Synthesis of Electrolytic Manganese Slag-Solid Waste-Based Geopolymers: Compressive Strength and Mn Immobilization.

The massive stockpiling of electrolytic manganese residue (EMR) has caused serious environmental pollution. In this study, EMR, coal gangue (CG), and fly ash (FA) were used as raw materials to obtain the optimal mix ratio based on Design-Expert mixture design. The effects of activator modulus, liquid-solid (L/S) ratio, and curing temperature on the mechanical properties of geopolymers were investigated. The results showed that the compressive strength of the prepared geopolymer was 12.0 MPa, and the 28d leaching of Mn was 0.123 mg/L under the conditions of EMR:CG:FA = 0.43:0.34:0.23, L/S = 0.9, a curing temperature of 60 °C, and a curing time of 24 h. This indicates that the geopolymer is an environmentally friendly material with high compressive strength. The mineral composition of the geopolymer is mainly hydrated calcium silicate and geopolymer gel. In addition, a more stable new mineral phase, MnSiO3, was generated. The Fourier transform infrared (FTIR) spectrogram showed that the peak at 1100 m-1 was shifted to 1112 cm-1, which indicated that a geopolymerization reaction had occurred. Through scanning electron microscopy (SEM) and energy dispersive spectrum (EDS) analysis, it was identified that the geopolymerization produced a large amount of amorphous gelatinous substances with a relatively dense structure, the major elements being oxygen, silicon, aluminum, calcium, and sodium.

Adsorption of Phosphate by Two-Step Synthesis of Ceramsite from Electrolytic Manganese Residue/Dredged Sludge.

Carrying out research on the management of electrolytic manganese residue (EMR) is necessary to maintain the environment and human health. The dredged sludge (DS) and water hyacinth (WH) generated from dredging projects are potential environmental threats, and therefore suitable methods need to be found for their treatment. In this study, ceramsite was prepared by a two-step low-temperature firing method using DS and EMR as raw materials, WH as a pore-forming additive, and aluminate cement as a binder for the adsorption of phosphorus from wastewater. The optimal ratio and process parameters of the ceramsite were determined by mechanical and adsorption properties. The static adsorption experiments were conducted to study the effect of ceramsite dosage and solution pH on the removal of phosphorus. At the same time, dynamic adsorption experiments were designed to consider the influence of flow rate on its actual absorption effect, to explore the actual effect of ceramsite in wastewater treatment, and to derive a dynamic adsorption model that can provide technical support and theoretical guidance for environmental management.

Reutilization of Reclaimed Asphalt Binder via Co-Pyrolysis with Rice Husk: Thermal Degradation Behaviors and Kinetic Analysis.

Realizing the utilization of reclaimed asphalt binder (RAB) and rice husk (RH) to reduce environmental pollution and expand the reutilization technique of reclaimed asphalt pavement (RAP), co-pyrolysis of RAB with RH has great potential. In this study, the co-pyrolysis behaviors, gaseous products, and kinetics were evaluated using thermogravimetric analysis and Fourier transform infrared spectroscopy (TG-FTIR). The results showed that incorporating RH into RAB improved its pyrolysis characteristics. The interactions between RAB and RH showed initial inhibition followed by subsequent promotion. The primary gaseous products formed during co-pyrolysis were aliphatic hydrocarbons, water, and carbon dioxide, along with smaller amounts of aldehydes and alcohols originating from RH pyrolysis. All average activation energy values for the blends, determined through iso-conversional methods, decreased with RH addition. The combined kinetic analysis revealed two distinct mechanisms: (1) at the lower conversion range, the pyrolysis of the blend followed a random nucleation and three-dimensional growth mechanism, while (2) at the higher conversion range, the control mechanism transitioned into three-dimensional diffusion.

Effect of electromagnetic induction drying on the drying-incineration process of dyeing sludge: focus on migration and conversion of sulfur.

