Dewatering Characteristics Research Articles

Enhancing activated sludge dewatering performance: Impact of alum dosage on dehydration characteristics and microstructure

Sludge flocs encapsulate a significant amount of bound water, resulting in poor dewatering efficiency. To address this issue, the addition of alum (KAl(SO4)2·12H2O) has emerged as an effective strategy for enhancing sludge dewatering performance. This research specifically investigates the effects of various alum dosages on the dewatering characteristics of sludge. The introduction of alum alters internal temperature, pH levels, and intracellular osmotic pressure, which facilitates the release of trapped water within the flocs. Additionally, alum accelerates sludge sedimentation and promotes the agglomeration of smaller particles into larger ones, further improving dewatering efficiency. However, determining the optimal alum dosage for sludge conditioning is essential, as excessive amounts can lead to a decrease in dewatering performance.

Study on demulsification characteristics of crude oil based on orthogonal dual frequency ultrasonic standing wave field

In this paper, we conducted an experimental study on the demulsification and dewatering characteristics of water-in-oil emulsions under orthogonal dual-frequency ultrasonic standing wave fields. Firstly, the absolute and relative dehydration rates are defined as the evaluation criteria to measure the effect of demulsification and dehydration; then, the influence laws of absolute and relative dehydration rates of water-in-oil emulsions under the action of single frequency standing wave field and orthogonal dual-frequency standing wave field by ultrasonic frequency, power, irradiation time, initial water content and concentration of emulsifier are analyzed in detail, and through data comparison and analysis, it was found that By comparing and analyzing the data, it was found that the relative water content remained between 1.0 and 2.0 in most cases under the action of orthogonal dual-frequency standing wave field, and the ratio of 1.2–1.8 is large, which highlighted the advantages of orthogonal dual frequency ultrasonic standing wave field.

Characterization of the dewaterability of excess aerobic granular sludge

Aerobic granular sludge technology has emerged as a promising wastewater treatment process. However, downstream granular sludge management framework is still challenging and lacks sufficient scientific coverage. This research aims to elucidate the dewatering characteristics of aerobic granular sludge compared to activated sludge. Several parameters, such as zeta potential, specific resistance to filtrate, capillary suction time, bound water content, and rheological behavior, were employed to obtain a comprehensive understanding of the dewatering capability of targeted sludge types. The results indicate that aerobic granular sludge has a higher demand for flocculant polymer than activated sludge (1.07 - 3.40 times). Additionally, aerobic granular sludge demonstrates higher resistance to filtrate (1.22 ± 0.09 - 6.59 ± 0.36 ×1011 m/kg) compared to activated sludge (2.93 ± 0.09 ×109 m/kg). The resistance to filtrate was shown to be positively associated with the average granules size. The usage of flocculant polymer significantly reduced the resistance to filtrate of all targeted samples. The bound water content of granular sludge (1.83 ± 0.37 - 4.31 ± 0.15 g/g TS) was higher than that of activated sludge (0.75 ± 0.13 g/g TS). According to the rheological data, aerobic granular sludge has a slightly higher apparent viscosity than activated sludge. The results of this study provide valuable insights into the potential implications of aerobic granular sludge dewatering at full-scale applications.

Optimizing sludge dewatering efficiency with ultrasonic Treatment: Insights into Parameters, Effects, and microstructural changes

Sludge dewatering plays a critical role in the efficient and cost-effective management of wastewater treatment plants. Ultrasonic treatment has emerged as a promising technique for improving dewatering processes. This study aims to evaluate the impact of ultrasonic treatment on sludge dewatering characteristics. A series of experiments were conducted to evaluate the dewatering characteristics of sludge under ultrasonic treatment. Experimental data was collected, and the effects of ultrasonic parameters on dewatering efficiency were analyzed. Ultrasound has the capacity to disintegrate sludge flocs, liberate tightly bound water, and enhance sludge dewatering capabilities. The application of ultrasound leads to the breakdown of sludge flocs, which facilitates a substantial amount of organic acids or carbonates. This, in turn, modifies the pH value of the sludge. Additionally, ultrasound induces instantaneous high temperature and pressure within the liquid phase, consequently elevating the temperature of the sludge slurry. Optimum ultrasound energy density and duration of ultrasound treatment exist. For the sludge samples analyzed in this investigation, it was determined that the optimal ultrasonic energy density is 9.8 W, while the optimal duration of ultrasound treatment is 30 s. Excessively escalating the sound energy density or prolonging the duration of ultrasound may yield unfavorable outcomes in terms of sludge dewatering effectiveness. To enhance sludge dewatering, it is crucial to select appropriate ultrasonic energy density and duration of ultrasonic treatment. This study demonstrates the positive impact of ultrasonic treatment on the dewatering characteristics of sludge. The findings provide valuable insights into the potential of ultrasonic technology for enhancing sludge dewatering.

