Publications by authors named "Qiyong Xu"

This work evaluated the effect of zero-valent iron (ZVI) particle size (150 μm-100 nm) on the performance of food waste anaerobic digestion (AD) under various acid stress conditions. The results indicated that ZVI significantly improved the AD performance, ensuring successful CH production even under high acid stress. However, the extent of this promoting effect was highly dependent on the particle size.

View Article and Find Full Text PDF

Anaerobic digestion of food waste is increasingly utilized for bioenergy generation, producing a byproduct known as food waste digestate (FWD), which has potential applications as a fertilizer within the circular economy. However, accumulating numerous pollutants in FWD poses significant challenges to environmental management and human health. The complex nature of these pollutants complicates both targeted and non-targeted chemical analyses, making safety evaluations difficult.

View Article and Find Full Text PDF

Co-landfill of municipal solid waste (MSW) and bottom ash (BA) has accelerated the scaling of the leachate collection systems (LCS). The matrix of biofilm formation and mineral deposition makes the scaling process in LCS more complicated. However, the fate of metals released from BA and the role of microorganisms in the leachate, which determine the chemical and biological scaling, are not well understood; the scale adsorption ability is little discussed.

View Article and Find Full Text PDF

Pyrolysis remains a promising method for the utilization of biogradable plastics. However, the kinetics and mechanisms of molten polymer pyrolysis are not well understood, and the effect of additives (mainly inorganic nucleating agents) on the reaction pathway has not been widely explored. In this work, we conducted a method using the thermogravimetric analysis-Fourier transform infrared spectrometry (TG-FTIR) combined with a model-fitting method, instead of a traditional method subjectively selecting a reaction model.

View Article and Find Full Text PDF
Article Synopsis
  • Membrane distillation (MD) is a potential method for treating high salinity water, but it faces challenges from scaling of sparingly soluble salts like calcium sulfate (CaSO), which can disrupt the process by increasing resistance and causing wetting.
  • This study investigates how the interactions between CaSO crystals and the membrane can change based on the crystals' shape and structure, using optical coherence tomography (OCT) for direct observation.
  • Results show that by adjusting the balance of crystallizing ions, particularly calcium, the growth of CaSO crystals can be controlled, helping to reduce negative interactions with the membrane and enhancing MD effectiveness.
View Article and Find Full Text PDF

This study explores the utilization of municipal solid waste incineration fly ash (MSWIFA) in geopolymer concrete, focusing on compressive strength and heavy metal leachability. MSWIFA was sourced from a Shenzhen waste incineration plant and pretreated by washing to remove soluble salts. Geopolymer concrete was prepared incorporate with washed or unwashed MSWIFA and tested under different pH conditions (2.

View Article and Find Full Text PDF
Article Synopsis
  • * Batch experiments showed that biochar helps sustain CH oxidation under stress from HMs and MPs by supporting diverse MOB and promoting polysaccharide secretion, mitigating environmental stress.
  • * While low levels of HMs slightly inhibited CH oxidation, higher concentrations boosted methanotrophic activities; MPs had a stronger impact, enhancing CH oxidation, especially when present with low HMs, leading to distinct microbial adaptations.
View Article and Find Full Text PDF

Speckle is a significant challenge for laser imaging systems, as it degrades the image quality. In this study, an improved theoretical model is established to describe the speckle features in free-space optical path. The model quantitatively defines the relationship between speckle contrast and five parameters: wavelength, screen surface roughness, light-spot diameter, incidence angle, and observation angle.

View Article and Find Full Text PDF

Polyethylene mulch films (MFs) are widely employed in agricultural land to enhance crop yield and quality, but the MF residue causes significant environmental concerns. To promote the sustainable application of MFs, it is essential to assess their fate throughout their service life and understand the underlying degradation mechanisms. In this study, surface-exposed and soil-buried MFs were separately collected from agricultural land in Inner Mongolia, China.

View Article and Find Full Text PDF

Pyrolysis has emerged as a promising technology for valorizing digestate resulting from the anaerobic digestion of food waste. However, the high NO emissions during pyrolysis limit its application. This study proposed a hydrothermal coupled pyrolysis process to control the element transfer in digestate during biochar production.

View Article and Find Full Text PDF

The measurement of germination index (GI) in composting is a time-consuming and laborious process. This study employed four machine learning (ML) models, namely Random Forest (RF), Artificial Neural Network (ANN), Support Vector Regression (SVR), and Decision Tree (DT), to predict GI based on key composting parameters. The prediction results showed that the coefficient of determination (R) for RF (>0.

View Article and Find Full Text PDF

Biochar amendment for landfill soil cover has the potential to enhance methane removal efficiency while minimizing the soil depth. However, there is a lack of information on the response of biochar-mediated soil cover to the changes in configuration and operational parameters during the methane transport and transformation processes. This study constructed three biochar-amended landfill soil covers, with reduced soil depths from 75 cm (C2) to 55 cm (C3) and 45 cm (C4), and the control group (C1) with 75 cm and no biochar.

