Xiaoying Liu

Biodegradable plastics (BPs) tend to replace conventional plastics, which increases the amount of BP waste entering the environment. The anaerobic environment exists extensively in nature, and anaerobic digestion has become a widely used technique for organic waste treatment. A few kinds of BPs have high biodegradability (BD) and biodegradation rat...

Bioconversion of CO2 into liquid fuels or chemicals, preferred medium chain carboxylic acids (caproic and caprylic acid), is an attractive CO2 utilization technology. The present study aims to investigate the effects of different ratios of H2/CO2 on regulating the distribution of C2‐C8 carboxylic acid products, while the headspace pressure of 1.5 b...

A promising strategy to alleviate the plastic pollution from traditional petroleum‐based plastics is the application of biodegradable plastics, in which polyhydroxyalkanoates (PHAs) have received increasing interest owing to their considerable biodegradability. In the PHAs family, poly(3‐hydroxybutyrate‐co‐3‐hydroxvalerate) (PHBV) has better mechan...

Efficient and harmless disposal of landfill leachate has attracted increasing attention. In this study, the bio-electro-Fenton method was investigated and developed to degrade the organic compounds in landfill leachate by hydroxyl radical oxidation. The optimal operational parameters (i.e., pH and external voltage) of the bio-electro-Fenton system...

The dramatic increase of textile wastes has become a major global concern, which calls for alternative practices to alleviate severe environmental pollution and waste of resources due to their improper disposal and management. Anaerobic digestion (AD) is a cost-effective and eco-friendly technology that allows the bioconversion of organic wastes in...

Copious amounts of cucumber vine (CV) derived from crop growing and harvesting are casually discarded in the field, posing severely negative impacts on public health and the ecological environment. Treating CV via anaerobic digestion (AD) could represent a promising approach while the recalcitrant lignocellulosic structure restricts its conversion...

A large amount of eggplant stalk (ES) is incinerated after harvesting of eggplant every year, which aggravates environmental pollution and waste of resources. Converting ES into methane through anaerobic digestion (AD) technology may be a potential treatment method, considering the low environmental impact and high energy recovery. Firstly, this st...

Catalytic ozonation with supported metal oxides is a promising strategy for addressing refractory pollutants in wastewater. In this study, γ-Al2O3 supported MnOx-CeOx catalysts (MC1, MC2, and MC3) obtained at different calcination temperatures (400 °C, 550 °C, and 700 °C) were applied as effective catalysts for ozonation and explored the feasibilit...

Straw pellets are widely promoted and expected to be a cleaner alternative fuel to unprocessed crop residues and raw coal in rural China. However, the effectiveness of these dissemination programs is not well evaluated. In this field study, emission characteristics of burning straw pellets, raw coal, and unprocessed corn cobs in heating stoves were...

With the continuously increasing demands of plastic products in the current society, the challenge of disposing plastic waste is constantly increasing, leading to the urgent need of mitigating plastic pollution. As a consequence, much attention has been paid to biodegradable plastics due to their degradability in a bio-active environment under cert...

Experimental investigation and model simulation was combined to identify the effect of metal ions on mitigating ammonia inhibition during anaerobic digestion. Five metal ions (Ca, Mg, Cu, Zn, Fe) were tested in reactors with 1 g-glucose/L/d and 5 g-N/L under fed batch operation. Ca addition was considered the optimal approach with a 25% increment i...

The serious environmental problem caused by traditional plastics has stimulated the popularization of biodegradable plastics (BPs). However, the rigorous prerequisite for the efficient degradation of BPs has not eliminated its potential hazard to nature. In most biosystems exists the anaerobic environment, but it is still controversial whether BPs...

Bioaugmentation is an attractive method to improve methane production (MP) in the anaerobic digestion (AD) process. In this study, to tackle the ammonia inhibition problem, a long-term (operating over 6 months) acclimatized consortia and a well-constructed consortia were selected as the bioaugmentation consortia for sequencing batch AD reactors fed...

Material addition is a potential method to alleviate ammonia inhibition in the anaerobic digestion process. In this study, seven materials were selected to examine their impact on methane production (MP). In the batch experiment, the reactors with “Magnetite + foam carrier” exhibited nearly a 56% increase in maximum MP rate. Different strategies of...

