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The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. This research used a customized laboratory setup to compare the filtration performance and fouling buildup during microfiltration with polymeric membranes of skim milk using 2 diafiltration media: ultrafiltration permeate and ultrapure water. Two filtration modes were evaluated: in stage 1, the diafiltration media was added in a 1:1 ratio, with the collection of permeate continuing until the initial protein concentration was restored. In stage 2, retentates and permeates were recycled to simulate fouling accumulation in a steady-state without altering the retentate composition. Utilizing water as the diafiltration medium resulted in higher flux and lower resistance values compared with using ultrafiltration permeate, irrespective of the filtration mode. The concentration had a significant effect on membrane resistance, with no noticeable time-dependent effect on fouling layer development after 60 min of filtration when the retentate composition remained constant. The protein composition of the permeate and extracted foulants were comparable between the 2 media, with caseins predominating in the fouling layer. [ABSTRACT FROM AUTHOR]

A polymeric ultrafiltration (UF) membrane was used for stormwater treatment, with the focus on evaluating the increase in the membrane process productivity by adding pulsatile fluid flow to UF membrane treatment. Sedimentation and sieving were used as pre-treatment. The result showed that increasing the pulse frequency from 0 to 4 Hz increased productivity from −6.6 to 82 LMH. UF membrane removed suspended solids, oil and turbidity below detection limit. The UF membrane also separated total coliforms, E. coli and P. aeruginosa below detection limit. Total organic carbon (TOC) was reduced by between 81%, in average. In addition, the UF membrane was able to reduce BOD7 and COD to below 7 mg/L in the permeate. According to the US EPA, WHO, and national regulations in Canada, Japan, and South Korea, treated stormwater can be used for flushing toilets and streets irrigation and agricultural use. [ABSTRACT FROM AUTHOR]

The depth culture influence (4, 8, and 16 m) and periods (upwelling and non-upwelling) on growth and survival of the pearl oyster Pinctada imbricata during 10 months in the southeastern Caribbean Sea (Cariaco Gulf) were evaluated. Monthly records were taken of survival, body growth, and fouling organisms of the pearl oyster, as well as weekly samples of the temperature, chlorophyll a, and seston of the water culture site. Monthly survival was above 92% at all depths. The variation in shell size and tissue mass of the oysters cultivated in the different depths showed a similar pattern, with slow growth during the non-upwelling period (June–October) and progressive growth during the upwelling period (November–April). The multivariate analysis showed that oyster growth was associated with the phytoplankton biomass at different depths, particularly during the upwelling period. Oysters at 4 m showed the greatest increases in all growth parameters, exceeding the minimum commercial size (50 mm) in 7 months. Hence, it is recommended that the culture of P. imbricata in the Gulf of Cariaco be started right before the upwelling season to take advantage of the high amount of food available during this period. It is also recommended that the suspended culture should not exceed 8 m for higher growth performance. [ABSTRACT FROM AUTHOR]

• Chlorella proteinosa was cultivated in an MPBR for secondary effluents treatment. • Highest TN removal rate of 23.8 mg/L/day was achieved at a lowest HRT of 8 hr. • Highest microalgae biomass productivity reached 20.2 mg/L/day at the HRT of 8 hr. • Bacterial nitrogen respiration was reduced by 95.5 % from an HRT of 24 hr to 8 hr. Further treatment of secondary effluents before their discharge into the receiving water bodies could alleviate water eutrophication. In this study, the Chlorella proteinosa was cultured in a membrane photobioreactor to further remove nitrogen from the secondary effluents. The effect of hydraulic retention time (HRT) on microalgae biomass yields and nutrient removal was studied. The results showed that soluble algal products concentration reduced in the suspension at low HRT, thereby alleviating microalgal growth inhibition. In addition, the lower HRT reduced the nitrogen limitation for Chlorella proteinosa 's growth through the phase-out of nitrogen-related functional bacteria. As a result, the productivity for Chlorella proteinosa increased from 6.12 mg/L/day at an HRT of 24 hr to 20.18 mg/L/day at an HRT of 8 hr. The highest removal rates of 19.7 mg/L/day, 23.8 mg/L/day, and 105.4 mg/L/day were achieved at an HRT of 8 hr for total nitrogen (TN), ammonia, and chemical oxygen demand (COD), respectively. However, in terms of removal rate, TN and COD were the largest when HRT is 24 hr, which were 74.5% and 82.6% respectively. The maximum removal rate of ammonia nitrogen was 99.2% when HRT was 8 hr. [Display omitted] [ABSTRACT FROM AUTHOR]

• High pH favored to form large and loose flocs for both coagulants though Al 13 flocs were more stable. • Large and loose flocs led to more porous cake and further generated lower reversible fouling. • In all pH conditions, Al 13 had higher HA removal than PACl due to higher removal of HA with lower MW. • Al 13 had low membrane fouling at acid pH and PACl favored to reduce membrane fouling at alkaline pH. Membrane fouling is a bottleneck issue that hindered the further application of ultrafiltration technology. To alleviate membrane fouling, coagulation-ultrafiltration (C-UF) process using polyaluminum chloride (PACl) and PACl-Al 13 with high proportion of Al 13 O 4 (OH) 24 7+ as coagulants, respectively, were investigated at various pH conditions. Results indicated that an increase in solution pH contributed to larger floc size and looser floc structure for both PACl and PACl-Al 13. It was conducive to the formation of more porous cake, as evidenced by mean pore area and pore area distribution of cake, leading to lower reversible fouling. Furthermore, humic acid (HA) removal presented a trend of first increasing and then decreasing with the increase of pH. The optimal HA removal was achieved at pH 6 regardless of coagulant type, suggesting that the slightest irreversible fouling should be occurred at this point. Interestingly, the irreversible fouling with PACl coagulant achieved a minimum value at pH 9, while the minimal irreversible fouling with PACl-Al 13 was observed at pH 6. We speculated that the cake formed by PACl could further intercept HA prior to UF process at alkaline pH. Furthermore, compared with PACl, PACl-Al 13 had a stronger charge neutralization ability, thus contributing to more compact floc structure and higher HA removal at various pH conditions. By UF fractionation measurement, higher HA removal for PACl-Al 13 was due to higher removal of HA with molecular weight less than 50 kDa. [Display omitted] [ABSTRACT FROM AUTHOR]

