Dan Tsang

Dan Tsang
The Hong Kong Polytechnic University | PolyU · Department of Civil and Environmental Engineering

PhD
Resources Engineering towards Carbon Neutrality

About

618
Publications
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Introduction
Resources Engineering towards Carbon Neutrality ( https://www.dan-tsang.com/ )

Publications

Publications (618)
Article
A novel biochar-based heterogeneous catalyst has been devised to facilitate isomerisation of glucose to fructose for achieving sustainable biorefineries. A series of aluminium-biochar composites (Al biochars) with wide-ranging properties were synthesised from waste wood biomass. These properties including surface area, porosity, crystalline/amorpho...
Article
We have developed a sustainable graphitic biochar for environmental remediation from wood waste through catalytic pyrolysis under the synergistic effects between CO2 and Cu heteroatoms, which for the first time are found to significantly enhance the oxygen functionalities, defective sites, and highly ordered sp2-hybridized carbon matrix. The copper...
Article
Nitrogen-doped graphitic biochar (NBC) has boosted the development of nonradical peroxymonosulfate (PMS) activation in environmental remediation. However, the specific role of nitrogen species played in NBC-based nonradical carbocatalysis remains vaguely interpreted. To pinpoint the critical nitrogen speciation, a sophisticated thermo-mechanochemic...
Article
Electroplating sludge is a hazardous waste due to its high potential to leach toxic elements into the natural environment. To alleviate this issue, we tailored magnesium phosphate cement (MPC) as a low-carbon material for stabilization/solidification (S/S) of Zn-rich electroplating sludge. The interaction between MPC and ZnO was investigated to cla...
Article
Biochar, a carbon-rich material made from the partial combustion of biomass wastes, is an emerging material of interest as it can remediate pollutants and serve as a negative carbon emission technology. In this Review, we discuss the application of biochar in municipal wastewater treatment, industrial wastewater decontamination and stormwater manag...
Article
As an important subtopic within phytoremediation, hyperaccumulators have garnered significant attention due to their ability of super-enriching heavy metals. Identifying the factors that affecting phytoextraction efficiency has important application value in guiding the efficient remediation of heavy metal contaminated soil. However, it is challeng...
Article
One promising method for mitigating low-temperature and low-concentration NO2 pollution is selective adsorption using porous solid materials. However, the corrosive nature of NO2 renders the development of an adsorbent with high and cyclable NO2 uptake a formidable challenge. Herein, we attempted to address this challenge by developing a microporou...
Article
Full-text available
Humanity needs innovative ways to combat the environmental burden caused by food waste, which is one of the critical global issues. We proposed food waste-derived engineered biochar (FWDEB) for CO2 capture from the life cycle perspective. FWDEB samples were prepared by carbonization and chemical activation for CO2 adsorption. FW400-KOH600(2), carbo...
Article
This study innovated the concept in designing an efficient and reusable microwave (MW) absorbent through concurrent exploitation of carbon graphitization, oxygen functionalization, and carbothermal iron reduction underpinned by an endothermic co-pyrolysis of wood waste and low-dosage iron. A powerful MW assimilation was accomplished from nanoscale...
Article
Biomass valorization to chemicals is an important application of this renewable resource. This study reports the production of two versatile value-added organic acids, i.e., gluconic acid (GOA) and glucuronic acid (GUA), from biomass-derived glucose via microwave-assisted catalytic oxidation. A series of novel low-cost biochar-supported Cu-based ca...
Article
The process water (PW) from acid-catalyzed hydrothermal carbonization (HTC) is still an environmental burden due to the enriched organics, nutrients, and salts. This study proposed a novel strategy to valorize food waste digestate into multifunctional hydrochar by recirculating the PW in the HCl-catalyzed HTC process. The produced multifunctional h...
Article
Taking advantage of the inherent structure in biomass for attractive chemical synthesis with high atom economy is vital for a sustainable future but remains a great challenge. Herein, we discovered a new route for glycolic acid (GcA) synthesis using various biomass-derived polyols as feedstock with an exceptionally high atom utilization (∼93%). Up...
Article
Full-text available
Net carbon management of agro-residues has been an important pathway for reducing the environmental burdens of agricultural production. Converting agro-residues into biochar through pyrolysis is a prominent management strategy for achieving carbon neutrality in a circular economy, meeting both environmental and social concerns. Based on the latest...
Article
Biochar has been demonstrated as an efficient amendment for immobilizing contaminants. However, a certain number of micro/nano-scale particles are inevitably present in the fresh or aged biochar, which may facilitate the downward transport of contaminants along the soil profile, posing a detrimental impact on the groundwater. Herein, the effects of...