Secondary sulfur pollution in dyeing sludge (DS) during drying and incineration is a major environmental problem necessitating in-situ control. To robustly immobilise sulfur during drying-incineration, the authors introduce an electromagnetic induction (EMI) drying method and reveal the corresponding migration and conversion of sulfur in DS. The EMI-drying efficiency reached 10.69%/min, five times that of thermal drying. EMI drying increases the relative sulfoxide ratio from that of thermal drying. In a sludge-sulfur model, the proposed treatment promoted the oxidation and decomposition of organic sulfur without noticeably affecting the inorganic sulfur. The selective oxidation process during EMI drying promotes sulfur stabilisation in dried DS, decreasing the performance and stability of DS combustion. The sulfur-containing pollutants released during the incineration of DS mainly contain H2S, followed by CH3SH and SO2. EMI drying increases the outputs of SO2 and CH3SH but decreases the outputs H2S and total sulfur compared with the outputs of thermal drying. Under the sulfur-model conditions, EMI promoted the conversion of inorganic sulfur to sulfur-containing gases (especially H2S) during incineration. In contrast, the sulfur stabilised by partial oxidation of organic sulfur in the EMI-dried DS was not easily converted to gaseous sulfur during subsequent combustion. Overall, EMI inhibits the release of sulfur during the combined drying-incineration process of DS.

Acute hearing and visual loss caused by thiamine deficiency.

BACKGROUND: Wernicke encephalopathy (WE) is a devastating acute or subacute neurological disorder caused by thiamine deficiency. Wernicke encephalopathy is characterized by the triad of ocular signs, cerebellar dysfunction, and confusion. Visual loss and hearing loss are less common findings in WE. Here, we report a case of Wernicke encephalopathy in a nonalcoholic liver cirrhosis patient who presented with acute bilateral deafness and bilateral blindness. CASE PRESENTATION: A 60-year-old Chinese man presented with a history of bilateral blindness and bilateral hypoacousia for 3 days. He had a history of liver cirrhosis and chronic hepatitis C virus infection and did not have a habit of alcohol consumption. Ophthalmologic and otologic examinations showed no obvious abnormalities. MRI findings revealed symmetric fluid-attenuated inversion recovery (FLAIR) hyperintensities in the bilateral medial dorsal thalamus, periventricular region around the third ventricle and tectum, and dorsal medulla oblongata. One day after hospitalization, the patient developed a mild coma. Based on the laboratory and neuroimaging findings, we diagnosed the patient with Wernicke encephalopathy. He soon regained consciousness after administration of thiamine. Both his visual acuity and his hearing function improved gradually. CONCLUSIONS: We suggest that Wernicke encephalopathy can present with bilateral blindness and bilateral deafness.

Study on the effect of biomass on sulfur release behavior from dyeing sludge incineration: Focusing on in-situ sulfur fixation mechanism based on model compounds.

Although incineration is a recommended disposal strategy for dyeing sludge (DS), sulfurous gases problem is severe. Wood sawdust (WS) and rice husk (RH) are eco-friendly and CO2-neutral additives to relieve sulfur emission from DS incineration. However, the interaction between organic sulfur and biomass is uninterpreted. This study explores the effect of WS and RH on the combustion behavior and sulfur evolution from organic sulfur model compound combustion via thermogravimetry (TG) with mass spectrometry (MS). Results indicated that the sulfone and mercaptan combustion activities in DS were more drastic than in other forms. WS and RH additives generally deteriorated the combustibility and burnout performance of model compounds. The combustion of mercaptan and sulfone in DS contributed to most gaseous sulfur pollutants, where CH3SH and SO2 were the predominant forms. WS and RH minimized the sulfur release from mercaptan and sulfone incineration, whose in-situ retention ratios reached 20.14 % and 40.57 %. The retention mechanism to sulfur could be divided into: (1) Diffusion stage: the closed structure of biomass residue restrained sulfurous gases from escaping. (2) Chemical reaction stage: multiple sulfation occurred and inhibited sulfur release. Ca/K sulfate and compound sulfates were predisposed and thermostable sulfur-fixing products for the mercaptan-WS and sulfone-RH co-combustion systems.