Soybean soapstock (SS) is one of the main solid wastes produced in the refinery of edible oil processing. In this study, the co-pyrolysis of SS with iron slag (IS) and aluminum scrap (AS) was carried out in a tubular furnace. The gas, liquid and solid products were characterized and the char yield decreased with increasing IS/AS ratio. IS and AS ca...

The rapid start-up and operating characteristics of simultaneous partial nitrification, anammox, and denitrification (SNAD) process was investigated using synthetic wastewater with a low C/N ratio (COD: NH4⁺-N = 200 mg/L: 200 mg/L) in a novel upflow microaerobic membrane bioreactor (UMMBR). The average removal efficiencies of COD, NH4⁺-N, and TN in...

Household heating stoves are commonly used for heating in rural China during winter and are responsible for a large portion of the particulate matter in the atmosphere. Pollutant emissions from household stoves are influenced by user behaviors in actual use, in addition to purely technological reasons (i.e., type and age of appliance) and installat...

Coal is China’s dominant energy source, among which bituminous coal is the most extensive and plentiful. Using bituminous coal resources to design a low-emission household fuel is very important for rural poverty areas. In this work, a new type of bituminous coal pellet (BCP) fuel using an automatic prototype pellet stove was designed for the first...

The effects of alkalinity addition with different strategies on the start‐up, performance and microbial community of completely autotrophic nitrogen removal over nitrite (CANON) were investigated over 450 days. In phase I, the alkalinity was increased gradually from 300 to 2000 mg/L to obtain the optimal range. In phase II, the reactor was restarte...

Recently, pyrolysis integrated with pelletization has received great attention. In the current study, various physical, mechanical, chemical and thermal characteristics of furfural residue pellets (FRPs), sewage sludge pellets (SSPs), furfural residue-sewage sludge pellets (FRSSPs) were studied at different pyrolysis temperature (200-850 oC) and re...

Greece and China are two agricultural countries in which a significant percentage of their biomass consists of agricultural and livestock wastes. In Greece, the management practice that is still applied is burning the majority of the agricultural residues in the field, while in China large amount of untreated agricultural waste causes serious adver...

A large amount of eggplant straw (ES) is incinerated after harvesting of eggplant every year, which aggravates environmental pollution and waste of resources. Converting ES into methane through anaerobic digestion (AD) technology may be a potential treatment method, considering the low environmental impact and high energy recovery. Firstly, this st...

A lab-scale single-channel press was employed for producing pellets and the effect of pressure, die temperature, moisture content (MC), particle size, and binding agent on pellet quality was investigated. Meanwhile, torrefaction subsequent to pelletization was performed and the quality of pellets was evaluated under different torrefaction condition...

With the development of agriculture, a huge amount of vegetable waste (VW) is produced every year, posing a large considerable environmental problem that cannot be ignored. Anaerobic digestion (AD), as an eco-friendly, efficient, and sustainable biomass conversion technology, may be used to address the pollution caused by VW. The compositional comp...

Vinegar residue (VR) is the dominated by-product associated with the process of industrial brewing vinegar. According to statistics, China’ s annual output of VR is around 3.0 million tons, most of which is disposed by landfill or incineration, causing severe resource waste and environment pollution. Anaerobic digestion (AD) may be a promising appr...

With growing popularity of durian and jackfruit, environment threats following improper management of durian shell (DS) and jackfruit peel (JP) are increasingly serious. Anaerobic digestion is a potential solution but concern on its unsatisfied efficiency from lignocellulosic recalcitrance remains. This work applied four representative pretreatment...

Biomass pelletization technology has recently gained significant interest, where pyrolyzed pellets have a very wide range of applications (e.g., as pellet fuels and adsorbents). In this study, furfural residue pellets (FRPs) were pyrolyzed at temperatures of 200–850 °C in a tube furnace. The physical and chemical properties of the pyrolyzed FRPs (P...

Having been generated with a tremendous amount annually, paper waste (PW) represents a large proportion in municipal solid waste (MSW) and also a potential source of renewable energy production through the application of anaerobic digestion (AD). However, the recalcitrant lignocellulosic structure poses obstacles to efficient utilization in this wa...

Anaerobic digestion (AD) is a widely used technology for converting organic wastes into biomethane with the advantages of clean energy production and few environmental impacts. Zucchini stem (ZS), the main waste produced from zucchini cultivation, is a potential feedstock for AD due to its high moisture and organic contents. This study investigated...