Article
Full-text available
To achieve clean and efficient utilization of food waste digestate (FWD), a novel strategy of combining acid pretreatment and co-hydrothermal carbonization was developed to prepare value-added hydrochar from food waste digestate. The acid pretreatment of FWD was carried out with 1 M HCl for 8 h at a solid-to-liquid ratio of 1:5. In addition to the...
Article
Understanding the arsenic (As) enrichment mechanisms in the subsurface environment relies on a systematic investigation of As valence species and their partitioning with the Fe (oxyhydr)oxide phases in the subsoil profile. The present study explored the distribution, speciation, partitioning, and (im)mobilization of As associated with Fe in four su...
Article
Engineered biochar derived from wood waste pyrolysis in molten salts were developed for effective CO2/N2 separation. The production conditions were customized to obtain the biochar with high CO2 capture capacity and CO2/N2 selectivity by tuning the type of molten salts (MgCl2-KCl, ZnCl2-KCl, ZnCl2-NaCl-KCl, and K2CO3-Na2CO3-Li2CO3), salt/feedstock...
Article
Lignocellulosic paper waste constitutes a major waste stream globally, which should be valorised for chemical production. However, paper properties (e.g., feedstock composition, cellulosic crystallinity, and thermal stability/degradability) vary with raw materials and pulping processes. This study investigated levulinic acid (LA), hydroxymethylfurf...
Article
To prevent the COVID-19 transmission, personal protective equipment (PPE) and packaging materials have been extensively used but often managed inappropriately, generating huge amount of plastic waste. In this review, we comprehensively discussed the plastic products utilized and the types and amounts of plastic waste generated since the outbreak of...
Article
Soil organic carbon (SOC) is a crucial component that significantly affects the soil fertility, soil remediation, and carbon sequestration. Here, we review the redox-induced transformation of potentially toxic elements (PTEs) through the abiotic impact of SOC. The complex composition of SOC includes humus, pyrogenic carbon (e.g., biochar), dissolve...
Book
Full-text available
Biochar in Agriculture for Achieving Sustainable Development Goals introduces the state-of-the-art of biochar for agricultural applications to actualize sustainable development goals and highlight current challenges and the way forward. The book focuses on scientific knowledge and biochar technologies for agricultural soil improvement and plant gro...
Article
The limited fossil fuel supply toward carbon neutrality has driven tremendous efforts to replace fuel vehicles by electric ones. The recycling of retired power batteries, a core energy supply component of electric vehicles (EVs), is necessary for developing a sustainable EV industry. Here, we comprehensively review the current status and technical...
Article
Full-text available
Food waste worldwide has been threatening the environment and resulting in high carbon emissions. Although anaerobic fermentation is a potential solution transforming food waste into valuable chemicals, a large amount of the fermentation residue remains as solid waste. For closing the circular economy loop for food waste valorization, we proposed a...
Article
Full-text available
Biochar application is a promising strategy for the remediation of contaminated soil, while ensuring sustainable waste management. Biochar remediation of heavy metal (HM)-contaminated soil primarily depends on the properties of the soil, biochar, and HM. The optimum conditions for HM immobilization in biochar-amended soils are site-specific and var...
Article
Microplastic (MP), an emerging contaminant, is globally prevalent and poses potential environmental threats and ecological risks to both aquatic and terrestrial ecosystems. When MPs enter into natural environments, they may serve as artificial substrates for microbial colonization and plastisphere formation, providing new ecological niches for micr...
Article
The addition of thermally conductive nanomaterials is an effective strategy for increasing the thermal conductivity of phase change materials (PCMs). However, nanomaterials are expensive and may significantly reduce the latent heat capacity of PCMs. In this study, low-cost and eco-friendly biochar microparticles were prepared from garlic stems, a c...
Article
The use of biochar to recover nitrogen and phosphorus from wastewater especially source-separated human urine is attractive from both economic and environmental standpoints. The widespread use of pharmaceuticals has raised concerns as they are not fully metabolized and ended up in human urine. The objective of this study is to examine adsorption of...
Article
Full-text available
In addition to climate change, plastic pollution is widely recognized as one of the most severe environmental concerns. Waste-plastic-derived advanced materials for carbon capture provide promising solutions to these environmental issues. However, the environmental sustainability and economic feasibility of such a novel approach are still unclear f...
Article
Incinerated sewage sludge ash is tested here as a cement and aggregate substitute in mortar blocks. It can be used at various percentages to reduce the overall cost of production and promote ash recycling. The compressive strength of the cast blocks was tested at 28 days to determine the optimal combination of ball milled ash (replacing cement) and...