Experimental investigation on electromagnetic induction thermal desorption for remediation of petroleum hydrocarbons contaminated soil.

A novel electromagnetic induction low temperature thermal desorption treatment (EMI LTTD) for petroleum hydrocarbons contaminated soil was introduced in this work. The removal rate of total petroleum hydrocarbons (TPH) under various factors, the morphology changes of soils as well as removal mechanism were investigated. Results suggested that increasing the heating temperature significantly increased the removal rate of TPH. At the beginning of 20 min, most of hydrocarbons (93.44-96.91 wt%) was removed with the temperature ranged from 200 °C to 300 °C. Besides, the initial contaminants concentration, particle size and thickness of soil slightly influenced the removal rate of TPH. Desorption kinetic study demonstrated that first-order model was well-described for desorption behavior. Response surface methodology analysis showed the temperature of 216 °C, the residence time of 21 min and the moisture content of 18% was an optimum condition recommended for potentially practical application. Under this condition, the results for the composition of hydrocarbons based on carbon number fractions indicated that the fractions of C10∼C16, C17∼C22 still existed in soil, while C23∼C28 was not detected after EMI LTTD treatment. Proposed mechanism was both hydrocarbons removed by evaporation at any temperature, while parts of heavy hydrocarbons was cracked within the soil close to induction medium, resulting in re-adsorption of light hydrocarbons. A buckwheat germination and growth test indicated that soil treated by EMI LTTD was potential in reutilization for planting.

Pyrolysis of hydrothermally dewatering sewage sludge: Highly efficient peroxydisulfate activation of derived biochar to degrade diclofenac.

The resource utilization of sewage sludge can solve its disposal issue essentially. Meanwhile the removal of diclofenac (DCF) in wastewater is an emerging environmental problem. In this study, a novel strategy of sludge utilizing via hydrothermal - peroxydisulfate (PDS) dewatering coupled pyrolysis process was proposed. The obtained sludge-derived biochar (HSC) could be as candidate to activate PDS to degrade DCF. Results indicated that exceed 90% of DCF was eliminated within 30 min in HSC-PDS/DCF ternary system under the optimized condition (0.6 mmol/L PDS and 0.5 mg/L HSC, without temperature and pH pre-adjusting). The inner mechanism of HSC-PDS/DCF system was revealed as follows: (1) Major: CO in quinones and ketone structure in HSC accelerated the degradation of DCF via non-radical pathway (electron transfer and 1O2). (2) Minor: Graphitic N structure accelerated the electron transfer and O2•- originated from defective sites involved into the redox. Several by-products were identified and two tentative degradation pathways of DCF (eg. dechlorination and C-N cleavage) were proposed.

Application value of a deep learning method based on a 3D V-Net convolutional neural network in the recognition and segmentation of the auditory ossicles.