Effect of initial water content on the dewatering performance of freeze-thaw preconditioned landfill sludge

Freeze-thawing (F/T) is an effective method of sludge dewatering preconditioning and has been studied in many studies. However, previous studies have taken landfill sludge from different regions, filled for different length of time or at different depth, resulting in large differences in initial water content and different treatment effects. Therefore, the effect of initial water content on the dewatering characteristics of F/T preconditioned landfill sludge has been investigated. The sludge with different initial water contents was firstly preconditioned by one F/T cycle. Then the F/T sludge was vacuum filtered and compared with the dewatering performance of FeCl3 preconditioned sludge with the same water content. Finally, the mechanism of the initial water content on the effect of F/T preconditioning was analyzed by the change of sludge internal composition. The results show that the higher the initial water content of the sludge, the greater the improvement of its dewatering performance after F/T preconditioning. The specific resistance and water content after filtration of sludge after F/T conditioning decreased greatly with the increase of the initial water content, reaching their respective minimum values of 13.3 × 1012 m/kg and 58.3% at 85% and 87.5%. These values are lower than the optimal values observed for the sludge conditioned by FeCl3. With the rise in initial water content, the driving force at the ice-water interface gains strength. Small particles aggregate into larger flocs, forming stable drainage channels that enhance the dewatering performance of sludge. Once the initial water content surpasses 85%, the squeezing force exerted by ice crystals amplifies the degree of cracking in sludge particles, releasing bound water and further decreasing the water content of sludge.

Advanced dewatering of digested sludge through oxidative decomposition of humic substances: A comprehensive study

Advanced dewatering of digested sludge, aimed at reducing the moisture content of digested sludge from 80 % to <60 %, has gained significant importance due to the increasing use of anaerobic digestion. Unlike the residual sludge, the digested sludge exhibits strong bonding with water and contains a higher concentration of humic substances. Therefore, the conversion of bound water in organic biomass into free water and its subsequent removal have become critical challenges. In this study, three different oxidants, namely H2O2, Fenton's reagent, and KMnO4, were selected to pretreat digested sludge, focusing on the hydroxyl radicals generated by the Fenton's reagent in the decomposition of organic compounds in digested sludge, exploring the changes in dewaterability and the mechanism of water conversion. Additionally, a lab-scale plate frame was used to simulate the advanced dewatering characteristics. The findings revealed that among the oxidants, only Fenton's reagent demonstrated an improved dewaterability. When dosed at 4.30 mmol/g dry sludge (Ds) and subjected to a pressure of 1000 kPa for 30 min, the moisture content of the sludge cake was reduced to 50.32 %. The accumulation of humic substances during the digestion process resulted in a shift in control from polysaccharides and proteins to humic substances that governed the hydrophilic groups. The selective oxidative decomposition of humic substances using hydroxyl radicals produced by Fenton's reagent enables the conversion of bound water into free water, which can be effectively removed by applying pressure.

Mixing effect on bio-methanation, settleability and dewaterability in the anaerobic digestion of sewage sludge fractions

Biomethanation and dewaterability characteristics of primary sludge (PS), secondary sludge (SS) and mixed sludge (MS) fractions were assessed after anaerobic stabilization under parallel batch and continuous mixing conditions at 35℃ in order to investigate the performance of the separate digestion system. Similar methane conversion/yield values were obtained in PS, SS and MS digestion with continuous mixing’s positive effect only in PS digestion. Continuous mixing resulted in 50% increase in the methane yield (600(+/-100) mL/g VSadd.d. SS digestion produced a comparable methane yield at 650(+/-100) mL/g VSadd.d showing no effect due to mixing pattern. Settling and dewaterability characteristics of the stabilized PS were superior to stabilized SS samples. A reverse relationship was obtained between settling and dewaterability characteristics where intermittent mixing enhanced settling ability while continuous mixing resulted in higher dewaterability of the stabilized sludges. Polyelectrolyte (PE) addition showed a negative effect on the settleability of the sludges. Low degree mixing resulted in 50% sludge volume reduction and an SVI of 64 mL/g VS compared to 25% volume reduction and 82 mL/g SVI in the continuous mixing mode for the stabilized PS. A similar trend for the stabilized SS but weaker values with 25% volume reduction and an SVI 182 mL/g in the intermittent mixing mode compared to 15% volume reduction and 200 mL/g VS SVI indicated a much lower settleability in the continuous mixing mode and compared to stabilized PS.