Microbial pretreatment to lignocellulosic biomass for anaerobic digestion (AD) has achieved increased attention; however, the low efficiency and unclear mechanism of oxygen parameter affecting this process performance limit its practical application. In this study, five readily available microbial consortia were developed to analyze the influences...

This study evaluated the methanogenic performance of typical substrates (acetate, formate, H2/CO2, and glucose) under low and high ammonia levels and the Anaerobic Digestion Model No.1 (ADM1) was extended and modified for better simulation and understanding of the process. Formate-utilizing and hydrogen-utilizing methanogenesis showed stronger ammo...

A single pellet press was employed for production of furfural residue pellets (FRPs) and wood pellets (WPs). The effects of temperature (70–200 ◦C), pressure (70–160 MPa), moisture content (MC) (5.5–28%), particle size (0.25–0.5 and 0.5–1.41 mm) and a binder on the physical and mechanical characteristics and energy con- sumption of FRPs and WPs wer...

Activated carbon (AC) was prepared from furfural residue (FR) in a horizontal tube reactor under a carbon dioxide atmosphere comparing one- and two-step activation methods. Considerable differences were observed between ACs produced from these two methods in microscopic morphology, structural properties, organic structure, and crystallinity. It sho...

The use of coal in Chinese households for winter heating emits harmful pollutants that severely affect indoor air quality and climate. Therefore, China has made efforts to transition into clean heating using improved heating stoves and biomass pellets. Although the economic and policy implications of such demonstration projects have been extensivel...

Torrefaction integrated with pelletization has gained increasingly interest as it enhances the characteristics of fuel pellets (e.g. hydrophobicity and energy density). In current study, torrefaction of furfural residue pellets (FRPs) and sawdust pellets (SPs) was performed by employing tubular reactor furnace, and quality of pellets was compared....

The effect of pH regulation in phase I on hydrolysis and acidogenesis rate, metabolites production, microbial community, and the overall energy recovery efficiency during two‐phase anaerobic digestion (AD) of food waste (FW) was investigated. pH strongly affected the acidogenesis rate and the yield of the fermentation products. The highest acidogen...

The disposal of large quantities of tobacco stalks and animal manures generated annually is among the serious challenges faced in China, especially the former, as its toxic composition (nicotine) can induce the risk of healthy impairment during tradition treatment process. Anaerobic digestion (AD) may be an efficient technique for tobacco stalks. N...

In this study, the performance of ofloxacin (OFX) degradation in synthetic wastewater using synthesized MnOx‐CeOx/γ‐Al2O3 as a heterogeneous ozonation catalyst was evaluated. The removal rates of OFX and chemical oxygen demand (COD) during 15‐day continuous‐flow experiments were 98.2% and 76.7% on average, respectively. An ozone index (mgCOD/mgO3)...

This study employs a microaerobic pretreatment that includes different microbial reagents combined with oxygen to enhance the energy conversion potential of rice straw (RS) via anaerobic digestion (AD) in a more cost-effective and time efficient manner. Five broad varieties of microbial reagents, liquid consortium (LC), cow manure (CM), sheep dung...

Vinegar residue (VR), a major by‐product in the vinegar brewing process, is generated at least three million tons annually in China. Currently major part of the disposal of VR is fulfilled by landfill and incineration, however, serious environment pollution along with such processes is a challenging issue. Anaerobic digestion (AD) can provide benef...

Anaerobic digestion (AD) is a widely applied technology for treating organic wastes to generate renewable energy in the form of biogas. The effectiveness of AD process depends on many factors, among which the most important is the presence of active and healthy microbial community in the anaerobic digesters, which needs to be explored. However, the...

Each year, about 2.4 million tons of zucchini stem (ZS) are discarded after harvesting of zucchini and result in serious environmental pollutions. This study adopted anaerobic digestion (AD) technology to convert ZS to clean energy and systematically investigated the methane production performance of ZS. For improving AD efficiency, organic loading...

The Anaerobic Digestion Model No.1 (ADM1) was extended for simulation of syngas biomethanation from lab-scale to pilot-scale, with the development of the gas-liquid mass transfer, the inhibition equations, and the biochemical reaction of CO and H2. In the lab-scale reactor, after increasing the syngas flow rate and syngas loading, the syngas conver...