Article
Electroactive Fe-biochar has attracted significant attention for As(III)/Cr(VI) immobilization through redox reactions, and its performance essentially lies in the regulation of various Fe/C moieties for desired redox performance. Here, a series of Fe-biochar with distinct Fe/C speciation were rationally produced via two-step pyrolysis of iron mine...
Article
Full-text available
The effects of catalytic hydrothermal (HT) pretreatment on animal manure followed by the addition of hydrochar on the nutrients recovery have not yet been investigated using a combination of chemical, microscopic, and spectroscopic techniques. Therefore, a catalytic HT process was employed to pretreat swine manure without additives (manure-HT) and...
Article
A considerable amount of food waste generated globally could be upcycled to synthesise platform chemicals to enhance environmental sustainability and help realise a circular economy. This study investigates the catalytic production of the vital platform molecule levulinic acid (LA) from bread waste, a typical stream of starch-rich food waste genera...
Article
Municipal solid waste incineration (MSWI) fly ash is a typical hazardous waste worldwide. In this study, an innovative magnesium oxysulfate cement (MOSC) binder was designed for stabilization/solidification (S/S) of MSWI fly ash, focusing on the interactions between MOSC binder and typical metallic cations (Pb 2+)/oxyanions (AsO 3 3-). Experimental...
Article
Improving the recovery of organic matter and phosphorus (P) from hazardous biowastes such as swine manure using acidic substrates (ASs) in conjunction with aerobic composting is of great interest. This work aimed to investigate the effects of ASs on the humification and/or P migration as well as on microbial succession during the swine manure compo...
Article
Although an increasing number of studies involving layered double hydroxide/biochar composites (LDH/BC) have been published recently, development of advanced modeling approaches of adsorption onto the composites and/or their testing and use in real soils and waters are rare. In this study, Zn(II) and As(V) sorption onto Mg-Fe LDH/BC composites was...
Article
Heteroatom doping is a promising technique to enhance biochar for effective environmental remediation. However, development of electroactive heteroatom-doped biochars, e.g., sulfur-doped biochar, has been hindered due to complex nature of non-stoichiometric biomass-derived carbon and changeable electrochemical state of dopants. Herein, we produced...
Article
Biochar is a waste-derived carbon-based material that can sequester carbon. This study proposed a revolutionary design of carbon-negative concrete with a large volume of biochar incorporation and elaborated the roles of biochar in the cement hydration and microstructure development of biochar-augmented concrete. Moreover, the total CO2 emissions an...
Chapter
According to the sustainable development goals set by the United Nations, great efforts should be made on improving soil health and developing sustainable green materials. As a renewable and economical carbonaceous material derived from biomass waste, biochar provides a nature-based solution in improving soil health and relieving energy crisis. Bio...
Article
Hydrothermal carbonization (HTC) provides a promising alternative to valorize food waste digestate (FWD) and avoid disposal issues. Although hydrochar derived from FWD alone had a low calorific content (HHV of 13.9 MJ kg⁻¹), catalytic co-HTC of FWD with wet lignocellulosic biomass (e.g., wet yard waste; YW) and 0.5 M HCl exhibited overall superior...
Article
Full-text available
Global development has been heavily reliant on the overexploitation of natural resources since the Industrial Revolution. With the extensive use of fossil fuels, deforestation, and other forms of land-use change, anthropogenic activities have contributed to the ever-increasing concentrations of greenhouse gases (GHGs) in the atmosphere, causing glo...
Article
Low-carbon stabilization/solidification (S/S) is of increasing importance for sustainable treatment of hazardous wastes. In this study, we integrated carbon-negative rice husk biochar (RBC) and yard waste biochar (YBC) as green additives into the binder for S/S of municipal solid waste incineration (MSWI) fly ash. Experimental results illustrated t...
Article
The science-informed design of stable carbonaceous materials as ‘green’ soil amendment will be indispensable for improving the soil fertility and carbon sequestration ability. In this study, a series of biochars were prepared from mineral-rich cellulosic corn straw (C), lignocellulosic pine wood (P), and lignin-rich walnut shell (W) at 500 or 700 °...
Article
The enhancing effect of As(III) oxidation on As stabilization by lime is routinely attributed to the lower solubility of Ca arsenates than Ca arsenites. However, this routine explanation is insufficient for the scenario of As(III) partial oxidation, in which Ca arsenites still predominate As leachability due to the relatively high solubility. In th...