The objective of this study is to develop the easy-to-clean and fouling resistant polylactic acid (PLA) ultrafiltration membranes made of stimuli-responsive materials. Here, N-isopropyl acrylamide (NIPAM) was polymerized on montmorillonite (MMT) to create a thermosensitive MPNI nanocomposite. FTIR, XRD, TGA, SEM, TEM and DLS results confirmed the successful polymerization of NIPAM on MMT. Thermosensitive ultrafiltration PLA membranes were fabricated by incorporating varying amounts of MPNI, ranging from 0.0 to 1.0 wt%. The modified membranes exhibited improved water uptake, porosity, mechanical strength, hydrophilicity, and pure water flux by incorporating MPNI. Furthermore, they demonstrated decreased hydrophilicity and water uptake in response to changes in water temperature. During humic acid (HA) filtration with a 10 ppm concentration, PLA-MPNI-0.75 membrane showed higher water flux (93 L. m2. h− 1) and better HA rejection (75%) compared to neat PLA. Moreover, employing a thermosensitive cleaning method, particularly by-passing warm water (above the lower critical solution temperature (LCST) of NIPAM through the membrane, resulted in improved in flux recovery ratio (FRR) for the PLA-MPNI membranes, while PLA was regenerated at around 40%. [ABSTRACT FROM AUTHOR]

An investigation aimed at recording NIS settlement by the employment of a bare artificial substratum constituted by caged lightweight expanded clay (EC) has been carried out in a confined marine basin. Packaged substratum, submitted to different organic treatments and a control was positioned in spring both in the water column and into the bottom sediment. Two months experiment provided 17 non-indigenous (NIS) versus 154 indigenous species (IS). Eleven "slow" colonizing NIS occurred at mean density of 0.2 ± 0.08 ind. L−1, whereas six species of "fast" colonizing NIS reached a mean density of 34.5 ± 13.0 ind. L−1 (individual organisms) and a coverage of 37.1 ± 31.6 cm2 L−1 (modular organisms). PCoA plots ordered assemblages according to time (from 48% up to 75% total variation) and to organic treatment (about 22%) both for individual and modular organisms. In general, organic contamination exerted negative effect both on NIS and IS, and the reference condition was preferred. Among individual NIS, the best colonizer in terms of density and biomass was primarily the sphaeromatid Paracerceis sculpta for both sediment-buried (64.78 ind-cm2 L−1 and 217.43 mg L−1) and suspended artificial substratum (143.94 ind-cm2 L−1 and 483.14 mg L−1). The amphinomid Linopherus canariensis prevailed in the buried artificial substratum (52.27 ind-cm2 L−1 and 92.81 mg L−1 respectively). Sessile and modular NIS appeared more susceptible to the initial organic contamination and the artificial substratum suspended into the water column was more suitable for these colonizers. Celleporaria brunnea (79.74 ind-cm2 L−1), Paraleucilla magna (66.69 ind-cm2 L−1), Hydroides elegans (12.49 ind-cm2 L−1) prevailed in the mean surface coverage among other NIS and IS species. The organic enrichment reduced to four up to five times the colonization rate of the first two species. Experimental data showed the great competitive capacity of NIS in the early stages of fouling, both under control and organically-enriched conditions, although this type of disturbance affected the whole fouling assemblage. [ABSTRACT FROM AUTHOR]

Integrating biocidal nanoparticles (NPs) into polyamide (PA) membranes shows promise for enhancing resistance to biofouling. Incorporating techniques can tailor thin‐film nanocomposite (TFN) membranes for specific water purification applications. In this study, silver‐based metal–organic framework Ag‐MOFs (using silver nitrate and 1,3,5‐benzentricarboxylic acid as precursors) are incorporated into PA membranes via three different methods: i) incorporation, ii) dip‐coating, and iii) in situ ultrasonic techniques. The characterizations, such as top‐surface and cross‐section scanning and transmission microscopy, reveal that the incorporation methods for the modified TFN membranes substantially control morphology and surface characteristics. For example, the in situ ultrasonically interlayered Ag‐MOFs showed the largest pores (average pore diameter of 14 Å ± 0.1), resulting in the highest water permeance (water flux of 10.9 LMH/bar for Na2SO4). It also show superior antifouling and anti‐biofouling performance, with a flux recovery ratio (FRR) of 94.1% in both fouling tests due to its improved surface hydrophilicity and the antibacterial properties of incorporated Ag‐MOFs. Conversely, the surface‐grafted dip‐coated Ag‐MOFs offered the highest salt rejection, attributed to its highly negatively charged surface and a dense PA network with narrow pores (average pore diameter of 10 Å ± 0.06). [ABSTRACT FROM AUTHOR]

Phosphorus-based additives are recognized as an effective strategy for alleviating slagging during Zhundong coal combustion. However, their efficacy to mitigate fouling issues caused by the substantial sodium release is constrained. In this work, ball-milled ash was combined with ammonium dihydrogen Phosphate (NH4H2PO4) to jointly address the challenges of fouling and slagging. The sodium release behavior, ash fusion temperatures (AFTs), and combustion characteristics were comprehensively investigated by using simultaneous thermal analyzer and other characterizing methods. The findings show that ball-milled ash, owing to its high reactivity, substantially enhanced the sodium retention percentage. The sodium retention mechanism of ball-milled ash is mainly attributed to solid–solid reactions, whereas NH4H2PO4 primarily serves to increase AFTs through gas–gas and gas–solid reactions. The highly reactive components within ball-milled ash also facilitate the reactions with NH4H2PO4 to form high melting-point phosphorus-based minerals. In terms of combustion characteristics, the inclusion of ball-milled ash leads to a noteworthy reduction in the burnout temperature, while the addition of NH4H2PO4 contributes to a moderate increase in the burnout index. Taking into account the three aspects of sodium release, AFTs, and combustion characteristics, the optimal combination strategy is the mass addition ratio of 0.05 for ball-milled ash and the PO43−/Na molar ratio of 1.0 for NH4H2PO4. [ABSTRACT FROM AUTHOR]

