@article{gao_huang_zhi_yao_wang_yang_han_lin_he_wei_et al._2022, title={Assessing the impacts of urbanization on stream ecosystem functioning through investigating litter decomposition and nutrient uptake in a forest and a hyper-eutrophic urban stream}, volume={138}, ISSN={1470-160X}, url={http://dx.doi.org/10.1016/j.ecolind.2022.108859}, DOI={10.1016/j.ecolind.2022.108859}, abstractNote={Rapid urbanization significantly affects freshwater systems by interfering with important ecological functions. The responses of different ecosystem functions in urban streams and their potential ecological effects remain largely unknown, impeding their management and restoration in many cases. In this study, we simultaneously assessed two important ecosystem functions, litter decomposition and nutrient uptake, and investigated the associated microbial and benthic macroinvertebrate communities in two subtropical streams (i.e., a forest headwater stream as a reference and an urban stream that was hyper-eutrophic). Litter decomposition was estimated using litter bags with two mesh sizes (i.e., 50 μm and 2 mm) and two leaf species with different qualities (i.e., Alangium chinense and Machilus leptophylla), with a total of 96 litter bags. Nitrogen (N) and phosphorus (P) uptake rates were measured in situ based on the spiraling model. We found that the decomposition rate of A.chinense was approximately seven times that of M. leptophylla in both streams. Moreover, in the urban stream, the litter decomposition rate (0.004 day−1) was one-third that of the forest stream (0.013 day−1), regardless of the litter species. Macroinvertebrates strongly contributed to litter decomposition in the forest stream, where decomposition rates were 1.8-fold higher in the coarse mesh compared to the fine mesh bags, while they had a negligible role in the urban stream (no significant difference between the two mesh bags). P uptake was higher (85-fold) and N uptake was lower (0.13-fold) in the urban compared to forest stream. Litter decomposition and nutrient uptake exhibit decoupled response. These findings show that litter decomposition by kcoarse/kfine metrics and the uptake of N and P are complementary and should be considered in the management and restoration of urban stream ecosystems.}, journal={Ecological Indicators}, publisher={Elsevier BV}, author={Gao, Jie and Huang, Yuyue and Zhi, Yue and Yao, Jingmei and Wang, Fang and Yang, Wei and Han, Le and Lin, Dunmei and He, Qiang and Wei, Bing and et al.}, year={2022}, month={May}, pages={108859} }
 @article{fan_shi_zhi_nie_lin_2022, title={Experimental and numerical study on multi-wave modes of H<sub>2</sub>/O<sub>2</sub> rotating detonation combustor}, volume={47}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85125622699&partnerID=MN8TOARS}, DOI={10.1016/j.ijhydene.2022.02.048}, abstractNote={H2/O2 are desirable propellants for rocket-based rotating detonation engines but are rarely reported. This report presents an experimental study on rotating detonations powered by H2/O2. A non-premixed three-dimensional numerical simulation was conducted via OpenFOAM-based code. The experimental results revealed more than five co-rotating detonation waves at various flow rates with a propagation speed below 2000 m/s. Furthermore, an adjustment stage was observed prior to the stabilization of the detonation in the N-wave mode. The wavenumber in the adjustment stage varied between N and N+1 when the flow rate was 153 g/s and between N-1 and N+1 at 186 g/s. The simulation results revealed that multiple waves and low filling heights characterized the flow field of the H2/O2 rotating detonation. The severe deflagration of the contact surface led to new detonation waves at excessive filling heights. This supports further exploration of the potential application of H2/O2 propellants in rotating detonation rocket engines.}, number={26}, journal={International Journal of Hydrogen Energy}, author={Fan, L.-Z. and Shi, Q. and Zhi, Y. and Nie, W.-S. and Lin, W.}, year={2022}, pages={13121–13133} }