Effect of chemical regulation combined with mechanical filtration on deep dewatering and consolidation characteristics of sludge.

To reveal the mechanism underlying deep dewatering of municipal sludge, this paper investigated the sludge characteristics from the perspective of soil mechanics, and analyzed the sludge physical and mechanical properties, stress as well as dewatering behavior during the dewatering process. Before and after cationic polyacrylamide (CPAM) and chitosan (HACC) conditioning, the pressure filtration dewatering time of treated sludge was shorter than that of raw sludge, and the water removal rate was greater than 70% at the 6 MPa pressure. However, with the increase in filter pressing time, the filtration resistance coefficient of sludge increased, and the water pressure in sludge pores rose up, and a longer time was needed for dissipation at the larger pressure, resulting in the slowdown of sludge consolidation. In addition, based on the three-stage Terzaghi Voigt model, when the pressure rose from 2 to 6 MPa, the time from filtration stage to compression stage of raw sludge was shortened, and the second stage played the most important role in the dewatering process. Compared with the raw sludge, the sludge filtration stage was shortened after CPAM or HACC conditioning, and the main dewatering mechanism changed from the second compression stage to the first compression stage, which means the bound water in sludge flocs was transformed into free water. This was also the reason why the dewatering, compression and consolidation rate of the conditioned sludge was faster than that of the raw sludge.

Analysis on the properties of hydrolyzed amino acids in typical municipal sludge.

In this study, amino acids, proteins, and microbial communities in sludge from different wastewater treatment plants (WWTPs) were analyzed. The results showed that the bacterial communities of different sludge samples were similar at the phylum level, and the dominant bacterial species in sludge samples with the same treatment process were the consistent. The main amino acids in EPS of different layers were different, and the amino acid results of different sludge samples were quite different, but the content of hydrophilic amino acids in all samples was higher than that of hydrophobic amino acids. And the total content of glycine, serine, and threonine related to sludge dewatering was positively correlated with protein content in sludge. In addition, the content of nitrifying bacteria and denitrifying bacteria in sludge was also positively correlated with the content of hydrophilic amino acids. In this study, the correlations between proteins, amino acids, and microbial communities in sludge were analyzed respectively, and the internal relationship was found. And it provided ideas for further study of sludge dewatering characteristics in the future.

Analysis of the effect of using divalent and trivalent iron compounds on sludge dewatering performance in thickening units

Abstract Sludge is one of the by-products of wastewater treatment plants (WWTPs). To assist biological processes, part of the produced sludge is returned to the treatment process and the excess is removed from the treatment plant whereby it undergoes thickening and dewatering. Numerous studies have been conducted to investigate the effect of different coagulants on dewatering from sludge, but the effect of using divalent iron for this purpose has not been investigated so far. In this research, the effect of divalent and trivalent iron compounds (ferrous sulfate and ferric chloride) on the dewatering of excess sludge of the first module of the Bojnourd WWTP (Iran) has been investigated. In this regard, first, the effect of different doses of each coagulant to optimize the dewatering characteristics of sludge was investigated and then the effect of pH change by adding lime was investigated. The results showed that the addition of optimal doses of FeSO4 (0.6 and 0.4 g/l) and lime (0.664 and 1.5866 g/l) reduced the capillary suction time of sludge by 30.6 and 32.7%, respectively, while reducing the moisture content of sludge cake by 26 and 30.6%.