This research explores the enhancement of polyethersulfone (PES) membranes through the incorporation of chitosan derived from the lignicolous fungus Ganoderma sp. Utilizing wet phase inversion and solution casting techniques, chitosan was successfully integrated into the PES matrix, as confirmed by Fourier Transform Infrared Spectroscopy (FT-IR), which indicated a high deacetylation degree of 75.7%. The incorporation of chitosan significantly increased the membrane hydrophilicity, as evidenced by a reduction in the water contact angle and a substantial improvement in pure water permeability, from 17.9 L m-2 h-1 bar-1 to 27.3 L m-2 h-1 bar-1. The membrane anti-fouling properties were also notably enhanced, with the Flux Recovery Ratio (FRR) increasing from approximately 60–80%. Moreover, the chitosan-modified PES/CS membrane, particularly at a 5% chitosan concentration, demonstrated exceptional efficacy in pollutant removal, achieving over 90% elimination of total suspended solids, cadmium (Cd), and lead (Pb), alongside a 79% reduction in color during the treatment of textile wastewater. [ABSTRACT FROM AUTHOR]

Biocatalytic membranes have great potential in various industrial sectors, with the immobilization of enzymes being a crucial stage. Immobilizing enzymes through covalent bonds is a complex and time-consuming process for large-scale applications. Polydopamine (PDA) offers a more sustainable and eco-friendly alternative for enzyme immobilization. Therefore, surface modification with polydopamine as mussel-inspired antifouling coatings has increased resistance to fouling. In this study, α-amylase enzyme was covalently bound to a bioactive PDA-coated polyethersulfone (PES) membrane surface using cyanuric chloride as a linker. The optimal activity of α-amylase enzyme immobilized on PES/PDA membrane was obtained at temperature and pH of 55°C and 6.5, respectively. The immobilized enzyme can be reused up to five reaction cycles with 55 % retention of initial activity. Besides, it maintained 60 % of its activity after being stored for five weeks at 4°C. Additionally, the immobilized enzyme demonstrated increased Michaelis constant and maximum velocity values during starch hydrolysis. The results of the biofouling experiment of various membranes in a dead-end cell demonstrated that the PES membrane's water flux increased from 6722.7 Lmh to 7560.2 Lmh after PDA modification. Although α-amylase immobilization reduced the flux to 7458.5 Lmh due to enhanced hydrophilicity, compared to unmodified membrane. The findings of this study demonstrated that the membrane produced through co-deposition exhibited superior hydrophilicity, enhanced coating stability, and strong antifouling properties, positioning it as a promising candidate for industrial applications. [Display omitted] • α-Amylase was covalently immobilized onto polydopamine-functionalized polyethersulfone membrane. • Surface modification with polydopamine generated a mussel-inspired coating to inhibit fouling. • The immobilization technique effectively preserved the activity of α-amylase enzyme. • The biocatalyst membrane exhibited superior stability and strong antifouling properties. [ABSTRACT FROM AUTHOR]

This study examines the polyvinylidene fluoride (PVDF) ultrafiltration membrane impregnated with the copper acetate monohydrate/nickel chloride/thiourea (CuNit) nanoparticle through its physical properties, chemical properties, water flux, humic rejection, and antifouling properties against peat water. The ultrafiltration membrane was fabricated via phase inversion by blending CuNit nanoparticles (1, 3, and 5 wt/wt PVDF %) and PVDF (16 wt %) in N‐Methyl‐2‐pyrrolidone (NMP, 42 wt %) as the solvent. The humic rejection and fouling test are conducted using peat water collected from the Beladin water treatment plant. As a result, M03, which has 1 wt/wt PVDF % of CuNit nanoparticle, gives a better result of pure water flux, humic rejection, and fouling recovery rate with a value of 82 L/m2 h, 93 %, and 40 % compared to pristine PVDF membrane. The fouling of M03 recorded a low total rate of fouling (76 %) that is caused by high reversible fouling and low irreversible fouling with a value of 0.16 and 0.59, respectively, compared to the pristine PVDF membrane. In conclusion, due to the agglomeration that occurs in the further addition of CuNit nanoparticles, coating or encapsulation must be done to improve the stability of nanoparticles and reduce the leach‐out problem as well as provide a good distribution between the nanoparticle and casting solution during the membrane fabrication. [ABSTRACT FROM AUTHOR]

Submarines and other underwater vessels are widely employed in the naval sector for defense purposes as well as in the civilian realm for scientifi c and recreational purposes. However, challenges such as biofouling caused by bacteria and algae can signifi cantly impact performance and environmental eff ects. This study investigated the impact of biofouling on the U209 submarine by analysing how the location of roughness aff ects drag, with particular emphasis on frictional drag. Computational Fluid Dynamics (CFD) was employed to assess the impact of biofouling on the turbulent fl ow characteristics of ship hull surfaces with varying roughness, operating within the range of velocity = 9.7 knot – 29.1 knot. The submarine analysis was conducted under complete submersion without any water disturbance. The increase in drag resulted from the variation in the surface of the submarine hull. The drag increased from 8.5% to 18.2% for partial hull roughness and from 30.5% to 46.9% for overall roughness. The entire surface irregularity of the hull led to a signifi cant increase in the drag. This can be explained by the results that as the surface area aff ected by biofouling increases, the amount of turbulent fl ow around the hull also increases, resulting in greater resistance, particularly in terms of frictional drag. [ABSTRACT FROM AUTHOR]

The increasing environmental concerns of conventional antifouling coatings have led to the exploration of novel and sustainable solutions to address the biofouling caused by Limnoperna fortunei. As a rapidly expanding invasive species, the fouling process of Limnoperna fortunei is closely associated with microbial fouling, posing significant threats to the integrity of aquatic infrastructure and biodiversity. This review discusses recent progress in the development of non-toxic, eco-friendly antifouling coatings that are designed to effectively resist biofouling without using toxic chemicals. Recent research has focused on developing novel non-toxic coatings that integrate natural bioactive components with advanced material technologies. These formulations not only meet current environmental standards and exhibit minimal ecological impact, but also possess significant potential in preventing the attachment, growth, and reproduction of Limnoperna fortunei. This review aims to provide scientific guidance by proposing effective and sustainable solutions to address the ecological challenges presented by Limnoperna fortunei. The insights gained from current research not only reveal novel antifouling methods, but also identify key areas for further investigation aimed at enhancing performance and environmental compatibility. [ABSTRACT FROM AUTHOR]

