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With the aim to establish clean and sustainable sludge treatment, green conditioning using natural flocculants has recently gained a growing interest. In this study, a variety of plant materials, namely Moringa (Moringa oleifera) seeds, Fenugreek (Trigonella foenum-graecum) seeds, Potato (Solanum tuberosum) peels, Aloe (Aloe vera) leaves, Cactus (Opuntia ficus indica) cladodes, and Phragmites (Phragmites australis) stems, were evaluated for their potential bioflocculant activity in conditioning sewage sludge. They were thoroughly characterized to determine their active flocculating compounds. Sludge dewaterability was evaluated by assessing various sludge parameters, including specific resistance to filtration (SRF), dryness of filtration cake (DC), and total suspended solid removal (TSS) from sludge filtrate. The collected results from various physicochemical characterizations of plant materials suggest that the main flocculating agents are carbohydrates in Cactus and Fenugreek and proteins in Moringa, Potato, and Phragmites. Additionally, all tested plant-based flocculants demonstrated effective dewatering performance. Interestingly, compared to the chemical flocculant polyaluminum chloride, Moringa and Cactus showed superior conditioning effects, yielding the lowest SRF values and the highest DC. As a result, the use of these natural flocculants improved sewage sludge filterability, leading to a significant removal of total suspended solids from the filtrate. The conditioning properties of Moringa and Cactus can be attributed to their high protein and sugar content, which facilitates the effective separation of bound water from solids through charge neutralization and bridging mechanisms. Thus, green conditioning using plant-based flocculants, particularly Moringa and Cactus materials, presents a promising and eco-friendly approach to enhance sewage sludge dewatering for safer disposal and valorization. [ABSTRACT FROM AUTHOR]

Hornification is a well-known phenomenon describing what happens during the drying of lignocellulosic materials, often within and between cellulosic pulp fibers. For wood fibers used in papermaking, this phenomenon decreases fiber wall swelling, and internal and external fibrillation. It reduces flexibility of damp fibers, which leads to a diminished ability to form effective fiber networks, resulting in lower paper strength. This work investigates how drying temperature affects the changes in fiber morphology, connects this to the changes in sheet behavior, and proposes a combination of bonding mechanisms for hornification. Results show that hornification depends on drying temperature; higher temperature gives higher degrees of hornification with decreased WRV of about half the numerical value, from 1.5 g/g for never-dried pulp to 0.7 g/g for hardwood pulp samples. Higher temperatures, above 100°C, also change the pulp color, as measured by increased yellowness. Decreased swelling capacity and pulp yellowness are connected. This indicates parallel reactions, which both contribute to hornification. The mechanisms are proposed to be chains of hydrogen bonds, dominating at low temperatures and providing no color change, and dehydration reactions via pyrolysis, giving a yellow-to-brown color shift. Compression strength measurements show that major hornification adversely affects sheet strength due to poor network bonding. However, minor hornification can be beneficial for applications where compression strength is an important parameter. [ABSTRACT FROM AUTHOR]

This article presents the results of a pilot study on the treatment of sludge from a water treatment plant in the city of Almaty, Republic of Kazakhstan, to ensure further disposal. The main objective of the study was to compare the efficiency of sludge drying by natural and artificial methods. The qualitative characteristics of the leachate from the dewatering unit, the chemical composition of the dried sludge and the granulometric analysis of the dried sludge were also studied. The greatest reduction in moisture content was recorded for drying in natural conditions (2.1%), but this process required the longest drying time. The leachate obtained from sludge dewatering was characterized by significant contamination (e.g., turbidity—55.65 on average, color—67.7, total Fe—5.15 mg/L, total N—79.6 mg/L, COD—311 mg/L, BOD—336.15 mg/L), which indicates the need for its pretreatment before further management in the technological system of the treatment station. The content of chemical substances contained in the dry residue of the sludge was also determined, of which aluminum was 0.94–13.8 mg/kg, silicon was 50.24–146.3 mg/kg, potassium was 1.72–5.51. mg/kg, calcium was 71.8–79.1 mg/kg, iron was 2.0–7.54 mg/kg and nickel was 0.9–4.4 mg/kg. A particle size analysis of the dried sludge showed that the majority fractions were fine and very fine sand, with a total of 20.2%, and silt and clay, with a total of 78.3%. Such properties justify the rationality of considering the reuse of dried sludge as a raw material for making, for example, construction materials or soil remediation material. [ABSTRACT FROM AUTHOR]

Coal gasification coarse slag (CGCS) has become a bulk coal-based solid waste that threatens the ecological environment. The high moisture content of carbon-rich coal coarse gasification slag (CR-CGCS) seriously limits its utilization. In this study, a pore water releasing method was proposed to promote the dewatering of CR-CGCS through size reduction with surface modification. Hexadecyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and kerosene were added during the grinding process, respectively. The results showed that kerosene can significantly improve the dewatering efficiency of CR-CGCS more than CTAB and SDS. The final moisture content of the CR-CGCS could be reduced from 47.50% to 33.01%. The SEM and FTIR results illustrated that kerosene could effectively reduce the content of oxygen-containing functional groups on the surface of CR-CGCS more than CTAB and SDS. Meanwhile, the PVM results showed that CR-CGCS modified by kerosene tended to form hydrophobic agglomerates. The LF-NMR results indicated that only the water in the macropores of CR-CGCS could be released in grinding process, but the water in micropores could be reduced when kerosene, CTAB, or SDS was added in grinding. This study provides new insight into enhancing the dewatering of CR-CGCS and theoretical support for the efficient utilization of CR-CGCS. [ABSTRACT FROM AUTHOR]