Objective: To explore the feasibility of a deep learning three-dimensional (3D) V-Net convolutional neural network to construct high-resolution computed tomography (HRCT)-based auditory ossicle structure recognition and segmentation models. Methods: The temporal bone HRCT images of 158 patients were collected retrospectively, and the malleus, incus, and stapes were manually segmented. The 3D V-Net and U-Net convolutional neural networks were selected as the deep learning methods for segmenting the auditory ossicles. The temporal bone images were randomized into a training set (126 cases), a test set (16 cases), and a validation set (16 cases). Taking the results of manual segmentation as a control, the segmentation results of each model were compared. Results: The Dice similarity coefficients (DSCs) of the malleus, incus, and stapes, which were automatically segmented with a 3D V-Net convolutional neural network and manually segmented from the HRCT images, were 0.920 ± 0.014, 0.925 ± 0.014, and 0.835 ± 0.035, respectively. The average surface distance (ASD) was 0.257 ± 0.054, 0.236 ± 0.047, and 0.258 ± 0.077, respectively. The Hausdorff distance (HD) 95 was 1.016 ± 0.080, 1.000 ± 0.000, and 1.027 ± 0.102, respectively. The DSCs of the malleus, incus, and stapes, which were automatically segmented using the 3D U-Net convolutional neural network and manually segmented from the HRCT images, were 0.876 ± 0.025, 0.889 ± 0.023, and 0.758 ± 0.044, respectively. The ASD was 0.439 ± 0.208, 0.361 ± 0.077, and 0.433 ± 0.108, respectively. The HD 95 was 1.361 ± 0.872, 1.174 ± 0.350, and 1.455 ± 0.618, respectively. As these results demonstrated, there was a statistically significant difference between the two groups (P < 0.001). Conclusion: The 3D V-Net convolutional neural network yielded automatic recognition and segmentation of the auditory ossicles and produced similar accuracy to manual segmentation results.

Adsorption Effect and Adsorption Mechanism of High Content Zeolite Ceramsite on Asphalt VOCs.

In order to meet the requirements of industrial-scale fixed beds and develop an excellent adsorbent for asphalt VOCs. Zeolite ceramsite containing binder was prepared and successfully applied to the inhibition of asphalt VOCs. The results showed that prepared zeolite ceramsite possessed a high degree of crystallinity, and its main crystal phase is zeolite. The micropores with a pore size of 0.88 nm dominated the pore size distribution of the material. The adsorption experiment of asphalt VOCs showed a lower VOCs adsorption effect of 8.72% at a small dosage of 5%, while at a large dosage of 50%, the adsorption effect of VOCs exceeded 45%. This might be caused by the quite small external specific surface area, which occupied only 8.3% of the total specific surface area, and the low intraparticle diffusion coefficient due to the micropores. Meanwhile, the kinetics diameters of most aromatic hydrocarbons, which were comparable to the pore size of micropores, and the increase in the intraparticle diffusion resistance of aliphatic hydrocarbon molecules were the important factors in obtaining high adsorption of aromatic hydrocarbons in asphalt VOCs. Furthermore, the results indicated that the particulate adsorbent with a microporous structure should be mixed into the asphalt as a fine aggregate rather than an asphalt modifier for better asphalt VOCs adsorption effect.

Microplastics in dyeing sludge: Whether do they affect sludge incineration?

Microplastics (MPs), as emerging contaminant detected in dyeing sludge (DS), inevitably affected the subsequent treatment and disposal of DS. However, the effect of MPs on the predominant disposal path (incineration) of DS remains far from explicit. This study used thermogravimetry-mass spectrometry (TG-MS) method to explore the effect of representative MPs, polyethylene terephthalate (PET) and polyvinyl chloride (PVC), on combustion characteristics, gas evolution and kinetics on DS combustion. Results showed that PET inhibited the whole combustion of DS by physical barrier. Relatively, PVC delayed the combustion of light volatile but promoted heavy volatile and char reaction due to HCl catalyst. Generally, MPs deteriorated the combustibility, burnout performance and combustion stability of DS. MPs aggravated HCl and gaseous N emissions. Noticeably, the interactions between DS and PVC accelerated the emissions of gaseous pollutants, especially under high dose condition. DAEM and FWO models could well describe the combustion kinetic of DS containing MPs. MPs led to an increase in activation energy of DS, namely, it deteriorated the combustion efficiency of DS. The combustion mechanisms could be divided into two stages: (1) diffusion (D3) stage: melted MPs blocked the gas channels, (2) chemical reaction (F3): the residual chars were thermally stable.

Global Bibliometric Developments on Solid Waste Recycling in Concrete Construction Engineering.

