optimal filtration rate for a quasi-bidisperse fluidized bed has been developed. The method is based on the use of heat transfer coefficients and optimal filtration rates of individual components of the bidisperse mixture. The equations for calculating the maximum heat-transfer coefficient and the optimal filtration rate in the bidisperse mixture has been obtained.

A Sew-Free Origami Mask for Improvised Respiratory Protection

Recently, respiratory aerosols with diameters smaller than 100 μm have been con- firmed as important vectors for the spread of SARS-CoV-2. While cloth masks afford some protection for larger ballistic droplets, they are typically inefficient at filtering these aerosols and require specialized fabrication devices to produce. We describe a fabrication technique that makes use of a folding procedure (origami) to transform a filtration material into a mask. These origami masks can be fabricated by non-experts at minimal cost and effort, provide adequate filtration efficiencies, and are easily scaled to different facial sizes. Using a mannequin fit test simulator, we demonstrate that these masks can provide optimal filtration efficiency and ease of breathing with minimal leak- age. Because this mask provides greater comfort compared to commercial alternatives, it is likely to promote greater mask wearing tolerance and acceptance.

Formation of Microfiltration Membranes from PMP/PIB Blends: Effect of PIB Molecular Weight on Membrane Properties

A series of microfiltration membranes were fabricated by the extraction of polyisobutylene (PIB) from its immiscible blends with polymethylpentene (PMP). Three PIB with different molecular weight of 7.5 × 104 (Oppanol B15), 34 × 104 (Oppanol B50) and 110 × 104 (Oppanol B100) g/mol, respectively, were used to evaluate the effect of molecular weight on the porous structure and transport properties of resulting PMP-based membranes. To mimic the conditions of 3D printing, the flat-sheet membranes were fabricated by means of melting of mixtures of various PMP and PIB concentrations through the hot rolls at 240 ∘ C followed by a quick cooling. The rheology study of individual components and blends at 240 ∘ C revealed that PIB B50 possessed the most close flow curve to the pure PMP, and their blends demonstrated the lowest viscosity comparing to the compositions made of PIB with other molecular weights (B15 or B100). SEM images of the cross-section PMP membranes after PIB extraction (PMP/PIB = 55/45) showed that the use of PIB B50 allowed obtaining the sponge-like porous structure, whereas the slit-shaped pores were found in the case of PIB B15 and PIB B100. Additionally, PMP/B50 blends demonstrated the optimum combinations of mechanical properties (str = 9.1 MPa, E = 0.20 GPa), adhesion to steel (adh = 0.8 kPa) and retention performance (R240 nm = 99%, R38 nm = 39%). The resulting membranes were non- or low-permeable for water if the concentration of PIB B50 in the initial blends was 40 wt.% or lower. The optimal filtration performance was observed in the case of PMP/B50 blends with a ratio of 55/45 (Pwater = 1.9 kg/m2hbar, R240 nm = 99%, R38 nm = 39%) and 50/50 (Pwater = 1100 kg/m2hbar, R240 nm = 91%, R38 nm = 36%).

Teknologi pengolahan air gambut menjadi air bersih dengan sistem koagulan dan filtrasi di Desa Buluh Cina, Kecamatan Siak Hulu, Kampar

The abundant peat water in Buluh Cina Village, Siak Hulu Subdistrict, Kampar is a natural potential that can be used for cooking and bathing purposes by processing peat water into clean water that is suitable for consumption. The purpose of this service activity is to treat peat water into clean water. The method used in this service activity is using coagulant and filtration technology. The optimal filtration and coagulant media used for peat water treatment consists of biosand filters with two media namely pumice and quartz sand. The dedication results reduce turbidity and color of peat water and reduce organic content, so that peat water is processed into clean drinking water. The lowest pH value before filtering is equal to 5.93 and the highest pH is found before filtering which is 6.23. This means that before filtering peat water is weak acidic. The lowest sample results after filtration with a slow sand filter that is equal to 6.42 and the highest pH after filtration of 7.5, which means that water is weakly basic. A good pH limit for water is 6.5 to 8.5 so this service proves that slow sand filters are considered effective enough to optimize water pH. Total dissolved solids (TDS) is one of the parameters for determining water quality, TDS shows the amount of solute solids in water. The result of peat water TDS is that the lowest TDS value before filtration is 46 mg / L and the highest TDS is found before filtering which is 49 mg/L. The lowest sample results after filtration with slow sand filter is 49 mg / L and the highest TDS after filtering is 83 mg/L.

Extraction from aqueous solutions ions of iron and lead by filter loading, created on the basis of steel melting slag

The aim of the present paper is investigation of removal of Fe3+ and Pb2+ ions from aqueous media by material on the basis of steel melting slag. It has been established that the process of water purification from Fe3+ and Pb2+ ions by this material proceeds by a mixed mechanism both due to the formation of slightly soluble silicates and also due to the formation of hydroxides. When the filtration rate varies from 2 to 10 column volumes per hour, the percentage of sorption remains within 91,5–99,8%. The most optimal filtration rate is 6 column volumes per hour. Material on the basis of steel melting slag absorbs of Fe (III) up to 5 mg-eq/g and Pb (II) 0.64–1.27 mg-eq/g.