The solids in sewage sludge are primarily composed of organic matter and offer new possibilities for sustainable sludge management, if considered as a stable biomass source in terms of quantity and quality. Reducing the volume of sludge with an extremely high moisture content is challenging, and enhanced dewatering through mechanical treatment is crucial from an environmental and sustainability perspective because it alleviates the reliance on thermal treatment. This study employed ultrasonication to enhance the dewatering efficiency of activated sludge. The disruption of sludge induced by ultrasonication notably facilitated the elimination of intracellular water during mechanical expression. Additionally, the ultrasonicated sludge was verified to be re-flocculated by introducing inorganic electrolytes such as Ca2+ (divalent cations), Al3+ (trivalent cations), and polyferric sulfate. Conversely, no re-flocculation of disrupted sludge was observed upon applying organic polymer flocculant. Under optimized conditions, the sludge re-flocculation progressed to form large flocs, leading to a decreased suspended solids (SS) value from 1423 to 73 mg/L and reduction in capillary suction time (CST) from over 2000 to 18 s. Following pretreatment, the moisture content of the mechanically expressed cake at 500 kPa decreased significantly from 76 wt% (untreated sludge) to less than 60 wt% (treated sludge) due to the elimination of intracellular water. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the use of commercial tannin derivatives, namely, tannin 1 (CT1), tannin 2 (CT2), tannin 3 (CT3), and extract of tannin produced from angico bark, as aggregation agent in hematite–silica systems. Hematite and quartz were used in aggregation tests at dosages of 1, 10, and 100 mg/L at pH values of 6–9. The zeta potential and Jar tests were conducted in the best conditions of aggregation tests. The condensed tannin content of the commercial reagents is approximately similar, and it exceeds the content found in the extract obtained from angico bark. CT3 demonstrated superior percentages of sedimented material for both minerals at a dosage of 10 mg/L and pH 7 (97.12% and 95.68% for hematite and quartz, respectively). The aggregation agent produced from the angico bark displayed good sedimentation results for hematite (>90%); however, the results for quartz were unsatisfactory. The isoelectric point shifts to pH 8 when each mineral was conditioned with CT3. The jar test revealed higher sedimentation of the compositions for the lowest velocity gradient (60 rpm) with low turbidity values in the supernatant; however, the lowest turbidity (24.71 NTU) is observed in the sample with a higher percentage of hematite. [ABSTRACT FROM AUTHOR]

The confined aquifer dewatering for long-deep excavations usually encounters challenges due to complicated geotechnical conditions, large excavation sizes, and high hydraulic pressures. To propose the most efficient scheme of confined aquifer dewatering for long-deep excavations, dewatering optimizations were performed using the simulation–optimization method. An open cut tunnel of the Jiangyin-Jingjiang Yangtze River Tunnel Project was taken as an example. The methods of finite element and linear programming (LP) were combined to optimize the dewatering process. A three-dimensional finite element model was developed. After simulating the pumping tests, hydraulic conductivity was inverted. Then, necessary parameters in the LP method were determined by simulating dewatering with each pumping well, and various LP models were developed based on some important influence factors such as dewatering sequence, considered pumping wells, and pumping rate limitation. Finally, the optimal pumping rates were solved and applied to the numerical model, with induced drawdown and ground settlement computed for comparison. The results indicate that the optimization can significantly reduce the required wells in the original design. Dewatering in the deepest zone exhibits the highest efficiency for long-deep excavations with gradually varying depths. For the dewatering sequence from the shallowest to the deepest zone, more pumping wells are required but less energy is consumed. Higher quantity and more advantageous locations of pumping wells in the LP model usually result in lower total pumping rate, drawdown, and ground settlement. If more pumping wells are considered in the deepest zone, pumping rate limitation of single well will only slightly increase the total pumping rate, number of required pumping wells, drawdown, and ground settlement.

The energy needed for the dewatering and drying of wet paper web represents around half of the energy consumption of papermaking processes. The present work examined whether the dewatering and drying of paper could be enhanced during a previous pulp drying process by pretreating the fibers with polyamide-epichlorohydrin (PAE). According to the hypothesis, the cured PAE restrains swelling and water absorption of water-wetted fibers by forming a fiber-bound, self-crosslinked polymer-network on the fiber surfaces. The hypothesis was tested by adding PAE to never-dried kraft pulp slurry followed by pulp thickening, drying, and final curing of the PAE-resin. After this, the PAE-treated fibers were dispersed in water, and their water retention values (WRV) and Shopper-Riegler values (○SR) were measured. The PAE pretreatments notably decreased the fibers´ WRV and ○SR, indicating improved water removal of paper web in the paper machine forming and drying section. Compared to chemical crosslinking pretreatments, which also can be used to decrease fibers WRV and ○SR-value, a notable advantage of PAE-pretreatment is milder required curing conditions of the PAE, which makes implementation of the method easier in practice. Due to decreased fiber-to-fiber bonding capability, the PAE-treated specialty fibers could take advantage especially as a bulking aid of paperboard, tissue, and absorbent materials.

Cellulose films, predominantly consisting of micro-nanocelluloses, are a new type of product with interesting properties for functional packaging applications. However, the potentially scalable production methodology has not yet been elucidated. Poor dewatering and high web shrinkage are issues that need solutions beyond what is available in conventional paper production. This research investigates a cyclic pressing method that shows potential in cellulose film consolidation. Cyclic pressing allows the MNFC films to be dewatered to about 90% solids while yielding a smooth, flat product. The results show no inherent physical limits for mechanical dewatering these high swelling webs, even at very high solids. Cyclic pressing allows controlled restraint during consolidation, which could be adjusted in an industrial setup to produce even films with desirable product characteristics.