 @article{zhi_paterson_call_jones_hesterberg_duckworth_poitras_knappe_2022, title={Mechanisms of orthophosphate removal from water by lanthanum carbonate and other lanthanum-containing materials}, volume={820}, ISSN={["1879-1026"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85123356200&partnerID=MN8TOARS}, DOI={10.1016/j.scitotenv.2022.153153}, abstractNote={Removing phosphorus (P) from water and wastewater is essential for preventing eutrophication and protecting environmental quality. Lanthanum [La(III)]-containing materials can effectively and selectively remove orthophosphate (PO4) from aqueous systems, but there remains a need to better understand the underlying mechanism of PO4 removal. Our objectives were to 1) identify the mechanism of PO4 removal by La-containing materials and 2) evaluate the ability of a new material, La2(CO3)3(s), to remove PO4 from different aqueous matrices, including municipal wastewater. We determined the dominant mechanism of PO4 removal by comparing geochemical simulations with equilibrium data from batch experiments and analyzing reaction products by X-ray diffraction and scanning transmission electron microscopy with energy dispersive spectroscopy. Geochemical simulations of aqueous systems containing PO4 and La-containing materials predicted that PO4 removal occurs via precipitation of poorly soluble LaPO4(s). Results from batch experiments agreed with those obtained from geochemical simulations, and mineralogical characterization of the reaction products were consistent with PO4 removal occurring primarily by precipitation of LaPO4(s). Between pH 1.5 and 12.9, La2(CO3)3(s) selectively removed PO4 over other anions from different aqueous matrices, including treated wastewater. However, the rate of PO4 removal decreased with increasing solution pH. In comparison to other solids, such as La(OH)3(s), La2(CO3)3(s) exhibits a relatively low solubility, particularly under slightly acidic conditions. Consequently, release of La3+ into the environment can be minimized when La2(CO3)3(s) is deployed for PO4 sequestration.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Zhi, Yue and Paterson, Alisa R. and Call, Douglas F. and Jones, Jacob L. and Hesterberg, Dean and Duckworth, Owen W. and Poitras, Eric P. and Knappe, Detlef R. U.}, year={2022}, month={May} }
 @article{liu_chen_ding_zhi_xu_hu_wang_mu_2022, title={Removal of humic acid from aqueous solution by a carbon nanotubes/ reduced graphene oxide composite hydrogel}, volume={253}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85128811728&partnerID=MN8TOARS}, DOI={10.5004/dwt.2022.28283}, abstractNote={In this study, three-dimensional (3D) porous network carbon nanotubes/reduced graphene oxide composite hydrogels (CNT-rGH) were synthesized through a facile hydrothermal method for the removal of macromolecular humic acid (HA). Brunauer–Emmett–Teller analyses indicated that incorporation of carboxylated multi-walled carbon nanotubes (COOH-MWCNT) renders the hydrogels with increased surface area, larger mean pore diameter, and higher intensity of mesoporous and macroporous structure. Such improvement was shown to facilitate adsorption site exposure on hydrogels, which enhanced the HA adsorption capacity. Incorporation of 50% proportion of COOH-MWCNT in the CNT-rGH (CNT50-rGH) exhibits optimal adsorption performance for HA. In addition, the initial aqueous pH value and the ionic strength were systematically studied to evaluate their impacts on HA adsorption by the CNT50-rGH. Adsorption kinetics data show that HA adsorption onto CNT50-rGH is in agreement well with pseudo-second-order kinetic model, indicating the principle and mechanism of chemisorption. The Langmuir model is the most relative adsorption isotherm to depict the HA adsorption, and the maximum HA adsorption capacity of the CNT50-rGH is determined at 270.27 mg/g. Through the XDLVO theory and controlled experiments reveals that hydrogen bonding interaction is the main adsorption mechanism of CNT50-rGH for HA adsorption.}, journal={Desalination and Water Treatment}, author={Liu, M. and Chen, W. and Ding, M. and Zhi, Y. and Xu, H. and Hu, K. and Wang, A. and Mu, X.}, year={2022}, pages={122–137} }
