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Efects of solution chemistry on arsenic(V) removal by low-cost adsorbents

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Journal of Environmental Sciences 2013年第11期25卷 2291-2298页

作者： Yuru wang Daniel c.w.tsang Department of civil and Environmental Engineering Hong Kong Polytechnic University Department of civil and Natural Resources Engineering University of Canterbury

Natural and anthropogenic arsenic （As） contamination of water sources pose serious health concerns, especially for small communities in rural areas. This study assessed the applicability of three industrial byproducts （coal fly ash, lignite, and green waste compost） as the low-cost adsorbents for As（V） removal under various field-relevant conditions （dissolved oxygen, As（V）/Fe ratio, solution pH, and presence of competing species）. The physico-chemical properties of the adsorbents were characterized by XRD, XRF, FT-IR, and NMR analysis. Batch experiments demonstrated that coal fly ash could provide effective As（V） removal （82.1%-95%） because it contained high content of amorphous iron/aluminium hydroxides for As（V） adsorption and dissolvable calcium minerals for calcium arsenate precipitation. However, the addition of lignite and green waste compost was found unfavourable since they hindered the As（V） removal by 10%-42% possibly due to dissolution of organic matter and ternary arsenate-iron-organic matter complexes. On the other hand, higher concentrations of dissolved iron （comparing As（V）/Fe ratios of 1：1 and 1：10） and dissolved oxygen （comparing 0.2 and 6 mg/L） only marginally enhanced the As（V） removal at pH 6 and 8. Thus, addition of dissolved iron, water aeration, or pH adjustment became unnecessary because coal fly ash was able to provide effective As（V） removal under the natural range of geochemical conditions. Moreover, the presence of low levels of background competing （0.8 or 8 mg/L of humic acid, phosphate, and silicate） imposed little influence on As（V） removal, possibly because the high adsorption capacity of coal fly ash was far from exhaustion. These results suggested that coal fly ash was a potentially promising adsorbent that warranted further investigation.

关键词： adsorption arsenic coal fly ash green waste compost lignite

chemical characteristics of aerosols at coastal station in Hong Kong.Ⅱ. Environmental behavior of trace elements during the April 1995 to April 1996

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Journal of Environmental Sciences 2004年第2期16卷 212-221页

作者： K.S.Lam Z.L.cheng S.c.Kot c.w.tsang Department of civil and Structural Engineering the Hong Kong Polytechnic UniversityResearch Center for Eco-Environmental Sciences Chinese Academy of SciencesDepartment of Mechanical Engineering The Hong Kong University of Science & Technology Clear Water BayDepartment of Applied Biology and Chemical Technology the Hong Kong Polytechnic University Hung Hom Hong Kong ChinaBeijing 100085 ChinaHong Kong ChinaHung Hom Hong Kong China

An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, cape D′Aguilar, in Hong Kong. The trace element composition of aerosol particles(TSP and PM 10 ) were measured and analyzed by using the Instrumental Neutron Activation Analysis(INAA) and Inductive couple Plasma-Mass Spectrometry(IcP-MS) techniques. The results showed that the polluted elements such as: V, Zn, As, Pb, cd, Sb, I, Se, Bi, with high enrichment factor(E.F) values, are derived from anthropogenic sources, while Sc, Al, Fe, Mn, Sm, La, Sr are less than 10 in E.F, these elements are related the crust and soil. The concentration of the trace elements are present seasonal variation i.e. summer low and winter high, whereas the V or noncrustal V(V *) present summer high and winter low, this phenomenon might be explained by local or regional oil combustion sources. Use three type of elemental ratio, e.g. La/Sm, Mn */V * and Bi/Al indicate that both TSP and PM 10 of La/Sm ratios are mainly related to soil and dust, Mn */V * are probably represent fossil combustion and Bi/Al are possibly associated with refuse incineration, ferromanganese alloys and aluminum production. The varimax rotation factor analysis for trace elements was performed. By means of the absolute principal component analysis(APcA) and multiple regression, the contribution of trace elements to possible sources and overall means of trace elements were estimated. The results showed that the present station is impacted by the anthropogenic species, although the quantities are different during the summertime and wintertime.