Depending on the ore quality, a washing process can be conducted with the bauxite, which basically consists of scrubbing the ore and screening in order to increase the available alumina grade, i.e., the alumina extractable using the Bayer Process, and reduce the impurity content. Tailings are usually disposed of in a tailings dam in the form of a slurry, which is a mixture of solid particles and liquid, consisting mainly of ultra-fine kaolinite, making the dewatering operation challenging. To reduce the environmental impact, mining companies are studying alternative methods to dewater the tailings, and different dewatering methods are available worldwide. The use of new technologies to dewater the tailings has contributed to facing the challenges of achieving sustainable development with their disposal. The decanter centrifuges are already an option for operations for the Canadian oil sands, gold ore in Peru, and nickel in New Caledonia; they are also being tested for iron ore in Brazil. In the present work, bauxite dewatering using the decanter centrifuge was evaluated to understand more about the behavior of these materials and to investigate the effects of various process parameters on the solid recovery and solid content of the flows, using three different kinds of equipment. The results indicated that decanter centrifuges can be used to achieve a high concentration of solids in the cake, with values ranging from 60% to 80% solids per weight and a great clarification in the liquid phase (centrate) from 0 to 6% solids per weight, values which mean the solid phase is suitable for reutilization in the processing circuit. Additionally, the present work provides a better understanding of how different solid contents feed can affect the behavior of the equipment. [ABSTRACT FROM AUTHOR]

The production of municipal sludge is increasing with the development of urbanization in these years. The municipal sludge usually has a high moisture content and contains large number of organic pollutants. Inappropriate treatment methods will lead to secondary pollution. Conventional mechanical dehydration can hardly meet the moisture content requirements for subsequent disposal. Flocculation is widely used in the sludge dewaterability enhancement for its economic efficiency and reliability. This paper provides a comprehensive review of flocculation-based techniques for municipal sludge dewatering. Firstly, the advantages and disadvantages of pretreatment techniques is elaborated. Even though flocculation is widely applied in sludge dewatering, deep dehydration always faces bottleneck in area such as removing cell bound water and changing the structure of EPS, etc. when using individual flocculation. Limited understanding of mechanisms and behaviors of joint technology of flocculation and physical/chemical/biological methods, have been highlighted as knowledge gaps in sludge dewatering. Some specific cases, mechanisms of action, practical considerations, dewatering effects and economic analyses of flocculation-coupled multiple technologies for deep sludge dewatering are analyzed in detail, Finally, the limitations, challenges and outlook of flocculants applied in sludge dewatering are comprehensively discussed. [ABSTRACT FROM AUTHOR]

This paper investigated the relationships of some physical and mechanical parameters of sediments and a typical clay during a natural dewatering process. Four sediments from different French river dams sampled by the Électricité De France group (EDF group) and a commercial kaolin clay used for comparative purposes were the focus of this study. Continuous dewatering was monitored in a laboratory by quantifying the percentage of water remaining in sediments or clay, drained and evaporated. Undrained shear strength was also assessed during the sediment or clay dewatering process, using the laboratory vane shear test. The samples were controlled along different dimensions during the dewatering process throughout the whole experiment. The results showed a certain interdependence between the physical parameters and the water content (ω), which was normalized by the liquidity limit (ω/LL) over time. This led to sigmoidal and exponential correlations when considering the percentage of water drained. The percentage of water remaining in the sediments or clay was characterized using the normalized water content, leading to exponential and power correlations. Both exponential and linear correlations were perfect for describing the evolution of the percentage of water evaporated. Other correlations were established for variations in void index, dry unit weight/solid unit weight ratio and undrained shear strength during the dewatering process. [ABSTRACT FROM AUTHOR]

As an industrial waste residue, Electrolytic Manganese Residue (EMR) can greatly promote sludge dewatering and further particle-size optimization can significantly strengthen sludge dewaterability. In this study, the effects of ammonium sulfate, calcium sulphate dihydrate, and manganese carbonate in EMR on sludge dewatering performance were investigated using the response surface optimization method. It was found that the optimized ratio of three components in EMR was 1.0:1.6:2.2 based on capillary suction time (CST), specific resistance of filtration (SRF), and zeta potential of dewatered sludge. The composition ratio of particle-size optimized EMR was modified based on the above optimization, resulting in a significant increase in sludge dewatering performance (CST and SRF reduced by 8.7% and 11.2%, respectively). Compared with those in original sludge, the content of bound extracellular polymeric substances in the conditioned sludge with optimized ratio was drastically reduced while that of soluble extracellular polymeric substances was slightly increased, which was in accordance with the decline of fluorescence intensity. These findings indicated the disintegration of extracellular polymeric substances, the enhancement of hydrophobicity, and dewatering properties of the sludge. In summary, optimized EMR can effectively intensify the dewaterability of sludge, providing a competitive solution for dewatering and further disposal of sludge. [ABSTRACT FROM AUTHOR]

Cellulose films, predominantly consisting of micro-nanocelluloses, are a new type of product with interesting properties for functional packaging applications. However, the potentially scalable production methodology has not yet been elucidated. Poor dewatering and high web shrinkage are issues that need solutions beyond what is available in conventional paper production. This research investigates a cyclic pressing method that shows potential in cellulose film consolidation. Cyclic pressing allows the MNFC films to be dewatered to about 90% solids while yielding a smooth, flat product. The results show no inherent physical limits for mechanical dewatering these high swelling webs, even at very high solids. Cyclic pressing allows controlled restraint during consolidation, which could be adjusted in an industrial setup to produce even films with desirable product characteristics. [ABSTRACT FROM AUTHOR]