The precise and visual analysis of solid waste recycling in concrete construction engineering is critical for the development of ecological civilization and for the secure supply of resources. This research makes a bibliometric analysis of the solid waste application in concrete construction engineering from 2000 to 2021 based on the Web of Science. The global bibliometric status, current research focus and future directions were used to indicate the global development of solid waste recycling in concrete construction engineering. The most reused solid wastes and most solid waste productive regions were concluded with this bibliometric analysis. China is far ahead of other countries in solid waste recycling in all aspects and heavy metal is one of the most prominent solid waste themes in China. By analyzing the most studied solid waste, fly ash appears to be the most popular and is widely used; half of the top ten-cited papers are correlated with it.

Magnetic biochar prepared by electromagnetic induction pyrolysis of cellulose: Biochar characterization, mechanism of magnetization and adsorption removal of chromium (VI) from aqueous solution.

This work introduces a novel methodology for synthesis of magnetic biochar from cellulose using an electromagnetic induction technology. More rough surfaces, sharp corners and edges, and compact regular pore structure with Fe3O4 and Fe2O3 of magnetic biochar was obtained. Such magnetic biochar possessed higher specific surface area (~236 m2/g) and micropore volume (0.144 m3/g). More hydroxyl groups of magnetic biochars decomposed and reacted with iron ions to form new chemical bonds. The coercivity and remanence of two magnetic biochars were calculated to be 125.76 Oe and 1.26 emu/g, 71.48 Oe and 1.31 emu/g. The total iron leaching rate were 0.94% and 1.28%, indicating magnetic biochar form wet pyrolysis process showed strong magnetization and iron loading stability (98.59%). Alternating electromagnetic field influenced the iron loading capacity and stability by Lorentz force during wet pyrolysis process. Such magnetic biochar can be used for removal of Cr(VI) from wastewater.

TG- MS study on in-situ sulfur retention during the co-combustion of reclaimed asphalt binder and wood sawdust.

Reclaimed asphalt binder (RAB) releases large amounts ·of hazardous sulfur-containing gases during combustion. This study attempts to introduce wood sawdust (WS) as an in-situ inhibitor of sulfur release during the combustion of refuse-derived fuel (RDF) blended with RAB-WS. The combustion characteristics, gaseous sulfur-containing products, interactions and combustion kinetics of RDF were investigated through thermogravimetry and mass spectrometry (TG-MS), and the mechanisms on migration and distribution of sulfur were revealed. Results indicated that WS additive inhibits the volatilization of light components and promotes the degradation of macromolecular components. WS addition improved the combustibility, burnout performance and combustion stability of RAB. The sulfur release of RAB-based RDF was mainly derived from resins and asphaltenes. WS addition generally decreased all gaseous sulfur-containing compounds (CH3SH, COS, SO2, CS2 and thiophene). Interactions between RAB and WS restrained all sulfur-containing gas emissions, and the normalized sulfur inhibition ratio reached 40.99 %. The Sarink and DAEM models could well describe the kinetic process of the co-combustion of RAB and WS. WS addition led to a decrease in activation energy, namely, it lowered the reaction barrier. Sulfur could be retained in-situ into incineration residue through the formation of sulfate minerals during the co-combustion of RAB and WS.

Comparative analysis for pyrolysis of sewage sludge in tube reactor heated by electromagnetic induction and electrical resistance furnace.