The effect of different bioaugmentation strategies on anaerobic digestion related to the alleviation of ammonia inhibition was investigated in a long-term operation. The long-term operation confirmed that bioaugmentation is a stable method. A 35% increase in methane production (MP) was observed in bottles bioaugmented with Methanosarcina barkeri (M...

Co-fermentation of CO and wastewater for H2 generation could be a promising technology to maximize energy recovery and minimize the operation requirement, but H2 consumption by homoacetogenesis remains the main challenge. The present study investigated the effect of different pH (initial and constant) and CO loading on CO and carbohydrate-rich wast...

Air pollutants from household heating stoves are attracting growing public concern. Although several previous studies have investigated the emissions of pollutants from the household heating stoves, the emission factors reported might be less representative because most of the studies conducted the measurement only during the relatively short perio...

Due to an approaching energy crisis, new energy sources with low pollution and high energy density are being urgently sought. Energy plants, as a new option, were widely studied and considered. In this work, the characteristics and biomethane production performance of giant grasses ( Pennisetum giganteum z.x.lin) with different harvest times were s...

Paper wastes comprise the main biodegradable fraction in municipal solid waste. One of the best ways to treat paper wastes is using it as a feedstock for biomethane production through anaerobic digestion (AD). However, the AD characteristics, kinetics, and energy potential of different paper wastes are not clear. In this study, four kinds of typica...

Background: The co-fermentation of syngas (mainly CO, H2 and CO2) and different concentrations of carbohydrate/protein synthetic wastewater to produce volatile fatty acids (VFAs) was conducted in the present study. Results: It was found that co-fermentation of syngas with carbohydrate-rich synthetic wastewater could enhance the conversion effici...

An integrated treatment system with co-fermentation of food waste (FW) and syngas generated from digestate pyrolysis was verified as a promising approach to improve biofuel recovery. Syngas was injected and co-fermented with the FW at different injection volumes starting from 560 mL (Stage II). More stable methane production (MP) was exhibited in t...

CO is a main component of syngas produced by the thermal gasification of biomass. The biological conversion of sole CO into medium-chain carboxylates (MCCs) has attracted considerable attention, although the process has a low efficiency. The present study demonstrated a process to achieve efficient MCCs production from short-chain carboxylates (SCC...

Anaerobic digestion (AD) is one of the most promising technologies for treating municipal solid waste (MSW) to produce clean energy in the form of biogas. Although AD has been efficiently employed in developed countries, however, its application in the developing countries is still far from enough. This paper for the first time identifies the detai...

Large-scale cultivation of switchgrass (SG) not only promotes the utilization efficiency of marginal land but also provides suitable feedstock for bioenergy production. To maximize the energy conversion capability of SG in anaerobic digestion (AD), various pretreatment strategies involved NaOH, KOH, Ca(OH)2, H2O2, HCl, H2SO4, and steam explosion we...

This work firstly investigated the suitable organic loading (OL) and feed to inoculum (F/I) ratio of three kinds of tobacco stalks (TS116, TS99, and TS85) during anaerobic digestion (AD) via response surface methodology (RSM). The highest experimental methane yield (EMY) of 148.1 mL/g VS was achieved from TS116 at OL of 20.2 g VS/L and F/I ratio of...

Effectiveness of steam explosion (SE) pretreatment for deconstructing the complex structural carbohydrates (SC) and lignin recalcitrance properties of rice straw (RS) for conjunctive improvement of biofuel yield and waste valorization was evaluated. This work exhibited successful pretreatment of RS at a different pressure (1.2, 1.5, and 1.8 MPa) an...

Anaerobic digestion (AD) is one of the best technologies for producing methane from biomass wastes with limited environmental impacts. Most AD plants need a continuous and stable supply of feedstock for their sustained operation for which lignocellulosic biomass can be effectively utilized. Switchgrass (SG), also known as Panicum virgatum, is a tal...

The effect of anaerobic activated sludge (AS) and granule sludge (GS) as inoculum on methane production (MP) with different ammonia levels were compared. About 35 % of MP loss were observed when ammonia level exceeded 3 g NH4+-N/L in AS reactors and 5 g NH4+-N/L in GS reactors. Propionate accumulation in GS reactors was 66 - 80 % lower than that in...