The energy needed for the dewatering and drying of wet paper web represents around half of the energy consumption of papermaking processes. The present work examined whether the dewatering and drying of paper could be enhanced during a previous pulp drying process by pretreating the fibers with polyamide-epichlorohydrin (PAE). According to the hypothesis, the cured PAE restrains swelling and water absorption of water-wetted fibers by forming a fiber-bound, self-crosslinked polymernetwork on the fiber surfaces. The hypothesis was tested by adding PAE to never-dried kraft pulp slurry followed by pulp thickening, drying, and final curing of the PAE-resin. After this, the PAE-treated fibers were dispersed in water, and their water retention values (WRV) and Shopper-Riegler values (°SR) were measured. The PAE pretreatments notably decreased the fibers' WRV and °SR, indicating improved water removal of paper web in the paper machine forming and drying section. Compared to chemical crosslinking pretreatments, which also can be used to decrease fibers WRV and °SR-value, a notable advantage of PAE-pretreatment is milder required curing conditions of the PAE, which makes implementation of the method easier in practice. Due to decreased fiber-to-fiber bonding capability, the PAE-treated specialty fibers could take advantage especially as a bulking aid of paperboard, tissue, and absorbent materials. [ABSTRACT FROM AUTHOR]

Robust approaches are needed for designing efficient dewatering systems of deep excavations below the water table to avoid unforeseen incidents (e.g., bottom instabilities in deep excavations and flooding, among others). This paper proposes a methodology, which integrates existing experiences, that was adopted to design the dewatering system of an excavation in the city of Barcelona (Spain). The approach consists of combining: (i) detailed geological and hydrogeological characterizations, (ii) numerical modelling for parameter estimation and drawdown predictions, and (iii) analytical assessment for stability evaluation and soil deformation predictions. The idea is that by combining a set of relatively easy to apply methods, it is possible to successfully solve a complex and risky problem. The methodology allows designing efficient dewatering systems, increasing safety and mitigating potential impacts of groundwater pumping. The most significant conclusion is that the most important step of the proposed approach is the hydrogeological characterization because it allows building realistic and representative numerical models to address most of the challenges associated to dewatering. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ground Improvement is the property of Journal of Ground Improvement Editorial Office 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.)

Lipid production using microalgae is challenging for producing low-value-added products. Harnessing microalgae for their fast and efficient CO2 fixation capabilities may be more reasonable since algal biomass can be utilized as a precursor for various products in a biorefinery approach. This study aimed to optimize the productivity and efficiency of Microchloropsis salina biomass production in open thin-layer cascade (TLC) photobioreactors under physical simulation of suitable outdoor climate conditions, using an artificial seawater medium. Continuous operation proved to be the most suitable operating mode, allowing an average daily areal productivity of up to 27 g m−2 d−1 and CO2 fixation efficiency of up to 100%. Process transfer from 8 m2 to 50 m2 TLC photobioreactors was demonstrated, but with reduced daily areal productivity of 21 g m−2 d−1 and a reduced CO2 fixation efficiency, most probably due to increased temperatures at midday above 35 °C. An automated overnight switch-off of the circulation pumps was implemented successfully, reducing energy and freshwater requirements by ~40%. The ideal conditions for continuous production were determined to be a dilution rate of 0.150–0.225 d−1, pH of 8.5, and total alkalinity of 200–400 ppm, facilitating efficient pilot-scale production of microalgal biomass in TLC photobioreactors. [ABSTRACT FROM AUTHOR]

Foaming agents as a combination of several components are usually used as soil conditioning during earth pressure balance shield (EPBS) tunnelling. These residues in waste EPBS muck lead to a series of new challenges for in-situ recycling, i.e., foams overflow flocculation tank. This study investigates the effects of residual foaming agent components and defoamers on defoaming-flocculation-filterpress characteristics of EPBS muck using an improved flocculation and filterpress system. Residual foam height (Hf), defoaming ratio (DFR), antifoaming ratio (AFR), total suspended substance (TSS), turbidity, moisture content (MC), and zeta potential (ZP) were selected as characterization indices. The microstructure of filterpress cakes was analyzed using a scanning electron microscope. Results demonstrate that an enhancement within 0.0-1.0wt.% for sodium fatty alcohol polyoxyethylene ether sulfate (AES) and alpha olefin sulfonate (AOS) significantly reduces DFR and AFR. The MC and ZP decline, while the Hf and turbidity enhance. The combinations of nonionic surfactants alkyl polyglycoside (APG) and fatty alcohol-polyoxyethylene ether (AEO) in a concentration range of 0.0-1.0wt.% with 0.2wt.% AES causes the Hf, DFR, AFR, turbidity, and ZP to exhibit absolutely different variations. The MC with the growth in both APG and AEO presents a trend of first decreasing and then increasing. By increasing foam stabilizers sodium carboxymethyl cellulose (CMC) and guar gum (GG) within 0.02-0.10wt.%, the AFR, TSS, and ZP enhance in varying degrees, while the Hf, DFR, and MC gradually reduce. With the increase of defoamers hydroxyl silicone oil-glycerol polyoxypropylene ether (H-G) and dimethyl silicone oil-glycerol polyoxypropylene ether (D-G) within 0.002-0.010wt.%, the DFR and AFR are significantly improved, while the TSS, turbidity, MC, and ZP display varying degrees of reduction. Moreover, defoaming-flocculation-filterpress mechanisms of EPBS muck are explored to provide a useful reference for actual in-situ recycling projects. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mineral-activated perxymonosulfate (PMS) shows dewaterability and triclosan removal. • Iron-rich minerals are more economical than traditional sources of Fe2+. • Rheological test demonstrates that siderite/PMS can promote sludge fragmentation. • Siderite could release Fe2+ more sustainably to persistently produce free radicals. High water and pharmaceutical and care products (PPCPs) bounded in sludge flocs limit its utilization and disposal. The advanced oxidation process of perxymonosulfate (PMS) catalyzed by iron salts has been widely used in sludge conditioning. In this study, two iron-rich minerals pyrite and siderite were proposed to enhance sludge dewatering performance and remove the target contaminant of triclosan (TCS). The permanent release of Fe2+ in the activation of PMS made siderite more effective in enhancing sludge dewater with capillary suction time (CST) diminishing by 60.5 %, specific resistance to filtration (SRF) decreasing by 79.2 %, and bound water content (BWC) dropping from 37.1 % to 2.6 % at siderite/PMS dosages of 0.36/0.20 mmol/g-TSS after 20 min of pretreatment. Pyrite/PMS performed slightly inferior under the same conditions and the corresponding CST and SRF decreased by 51.5 % and 71.8 % while the BWC only declined to 17.8 %. Rheological characterization was employed to elucidate the changes in sludge dewatering performance, with siderite/PMS treated sludge showing a 48.3 % reduction in thixotropy, higher than 28.4 % of pyrite/PMS. Oscillation and creep tests further demonstrated the significantly weakened viscoelastic behavior of the sludge by siderite/PMS pretreatment. For TCS mineralization removal, siderite/PMS achieved a high removal efficiency of 43.9 %, in comparison with 39.9 % for pyrite/PMS. The reduction in the sludge solids phase contributed the most to the TCS removal. Free radical quenching assays and EPR spectroscopy showed that both siderite/PMS and pyrite/PMS produced SO 4 -· and ·OH, with the latter acting as the major radicals. Besides, the dosage of free radicals generated from siderite/PMS exhibited a lower time-dependence, which also allowed it to outperform in destroying EPS matrix, neutralizing the negative Zeta potential of sludge flocs, and mineralizing macromolecular organic matter. [ABSTRACT FROM AUTHOR]