STUDY OF DEWATERING CHARACTERISTICS OF EUCALYPTUS WOOD BY SUPERCRITICAL CO2

Wood collapse is a major defect for their applications in solid wood production. Supercritical CO2(ScCO2) dewatering can quickly remove water in wood and effectively reduce the capillary tension leading to collapse of wood structure. In this study, Eucalyptus exsertaF.V. Muellwoodwas dewatered using ScCO2at 35,45,55°Cand 15,20,25 MPa, separately. The dewatering characteristics and wood deformationwere statistically analyzed and compared after dewatering. The results show that the dewatering rateof ScCO2isaffected by moisture content (MC)of wood, showing the higher the MC, the faster the dewatering. Itisalso affected significantly by pressure, indicating increased dewatering ratewith thepressure. The effect of temperature on dewatering rate is not apparent as the pressure is less than 25MPa, but it becomes significantat 25MPacondition, showing an increased dewatering rate with temperature. In this experiment, the greatest dewatering rate was 19.8%·h-1at 55°Cand 25MPa. The transversal shrinkage of all specimens after 5 cycles dewatering waslower than1.5%, indicating the ScCO2dewatering could effectively inhibit collapse of eucalyptus wood structure. Thetransversal shrinkage decreases with the pressure, and is not affected significantly by temperature.

Effect of freezing temperature on dewatering, consolidation properties, and microstructure of landfill sludge

There is currently a considerable amount of landfill sludge (LS) accumulating worldwide, threatening the surrounding environment and land safety. It is urgent to dewater and reduce LS. Chemical conditioning is the most common treatment for LS, which can pollute the environment and limit resource exploitation. Therefore, a more environmentally friendly and efficient freeze-thaw combined vacuum preloading method is proposed. Experimental studies were conducted to investigate the influence of different freezing temperatures on the dewatering properties, compression and consolidation features, and the mechanism of microstructural change in LS. The results show that the freezing temperature has an important influence on the dewatering, compression, vacuum drainage, consolidation, and microstructure characteristics of LS. The compressibility of LS does not improve when the freezing rate is too high. Freeze-thaw cycles can improve sludge's permeability and consolidation properties by one to two orders of magnitude, and a suitable freezing temperature can significantly improve sludge's permeability and consolidation properties. After vacuum drainage and consolidation, the maximum volume reduction ratio of sludge can reach 55.3%, and the water content of LS can be reduced from 86% to 66%. The distribution of large pores and mesopores in LS increases as the freezing temperature decreases, reaching a maximum of −15 °C, which can substantially improve permeability, drainage, and consolidation efficiency.

Efficient dewatering of waste gasification fine slag based on mechanical pressure-vacuum fields: Dewatering characteristics, energy optimization and potential environmental benefits

Landfill is the major waste disposal method of high-moisture coal gasification fine slag (GFS) which causes the pollution of soil and water and brings the waste of resources. GFS efficient dewatering is an urgent problem to be solved, which is beneficial to realize its resource utilization. In this paper, mechanical pressure and vacuum coupling energy fields are applied to carry out the dewatering processes of GFS. The pressure field provides strong power for water migration, which makes water leave the particle system, while the vacuum field provides traction for water removal from system. The fine slag produced from Coal-to-methanol (named JC) with larger size particles tends to form “bridging” frameworks among particles, which provides water occurrence space and increases the moisture migration resistance. The mechanical dewatering process has an energy advantage interval, when the sample moisture is reduced to a certain degree, the mechanical force field is mainly used for particle friction and breakage but not for moisture migration. Through dewatering process energy optimization, high moisture gasification fine slag can be removed about 15% water within 30s and energy consumption of efficient dewatering is 2.63 kJ/g which is much lower than that of drying. Efficient dewatering is benefit to the GFS recycling which reduces hazardous materials release to environment. The potential effects of high efficiency dewatering process on GFS resource utilization and the possible eco-design framework for products recycled from the waste GFS were proposed. The research results will provide theoretical guidance for the gasification fine slag efficient dewatering and is benefit to the environment.

The impacts of high salinity and polymer properties on dewatering and structural characteristics of flocculated high-solids tailings