关键词： TSP PM 10 trace elements enhancement factor element ratios seasonal variation factor analysis

On the Variability and correlation of Surface Ozone and carbon Monoxide Observed in Hong Kong Using Trajectory and Regression Analyses

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Advances in Atmospheric Sciences 2004年第1期21卷 141-152页

作者：王体健 K.S.LAM c.w.tsang S.c.KOT Department of Atmospheric Sciences Nanjing University Nanjing 210093 Environmental Engineering Unit Department of Civil & Structural Engineering The Hong Kong Polytechnic University Hong Kong Environmental Engineering Unit Department of Civil & Structural Engineering The Hong Kong Polytechnic University Hong Kong Department of Mechanical Engineering Hong Kong University of Science & Technology Hong Kong

This paper investigates, the variability and correlation of surface ozone (Os) and carbon monoxide (cO) observed at cape D'Aguilar in Hong Kong from 1 January 1994 to 31 December 1995. Statistical analysis shows that the average O3 and cO mixing ratios during the two years are 32±17ppbv and 305±191 ppbv, respectively. The O3/cO ratio ranges from 0.05 to 0.6 ppbv/ppbv with its frequency peaking at 0.15. The raw dataset is divided into six groups using backward trajectory and cluster analyses. For data assigned to the same trajectory type, three groups are further sorted out based on cO and NOX mixing ratios. The correlation coefficients and slopes of O3/cO for the 18 groups are calculated using linear regression analysis. Finally, five kinds of air masses with different chemical features are identified: continental background (cB), marine background (MB), regional polluted continental (RPc), perturbed marine (P*M), and local polluted (LP) air masses. Further studies indicate that O3 and cO in the continental and marine background air masses (cB and MB) are positively correlated for the reason that they are well mixed over the long range transport before arriving at the site. The negative correlation between O3 and cO in air mass LP is believed to be associated with heavy anthropogenic influence, which results from the enhancement by local sources as indicated by high cO and NOx and depletion of O3 when mixed with fresh emissions. The positive correlation in the perturbed marine air mass P*M favors the low photochemical production of O3. The negative correlation found in the regional polluted continental air mass RPc is different from the observations at Oki Island in Japan due to the more complex O3 chemistry at cape D'Aguilar.

关键词： ozone carbon monoxide trajectory

Engineering and microstructure properties of contaminated marine sediments solidified by high content of incinerated sewage sludge ash

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第3期13卷 643-652页

作者： Jiang-Shan Li Yifan Zhou Xin chen Qiming wang Qiang Xue Daniel c.w.tsang chi Sun Poon State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China IRSM-cAS/HK PolyU Joint Laboratory on Solid waste Science Hung HomKowloonHong KongChina Hubei Province Key Laboratory of contaminated Sludge and Soil Science and Engineering Wuhan430071China Department of civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

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 *** present study investigates the use of high content(20%of sediment by mass)of ISSA in combination with cement/lime for solidification/stabilization(S/S)treatment of cMSs to provide a way to reuse the wastes as construction *** results showed that ISSA being a porous material was able to absorb a large amount of water rendering a more efficient solidification process of the marine sediment which normally had a very high water content(w80%).The S/S treatment improved the engineering properties of the sediment,but reduced the workability,especially for the lime-treated *** can be used to replace ordinary Portland cement(OPc)for better heavy metal immobilization and carbon emission *** hardened sediment samples prepared with 10%of lime and 20%of ISSA could attain a strength of 1.6 MPa after 28 d of *** addition,leaching tests confirmed that there was no environmental risk induced by these stabilized *** formation of hydrated cementitious compounds including calcium silicate hydrate(ceSeH)/calcium aluminate silicate hydrate(c-A-S-H)/hydrocalumite/calcite was mainly responsible for the strength development in the ISSA/lime-treated sediments.