With a growing need to reduce greenhouse gas emissions, innovative carbon dioxide sorbents are being sought. One of the sorbents being tested is nanoparticle ferric hydrosol (FFH). In parallel with sorbent testing, it is also necessary to test the used sorbent after carbon dioxide capture (FFHCO2) and to develop an optimal method for its processing and management. The research described in this article evaluated the potential use of FFHCO2 in dewatering, coagulation and bioleaching processes. The research results indicate that the basic strategy for dealing with waste FFHCO2 sorbent should be to minimize the amount of waste by volume reduction—dewatering. Recycling of FFHCO2 as an iron waste coagulant or its processing products by bioleaching had no technological justification. It is only proposed to recover the material—iron compounds—if it is environmentally and economically justified. [ABSTRACT FROM AUTHOR]

Building and ground settlement due to construction dewatering is a well-studied topic. However, most previous investigations have not considered the barrier effect of an adjacent underground structure on the drawdowns and resulting settlements. In this study, the barrier effect and its influence during construction dewatering for a metro station foundation pit is investigated. There are five aquifers at the foundation pit site, and a row of buildings supported on pile foundations, which act as an underground barrier to flow, is present on one side of the pit. On the other sides, there are no deep underground structures to impede groundwater flow. Field monitoring of the groundwater level drawdown, diaphragm wall movement, and ground and building settlements on both sides of the pit was carried out during dewatering. The results indicate that on the side with the pile foundations, the groundwater level drawdown, ground settlement, differential settlement, and angular distortion of building incurred by dewatering were relatively greater, but the diaphragm wall movements were relatively smaller. The effect of preexisting barriers should be considered in the assessment of construction dewatering-induced drawdowns, soil settlements, and building movements. [ABSTRACT FROM AUTHOR]

We address the challenges of limescale deposition and its management in urban construction sites, specifically within the Sumayil North project in Tel Aviv. Jet grouting, a method increasingly favored over conventional dewatering techniques for its minimal environmental impact and efficiency, is scrutinized for its unintended consequences on groundwater chemistry, particularly in relation to limescale formation. Our investigation centers on a dual approach: dissecting the geochemical dynamics leading to limescale deposition following jet grouting operations, and evaluating a remedial acid injection strategy implemented to counteract this phenomenon. We identify the critical factors influencing aquifer water chemistry through a detailed hydro-chemical analysis encompassing the Pleistocene Coastal Aquifer's dynamics. The study reveals that the interaction between grout components and aquifer water significantly alters groundwater pH, driving the precipitation of calcium carbonate. The subsequent implementation of a sulfuric acid injection regimen successfully mitigated limescale accumulation, restoring pumping efficiency and neutralizing pH levels. We propose a workflow to manage and prevent limescale, emphasizing preemptive measures like custom grout compositions and controlled dewatering, with strict post-intervention groundwater monitoring. This approach balances operational efficiency, infrastructure integrity, and environmental stewardship in urban construction projects interfacing with sensitive aquifer systems. [ABSTRACT FROM AUTHOR]

This study delves into the dynamic evolution of solids content in a pilot-scale through air drying tissue machine, aiming to enhance comprehension and refine optimization strategies for tissue manufacturing. It focuses on development of solids content throughout the process. Analyzing the interaction between process parameters and solids content provides deeper insights into water removal dynamics. The research employs solid contents monitoring techniques in pilot scale, offering a detailed view of solids content evolution from the wet web's inception to the final tissue product. It significantly highlights the impact of key parameters, particularly pulp refining, on solids content across all positions of the pilot machine. Additionally, the study emphasizes the influence of vacuum system configurations, identifying the relationship between energy expended in the vacuum system and evaporation energy. Furthermore, the results indicate that compression and air displacement dewatering in vacuum boxes are less speed-sensitive compared to heat-driven evaporation in the TAD- and Yankee cylinders. Solid contents at all positions in the tissue machine correlates between various dewatering elements. Optimizing site-specific dewatering and evaporation strategies can potentially save drying energy in the Yankee drying phase which hold promise for enhanced energy and resource utilization, aligning with demands for sustainable manufacturing practices. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature 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.)