In seeking to better understand the inline flocculation technique for enhanced water recovery from concentrated fine-particle suspensions, polymers of different molecular weight (MW) and chemistry were used to treat a synthetic tailings slurry in a low-shear mixer for continuous flocculation under controlled conditions. The effects of dissolved salts in the slurry and polymer solution make-up water on dewatering performance were evaluated for conventional acrylamide/acrylate copolymers (BASF Magnafloc® products) and an alternative functional chemistry polymer (BASF Rheomax® DR 1050). The properties of the separated liquid and solid phases were examined to understand the impacts of salinity and polymer type on the formation of rapidly dewatering flocculated material. Higher concentrations of NaCl (0.006–0.6 M) and CaCl2 (0.006–0.06 M) salts in the unflocculated slurries formed larger coagulated structures, with focussed beam reflectance measurement (FBRM) showing greater pre-aggregation for the divalent salt. NaCl slurries show edge-to-edge (EE) and edge-to-face (EF) inter-particle associations that are open and easily disrupted while more compact face-to-face (FF) contacts are observed in CaCl2 slurries. For concentrated NaCl slurries, the dosing of medium-to-high MW polymers is generally preferred to maximise net water recovery, with the implication being that bridging mechanisms are still at play in high solids applications. In calcium-enriched slurries, the lower MW conventional copolymer gave comparatively better water returns than the other polymers when applied under low shear conditions, highlighting quite distinct aggregation processes compared to low solids flocculation. These results provide insight on the fundamental complexity of the ionic strength dependence of high solids-high dosage tailings flocculation, towards informing reagent polymer dosing and offering greater flexibility for end-of-pipe dewatering schemes.

Use of brick waste for mortar-substrate optimisation of mortar-masonry systems

This paper investigates the effect of brick dust on the water-releasing properties and dewatering of hydrated lime mortars. Dewatering in masonry occurs when freshly mixed mortar is applied to a dry substrate (e.g. fired bricks, stone) and can influence the physical and mechanical properties of the mortar and the mortar-masonry bond. Controlling these properties provides an important opportunity to optimise performance. This study evaluates the water transport kinetics of hydrated lime-brick dust mortars. The study demonstrates that the particle size distribution of the brick dust can effectively control transfer sorptivity and dewatering time. The measured dewatering times correlated to theoretically calculated values demonstrating the ability to accurately predict the dewatering characteristics of a mortar from a knowledge of the mix design. The use of waste brick dust in hydrated lime mortars provides an environmentally friendly alternative to waste disposal by routes such as landfill.

Variability of faecal sludge characteristics and its implication for dewaterability across different on-site sanitation containments in unplanned settlements in Dar es Salaam, Tanzania

Abstract This article evaluates the physical-chemical parameters of Faecal Sludge (FS) as possible predictors of dewatering performances. Also, the variability of FS dewatering characteristics was assessed from different containments and in different seasons in relationship with dewatering performance. A total of 120 samples were collected and analyzed during the rainy and dry seasons in April and July 2019, respectively, to capture seasonal variability. FS from pit latrines (PT) took longer to dewater followed by mixer containments, while soak-away sludge (SO) took a relatively short time to dewater. Also, FS from PT was found to have a high amount of settled solids, hence high % of TS in dry cakes. Slow dewatering and turbid supernatant corresponded to high pH, electrical conductivity and total solids, but cake solids after dewatering were correlated with total solids of FS. The FS dewaterability was higher for SO (DI = 0.9) and least for PT (DI = 0.3). Seasonal variability of FS dewaterability within the containments was higher for PT (DI = 0.74) and least for SO (DI = 0.5). Planning of FS treatment plants including sizing and design for effective dewatering performance, variation of physical-chemical dewatering predictors in sources and season could provide a relatively low-cost way to predict dewatering performance.

Enhancing sludge conditioning and dewatering characteristics by active surfaces modified with fast recombining immobilized nanoparticles

Nichrome is a composite of nickel chromium alloys and commonly used as resistance wire for heating equipment. In this study, ability of multilayered heterojunctions between Cr+3-TiO2 and Ni2+-TiO2 nanoparticles to disintegrate acidified slurry sludge was investigated experimentally. Recombination and photoactivity of the Cr3+ and Ni2+ nanoparticles were optimized alternating their atomic mass fractions in the nanocomposites by their heating ability, using a central composite statistical design approach. Effects of the applied method on sludge conditioning, stabilization, and drying behaviors were systematically investigated. Temperature increase (ΔT) at the highest volatile suspended solids (VSS) oxidation level in the treated sludge samples were 2 ± 1 °C, 5 ± 1 °C, and 20 ± 1 °C for “UV C + H2O2-no catalyst,” pure and Cr-Ni-TiO2 thin films (TFs), respectively. Obtained results also indicated that the modified TiO2 nanoparticles were able to decrease sludge bound water content by 45 ± 1% efficiency. Cr3+ and Ni+2 co-doped TF functioned to decrease the unit drying energy from 236 ± 10 kJ kg−1 H2Oevaporated to 140 ± 10 kJ kg−1 H2Oevaporated. Drying profiles of raw and treated the sludge samples were fitted to Henderson and Pabis Model. Drying constants (k) for raw and treated sludge samples by pure TiO2 and Cr-Ni-TiO2 TFs were found to be 0.11 ± 0.01 min−1, 0.12 ± 0.01 min−1, and 0.19 ± 0.01 min−1, respectively. VSS degradation followed pseudo-first-order reaction kinetics in the all assayed conditions and pseudo-first-order reaction rates (k obs) for pure and the modified TFs were determined as 6 × 10−4 min−1 and 4 × 10−3 min−1, respectively. 2,2′,5-Trichlorobphennyl, 2,2′,5,5′-Tetrachlorobiphenyl, 2,3′,4,4′,5-Pentachlorobiphenyl, and 2,2′,3,4,4,5,5′-Heptachlorobiphenyl were detected in raw sludge and after the photocatalytic oxidation through Cr3+ and Ni2+ co-doped TiO2 TF reactor, their total concentration was reduced from 4.36 mg kg−1 to 9.76 × 10−3 mg kg−1.