Article
Low-carbon stabilization/solidification (S/S) is of increasing importance as an option for the treatment of municipal solid waste incineration fly ash (MIFA). This study tailored four binders (e.g., ordinary Portland cement (OPC), calcium aluminate cement (CAC), phosphate-modified OPC, and phosphate-modified CAC) for S/S of MIFA and evaluated the c...
Article
Sustainable biorefinery depends on the development of efficient processes to convert locally abundant, energy-rich renewable biomass into fuels, chemicals, and materials. Hydrothermal processing has emerged as an attractive approach for wet biomass conversion with less environmental burden. Although considerable efforts have been made in sustainabl...
Chapter
Hazardous waste management is one of the most significant sectors in utility services. In view of the growing amount of waste and the shortage of energy and resources, the conventional waste treatment approaches could hardly fulfill the need of sustainable development, and would cause various concerns to the environment, ecological systems, and pub...
Chapter
Green and sustainable remediation refers to the site-specific use of materials, processes, techniques, and procedures that alleviate environmental risk while balancing economic, social, and environmental impacts. Green and sustainable remediation has drawn numerous interest due to the awareness of sustainable development and potential side effects...
Chapter
Contaminated soils have negative impacts on human health and the environment in many countries. Stabilization/solidification (S/S) as a time- and cost-effective approach is widely used in the remediation of contaminated soil/sediment. However, there are two main limitations for the conventional S/S method: the high carbon footprint and low compatib...
Chapter
Considering the overexploitation of resources and environmental consequences, sustainable management and resourceful utilization of different waste materials are of great research interest globally. Among different strategies, cement-based stabilization/solidification (S/S) technology has been recently considered as a highly efficient technique. Co...
Article
Data mining and knowledge discovery by machine learning (ML) have recently come into application in environmental remediation, especially the exploration for the multifactorial process such as hexavalent chromium [Cr(VI)] removal by iron-biochar composite (Fe-BC). The Cr(VI) removal capacity of Fe-BC was concurrently controlled by impregnated iron...
Article
Contamination of paddy soils by arsenic (As) is of great concern for human health and the environment. The impact of animal-derived biochar on As mobilization under fluctuating redox conditions in paddy soils has not been studied. Consequently, we investigated the effects of pig carcass-derived biochar (PB) on As (im)mobilization in a contaminated...
Article
The accumulation of microplastics (MPs) and nanoplastics (NPs) in terrestrial and aquatic ecosystems has raised concerns because of their adverse effects on ecosystem functions and human health. Plastic waste management has become a universal problem in recent years. Hence, sustainable plastic waste management techniques are vital for achieving the...
Article
Anaerobic digestion (AD) is a widely used technology to valorise food waste for biogas production yet a considerable amount of digestate remains under-utilised. Sustainable management and recycling of the nutrient-rich food waste anaerobic digestate (FWD) is highly desirable for closing resource loop and actualising circular economy. This work revi...
Article
In this study, biochar supported iron sulfide (FexSy) composite (FexSy@biochar) was synthesized and utilized as a persulfate (PS) activator for benzene removal from contaminated groundwater. The FexSy@biochar/PS system exhibited excellent performance in benzene adsorption and subsequent degradation. The optimal conditions for benzene removal in thi...
Article
Hexafluoropropylene oxide dimer acid (GenX) has been marketed as a substitute for perfluorooctanoic acid (PFOA) to reduce environmental and health risks. GenX and PFOA have been detected in various natural water sources, and adsorption is recognized as a typical treatment process for PFOA removal. In this paper, comparisons of GenX and PFOA adsorpt...
Article
In this study, N-functionalized biochars with varied structural characteristics were designed by loading poplar leaf with different amounts of urea at 1:1 and 1:3 ratios through pyrolysis method. The addition of urea significantly increased the N content of biochar and facilitated the formation of amine (-NH-, -NH2), imine (-HCNH), benzimidazole (-...
Article
Recent studies show that fast hydropyrolysis (i.e., pyrolysis under hydrogen atmosphere operating at a rapid heating rate) is a promising technology for the conversion of biomass into liquid fuels (e.g., bio-oil and C4+ hydrocarbons). This pyrolysis approach is reported to be more effective than conventional fast pyrolysis in producing aromatic hyd...
Article
Mobilization of trace metals in the rhizosphere of macrophytes is controlled by root-driven chemical changes, especially the steep gradients of O2 and pH from the rhizosphere to bulk sediments. Here, the O2 and pH dynamics, and the distribution of trace metal, in the rhizosphere of Vallisneria spiralis were obtained using planar optodes and diffusi...