关键词： contaminated marine sediment(cMS) Incinerated sewage sludge ash(ISSA) Solidification/stabilization(S/S) Heavy metals construction material

wood waste biochar promoted anaerobic digestion of food waste:focusing on the characteristics of biochar and microbial community analysis

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Biochar 2022年第1期4卷 152-163页

作者： chao Zhang Rui Yang Meichen Sun Shicheng Zhang Mingjing He Daniel c.w.tsang Gang Luo Department of Environmental Science&Engneering Shanghai Key Lab Atmospher Particle Pollution&PreventionFudan UniversityShanghai 200438People’s Republic of China Shanghai Technical Service Platform for Pollution control and Resource Utilization of Organic waste Shanghai 200438People’s Republic of China Shanghai Institute of Pollution control and Ecological Security Shanghai 200092People’s Republic of China Department of civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Research Institute for Future Food The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

Anaerobic digestion(AD)has been considered as a promising technique for food waste(Fw)***,the accumulation of volatile fatty acids(VFAs)restricts the stability of anaerobic *** present study investigated the use of biochar produced at different conditions(750℃-30 min,750℃-60 min,750℃-120 min,550℃-60 min,650℃-60 min,850℃-60 min,950℃-60 min)for enhancing the AD of *** experiments showed that all the biochar increased the methane production rates and biochar obtained at 750℃-60 min resulted in the highest enhance-ment by 21.5%.It was further showed surface oxygen-containing functional groups and graphitization degree of biochar were the critical factors for improving methane *** analysis showed that biochar addi-tion formed different microbial communities,and Methanosaeta,Romboutsia,and norank_f_Anaerolineaceae were enriched,which might be correlated with direct interspecies electron transfer(DIET).This research showed biochar could enhance the AD of Fw and also revealed the main characteristics of biochar relating with the enhancement of AD.

关键词： Anaerobic digestion Food waste wood waste biochar Methane production Sustainable waste management

catalytically active interfaces in titania nanorod-supported copper catalysts for cO oxidation

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Nano Research 2020年第2期13卷 533-542页

作者： wasim U.Khan Season S.chen Daniel c.w.tsang wey Yang Teoh Xijun Hu Frank L.Y.Lam Alex c.K.Yip Department of chemical and Process Engineering The University of canterbury Christchurch 8041New Zealand Department of civil and Environmental Engineering.The Hong Kong Polytechnic University Hong Kong.China School of chemical Engineering The University of New South WalesSydneyNSW 2052Australia Department of chemical and Biological Engineering The Hong Kong University of Science and TechnologyHong KongChina

One-dimensional titanium dioxide nanorod(TNR)-supported cu catalysts(2.5 wt.%-12.5 wt.%)were synthesized using deposition-precipitation.X-ray photoelectron spectroscopy,temperature programmed reduction and cO chemisorption measurements showed that cu doping over TNR offered metal-support interactions and interfacial active sites that had a profound impact on the catalytic *** role of the cu-TNR interface was investigated by comparing the catalytic activity of cu-TNR catalysts with that of pure cuO nanoparticles in cO *** presence of highly dispersed copper species,a high number of interfacial active sites,cO adsorption capacity and surface/lattice oxygen were found to be responsible for the excellent activity of 7.5cU-TNR(ie,cu loading of 7.5 wt.%on TNR).Moreover,the cu-TNR catalysts followed the Langmuir-Hinshelwood reaction mechanism with 7.5cU-TNR,exhibiting an apparent activation energy of 44.7 kJ/*** TNR-supported cu catalyst gave the highest interfacial catalytic activity in medium-temperature cO oxidation(120-240℃)compared to other commonly used supports,including titanium dioxide nanoparticles(TiO2-P25),silica(SiO2)and alumina(Al20g)in which copper species were nonhomogeneously *** study confirms that medium-temperature cO oxidation is highly sensitive to the morphology and structure of the supporting material.