Tobacco stalk, a common agricultural waste derived from the harvest of tobacco, caused serious environmental pollution in China. In this study, the performance of biomethane production and characteristics of four varieties of tobacco stalk were investigated for the first time. The results showed that the highest cumulative methane yield of 130.2 mL...

Anaerobic digestion (AD) is an established method for sustainable energy production. Anaerobic digestion model No.1 (ADM1) was used to simulate methane production (MP) and volatile fatty acid (VFA) concentrations at different ammonium concentrations. In accordance with the incomplete description of several biochemical reactions and the omission of...

Biochar is a carbonaceous and porous product that is yielded from the pyrolysis of feedstock under the O 2-limited atmosphere, and recently it has gained considerable attention in the agricultural area to serve as a soil amendment and simultaneously to sequester biogenic carbon. Pyrolysis conditions of biochar significantly affect its characteristi...

The effect of bioaugmentation with different microorganisms on anaerobic digestion to mitigate the ammonia inhibition problem was investigated. Seven pure strains of microorganisms (including obligate aceticlastic methanogen, facultative aceticlastic methanogen, hydrogenotrophic methanogen, syntrophic acetate oxidizing bacteria (SAOB) were selected...

The physicochemical, morphology properties and the sorption capacities of discarded mushroom-stick biochar (DMB) prepared under different pyrolysis temperatures from 300 °C to 800 °C were explored. Results showed that the yield and surface oxygen-containing group of DMB prepared at 300 °C (DMB3) were higher than that of DMB prepared at higher pyrol...

Activated carbon has been widely used as adsorbents, catalyst support and energy storage materials. Microwave heating is a promising technique for thermochemical treatment and activation of activated carbons due to its fast, selective, uniform and volumetric heating. Previous reviews mainly focused on specific feedstocks (e.g. agricultural biomass...

This study investigated methane production, long-chain fatty acids (LCFAs) profile, and predominant microorganisms in anaerobic digestion (AD) of lipid-rich swine slaughterhouse waste (SSW). The maximum methane yield was 999.2 mL/g VS. LCFAs, as inhibitory hydrolysis products, accumulated first to 1165 mg/L on day 3, and then decreased sharply to 1...

Durian shell (DS), a kind of fruit waste with a very large annual production yield, is mainly discarded in Asia. Currently, finding a reasonable method to utilize this bioresource is urgently needed. The effective technique of anaerobic digestion (AD) for the utilization of DS has seldom been reported. In this study, the anaerobic co-digestion of D...

Engineering representing the backbone of a nation aims to migrate towards the knowledge economy. The strengthening of engineering education leads to the nation’s self-reliance while building indigenous capabilities. The current study attempts to compare engineering education in China with Pakistan, Europe, and the USA in context of One Belt, One Ro...

Solid-state anaerobic digestion is an attractive way to convert corn straw and chicken manure into bioenergy. This study investigated the performance of solid-state co-digestion of NaOH-pretreated corn straw and chicken manure at mixing ratios of 1:0, 3:1, 1:1, 1:3, and 0:1 under mesophilic (37 °C) condition. Additionally, high-throughput sequencin...

Anaerobic digestion (AD) is a promising technology for treating food waste, as it has high energy recovery and controls environmental problems. The biogasification performance of food waste was observed by changing the process parameters such as hydraulic retention time (HRT) and organic loading rate (OLR). A continuously stirred tank reactor (CSTR...

Pollutant emissions from incomplete combustion of raw coal in low-efficiency residential heating stoves greatly contribute to winter haze in China. Semi-coke coals and improved heating stoves are expected to lower air pollutant emissions and are vigorously promoted by the Chinese government in many national and local plans. In this study, the therm...

This study investigated the pyrolysis characteristic of textile dyeing sludge (DS) using an auger pyrolyser under microwave irradiation at different pyrolysis temperature. The migration and distribution characteristic of heavy metals and their potential ecological risks were investigated using inductively coupled plasma mass spectrometry (ICP-MS) t...

Sweet potato vine (SPV) is an abundant agricultural waste, which is easy to obtain at low cost and has the potential to produce clean energy via anaerobic digestion (AD). The main objectives of this study were to reveal methane production and process stability of SPV and the mixtures with animal manure under various total solid conditions, to verif...