Developing a novel bio-coagulant based on plant seeds using effective and affordable technique is an innovative way to advance bio-coagulant research in both developed and developing countries. This study investigates the potentiality and capacity of new bio-coagulants from Cucumeropsis mannii and Luffa acutangula seed proteins extract and purify for fecal sludge dewatering. A factorial design was made to obtain the best overall process optimization and improve the reaction between the coagulation/flocculation factors to provide suitable conditions for fecal sludge dewatering and concentrate a maximum of organic matter for biogas production. The experimental method identifies the potential parameters and the plant seed components that could interact based on different dosages used to optimize the treatment. To enhance the treatment, 10 mg/l of protein solution with a concentration of 10 g/l at pH 7.25 is considered a low-level dosage, and 20 mg/l of protein solution with a concentration of 20 g/l at pH 7.25 is considered a high-level dosage. The results have shown that the dosage of 20 mg/l of protein solution with a concentration of 20 g/l at pH 7.25 is optimal, with 99.17% turbidity, 99.58% COD and 99.13% ammonia nitrogen removal for C. mannii while L. acutangula seed proteins remove 97.67% turbidity, 98.49% COD and 98.7% ammonia nitrogen and recover 80% of water during fecal sludge dewatering. [ABSTRACT FROM AUTHOR]

A major challenge for upgrading hydrothermal liquefaction biocrude into sustainable aviation fuel is the presence of inorganic material. Unlike commercial crude oil or biofuel from energy crops, excessive amounts of contaminants such as salt, water, and ash in biocrude oil from hydrothermal liquefaction can cause catalyst deactivation during hydroprocessing, decreased distillation efficiency, and equipment fouling from alkali deposits. Therefore, efficient removal of these impurities in HTL biocrude oil is essential. This work investigated a novel 3-stage pretreatment process, removing water, salt, and ash without chemicals, to produce a HTL biocrude oil precursor suitable for hydroprocessing. The influence of water to oil (W:O) ratio, temperature, and time on desalting efficiency was determined. After pretreatment, 81% of salt was removed, reducing total salt content to

It is an important prerequisite for proper disposal and resource utilization of sludge to improve its dewaterability with conditioning pretreatment. Conditioning based on flocculation is the most reliable and widely used technology for improving sludge dewaterability due to its significant effects and controllable costs. In addition, the combined flocculants can play a synergistic role and have more diverse functionality, which is a research hotspot of sludge dewatering. The current situation of sludge disposal and treatment, as well as the difficulties in sludge dewatering were introduced. The mechanism and application of various flocculants or their combined usage were elaborated. This paper is expected to provide theoretical basis and application reference for the utilization of flocculation-based technology to enhance sludge dewaterability.

We address the challenges of limescale deposition and its management in urban construction sites, specifically within the Sumayil North project in Tel Aviv. Jet grouting, a method increasingly favored over conventional dewatering techniques for its minimal environmental impact and efficiency, is scrutinized for its unintended consequences on groundwater chemistry, particularly in relation to limescale formation. Our investigation centers on a dual approach: dissecting the geochemical dynamics leading to limescale deposition following jet grouting operations, and evaluating a remedial acid injection strategy implemented to counteract this phenomenon. We identify the critical factors influencing aquifer water chemistry through a detailed hydro-chemical analysis encompassing the Pleistocene Coastal Aquifer’s dynamics. The study reveals that the interaction between grout components and aquifer water significantly alters groundwater pH, driving the precipitation of calcium carbonate. The subsequent implementation of a sulfuric acid injection regimen successfully mitigated limescale accumulation, restoring pumping efficiency and neutralizing pH levels. We propose a workflow to manage and prevent limescale, emphasizing preemptive measures like custom grout compositions and controlled dewatering, with strict post-intervention groundwater monitoring. This approach balances operational efficiency, infrastructure integrity, and environmental stewardship in urban construction projects interfacing with sensitive aquifer systems.

Abstract Significant co-conditioning of aluminum-based sludge using alternative conditioner (natural biopolymer-magnetite/H2O2) as a Fenton conditioner for improving the sludge dewaterability is investigated in the current study. Firstly, natural biopolymer/magnetite (NBP-M) were prepared in various ratios and the samples labeled as (NBP-M-(1:1); NBP-M-(1:3) and NBP-M-(2:1). Focuses were placed on factors influencing such novel Fenton conditioner. Capillary suction time (CST) was utilized to assess sludge dewaterability. Experiments have exhibited that significant development of alum sludge dewaterability could be attained at minimum reaction time and using low concentrations of the applied catalyst, i.e. natural biopolymer/magnetite and H2O2. It was found that sludge conditioning and dewaterability became better with increasing both reagents concentrations. A Box–Behnken experimental design based on the response surface methodology was investigated to explore the optimum of the influencing variables, i.e. catalyst (NBP-M) concentration, H2O2 loading and pH. The optimized values for NBP-M, H2O2, and pH are 46 and 380 mg/L, respectively at pH 3.0, at which the CST reduction efficiency of 58 ± 3% can be attained, this approved with that predicted by an established polynomial model in the current investigation.

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Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute 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.)