Synthesis of a copolymeric system and its flocculation performance for iron ore tailings

The medium grade iron ores contain high ultrafine fractions of soft slime which result in poor dewatering characteristics. Herein, a detailed study was conducted to assess the settling behaviour of iron slimes or tailings using a novel starch-based binary graft copolymeric flocculant (St-g-(pAAm-co-pSS)) and the performance was compared with four commercial reagents. The copolymer has been synthesized by grafting of acrylamide and sodium p-styrene sulfonate on starch using free radical polymerization. The polymer demonstrated outstanding settling behaviour with respect to settling speed and capacity to remove turbidity during iron-ore tailings flocculation as compared to other commercial reagents. An optimal dosage of synthesized reagent has been recommended based on the mud-level index and settling rate, for single-step and multi-step addition to the iron tailings slurry. The synthesized reagent has been assessed upon its capacity to produce clear overflow water and compaction of the solids.

Study on the Effect of Chemical Conditioning on the Consolidation Characteristics of Municipal Sludge in Landfill Depot

Vacuum preloading is one of the effective methods for in-situ dewatering and reduction treatment of municipal sludge landfill, but because the consolidation coefficient of municipal sludge is 1 or 2 orders of magnitude smaller than that of sludge, the drainage consolidation technology will face the problem of vacuum for too long. In order to improve the consolidation characteristics of sludge, combined with the chemical conditioning technology in the field of water treatment, firstly, the chemical conditioner suitable for landfill sludge was selected. The effects of different conditioning combinations on sludge dewatering characteristics were studied by microscopic testing techniques (zeta potential analysis and environmental scanning electron microscope analysis) and vacuum filtration test and consolidation test. The results show that the combination of ferric chloride and calcium oxide can significantly improve the dewatering characteristics of sludge. After conditioning with 10% ferric chloride and 10% calcium oxide (relative to sludge dry base), the specific resistance of sludge is reduced from 2 × 1013m/kg to 3 × 1012m / kg, and the consolidation coefficient is 3.5-10 times higher than that of original sludge, which lays a foundation for improving the efficiency of vacuum preloading treatment. In addition, from the results of vacuum filtration test and consolidation test of sludge, it can be found that there is a good negative linear relationship between specific resistance and consolidation coefficient of sludge. Compared with the consolidation test, the vacuum filtration test is simple and easy, so it can be used as an effective means to select sludge conditioner or test the conditioning effect.

Optimization of microwave treatment for dewaterability enhancement of electroplating sludge

In this study, the dewaterability characteristics of electroplating sludge have been investigated after treatment with microwave irradiation. While specific resistance to filtration (SRF) was used to evaluate sludge dewaterability, water content (WC) in sludge and soluble chemical oxygen demand (SCOD) were determined to describe the observed changes in sludge dewaterability. SRF of sludge decreased from 3.54E + 09 m/kg to 4.33E + 08 m/kg, and WC decreased from 98.56 wt.% to 94.37 wt.% after microwave treatment at 800 W and 120 s. Sludge solubilization increased with microwave power, but deteriorated at higher contact times due to adverse effects of sustained microwave irradiation. A full factorial design along with response surface analysis was applied to determine an optimum combination of microwave power and contact time for effective dewaterability enhancement. Based on statistical observations and numerical optimization using desirability function analysis, 800 W and 141 s was the optimal conditioning requirement which yielded minimum SRF and WC, while also ensuring maximum sludge disintegration.