 @article{zhi_zhao_qian_faria_lu_wang_li_han_tao_he_et al._2022, title={Removing emerging perfluoroalkyl ether acids and fluorotelomer sulfonates from water by nanofiltration membranes: Insights into performance and underlying mechanisms}, volume={298}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85134466650&partnerID=MN8TOARS}, DOI={10.1016/j.seppur.2022.121648}, abstractNote={Although nanofiltration (NF) has been widely reported for removing long-chain per- and polyfluoroalkyl substances (PFAS) from water, little is known about the correlations between removal efficacy and PFAS/membrane characteristics, especially for emerging PFAS with shorter polyfluoroalkyl chain or containing fluoroether moieties. A systematic study of treatment of structurally diverse PFAS by NF can help predict the behavior of more unknown compounds during NF process. In this study, we conducted filtration experiments with five commercial NF membranes. Results show that seven legacy PFAS, three emerging perfluoroalkyl ether acids (PFEA) and two fluorotelomer sulfonates (FTS) can be removed simultaneously during the NF process, with rejection ranging from 66.0% to > 99.9%. The removal efficiency of five membranes decreased successively as DK > NF90 > XN45 > NF270 > DL. Rejection of FTS and PFEA by DK membranes were 88.3% to 97.1% and 81.7% to > 99.9%, respectively. Correlation analysis revealed that PFAS molecular structure and membrane characteristics significantly affect PFAS rejection. PFAS molecular weight (MW) and hydrophobicity (logKow) and membrane intrinsic structural characteristics (e.g., molecular weight cut-off (MWCO), water permeability, and salt selectivity) are among the most significant parameters impacting PFAS removal. The findings imply that both steric hindrance and hydrophobic interactions contribute to PFAS rejection. Moreover, the mass of PFAS adsorbed on the membrane was positively correlated with their molecular parameters (i.e., MW and logKow) and weakly correlated with membrane properties, suggesting that the adsorption and rejection of PFAS have similar driving forces. This study provides critical insights into the application of NF for emerging PFAS removal for both the scientific community and private industry, concerning water purification processes and remediation of thousands of PFAS-impacted sites.}, journal={Separation and Purification Technology}, author={Zhi, Y. and Zhao, X. and Qian, S. and Faria, A.F. and Lu, X. and Wang, X. and Li, W. and Han, L. and Tao, Z. and He, Q. and et al.}, year={2022} }
 @article{chen_han_yao_zhi_liu_zhang_han_2021, title={Donnan Dialysis-Osmotic Distillation (DD-OD) Hybrid Process for Selective Ammonium Recovery Driven by Waste Alkali}, volume={55}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85106482836&partnerID=MN8TOARS}, DOI={10.1021/acs.est.0c08772}, abstractNote={This work proposed an innovative and energy-efficient Donnan Dialysis (DD) and Osmotic Distillation (OD) hybrid process for alkali-driven ammonium recovery from wastewater. The efficiency and feasibility of ammonium removal and recovery from synthetic and real wastewater using NaOH and waste alkali were investigated. Ammonium in the feed first transported across the cation exchange membrane and accumulated in the receiver chamber. It is then deprotonated as ammonia, passing through the gas permeable membrane and finally is fixed as ammonium salt in the acid chamber. Our results indicated that employing waste alkali (red mud leachate) as driving solution led to excellent ammonium recovery performances (recovery efficiency of >80%), comparable to those of NaOH solution. When the initial ammonium concentration was 5 and 50 mM, the waste alkali driven DD-OD process achieved acceptable NH4+-N flux density of 16.8 and 169 g N m-2 d-1, at energy cost as low as 8.38 and 2.06 kWh kg-1 N, respectively. Since this alkali driven DD-OD hybrid process is based on solute concentration (or partial pressure) gradient, it could be an energy-effective technology capable of treating wastewaters containing ammonium using waste alkali to realize nutrients recovery in a sustainable manner.}, number={10}, journal={Environmental Science and Technology}, author={Chen, C. and Han, M. and Yao, J. and Zhi, Y. and Liu, Y. and Zhang, C. and Han, L.}, year={2021}, pages={7015–7024} }