Fouling, the accumulation of undesirable material on manufacturing equipment surfaces, poses a pervasive challenge in industrial processes. In the food industry, the complex interactions among these compounds can give rise to stubborn deposits that deviate from conventional cleaning protocols. In this work, the forces and removal mechanisms of model fouling agents composed of mixtures of starch, whey protein, and lard deposited on solid surfaces of relevant industrial interest (i.e. stainless steel, aluminium, and PTFE) are investigated using a multi-length scale approach, involving milli-manipulation and a lab-simulated Clean-In-Place (CIP) system. The forces involved in the removal process, the types of failure observed when the deposits are subjected to shear stress (adhesive, mixed, or cohesive), and the performance of the CIP system are systematically analysed as a function of the cleaning treatments applied. For stainless steel surfaces, alkaline treatment seems to facilitate the cleaning of lard and starch deposits, while the whey foulant removal tends to be more effective using hot water under the conditions tested. Hot water is effective for stainless steel and PTFE surfaces, reducing the mechanical shear stress required, while the alkaline treatment demonstrated superior efficacy for aluminium surfaces. These findings emphasise the importance of customising cleaning protocols for CIP optimisation. [ABSTRACT FROM AUTHOR]

This study investigated the potential impact of salinity levels on the treatment performance and membrane fouling of MBR seeded with sludge from saline industrial effluent treatment plants. A pilot-scale MBR received mixed saline industrial effluents at an organic loading rate (OLR) of 1.3 g COD/L·d and a feed-to-micro-organism (F/M) ratio of 0.33 g COD/g TSS. The effects of the variable salt concentrations of 5, 10, 20, and 25 g/L were investigated. The ranges of ammonia and total nitrogen (TN) concentrations were 22.2–26.3 mgN/L and 55.1–59.2 mgN/L, respectively. The MBR achieved promising results for chemical oxygen demand (COD) and biochemical oxygen demand (BOD), with removal ranges of 95.4–97.2% and 98.3–98.8%, respectively. The system provides 93.2–96.7% and 81.6–92.5% for ammonia and TN removal. Up to a 20 g/L salinity level, there were no significant effects on treatment performance, but 25 g/L significantly declined daily and specific COD removal load. Despite this, residual values at 25 g/L were better and met the Saudi standard for effluent discharge. This is due to membrane fouling which declined the flux rate with a spontaneous reduction of OLR and F/M ratio. The MBR system inoculated with high-salinity-adapted sludge could be managed to release treated effluent that meets Saudi disposal limits by modifying the F/M ratio via reducing the flux or increasing the mixed liquor suspended solid (MLSS) concentration. [ABSTRACT FROM AUTHOR]

The Electrodialysis with Filtration Membrane (EDFM) system has shown promise in juice enrichment, but further optimization is needed. This study evaluated the effect of processing duration (3 and 6 h) on juice composition, process efficiency, and membrane fouling. Results demonstrated a significant impact of processing time on juice composition, especially anthocyanin and mineral content. Two anthocyanin-depleted juices (−18.94% and −30.70%) and two anthocyanin-enriched juices (26.21% and 44.21%) were produced. Similar energy (1512.13 Wh/g of anthocyanins) was required to migrate equivalent amounts of anthocyanins over both time periods, with no impediment due to fouling observed, although the system's resistance increased (2.5-fold after 3 h, 3.2-fold after 6 h). Membrane fouling was characterized through conductivity, thickness, ATR-FTIR, SEM-EDX, and foulant identification. Minimal anthocyanin accumulation occurred on cation-exchange membranes (CEM), while anthocyanins and PACs concentrated within the filtering layer of filtration membranes (FM). However, fouling did not increase with longer processing. Structural alterations were noted in anion-exchange membranes (AEMs), suggesting instability under high electric fields. Overall, EDFM effectively enriched cranberry juice with anthocyanins, but further research is necessary to address AEM degradation under limiting current density conditions. [ABSTRACT FROM AUTHOR]

Multi-layer membrane filtration is a widely used technology for separating and purifying different components of a liquid mixture. This technique involves passing the liquid mixture through a series of membranes with decreasing pore sizes, which allows for the separation of different components according to their molecular size. This study investigates the filtration process of a fluid through a two-dimensional porous medium designed for seawater desalination. The focus is on understanding the impact of various parameters such as the coefficient of friction, velocity, and the number of layers on filtration efficiency. The results reveal that the number of layers plays a crucial role in desalination, with an increase in layers leading to enhanced filtration quality, following a power law relationship. The study explores the influence of the coefficient of friction on filtration performance, emphasizing its significant effect on the number of particles filtered over time. Additionally, the role of the initial velocity in filtration efficiency is examined, showing distinct effects at both high and low velocities. Biofouling is identified as a factor influencing filtration, with an initial increase in filtered particles followed by a decline due to particle accumulation in pores. [ABSTRACT FROM AUTHOR]

The diverse composition of milk throughout the year can potentially impact subsequent processing in the dairy industry and the quality of the final products. This fluctuation in milk composition is influenced by direct and indirect factors like seasonal variability. Milk powders are produced through a complex process and are intended for various end uses and require consistency of composition along with desirable physical and functional properties. This review aims to report technical challenges and limitations related to the functional and quality characteristics of milk powder and highlight recent approaches used to mitigate seasonally related differences in milk composition. [ABSTRACT FROM AUTHOR]

A hull and propeller biofouling assessment framework is presented and demonstrated using a bulk carrier as a case study corresponding to an operational period of two and a half years. The aim is to support the decision-making process for optimizing maintenance related to hull and propeller cleaning actions. For the degradation assessment, an appropriate key performance indicator is defined comparing the expected shaft power required with the measured power under the same operational conditions. The power prediction models are data-driven based on machine learning algorithms. The process includes feature engineering, filtering, and data smoothing, while an evaluation of regression algorithms of the decision tree family is performed. The extra trees algorithm was selected, presenting a mean absolute percentage error of 1.1%. The analysis incorporates two prediction models corresponding to two different approaches. In the first, the model is employed as a reference performance baseline representing the clean vessel. When applied to a dataset reflecting advanced stages of biofouling, an average power increase of 11.3% is predicted. In the second approach, the model entails a temporal feature enabling the examination of scenarios at different points in time. Considering synthetic data corresponding to 300 days since hull cleaning, it was derived that the fouled vessel required an average 20.5% increase in power. [ABSTRACT FROM AUTHOR]