Significant co-conditioning of aluminum-based sludge using alternative conditioner (natural biopolymer-magnetite/H2O2) as a Fenton conditioner for improving the sludge dewaterability is investigated in the current study. Firstly, natural biopolymer/magnetite (NBP-M) were prepared in various ratios and the samples labeled as (NBP-M-(1:1); NBP-M-(1:3) and NBP-M-(2:1). Focuses were placed on factors influencing such novel Fenton conditioner. Capillary suction time (CST) was utilized to assess sludge dewaterability. Experiments have exhibited that significant development of alum sludge dewaterability could be attained at minimum reaction time and using low concentrations of the applied catalyst, i.e. natural biopolymer/magnetite and H2O2. It was found that sludge conditioning and dewaterability became better with increasing both reagents concentrations. A Box–Behnken experimental design based on the response surface methodology was investigated to explore the optimum of the influencing variables, i.e. catalyst (NBP-M) concentration, H2O2 loading and pH. The optimized values for NBP-M, H2O2, and pH are 46 and 380 mg/L, respectively at pH 3.0, at which the CST reduction efficiency of 58 ± 3% can be attained, this approved with that predicted by an established polynomial model in the current investigation. [ABSTRACT FROM AUTHOR]

This study investigated the influence of bulk nanobubbles (NBs) on the flocculation and filtration behavior of kaolin suspensions treated with cationic polyacrylamide (CPAM). Traditionally, flocculation relies on bridging mechanisms by polymers like CPAM. The present work examines the possibility of combining NBs with CPAM to achieve more efficient kaolin separation. The settling behavior of kaolin suspensions with and without bulk nanobubbles was compared. The results with 2 mL CPAM and 300 s settling time revealed that bulk NBs significantly enhanced flocculation efficiency, with supernatant zone height reductions exceeding 50% compared to CPAM alone, indicating a faster settling rate resulting from bulk NBs. This improvement in the settling rate is attributed to NBs' ability to reduce inter-particle repulsion (as evidenced by a shift in zeta potential from −20 mV to −10 mV) and bridge kaolin particles, complementing the action of CPAM. Additionally, the study demonstrated that bulk NBs improved dewatering characteristics by lowering the medium resistance and specific cake resistance during filtration. These findings pave the way for the utilization of bulk NBs as a novel and efficient strategy for kaolin separation in mineral processing, potentially leading to reduced processing times and lower operational costs. [ABSTRACT FROM AUTHOR]

The increase in water content during biodiesel storage poses a significant challenge that necessitates finding a solution. One proposed approach is the implementation of a thermal vacuum dewatering system for biodiesel, which effectively reduces the water content to meet the required specifications. In this study, the evaporator tank is the main component of the dewatering system. While the current water content reduction meets the standard, continuous optimization is essential to achieve a water content in biodiesel below 200 ppm. This research aims to optimize the turbulent flow within the evaporator tank by employing a pipe sparger with various hole configurations through computational fluid dynamics (CFD) simulations. Additionally, these simulations aim to enhance the understanding of biodiesel flow behavior as it passes through the orifice plate and pipe sparger, ultimately identifying the best operational conditions. The research encompasses CFD simulations of the evaporator tank using both orifice plate and pipe sparger setups. Four models were investigated: evaporator tank equipped with an orifice plate, pipe sparger A, pipe sparger B, and pipe sparger C. The simulation results indicate that the evaporator tank with pipe sparger C offers the most optimal turbulent flow, as evidenced by the velocity distribution observed at Re=5000, Re=10000, and Re=50000. Consequently, installing pipe sparger C in the evaporator tank holds promise for achieving higher water content reduction compared to the orifice plate, pipe sparger A, and pipe sparger B configurations. [ABSTRACT FROM AUTHOR]

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To simultaneously solve problems in an eco-friendly manner, introducing a waste residual as a sustainable conditioner to aid alum sludge dewatering is suggested as a cradle-to-cradle form of waste management. In this regard, the superiority of deep dewatering alum sludge with a powdered wood chip composite residual as a novel conditioner was explored, whereby traditional conventional conditioners, i.e., polyelectrolytes and lime, were substituted with powdered wood chips. Initially, Fe3O4 was prepared at the nanoscale using a simple co-precipitation route. Next, wooden waste was chemically and thermally treated to attain cellulosic fine powder. Subsequently, the resultant wood powder and Fe3O4 nanoparticles were mixed at 50 wt % to attain a wood powder augmented with iron, and this conditioner was labeled nano-iron-cellulose (nIC-Conditioner). This material (nIC-Conditioner) was mixed with hydrogen peroxide to represent a dual oxidation and skeleton builder conditioning substance. Characterization of the resultant conditioner was carried out using transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) transmittance spectrum analysis. The feasibility of the experimental results revealed that the moisture content in the sludge cake was lower after conditioning, and the capillary suction time (CST) was reduced to 78% compared to that of raw alum sludge after 5 min of dewatering time. Moreover, the optimal system parameters, including nIC-Conditioner and H2O2 concentrations, as well as the working pH, were optimized, and optimal values were recorded at 1 g/L and 200 mg/L for nIC-Conditioner and H2O2, respectively, with a pH of 6.5. Additionally, scanning electron microscope (SEM) analyses of the sludge prior to and after conditioning were conducted to verify the change in sludge molecules due to this conditioning technique. The results of this study confirm the sustainability of an alum sludge and waste management facility. [ABSTRACT FROM AUTHOR]

