Relation between hydrophilic/hydrophobic characteristics of sludge extracellular polymeric substances and sludge moisture-holding capacity in hot-pressing drying.

Sludge poses a serious threat to the environmental health. Hot-pressing drying has been proven efficient in sludge treatment because of the reduced thermal contact resistance, rapid increase in sludge temperature, and high drying rate. Sludge extracellular polymeric substances (EPS) significantly influence moisture transfer.

Experimental analysis on products distribution, characterization and mechanism of waste polypropylene (PP) and polyethylene terephthalate (PET) degradation in sub-/supercritical water.

Supercritical water (SCW) treatment of plastics is a clean technology in the 'waste-to-energy' path. In this work, PP and PET plastics were processed by sub-/supercritical water. The results showed that temperature was the most important factor of the PP and PET degradation.

Fast pyrolysis kinetics of waste tires and its products studied by a wireless-powered thermo-balance.

Fast pyrolysis is commonly used in industrial reactors to convert waste tires into fine chemicals and fuels. However, current thermogravimetric analyzers are facing limitations that prevent the acquisition of kinetic information. To better understand the reaction kinetics, we designed a novel thermo-balance device that was capable of in-situ weight measurement during rapid heating.

The interactions between mixed waste from discarded surgical masks and face shields during the degradation in supercritical water.

The widespread use of surgical masks made of polyolefin and face shields made of polyester during pandemics contributes significantly to plastic pollution. An eco-friendly approach to process plastic waste is using supercritical water, but the reaction of mixed polyolefin and polyester in this solvent is not well understood, which hinders practical applications. This study aimed to investigate the reaction of waste surgical masks (SM) and face shields (FS) mixed in supercritical water.

Adsorption performance and mechanism of cationic and anionic dyes by KOH activated biochar derived from medical waste pyrolysis.

The massive generation of medical waste (MW) results in a series of environmental, social, and ecological problems. Pyrolysis is one such approach that has attracted more attention because of the production of value-added products with lesser environmental risk. In this study, the activated biochar (ABC600) was obtained from MW pyrolysis and activated with KOH.

Experimental analysis on products distribution and characterization of medical waste pyrolysis with a focus on liquid yield quantity and quality.

The massive generation of medical waste (MW) poses a serious risk to the natural environment and human health. The pyrolysis technique is proposed as a potential treatment for MW to tackle the associated environmental issues and produce value-added products. In this work, medical waste pyrolysis has been conducted at various temperatures using a fixed bed reactor with a 20 °C·min heating rate and nitrogen was used as a career gas with a flow rate of 100 ml·min.

Effect of in-situ torrefaction and densification on the properties of pellets from rice husk and rice straw.

The research on preparing high-quality pellets by combining torrefaction and densification of biomass has received widespread attention. This paper investigated the influence of torrefaction temperature on biomass and evaluated the quality of three kinds of pellets (raw pellets, ex-situ torrefied densified pellets and in-situ torrefied densified pellets). When the torrefaction temperature was raised to 300 °C, the energy yield of rice straw (RS) and rice husk (RH) quickly decreased to 71.

Hydrogen-rich syngas from wet municipal solid waste gasification using Ni/Waste marble powder catalyst promoted by transition metals.

Gasification of wet municipal solid waste (MSW) coupled with in-situ CO capture is an attractive option for MSW disposal, allowing chemical and energy recovery. In this study, the Ni-CaO based catalysts were prepared with waste marble powder (WMP) as an alternative to CaO and promoted by different transition metals (i.e.

Enhancement of conductive drying of sewage sludge with mechanical compression: Drying kinetics, and interfacial heat transfer behavior.

Improving sludge drying efficiency is of tremendous importance for public health, subsequent treatment, and comprehensive utilization. The interfacial thermal resistance between sludge and hot wall greatly limits the conductive drying performance. This study employed mechanical compression to decrease the interfacial thermal resistance.

Mechanical compression assisted conductive drying of thin-film dewatered sewage sludge: Process performance, heat and mass transfer behavior.

The improvement in heat transfer efficiency between the hot wall and sewage sludge was a critical issue to enhance the conductive drying performance. The drying behavior of thin-film dewatered sewage sludge was investigated based on a conductive dryer assisted with mechanical compression at hot wall temperatures of 120-210 °C. The heat and mass transfer behavior of the sludge in the conductive drying process alone was compared to those in the mechanical compression assisted conductive drying process at three external mechanical loads of 25, 100, and 200 kPa.

Doping strategy, properties and application of heteroatom-doped ordered mesoporous carbon.