In this study, the combination of the conventional membrane bioreactor (MBR) process with attached growth system using moving bed (MBMBR) and fixed bed (FBMBR) for simultaneous removal of organic carbon, nitrogen, and phosphorus from wastewater was carried out at a pilot-scale application. The effluent was monitored daily for COD, NO3, PO4, and pH concentrations to achieve COD removal and nitrogen and phosphorus stabilization. After achieving equilibrium, sampling was done twice a week from the raw wastewater tank, aerated reactor, and effluent. Various parameters including MLSS, MLVSS, SVI, nitrate, and total phosphorus were measured by standard methods and the effects of variables such as retention time and optimal conditions were investigated in the MBMBR and FBMBR reactors. The results showed that the membrane fouling rate in the MBMBR reactor was higher than that in the FBMBR reactor; and the nitrogen and phosphorus removal efficiency in the FBMBR reactor was significantly higher than that in the MBMBR reactor. The combined MBR process with a fixed and moving bed depicted a suitable capability for removing organic carbon, nitrogen, and phosphorus. It was found that the membrane bioreactors benefited from a higher efficiency, especially the FBMBR reactor, in removing parameters such as phosphorus, nitrogen, and organic matter compared to the MBMBR reactor. In general, it can be concluded that the type of biofilm carrier medium affects membrane fouling and sludge filterability. [ABSTRACT FROM AUTHOR]

This work proposes an octopus‐inspired smart skin for fouling release. The skin consists of twisted spiral artificial muscles (TSAMs) embedded between two layers of elastomer. Upon electro‐thermal actuation, TSAMs undergo vertical displacement (similarly to octopus' papillae dermal muscles) and mechanically deform the top layer of the skin where the biofilm is attached. The release is achieved by generating a critical strain on the skin's top layer. In this paper, a physics‐based mechanical model is proposed to describe the fouling release mechanism of the smart skin. The model relates the critical strain to the mechanical properties of the biofilm, as well as the mechanical and electro‐thermal properties of the TSAMs. The model is experimentally validated, and a robust controller is implemented to achieve the desired critical strain and then perform release for two different types of biofilms: bacterial‐based Escherichia coli and diatom‐based Amphora coffeaeformis. [ABSTRACT FROM AUTHOR]

In contrast to expectations, even buoyant microplastics like polyethylene and polypropylene are found at high concentrations in deep sediment traps and deep-sea sediments. To explain the presence of such buoyant microplastic particles at great ocean depths, several vertical transport mechanisms are under discussion with biofouling as one of the most referred. Biofouling is thought to increase the density of microplastic particles to the point that they sink to the deep sea, but this has mostly been shown on large microplastic particles ≥ 1 mm. However, although microplastics are defined as particles between 1 and 5000 μm, most microplastics are < 100 μm. In the ocean plastic particles continuously fragment, converting each "large" particle into several "small" particles, and particle abundance increases drastically with decreasing size. We argue that biofouling is not a reasonable transport mechanism for small microplastic particles ≤ 100 μm, which form the majority of microplastics. Biofilm density depends on its community and composition. A biofilm matrix of extracellular polymeric substances and bacteria has a lower density than seawater, in contrast to diatoms or large organisms like mussels or barnacles. We suggest that a small microplastic particle cannot host a biofilm community consisting of the heavy organisms required to induce sinking. Furthermore, to reach the deep sea within a reasonable timespan, a microplastic particle needs to sink several meters per day. Therefore, the excess density has to not only exceed that of seawater, but also be large enough to enable rapid sinking. We thus argue that biofouling cannot be an efficient vertical transport mechanism for small microplastic. However, biofouling of small microplastic may promote the likelihood of its incorporation into sinking marine snow and increase the probability of its ingestion, allowing its transport to depth. [ABSTRACT FROM AUTHOR]

The primary approach to managing biofouling in industrial water systems involves the large‐scale use of biocides. It is well‐established that biofilms are 'cell factories' that release planktonic cells even when challenged with antimicrobials. The effect of isothiazolinone on the metabolic activity and biomass of mixed Pseudomonas biofilms was monitored in real‐time using the CEMS‐BioSpec system. The exposure of biofilms to the minimum inhibitory concentration (1.25 mg L−1) of biocide did not impact planktonic cell production (log 7.5 CFU mL−1), while whole‐biofilm metabolic activity and biomass accumulation increased. Only the maximum biocide concentration (80 mg L−1) resulted in a change in planktonic cell yields and temporal inhibition of biofilm activity and biomass, a factor that needs due consideration in view of dilution in industrial settings. Interfacing the real‐time measurement of metabolic activity and biomass with dosing systems is especially relevant to optimizing the use of biocides in industrial water systems. [ABSTRACT FROM AUTHOR]

The performance of heat pump systems for heating and cooling heavily relies on the thermal conditions of their reservoirs. This study introduces a novel thermal reservoir, detailing a 2017 project where the Municipality of Stavanger installed a heat exchanger system on the wall of a main wastewater tunnel beneath the city center. It provides a comprehensive account of the system's design, installation, and performance, and presents an Artificial Neural Network (ANN) model that predicts heat pump capacity, electricity consumption, and outlet temperature across seasonal variations in wastewater temperatures. By integrating domain knowledge with the ANN, this study demonstrates the model's capability to detect anomalies in heat pump operations effectively. The network also confirms the consistent performance of the heat exchangers from 2020 to 2024, indicating minimal fouling impacts. This study establishes wastewater heat exchangers as a safe, effective, and virtually maintenance-free solution for heat extraction and rejection. [ABSTRACT FROM AUTHOR]

Micro heat exchangers improve heat and mass transfer compared to conventional heat exchangers, enabling more energy‐efficient applications. However, their sensitivity to fouling limits broader industrial application. This approach presents a combined investigation of fouling and cleaning in microscale heat exchangers using two test rigs. Individual sets of analysis methods are developed to improve the understanding of heat and mass transfer on the microscale. In addition to known methods, such as pressure loss analysis, newly developed and established image analysis techniques are used to monitor fouling and cleaning. Based on the presented methods, it is possible to predict the initial position of thermally induced fouling and to demonstrate the applicability of automated cleaning on the microscale. [ABSTRACT FROM AUTHOR]