Article
Wood waste-derived biochar with tunable carbon structure and surface functionality has a great potential for various environmental applications and circular economy; however, a holistic understanding on the application-oriented production of high-efficacy biochar is lacking. Thus, the co-impacts of different pyrolysis conditions (temperature and du...
Article
The science-informed design of ‘green’ carbonaceous materials (e.g., biochar and activated carbon) with high removal capacity of recalcitrant organic contaminants (e.g., pharmaceuticals and personal care products (PPCPs)) is indispensable for promoting sustainable wastewater treatment. In this study, machine learning (ML) incorporating PPCPs and bi...
Article
Tailored manipulation of iron speciation has become a critical challenge for the further development of Fe-biochar as an economical and eco-friendly amendment for arsenic (As) immobilization. Herein, a series of Fe-biochars with manipulated iron speciations were fabricated by controlling the carbon structures and pyrolysis conditions. Results revea...
Article
Thallium (Tl) is an extremely toxic metal, while its occurrence and fate in paddy soil environment remain understudied. Herein, the enrichment and migration mechanisms and potential health risks of Tl and metal(loid)s were evaluated in paddy soils surrounding an industrial park utilizing Tl-bearing minerals. The results showed that Tl contamination...
Article
Thallium (Tl) is a highly toxic trace metal. Lead (Pb)‑zinc (Zn) smelting, which is a pillar industry in various countries, is regarded as one of the dominant anthropogenic sources of Tl contamination in the environment. In this study, thallium isotope data have been evaluated for raw material and a set of industrial wastes produced at different st...
Article
Phosphorus (P) availability is closely related to the distributions of pH, O2 and phosphatase activities in the rhizosphere of plants growing in soils and sediments. In this study, the P uptake processes and mechanisms of Vallisneria natans (V. natans) during two vegetation periods (i.e., week three and six) were revealed using three noninvasive 2D...
Article
Biochar modification is widely used to improve its capability for environmental application, while its impact on carbon sequestration potential is unknown. Herein, the oxidation-resistance stability of biochar with different activation processes was first evaluated, which is crucial for sustainable production of engineered biochar. Thermal activati...
Article
Mono- and co-sorption of the three antibiotics i.e., norfloxacin (NOR), sulfamerazine (SMR) and oxytetracycline (OTC), to raw and NH4⁺-modified cassava waste biochar added to aqueous solutions were investigated. The NH4⁺-modified biochar showed higher sorption affinity for both NOR and SMR than the raw biochar, while the raw biochar showed higher s...
Article
Full-text available
Management of incinerated sewage sludge ash (ISSA) and dredged contaminated marine sediments (CMSs) is a great challenge for Hong Kong and other coastal cities due to limited landfilling capacity. The present study investigates the use of high content (20% of sediment by mass) of ISSA in combination with cement/lime for solidification/stabilization...
Article
Gluconic acid (GOA) and glucaric acid (GAA) are valuable chemicals for a wide range of applications, yet conventional technologies for their production suffer from low efficiency, high cost, and especially environmental concerns. It is imperative to develop sustainable heterogeneous catalytic systems exhibiting promising catalytic activity and good...
Article
Atmospheric NO2 removal is urgent and necessary due to its negative effects on the eco-system. Here we developed the chrysanthemum flower-like silica (KCC-1) loaded with highly dispersed copper nanoparticles for efficient NO2 removal under ambient conditions. We carefully studied the NO2 removal performance of Cu-KCC-1 materials with different copp...
Article
NO2 is a potent air pollutant because of its deleterious effects on human beings and other organisms. The state-of-the-art catalysis-based deNOx techniques (e.g., selective catalytic/non-catalytic reduction) are incapable of ambient NO2 abatement due to their low efficiency at temperatures below 300 °C. It is thus conceivable to directly capture NO...
Article
Producing commodity aromatic hydrocarbons from textile waste is a promising approach to promote carbon neutrality and circular economy. Catalytic degradation of flax waste (FW) to generate furans and its subsequent Diels-Alder transformation to monocyclic aromatic hydrocarbons over USY zeolite were conducted. Experimental results indicated that USY...
Article
Biochar is an emerging, cost-effective, and renewable carbonaceous material with abundant functional groups and tuneable mesoporous structure, showing a promising performance in fertility improvement, nutrient retention, microbial activity enhancement, contaminant immobilization, etc. Dissolved organic matter (DOM) from biochar, which can be readil...
Article
Elevated As(III) and Fe(II) levels in shallow reducing groundwater can be frequently re-oxidized by introducing O2 due to natural/anthropogenic processes, thus leading to oxidative precipitation of As as well as Fe. Nevertheless, the geochemical process may be impacted by co-existing engineered black carbon due to its considerable applications, but...