 @article{huang_li_gao_wang_yang_han_lin_min_zhi_grieger_et al._2021, title={Effect of microplastics on ecosystem functioning: Microbial nitrogen removal mediated by benthic invertebrates}, volume={754}, ISSN={["1879-1026"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85090347843&partnerID=MN8TOARS}, DOI={10.1016/j.scitotenv.2020.142133}, abstractNote={While ecotoxicological impacts of microplastics on aquatic organisms have started to be investigated recently, impacts on ecosystem functions mediated by benthic biota remain largely unknown. We investigated the effect of microplastics on nitrogen removal in freshwater sediments where microorganisms and benthic invertebrates (i.e., chironomid larvae) co-existed. Using microcosm experiments, sediments with and without invertebrate chironomid larvae were exposed to microplastics (polyethylene) at concentrations of 0, 0.1, and 1 wt%. After 28 days of exposure, the addition of microplastics or chironomid larvae promoted the growth of denitrifying and anammox bacteria, leading to increased total nitrogen removal, in both cases. However, in microcosms with chironomid larvae and microplastics co-existing, nitrogen removal was less than the sum of their individual effects, especially at microplastics concentration of 1 wt%, indicating an adverse effect on microbial nitrogen removal mediated by macroinvertebrates. This study reveals that the increasing concentration of microplastics entangled the nitrogen cycling mediated by benthic invertebrates in freshwater ecosystems. These findings highlight the pursuit of a comprehensive understanding of the impacts of microplastics on the functioning in freshwater ecosystems.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Huang, Yuyue and Li, Wei and Gao, Jie and Wang, Fang and Yang, Wei and Han, Le and Lin, Dunmei and Min, Bolin and Zhi, Yue and Grieger, Khara and et al.}, year={2021}, month={Feb} }
 @article{xu_shi_lv_liu_yang_qian_fujibayashi_zhi_wang_nomura_et al._2021, title={Hydrodynamic-Driven Changes in the Source and Composition of Sedimentary Organic Matter via Grain Size Distribution in Shallow Lakes}, volume={126}, ISSN={["2169-8961"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85119855663&partnerID=MN8TOARS}, DOI={10.1029/2021JG006502}, abstractNote={Abstract}, number={11}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES}, author={Xu, Xiaoguang and Shi, Ruijie and Lv, Chengxu and Liu, Huazu and Yang, Wei and Qian, Shenhua and Fujibayashi, Megumu and Zhi, Yue and Wang, Guoxiang and Nomura, Munehiro and et al.}, year={2021}, month={Nov} }
 @article{zhi_call_grieger_duckworth_jones_knappe_2021, title={Influence of natural organic matter and pH on phosphate removal by and filterable lanthanum release from lanthanum-modified bentonite}, volume={202}, ISSN={0043-1354}, url={http://dx.doi.org/10.1016/j.watres.2021.117399}, DOI={10.1016/j.watres.2021.117399}, abstractNote={Lanthanum modified bentonite (LMB) has been applied to eutrophic lakes to reduce phosphorus (P) concentrations in the water column and mitigate P release from sediments. Previous experiments suggest that natural organic matter (NOM) can interfere with phosphate (PO4)-binding to LMB and exacerbate lanthanum (La)-release from bentonite. This evidence served as motivation for this study to systematically determine the effects of NOM, solution pH, and bentonite as a La carrier on P removal. We conducted both geochemical modeling and controlled-laboratory batch kinetic experiments to understand the pH-dependent impacts of humic and fulvic acids on PO4-binding to LMB and La release from LMB. The role of bentonite was studied by comparing PO4 removal obtained by LMB and La3+ (added as LaCl3 salt to represent the La-containing component of LMB). Our results from both geochemical modeling and batch experiments indicate that the PO4-binding ability of LMB is decreased in the presence of NOM, and the decrease is more pronounced at pH 8.5 than at 6. At the highest evaluated NOM concentration (28 mg C L−1), PO4-removal by La3+ was substantially lower than that by LMB, implying that bentonite clay in LMB shielded La from interactions with NOM, while still allowing PO4 capture by La. Finally, the presence of NOM promoted La-release from LMB, and the amount of La released depended on solution pH and both the type (i.e., fulvic/humic acid ratio) and concentration of NOM. Overall, these results provide an important basis for management of P in lakes and eutrophication control that relies on LMB applications.}, journal={Water Research}, publisher={Elsevier BV}, author={Zhi, Yue and Call, Douglas F. and Grieger, Khara D. and Duckworth, Owen W. and Jones, Jacob L. and Knappe, Detlef R.U.}, year={2021}, month={Sep}, pages={117399} }