The applicability of a fluidically heated spinning disk apparatus (SDA) was tested for investigating the influence of the tangential velocity on the deposition of particulate material systems, in particular on latex particles. First, the SDA was characterized for particle fouling investigations with micro glass beads as a model system, then, a first series of tests was carried out with a real material system, a vinyl acetate/Versa 10 copolymer. Experiments were performed for a duration of 1 h and a tangential velocity up to 0.3 m s−1. The fouling process was characterized by the local fouling layer thickness and the calculated local mass‐based fouling resistance. A decrease in fouling resistance along the radius of the rotating disk as a function of the tangential velocity was observed. [ABSTRACT FROM AUTHOR]

Fouling mitigation provides many challenges in process equipment, especially in heat exchangers. In this work, the fouling behaviors of two polymers are compared to 1.4301 stainless steel (SS) in calcium sulfate solutions. An experimental setup that allows to classify the materials quickly and under varying process conditions is used to determine the fouling behavior. Results are compared to a screening apparatus which can test up to three materials simultaneously. Finally, the cleaning behavior of all three materials is investigated. Results show that polyether ether ketone (PEEK) is superior to SS in mitigating fouling and is easier to clean; however, polyether ether ketone with 30 % talcum (TKT) is not. This is attributed to the surface roughness of the materials. [ABSTRACT FROM AUTHOR]

Fouling is a challenge in many processes, especially in heat exchangers and evaporators. Even though many treatments have been developed to mitigate fouling on metallic surfaces, no standardized method exists to compare equipment based on its antifouling performance. In this work, a screening apparatus is presented, which allows to compare samples of treated metallic surfaces based on thermal fouling resistance. A parameter screening and a ranking of three differently treated metallic surfaces using two model substances, namely, whey protein concentrate (WPC) and calcium sulfate, are demonstrated. [ABSTRACT FROM AUTHOR]

Fouling in columns is a persistent challenge in the chemical process industry, leading to decreased efficiency and increased operating costs. This paper presents an investigation into fouling behavior on individual random packing elements in packed columns using computational fluid dynamics (CFD) simulations. The study aims to gain a deeper understanding of how fouling grows and impacts the flow behavior, predicting areas susceptible to fouling and providing insights for improved design. The simulation results are validated against experimental results and show good agreement. [ABSTRACT FROM AUTHOR]

Fouling on column internals leads to many malfunctions in chemical processes every year. Despite the importance for the industry, only a few systematic studies exist on the fouling of column internals. Here, a new screening test rig is presented for the rapid and easy characterization of a wide range of internals with respect to their fouling tolerance. A countercurrent of saturated NaCl/water solution and air is used to force crystallization fouling. Photographs help to identify the initial points of fouling on two random packings and provide insights into the growth of deposits. In addition, the fouling tolerance of five different trays is investigated, demonstrating that trays with larger curtain area show greater fouling tolerance. [ABSTRACT FROM AUTHOR]

The hydraulic calculation of column internals is crucial for their design. The various fouling effects (due to crystallization, particles, chemical reaction) influence the hydraulics of columns in different ways (capacity, separation efficiency). However, current hydraulic models are based on clean systems and do not consider fouling. By properly taking into account the geometrical parameters affected by fouling, the classical models can be used to calculate the state of internals as they evolve over time. [ABSTRACT FROM AUTHOR]

Unwanted deposit formation on heat and/or mass transfer surfaces (fouling) also leads to problems during operation of columns. Column fouling thus also contributes to global warming through increased energy demand and operational disturbances. The newly developed standard apparatus for investigating column fouling, which was developed as part of the SAMARA joint project funded by the BMWK, makes it possible to clarify the processes involved in the formation and prevention of fouling in columns and to take targeted countermeasures. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The marine algae Ulva spp. are commonly used as model biofouling organisms. As biofouling studies are primarily conducted using field-collected specimens, factors including species identity, seasonal availability, and physiological status can hinder the replicability of the results. To address these limitations, a protocol was developed for the on-demand laboratory culture and release of Ulva zoospores. The biofouling potential of laboratory-cultured and field-collected Ulva blades was compared using a waterjet. No significant differences were found between field and laboratory-cultured samples in either spore adhesion (before waterjet) or the proportion of spores retained after waterjet exposure. However, there was significant variability within each session type in pre- and post-waterjet exposures, indicating that spore adhesion and retention levels vary significantly among trial runs. In addition, all our laboratory cultures were Ulva Clade C (LPP complex). In contrast, our field samples contained a mix of Ulva Clade C, U. compressa clade I, and U. flexuosa Clade D. This protocol for on-demand production of Ulva spores can improve biofouling research approaches, enables comparison of results across laboratories and regions, and accelerate the development of anti-biofouling strategies. [ABSTRACT FROM AUTHOR]

Membrane fouling caused by effluent organic matter (EfOM) limits its further application in wastewater reuse. In this study, the effect of UV/chlorine pretreatment on membrane fouling was investigated in treating secondary effluent by ultrafiltration (UF) process. The relation between organic matter changes and fouling alleviation after UV/chlorine pretreatment was also studied according to the molecular weight (MW) changes in various resin fractions derived from EfOM. Results showed that UV/chlorine pretreatment effectively alleviated irreversible fouling, whereas chlorine pre-oxidation primarily mitigated reversible fouling. UV/chlorine pre-oxidation reduced 18% of reversible membrane fouling and 38% of irreversible membrane fouling at a chlorine dosage of 8 mg/L, indicating better performance in membrane fouling mitigation than chlorine pre-oxidation. UV/chlorine pre-oxidation also decreased dissolved organic matter in the UF permeate. The hydrophobic acidic (HPO-A) fraction caused dominant membrane fouling, while the hydrophilic (HPI) fraction contained most of high MW organic matter. Pre-oxidation changed the polarity of organic matter in the HPO-A fraction and decomposed the organics of high MW in the HPI fraction, which alleviated membrane fouling. These results showed that UV/chlorine pre-oxidation was a prospective pretreatment process prior to UF in wastewater reclamation. [ABSTRACT FROM AUTHOR]