View Article and Find Full Text PDF

Manipulating the methanotroph (MOB) composition and microbial diversity is a promising strategy to optimize the methane (CH) biofiltration efficiency of an engineered landfill cover soil (LCS) system. Inoculating soil with exogenous MOB-rich bacteria and amending soil with biochar show strong manipulating potential, but how the two stimuli interactively shape the microbial community structure and diversity has not been clarified. Therefore, three types of soils with active CH activities, including paddy soil, river wetland soil, and LCS were selected for enriching MOB-dominated communities (abbreviated as B_PS, B_RWS, and B_LCS, respectively).

View Article and Find Full Text PDF

Nanostructured bismuth vanadate (BiVO) is at the forefront of emerging photoanodes in photoelectrochemical tandem devices for solar water splitting owing to the suitable band edge position and efficient charge separation capability. However, the (photo)chemical corrosion involving V dissolution limits the long-term stability of BiVO. Herein, guided by DFT calculations, we introduce an ALD-derived NiO catalyst layer on BiVO to stabilize the surface Bi-O bonds, facilitate hole extraction, and thus suppress the V dissolution.

View Article and Find Full Text PDF

Biofilm formation on plastic surface is a growing concern because it can alter the plastic surface properties and exacerbate the ecological risk. Identifying key factors that affecting biofilm formation is critical for effective pollution control. In this study, the poly (ethylene terephthalate) (PET) was aged in water and air conditions with UV irradiation, then incubated in the digestate of food waste anaerobic digestion to allow biofilm formation.

View Article and Find Full Text PDF

The food waste (FW) digestion performance can be enhanced by introducing iron oxide (IO) into digesters. However, the role of IO in continuous two-stage digesters in enhancing the FW anaerobic digestion remains unclear. In this study, the effect of IO on the bioenergy recovery from a two-stage digestion process was investigated.

View Article and Find Full Text PDF
Article Synopsis
  • Halogenated organic compounds in wastewater are problematic because they can remain in the environment and accumulate in living organisms, yet not much is known about them on a molecular level.
  • Researchers conducted a study using advanced techniques to screen for these compounds in waste leachates and their concentrates, identifying 438 unique chlorine- and bromine-containing organic formulas.
  • The study found that traditional extraction methods were less effective than mixed-sorbent techniques, which revealed that over 75% of these compounds remained stable even after undergoing additional treatment processes, highlighting their persistence as contaminants in wastewater.
View Article and Find Full Text PDF

The ability of biochar to enhance the oxidation of methane (CH) in landfill cover soil by promoting the growth and activity of methane-oxidizing bacteria (MOB) has attracted significant attention. However, the optimal characteristics of digestate-derived biochar (DBC) for promoting the MOB community and CH removal performance remain unclear. This study examined how the CH oxidation capacity and respiratory metabolism of MOB life process are affected by the application of DBC compared with the most commonly used woody-derived biochar (WBC).

View Article and Find Full Text PDF

The persistence and potential fouling risks associated with humic substances and bacteria present in leachate have gained increasing attention. Therefore, developing efficient and environmentally compatible technologies for their removal is essential. This study presented the hydrothermal synthesis of a photocatalyst by coupling carbon dots (CDs) and bulk TiO (P25).

View Article and Find Full Text PDF

The clogging of leachate collection systems (LCSs) is a typical challenge for landfills operation. Although clogging occurs in different LCS components, its spatial-temporal distributions remain unclear. This study aimed to systematically investigate the dynamic clogging development in simulated LCSs by monitoring changes in clogging characteristics over time.

View Article and Find Full Text PDF

Fenton is one of the most promising processes for the removal of dissolved organic matter (DOM). It has always been highly suspected that derived-DOM would be generated during Fenton reaction, but there is lack of direct evidence at the molecular level. The present study explored the molecular properties of the derived-DOM of five common Fenton technologies for degradation of nine landfill organics including leachates and concentrates based on UPLC Orbitrap MS/MS analysis.

View Article and Find Full Text PDF

Hydrothermal liquid digestate has been widely accepted as a substrate in anaerobic digestion (AD) for energy recovery. However, the potential negative impacts of hydrothermal liquid digestate on AD remain unclear. In this study, the organic biodegradability of hydrothermal liquid digestate produced from hydrothermal treatment (HTT) at different temperatures was analyzed, and the formation and degradation process of potential inhibitory substances were discussed.

View Article and Find Full Text PDF

A two-stage process, consisting of a leach-bed reactor (LBR) and an up-flow anaerobic sludge blanket reactor (UASB), has been commonly adopted to improve food waste anaerobic digestion. However, its application is limited due to low hydrolysis and methanogenesis efficiencies. This study proposed a strategy of incorporating iron-carbon micro-electrolysis (ICME) into the UASB and recirculating its effluent to the LBR to improve the two-stage process efficiency.

View Article and Find Full Text PDF

The treatment of digestate from food waste (DFW) has emerged as the bottleneck for food waste anaerobic digestion. DFW generally contains abundant nutrients that can be recycled by composting. However, the effect of DFW-based compost on soil improvement has not been extensively explored.

View Article and Find Full Text PDF

Co-landfilling of bottom ash (BA) accelerates the clogging of leachate collection systems (LCSs) and increases the risk of landfill failure. The clogging was mainly associated with bio-clogging, which may be reduced by quorum quenching (QQ) strategies. This communication reports on a study of how isolated facultative QQ bacterial strains from municipal solid waste (MSW) landfills and BA co-disposal landfills.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionimf8f8al7ttme49u5h4stlktiv6ji85q): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once