 @article{yang_yao_he_huang_liu_zhi_qian_yan_jian_li_2021, title={Nitrogen removal enhanced by benthic bioturbation coupled with biofilm formation: A new strategy to alleviate freshwater eutrophication}, volume={292}, ISSN={["1095-8630"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85106359750&partnerID=MN8TOARS}, DOI={10.1016/j.jenvman.2021.112814}, abstractNote={Excessive nitrogen input into the water caused eutrophication thereby reducing biodiversity and degrades freshwater function. Nitrogen pollution in sediments is one key reason that makes eutrophication difficult to control. The physicochemical technologies such as dredging and coverage for sediment pollution easily destroyed and homogenized aquatic habitats. To alleviate freshwater eutrophication in ecological way, this work combined the functions of bioturbation and biofilm to test their effect on the removal of nitrogen from sediment and water. The total nitrogen removal by employing the coupled function (bioturbation + biofilm, SCB) was greater than that of the single function (bioturbation or biofilm). The mean efficiency of total nitrogen removal in SCB treatment was 3.19 times that of the control without chironomids nor biofilm medium. Chironomid bioturbation promoted nitrogen release from sediments to the overlying water. Biofilm enhanced the conversion and removal of nitrogen stirred up by chironomids, resulting the lowest concentration of total nitrogen in overlying water of SCB treatment. The enhancement of nitrogen removal may be due to the coupled function increased the abundance of denitrifying and anammox functional bacteria in sediment and biofilm. Therefore, the method of combining benthic animals with biofilm medium is not only a viable solution for reducing sedimentary nitrogen loading in freshwater ecosystems, but also a solution to mitigate eutrophication in the overlying water. The restoration and management for aquatic ecosystems should consider protecting habitat for benthic organisms while maintaining heterogeneity for biofilm.}, journal={JOURNAL OF ENVIRONMENTAL MANAGEMENT}, author={Yang, Wei and Yao, Jingmei and He, Yan and Huang, Yuyue and Liu, Huazu and Zhi, Yue and Qian, Shenhua and Yan, Xiaoman and Jian, Shuai and Li, Wei}, year={2021}, month={Aug} }
 @misc{zhi_zhang_hjorth_baun_duckworth_call_knappe_jones_grieger_2020, title={Emerging lanthanum (III)-containing materials for phosphate removal from water: A review towards future developments}, volume={145}, ISSN={["1873-6750"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85090951095&partnerID=MN8TOARS}, DOI={10.1016/j.envint.2020.106115}, abstractNote={The last two decades have seen a rise in the development of lanthanum (III)-containing materials (LM) for controlling phosphate in the aquatic environment. >70 papers have been published on this topic in the peer-reviewed literature, but mechanisms of phosphate removal by LM as well as potential environmental impacts of LM remain unclear. In this review, we summarize peer-reviewed scientific articles on the development and use of 80 different types of LM in terms of prospective benefits, potential ecological impacts, and research needs. We find that the main benefits of LM for phosphate removal are their ability to strongly bind phosphate under diverse environmental conditions (e.g., over a wide pH range, in the presence of diverse aqueous constituents). The maximum phosphate uptake capacity of LM correlates primarily with the La content of LM, whereas reaction kinetics are influenced by LM formulation and ambient environmental conditions (e.g., pH, presence of co-existing ions, ligands, organic matter). Increased La solubilization can occur under some environmental conditions, including at moderately acidic pH values (i.e., < 4.5–5.6), highly saline conditions, and in the presence of organic matter. At the same time, dissolved La will likely undergo hydrolysis, bind to organic matter, and combine with phosphate to precipitate rhabdophane (LaPO4·H2O), all of which reduce the bioavailability of La in aquatic environments. Overall, LM use presents a low risk of adverse effects in water with pH > 7 and moderate-to-high bicarbonate alkalinity, although caution should be applied when considering LM use in aquatic systems with acidic pH values and low bicarbonate alkalinity. Moving forward, we recommend additional research dedicated to understanding La release from LM under diverse environmental conditions as well as long-term exposures on ecological organisms, particularly primary producers and benthic organisms. Further, site-specific monitoring could be useful for evaluating potential impacts of LM on both biotic and abiotic systems post-application.}, journal={ENVIRONMENT INTERNATIONAL}, author={Zhi, Yue and Zhang, Chuhui and Hjorth, Rune and Baun, Anders and Duckworth, Owen W. and Call, Douglas F. and Knappe, Detlef R. U. and Jones, Jacob L. and Grieger, Khara}, year={2020}, month={Dec} }