关键词： supported catalysts nanorod oxygen species interfacial active sites cO oxidation

carbon-negative cement-bonded biochar particleboards

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Biochar 2022年第1期4卷 219-227页

作者： Liang chen Yuying Zhang claudia Labianca Lei wang Shaoqin Ruan chi Sun Poon Yong Sik Ok Daniel c.w.tsang Department of civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina State Key Laboratory of clean Energy Utilization Zhejiang UniversityHangzhou 310027China college of civil Engineering and Architecture Zhejiang UniversityHangzhou 310058China Research centre for Resources Engineering Towards carbon Neutrality The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Korea Biochar Research center APRU Sustainable Waste Management Program&Division of Environmental Science and Ecological EngineeringKorea UniversitySeoul 02841Korea

Biochar from bio-waste pyrolysis presents excellent cO_(2) sequestration *** study innovated the design of cement-bonded particleboards utilizing a substantial amount of 50-70 wt.%pre-soaked biochar to render the products *** investigated the roles of biochar in magnesium oxysulfate cement(MOSc)system and demonstrated good mechanical and functional properties of biochar cement *** the presence of biochar,the amounts of hydration products were enriched in the cement systems as illustrated by the thermogravi-metric analyses(TGA)and X-ray diffraction(XRD).we further incorporated supplementary cementitious materials(ScMs)and generated 5 Mg(OH)_(2)⋅MgSO_(4)·7H_(2)O(5-1-7)phase in the MOSc *** a result,our designs of biochar particleboards satisfied the standard requirements for flexural strength(>5.5 MPa)and thickness swelling(char particleboards presented a low thermal conductivity as the biochar pores disrupted thermal bridging within *** illustrated that the high dosage ratio of biochar could significantly offset the cO_(2) emissions of the particleboards(i.e.,carbon-negative)via life cycle *** economic profits could also be accomplished for the biochar *** instance,the 50Bc-MOSc bonded particleboard(with 50 wt.%pre-soaked biochar as aggregate,50 wt.%MOSc as binder)with promising mechanical properties could store 137 kg cO_(2) tonne^(−1) and yield an overall economic profit of 92 to 116 USD m^(−3) depending on the carbon prices in different *** summary,our new designs of carbon-negative biochar particleboards could curtail carbon emissions in the construction materials and promote the realization of carbon neutrality and circular economy.

关键词： Biochar-cement composite carbon neutrality wood waste biochar Magnesium oxysulfate cement climate-positive construction materials

Biochar as construction materials for achieving carbon neutrality

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Biochar 2022年第1期4卷 194-218页

作者： Yuying Zhang Mingjing He Lei wang Jianhua Yan Bin Ma Xiaohong Zhu Yong Sik Ok Viktor Mechtcherine Daniel c.w.tsang Department of civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina State Key Laboratory of clean Energy Utilization Zhejiang UniversityHangzhou 310027China Laboratory for waste Management Nuclear Energy and SafetyPaul Scherrer Institute5232 VilligenSwitzerland School of civil Engineering University of LeedsWest YorkshireLeedsUK Korea Biochar Research center APRU Sustainable Waste Management Program&Division of Environmental Science and Ecological EngineeringKorea UniversitySeoulKorea Institute of construction Materials Technische Universität Dresden01062 DresdenGermany Research centre for Resources Engineering towards carbon Neutrality The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

Biochar is a waste-derived material that can sequester carbon at a large *** development of low-carbon and sustainable biochar-enhanced construction materials has attracted extensive ***,having a porous nature and highly functionalised surface,can provide nucleation sites for chemical reactions and exhibit compatibility with cement,asphalt,and polymer *** study critically reviewed the state-of-the-art biochar-enhanced construction materials,including biochar-cement composites,biochar-asphalt composites,biochar-plastic composites,*** efficacies and mechanisms of biochar as construction materials were articulated to improve their functional *** critical review highlighted the roles of biochar in cement hydration,surface functional groups of engineered biochar for promoting chemical reactions,and value-added merits of biochar-enhanced construction materials(such as humidity regulation,thermal insulation,noise reduction,air/water purification,electromagnetic shielding,and self-sensing).The major properties of biochar are correlated to the features and functionalities of biochar-enhanced construction *** advances in our understanding of biochar’s roles in various composites can foster the next-generation design of carbon-neutral construction materials.

关键词： Engineered biochar Biomass waste management carbon-negative materials carbon neutrality Supplementary cementitious materials Sustainable construction

Metal Extraction From contaminated Soils by Edds washing Under Edds Excess conditions

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Metal Extraction From Contaminated Soils by Edds Washing Und...