To date, tremendous achievements have been made to produce ordered mesoporous carbon (OMC) with well-designed and controllable porous structure for catalysis, energy storage and conversion. However, OMC as electrode material suffers from poor hydrophilicity and weak electrical conductivity. Numerous attempts and much research interest have been devoted to dope different heteroatoms in OMC as the structure defects to enhance its performance, such as nitrogen, phosphorus, sulphur, boron, and multi heteroatoms.

The Determination of Pore Shape and Interfacial Barrier of Entry for Light Gases Transport in Amorphous TEOS-Derived Silica: A Finite Element Method.

The interfacial barrier of entry for light gas transport in a nanopore was a crucial factor to determine the separation efficiency in membrane technologies. To examine this effect, amorphous silica was prepared by sol-gel process, and its characterization results revealed that the commonly used cylindrical pore shape failed to represent the adsorption behavior of gases, but instead the pore shape had to be represented by a slit pore model. A finite element method (FEM) was developed to analyze the interfacial resistance by integrating a Lennard-Jones (LJ) potential over the layer area.

Influencing mechanism of zinc mineral contamination on pyrolysis kinetic and product characteristics of corn biomass.

The metal mineral has a complex influence on the thermal decomposition of biomass due to the sophisticated structure of biomass and parallel reactions. Therefore, the influencing mechanisms of metal minerals on biomass decomposition kinetic expressions needed to be thoroughly investigated. In this study, the decomposition of the three major components of biomass was considered separately.

Integrated thermal behavior and compounds transition mechanism of municipal solid waste incineration fly ash during thermal treatment process.

Thermal behavior of municipal solid waste incineration (MSWI) fly ash is extremely complicated due to the simultaneously occurred reactive processes and the products with different chemical compositions, therefore, the investigation of chemical compounds transition behavior and mechanism during the integrated thermal process is of great significance. In this study, the macro-thermal treatment of fly ash and thermo-gravimetric analysis via non-isothermal methods were carried out and Málek method was firstly introduced to explore the mechanism of multi-step reaction for fly ash. The mineral transition results suggested that the halite, sylvite in the raw fly ash transformed to more complex crystals in treated samples, such as chlorellestadite, polyhalite and enstatite during the thermal process.

Synergistic effects of anionic surfactants on adsorption of norfloxacin by magnetic biochar derived from furfural residue.

Norfloxacin (NOR) is a persistent organic pollutant and can be effectively removed from effluent by adsorption of biochar. However, the presence of other emerging contaminants, such as surfactants, will potentially alter adsorption performance of norfloxacin by biochar and the molecular-scale mechanisms of the interaction between surfactants and biochar remain poorly understood. In this study, adsorption of norfloxacin on magnetic biochar prepared with iron-containing furfural residue (FRMB) in the presence or absence of anionic surfactants was investigated.

Kinetic analysis for cyclic CO capture using lithium orthosilicate sorbents derived from different silicon precursors.

A series of Li4SiO4 was synthesized using LiNO3 and six different silicon precursors. The precipitated-silica-derived Li4SiO4 presented the highest CO2 capacity in a 10 h sorption test, and ZSM-5-derived Li4SiO4 demonstrated the most rapid CO2 sorption. The CO2 sorption kinetics predominantly followed the nucleation mode and could be accurately described by the Avrami-Erofeev model.

Enhanced Hydrogen Production from Sawdust Decomposition Using Hybrid-Functional Ni-CaO-CaSiO Materials.

A hybrid-functional material consisting of Ni as catalyst, CaO as CO sorbent, and CaSiO as polymorphic "active" spacer was synthesized by freeze-drying a mixed solution containing Ni, Ca and Si precursors, respectively, to be deployed during sawdust decomposition that generated gases mainly containing H, CO, CO and CH. The catalytic activity showed a positive correlation to the Ni loading, but at the expense of lower porosity and surface area with Ni loading beyond 20 wt %, indicating an optimal Ni loading of 20 wt % for Ni-CaO-CaSiO hybrid-functional materials, which enables ∼626 mL H (room temperature, 1 atm) produced from each gram of sawdust, with H purity in the product gas up to 68 vol %. This performance was superior over a conventional supported catalyst Ni-CaSiO that produced 443 mL H g-sawdust under the same operating condition with a purity of ∼61 vol %.

Spray-Dried Sodium Zirconate: A Rapid Absorption Powder for CO Capture with Enhanced Cyclic Stability.

Improved powders for capturing CO at high temperatures are required for H production using sorption-enhanced steam reforming. Here, we examine the relationship between particle structure and carbonation rate for two types of Na ZrO powders. Hollow spray-dried microgranules with a wall thickness of 100-300 nm corresponding to the dimensions of the primary acetate-derived particles gave about 75 wt % theoretical CO conversion after a process-relevant 5 min exposure to 15 vol % CO .