The petroleum refining business consumes approximately 0.2 MMBTU/BBL of energy annually. This consumption is mitigated using heat integration techniques. However, a significant challenge in this process is fouling in the preheat train network of heat exchangers. Fouling necessitates regular cleaning, leading to substantial operational inefficiencies and costs, with annual losses estimated at nearly $16.5 billion. To address this issue, implementing a predictive maintenance model is crucial for performing maintenance at optimal periods, thereby reducing these losses. The study proposes an artificial neural network (ANN) developed using MATLAB's nntool, trained on industrial heat exchanger samples that were preprocessed in Microsoft Excel. This ANN model is designed to forecast fouling patterns in shell and tube heat exchangers. The model's accuracy and effectiveness were validated using R2 (coefficient of determination) and RMSE (root mean square error) measures. The results indicated that the EA-307 Feed-Forward Back-Propagation Neural Network (FFBPNN) model delivered satisfactory performance, with an R2 value of 0.9961. This high level of accuracy underscores the significant impact of the number of neurons on the model's predictive output. Furthermore, the model's testing on a new dataset yielded impressive results, achieving an R2 value of 0.966. This demonstrates the model's robustness and reliability in predicting fouling patterns, facilitating improved maintenance schedules, and minimizing the financial losses associated with fouling. The study highlights the potential of advanced neural network models to significantly enhance the operational efficiency of petroleum refineries by enabling more precise and timely maintenance interventions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Xi'an Jiaotong University is the property of Editorial Office of Journal of Xi'an Jiaotong University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biomass serves as an alternative energy solution for decarbonizing coal-fired power plants, which have been reactivated in several countries due to the global energy crisis. Oil palm waste, owing to its abundant availability, holds significant potential as a biomass fuel. This study aimed to investigate the combustion performance of various oil palm wastes in comparison to coal. Biomass combustion is associated with ash-related problems such as slagging, fouling, and corrosion, which may accelerate ash deposit acceleration, reduce heat transfer, and damage refractory equipment in boilers. Ash-related problems were evaluated using the method commonly adopted for solid fuel, including experimental drop tube furnace combustion and ash observation. The results indicate that each oil palm waste has different combustion characteristics. Palm leaves, empty fruit bunch, and palm fronds with clean probe observation have a relatively low tendency of slagging and fouling and can be recommended as biomass fuel for co-firing. However, their high alkali and iron contents need to be considered. Palm fiber has similar combustion characteristics to coal, but it has a high slagging and fouling tendencies. The palm stems with high chlorine content have a high corrosion tendency confirmed by probe observation, scanning electron microscopy, and X-ray diffraction analyses. [ABSTRACT FROM AUTHOR]

Biofouling, the accumulation of marine organisms on submerged surfaces, presents significant operational challenges across various marine industries. Traditional detection methods are labor intensive and costly, necessitating the development of automated systems for efficient monitoring. The study presented in this paper focuses on detecting biofouling on tidal stream turbine blades using camera-based monitoring. The process begins with dividing the video into a series of images, which are then annotated to identify and select the bounding boxes containing objects to be detected. These annotated images are used to train YOLO version 8 to detect biofouled and clean blades in the images. The proposed approach is evaluated using metrics that demonstrate the superiority of this YOLO version compared to previous ones. To address the issue of misdetection, a data augmentation approach is proposed and tested across different YOLO versions, showing its effectiveness in improving detection quality and robustness. [ABSTRACT FROM AUTHOR]

ABSTRACT: This research used a customized laboratory setup to compare the filtration performance and fouling buildup during microfiltration with polymeric membranes of skim milk using 2 diafiltration media: ultrafiltration permeate and ultrapure water. Two filtration modes were evaluated: in stage 1, the diafiltration media was added in a 1:1 ratio, with the collection of permeate continuing until the initial protein concentration was restored. In stage 2, retentates and permeates were recycled to simulate fouling accumulation in a steady-state without altering the retentate composition. Utilizing water as the diafiltration medium resulted in higher flux and lower resistance values compared with using ultrafiltration permeate, irrespective of the filtration mode. The concentration had a significant effect on membrane resistance, with no noticeable time-dependent effect on fouling layer development after 60 min of filtration when the retentate composition remained constant. The protein composition of the permeate and extracted foulants were comparable between the 2 media, with caseins predominating in the fouling layer.

Objectives The fouling and wetting of membranes in membrane distillation processes can significantly reduce membrane performance, thereby affecting overall process efficiency. The purpose of this study is to develop methods for restoring the performance of membranes used in a membrane distillation pilot plant operated in the Middle East by testing and optimizing various cleaning methods. This aims to maintain the long-term performance and improve the operational efficiency of the pilot plant through the reuse of restored membranes. Methods To analyze the main fouling substances on the hollow fiber membranes collected from a module operated in a pilot plant, FTIR, XRD, and SEM analysis techniques were employed. A lab-scale module was fabricated using the collected membranes, and cleaning methods were applied. Citric acid was used for cleaning to restore membrane performance, which was evaluated by measuring water permeability and conductivity before and after cleaning. Results and Discussion FTIR and XRD analyses revealed that the main fouling substances on the membranes used in the pilot plant were NaCl, CaCO3, and CaSO4. SEM and ICP analyses confirmed that the membranes near the feed inlet of the module experienced severer fouling compared to those near the outlet. The cleaning method involving pump circulation after inducing artificial wetting was found to be the most effective for restoring membrane performance. Notably, when a high concentration of citric acid was used, almost all fouling substances on the membrane surface were removed, restoring membrane performance to nearly its original state. Conclusion The cleaning method involving artificial wetting followed by pump circulation was determined to be the optimal method for successfully restoring the performance of membranes fouled and wetted in membrane distillation processes.

Abstract This research explores the enhancement of polyethersulfone (PES) membranes through the incorporation of chitosan derived from the lignicolous fungus Ganoderma sp. Utilizing wet phase inversion and solution casting techniques, chitosan was successfully integrated into the PES matrix, as confirmed by Fourier Transform Infrared Spectroscopy (FT-IR), which indicated a high deacetylation degree of 75.7%. The incorporation of chitosan significantly increased the membrane hydrophilicity, as evidenced by a reduction in the water contact angle and a substantial improvement in pure water permeability, from 17.9 L m-2 h-1 bar-1 to 27.3 L m-2 h-1 bar-1. The membrane anti-fouling properties were also notably enhanced, with the Flux Recovery Ratio (FRR) increasing from approximately 60–80%. Moreover, the chitosan-modified PES/CS membrane, particularly at a 5% chitosan concentration, demonstrated exceptional efficacy in pollutant removal, achieving over 90% elimination of total suspended solids, cadmium (Cd), and lead (Pb), alongside a 79% reduction in color during the treatment of textile wastewater.