A comparative study was conducted on the pyrolysis of sewage sludge in tube reactors heated by electromagnetic induction (EMI) and conventional electrical resistance furnace (ERF). A minimal effect of pyrolysis temperature and initial moisture content on the distribution of pyrolytic products was obtained. Compared with the counterpart from ERF pyrolysis, the bio-char from EMI pyrolysis exhibited less ash content (46.38 wt%) and higher organic matter content (53.62 wt%). SEM and FTIR test showed similar microstructure characterizations in the two bio-chars. The specific area of bio-char from EMI pyrolysis was 8.6 m2/g. EMI pyrolysis increased the total content of aliphatic/aromatics in the bio-oil from 10.8 wt% to 15.6 wt% and the hydrogen/carbon monoxide in the bio-gas from 33.8 vol% to 41.1 vol% because of possible cracking and reforming reactions. Increased sulfur content in the bio-oil and decreased hazard gas content (such as hydrogen sulfide and sulfur dioxide) in the bio-gas were obtained during EMI pyrolysis. The actual energy consumption for EMI and ERF pyrolysis were 4.62 MJ/kg and 6.65 MJ/kg. Increasing the feedstock content would reduce the energy consumption unit energy consumption. Less system energy loss during EMI pyrolysis might explain the higher energy recovery from EMI pyrolysis than that from ERF. Despite some disadvantages, EMI pyrolysis shows potential in real-plant applications.

Effects of electromagnetic induction on migration and speciation of heavy metals in drying sewage sludge: Mechanistic insights.

Novel and efficient drying method based on electromagnetic induction plate (EMI-P) heating was used to treat sewage sludge (SS). This work focused on the effects of EMI-P action on heavy metals (HMs) in dried SS. Surface functional groups, surface chemistry and microstructures of SS treated were investigated and compared to provide insights into the transformation mechanisms of HMs during EMI-P drying process. The results show that the EMI-P-dried SS showed undesirably total concentrations of Cd and Zn and leaching concentrations of HMs (Cr, Ni, Zn, Cd and As) exceeded the Chinese ground water standard (GB/T14848-2017). Ni, Zn, and As in the EMI-P-dried SS still exhibited high mobility, the leaching percent of Ni, Zn, and As (under 300 V and 500 V) can reach up to 28.56%/10.36%, 26.96%/26.61% and 30.64%/23.14%, respectively. Compared with conventional thermal drying, the EMI-P method can effectively reduce the eco-toxicity derived from HMs by 28.06% under 500 V condition. The stabilization effect of the EMI-P action can be attributed to the following: (1) EMI-P action promoted the generation of surface complexes with HMs, (2) HMs adsorption by silicate minerals was enhanced under high-frequency magnetic fields and (3) honeycomb structures of EMI-P dried SS with micropores provided abundant active sites to bond with HMs.

Co-combustion behavior of dyeing sludge and rice husk by using TG-MS: Thermal conversion, gas evolution, and kinetic analyses.

Co-combustion of dyeing sludge (DS) and rice husk (RH) is a promising energy-from-waste method. The aim of this work was to investigate and quantify the effect of RH additive on combustion performance, gas evolution (especially gaseous pollutants) and kinetics during DS combustion by thermogravimetry-mass spectrometry method. Results revealed that the introduction of RH improved the combustibility, burnout performance and combustion stability of DS. Optimal RH addition (10% RH) reduced the emission of gaseous pollutants (NH3, NO2, COS, SO2 and CS2). The interaction between DS and RH inhibited the devolatilization reaction and emission of gaseous sulfur substances, and it also restrained NO2 emission under optimal RH additive amount. A four-interval kinetic model (D1 â†’ F3 â†’ D1 â†’ F3) was established to describe the co-combustion process (R2 greater than 0.9999). RH addition, especially at high doses, led to an increase in activation energy relative to DS.

Diagnostic value of magnetic resonance and computed tomography colonography for the diagnosis of colorectal cancer: A systematic review and meta-analysis.