Geotextile tubes have been presented as a viable alternative for dewatering sludge generated in different industries, characterised by having fine grain and high moisture content. The material commonly used to develop this system is woven geotextile due to its high strength properties. However, nonwoven geotextile tubes are a possible underexplored alternative that have good cost benefits. This paper presents the geometric and strain behaviour of two full-scale nonwoven geotextile tubes used for dewatering water treatment plant (WTP) sludge. Four technologies were used to monitor the full-scale tests: ultrasonic sensor (US), perspective laser tracking (PLT), light detection and ranging (LIDAR) and draw wire sensor (DWS). The geometric parameters of a quarter of the cross-section and the strains in the geotextile were obtained during sequential fills. These data were compared with results obtained from an analytical method based on membrane theory that considers the non-linear-elastic behaviour of the geotextile. The DWS and LIDAR technologies were the most suitable for monitoring the strains and shapes of the tubes, respectively. Good agreement was found between analytical and experimental results, indicating the applicability of the adopted method to the design of the first filling cycle of the monitored nonwoven geotextile tubes. [ABSTRACT FROM AUTHOR]

This case study utilizes data from the Roy Hill iron ore mine, which has a daily water balance of abstraction, use, and surplus disposal, to address the problem of water management prediction at a global level by analysing the results of each modelling task and evaluating the presence of potential critical scenarios with an automated, mathematically rigorous tool. This paper describes the development of a software application that aggregates the results of the various water management models built for each task and provides the optimal utilisation of water to minimise water disposal and thereby maximise water usage. The business benefits of this work include the ability to calculate the net present cost (NPC) for new water infrastructure configurations in an integrated way. Investing in capital projects for water management and evaluating various scenarios helps determine the optimal water infrastructure configuration, minimizing operational impact. Traditionally, water has not been viewed as a significant cost; however, the cost of water infrastructure is now one of the highest business investments in the mining industry of the Pilbara region of Western Australia. Introducing the concept of NPC for water in the mining industry is a novel approach to making informed decisions on water expenses and investments. The key to success lies in using automated modelling to achieve the most efficient environmental and operational balance. This approach reduces individual decision-making and leads to a more cost-effective and beneficial production outcome. [ABSTRACT FROM AUTHOR]

The mining industry is confronted with substantial challenges in achieving environmental sustainability, particularly regarding water usage, waste management, and dam safety. The increasing global demand for minerals has led to increased mining activities, resulting in significant environmental consequences. By 2025, an estimated 19 billion tons of solid tailings are projected to accumulate worldwide, exacerbating concerns over their management. Tailings storage facilities represent the largest water sinks within mining operations. The mismanagement of water content in tailings can compromise their stability, leading to potential dam failures and environmental catastrophes. In response to these pressing challenges, the mining industry is increasingly turning to innovative solutions such as tailings dewatering and water reuse/recycling strategies to promote sustainable development. This review paper aims to (I) redefine the role of mine tailings and explore their physical, chemical, and mineralogical characteristics; (II) discuss environmental concerns associated with conventional disposal methods; (III) explore recent advancements in dewatering techniques, assessing their potential for water recovery, technical and economic constraints, and sustainability considerations; (IV) and present challenges encountered in water treatment and recycling within the mining industry, highlighting areas for future research and potential obstacles in maximizing the value of mine tailings while minimizing their environmental impact. [ABSTRACT FROM AUTHOR]

In industrial processes, filter cakes often have an uneven height, which can affect displacement washing and mechanical dewatering. To facilitate future research on the impact of cake geometry, we propose two methods for reproducible cake formation of filter cakes with uneven cake height. These methods must ensure that cake geometry is the only varying factor, and no other inhomogeneities occur, to enable systematic investigations into cake geometry. We examine filter cakes with four distinct inhomogeneous geometries and compare their cake structure to that of a regular filter cake with uniform height. This comparison demonstrates that the proposed methods for cake formation of filter cakes with uneven height do not affect the cake structure. [ABSTRACT FROM AUTHOR]

A data-driven approach is used to show the significant discrepancy between the coefficients of permeability that are estimated through packer field tests and those back-calculated from the actual discharge pumped out of randomly fractured rock masses (i.e., masses that do not have predominate oriented fracture sets) using either dewatering or pumping well systems. The presented data, some of the richest of its kind, are used to develop a novel correlation between the estimated and back-calculated coefficients of permeability. A procedure is proposed to evaluate the permeability of the rock masses that considers two different but frequently encountered scenarios: (1) lack of any field permeability test data; or (2) only packer test results are available. Numerical examples are presented to illustrate how the suggested procedure could be used. It constitutes an advance in the state of practice because the commonly used procedures to estimate the permeability of randomly fractured rock masses employ the direct use of packer field test results, which, as the data shows, could be orders of magnitudes out. The proposed procedure could be particularly useful for practitioners when faced with cases where field pumping tests are not feasible due to budget, time constraints, or both. It gives them a simple and reliable approach (based on case histories) to produce preliminary designs of dewatering systems in randomly fractured rocks. [ABSTRACT FROM AUTHOR]

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Dewatering is a critical step in cassava flours processing. Compression dewatering kinetics are useful to understand and design a dewatering operation. The dataset presents dewatering kinetics measured in a filtration–consolidation cell at constant pressure between 4 and 21 bar, on several cassava mashes (three batches fragmented at two particle size distributions (PSDs)). The dataset comprises, for each dewatering kinetic measurement, filtrate mass, cake height, data to estimate the pressure applied on the product (i.e. air pressure, compression force) as a function of time; and the moisture content measurements of the fresh and dewatered cassava and of the filtrate. A commented python script is included to read the dewatering experimental files and plot the kinetics Furthermore, the dataset extends its utility by including particle size distributions (PSDs) obtained from six cassava batches, subjected to several protocol variants. These data are useful for understanding the phenomena involved in cassava dewatering. They also serve as a valuable resource for researchers, designers, and operators to design cassava dewatering.