Multiple ERI (Electron Repulsion Integral) tensor contractions (METC) with several matrices are ubiquitous in quantum chemistry. In response theories, the contraction operation, rather than ERI computations, can be the major bottleneck, as its computational demands are proportional to the multiplicatively combined contributions of the number of excited states and the kernel pre-factors. This paper presents several high-performance strategies for METC. Optimal approaches involve either the data layout reformations of interim density and Fock matrices, the introduction of intermediate ERI quartet buffer, and loop-reordering optimization for a higher cache hit rate. The combined strategies remarkably improve the performance of the MRSF (mixed reference spin flip)-TDDFT (time-dependent density functional theory) by nearly 300%. The results of this study are not limited to the MRSF-TDDFT method and can be applied to other METC scenarios. [ABSTRACT FROM AUTHOR]

Abstract Of the processes that are approved to produce synthetic kerosene for use in jet fuel, about half produce olefinic kerosene that is hydrotreated. The alkene concentration in synthetic kerosene is indirectly regulated through the thermal oxidative stability specification. Perceptions about the deleterious influence of alkenes on thermal oxidative stability suggest that olefinic kerosene must be deeply hydrogenated. The extent of olefin saturation required has economic implications. To evaluate what an acceptable alkene concentration in synthetic kerosene is, the impact of alkene concentration on the outcome of the jet fuel thermal oxidative stability test (JFTOT) performed at 325°C in accordance with the ASTM D3241 standard test method was experimentally evaluated. Model synthetic kerosene mixtures to which different concentrations of alkenes (1‐decene, α‐methylstyrene, indene) were added, as well as control samples were studied. In the concentration range investigated, up to 10 wt% 1‐decene, 5 wt% α‐methylstyrene, and 2 wt% indene did not lead to increased fouling in the JFTOT. Fouling passed through a minimum value with increasing alkene concentration and alkene concentration on its own was a poor predictor of thermal oxidative stability. Analysis of the kerosene collected after passing through the JFTOT found measurable changes in density and refractive index. Dissolved oxygen reacting during thermal oxidative stability testing was accounted for mostly in oxygen‐containing products in the kerosene boiling range, which indicated that the heavier products were mainly hydrocarbon in nature. In addition to initiation by autoxidation, the investigation also pointed to the existence of a second thermally initiated fouling pathway that does not require the presence of oxygen.

The study aimed to explore the effects of biomass co-firing of coal using acacia wood bark at circulating fluidized bed (CFB) boiler coal-fired power plant with 110 MWe capacity. The analysis focused on main equipment parameters, including the potential for slagging, fouling, corrosion, agglomeration, fuel cost, and specific environmental factors. Initially, coal and acacia wood bark fuel were blended at a 3% mass ratio, with calorific values of 8.59 MJ/kg and 16.59 MJ/kg, respectively. The corrosion due to chlorine and slagging potential when using wood bark was grouped into the minor and medium categories. The results showed that co-firing at approximately 3% mass ratio contributed to changes in the upper furnace temperature due to the variation in heating value, high total humidity, and a less homogeneous particle size distribution. Significant differences were also observed in the temperature of the lower furnace area, showing the presence of a foreign object covering the nozzle, which disturbed the ignition process. A comparison of the seal pot temperature showed imbalances as observed from the temperature indicators installed on both sides of boiler, with specific fuel consumption (SFC) increasing by approximately 0.17%. During the performance test, the price of acacia wood bark was 0.034 USD/kg, resulting in fuel cost of 0.023355 USD/kWh, adding 0.061 cent/kWh to coal firing cost. Despite co-firing, the byproducts of the combustion process, such as SO2 and NOx, still met environmental quality standards in accordance with government regulations. However, a comprehensive medium- and long-term impact evaluation study should be carried out to implement co-firing operations using acacia wood bark at coal-fired power plant. Based on the characteristics, such as low calorific value, with high ash, total moisture, and alkali, acacia wood bark showed an increased potential to cause slagging and fouling.

The present investigation focuses on using commercially available MF, UF, and NF membranes to eliminate Fe from real groundwater. The impact of process parameters, including applied pressure, temperature, pH, time, and concentration, on flux and Fe removal% is investigated. Results of the permeation test confirm higher permeability for MF membranes (214.71 L/m2.h.bar) than that for NF (2.708 L/m2.h.bar) and UF (56.52 L/m2.h.bar) membranes. The FESEM-EDS characterization confirms the deposition of dominant foulant Fe particles over the membrane surface. At 2 bar applied pressure (temperature = 30 °C, pH = 6.13, and concentration = 6.62 ppm), MF, UF, and NF can eliminate 93.5, 90.2, and 100% Fe, respectively. However, UF and NF exhibit much lower fluxes (72.43 and 3.85 L/m2.h, respectively) compared to MF (317.13 L/m2.h) at the same process conditions. NF eliminates 100% Fe from start to end with rising pressure, while MF (62.16–100) and UF (87.09–100) show gradually improved removal rates. Above pH 6, all membranes demonstrate higher Fe rejection because the oxidation rate of ferrous iron increases at a high pH. With increasing concentration (6–500 ppm), Fe removal efficiency increases for NF (88.26–94.18%) but decreases for both MF (89.63–23.64%) and UF (27.66–14.4%). To validate experimental findings, five machine learning (ML) regression models are scrutinized using various statistical measures. HIGHLIGHTS Treatment of highly Fe-contaminated real groundwater by MF, UF, and NF flat sheet membranes.; MF shows much higher flux (317.13 L/m2.h) and 100% Fe removal, and is the best membrane.; FESEM-EDS confirms the deposition of dominant foulant Fe over membrane surfaces.; Effects of pressure, pH, temperature, time, and concentration on flux and Fe removal are demonstrated.; Machine learning effectively legitimates the experimental data with fewer errors.;