BACKGROUND: Surgical resection is the recommended procedure for colorectal cancer (CRC), but majority of the patients were diagnosed with advanced or metastatic CRC. Currently, there were inconsistent results about the diagnostic value of magnetic resonance colonography (MRC) and computed tomography colonography (CTC) in early CRC diagnosis. Our study conducted this meta-analysis to investigate the diagnostic value of MRC and CTC for CRC surveillance. METHODS: A comprehensive literature search was conducted in PubMed, Embase, and the Cochrane library to select relevant studies. The summary sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the receiver operating characteristic curves (AUC) were calculated to evaluate the diagnostic value of MRC and CTC, respectively. RESULT: Twenty-five studies including 2985 individuals were selected in the final analysis. Eight studies evaluated the diagnostic value of MRC, and 17 studies assessed CTC. The summary sensitivity, specificity, PLR, NLR, DOR, and AUC in MRC for early detection of CRC were 0.98 (95% confidence interval, CI: 0.80-1.00), 0.94 (95% CI: 0.85-0.97), 15.48 (95% CI: 6.30-38.04), 0.02 (95% CI: 0.00-0.25), 115.09 (95% CI: 15.37-862.01), and 0.98 (95% CI: 0.97-0.99), respectively. In addition, the sensitivity, specificity, PLR, NLR, DOR, and AUC of CTC for diagnosing CRC were 0.97 (95% CI: 0.88-0.99), 0.99 (95% CI: 0.99-1.00), 154.11 (95% CI: 67.81-350.22), 0.03 (95% CI: 0.01-0.13), 642.51 (95% CI: 145.05-2846.02), and 1.00 (95% CI: 0.99-1.00). No significant differences were found between MRC and CTC for DOR in all the subsets. CONCLUSION: The findings of meta-analysis indicated that MRC and CTC have higher diagnostic values for early CRC diagnosis. However, the DOR for diagnosing CRC between MRC and CTC showed no significance.

Performance Analysis of Compound Rubber and Steel Slag Filler Modified Asphalt Composite.

A new treatment method of combined crumb rubber and steel slag modifier for asphalt binders was proposed in this work. The viscosity, rheological properties, and thermogravimetric analysis of modified asphalt mortar were then investigated. The modified asphalt composite was prepared in laboratory by two steps. Rubber powder was firstly added into hot asphalt flux to make rubber modified asphalt (RA), and then RA binders were wrapped with steel slag powder by granulation machine to make compound rubber and steel slag filler modified asphalt composite (RSAC). Test results showed that the viscosity-temperature susceptibility of RSAC was superior to that of modified asphalt binder with only one additive. The softening point differences of RSAC was 2.1 °C. The complex modulus and phase angle were significantly influenced by the addition of steel slag fillers. Creep tests show that a better anti-permanent deformation performance of RSAC can be obtained, which means a better low temperature performance could be predictable. The CAM (Christensen-Anderson-Marasteanu) and Burgers models can be used to describe the change of complex modulus and viscous-elasticity performance of RSCA. The lower value of me (0.6344) and R (0.1862) from the CAM model indicated that RSAC was slightly related to the sensibility of frequency. The higher value of λ∞ and E0 of RSAC indicated a better ability of shear-creep resistance.

Pyrolysis of sewage sludge by electromagnetic induction: Biochar properties and application in adsorption removal of Pb(II), Cd(II) from aqueous solution.

Pyrolysis of sewage sludge was studied by electromagnetic induction (EMI) heating method and in a laboratory-scale reaction installation. Basic properties and adsorption of heavy metals Pb and Cd on biochar from EMI pyrolysis of sewage sludge was investigated. Experimental results indicate that EMI pyrolysis temperature was determined by the relationship between working voltage of EMI device and induction media. Biochar yield rate ranged from 89.7% to 51.2% at temperature from 300 to 600 °C. Elements, surface characterizations and micromorphology, thermogravimetric properties as well as gas evolution changed with increasing pyrolysis temperature. Hydroxyl groups were decomposed during EMI pyrolysis process. Heavy metals in biochar was leached through TCLP and higher leachability was obtained in biochar pyrolyzed at 400 °C compared to other biochar products. A higher adsorption removal efficiency of Pb and Cd was obtained by EMI pyrolyzed biochar. Langmuir and pseudo-first-order models were used for description of adsorption isotherm and kinetics.