 @article{mejia-avendaño_zhi_yan_liu_2020, title={Sorption of Polyfluoroalkyl Surfactants on Surface Soils: Effect of Molecular Structures, Soil Properties, and Solution Chemistry}, volume={54}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85079020881&partnerID=MN8TOARS}, DOI={10.1021/acs.est.9b04989}, abstractNote={Zwitterionic, cationic, and anionic per- and polyfluoroalkyl substances (PFASs) are identified in aqueous film-forming foam (AFFF) concentrates and AFFF-impacted sites. However, the mobility potential of zwitterionic and cationic PFASs is poorly understood, preventing reliable site assessment. The study aimed to elucidate the mobility behaviors of PFASs of various charge states in saturated soil-water systems and assess critical influencing factors. Five anionic, three zwitterionic, and one cationic PFASs were investigated in five soils through batch sorption experiments. Pairwise comparison revealed that the quaternary ammonium group imparted a strong affinity of cationic perfluorooctaneamide ammonium compound (PFOAAmS) for soils. The influence of the quaternary ammonium group is mitigated in polyfluoroalkyl betaines, yet perfluorooctane sulfonamidoalkyl betaine (PFOSB) showed strong sorption in selected soils. Two soil bulk properties showed some correlations with the soil-water distribution coefficient (Kd). A positive correlation with the fraction of soil organic carbon was found only for anionic PFASs, whereas cation exchange capacity had an approximate positive correlation with Kd only for PFOAAmS. Water chemistry (Ca2+ and pH) influences the sorption of non-anionic PFASs in very distinct fashions or even in opposite trends to what was known for anionic PFASs. Sorption was insensitive to pH changes except for PFOSB; PFOSB underwent profound sorption reduction because its speciation occurs around neutral pH while the two other betaines and PFOAAmS have pKa values that are outside of the environmentally relevant range. The lack of correlations suggests that the transport potential of PFASs is probably highly site-specific. It remains a challenge in deciphering PFAS sorption mechanisms and predicting how AFFF plumes migrate.}, number={3}, journal={Environmental Science and Technology}, author={Mejia-Avendaño, S. and Zhi, Y. and Yan, B. and Liu, J.}, year={2020}, pages={1513–1521} }
 @article{zhi_liu_2019, title={Column chromatography approach to determine mobility of fluorotelomer sulfonates and polyfluoroalkyl betaines}, volume={683}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85066039064&partnerID=MN8TOARS}, DOI={10.1016/j.scitotenv.2019.05.149}, abstractNote={Betaine-based polyfluoroalkyl surfactants are major perfluoroalkyl and polyfluoroalkyl surfactants (PFASs) found in many aqueous film-forming foams (AFFF) impacted sites, while the transport behavior (i.e., mobility and adsorption) of PFAS-based betaines in groundwater and natural geosorbents interfaces remains unclear. To fill the knowledge gap, partitioning between of 15 AFFF-relevant PFASs, including 3 fluorotelomer sulfonates (FTSAs) and 3 polyfluoroalkyl betaines, and a model soil organic matter (SOM) were systematically assessed using a modified column chromatography approach. Results show that the retention of FTSAs (perfluoroalkyl chain-length of 4, 6, and 8) to SOM are similar to that of corresponding legacy perfluoroalkyl sulfonic acids (PFSAs) with the same chain length; FTSAs also respond to changes in solution chemistry similarly as PFSAs. At a solution pH of 5.9, based on the equilibrium speciation of the betaine-PFASs together with the experimental observations, the predominance of the neutral species over zwitterions gives rise to the relatively higher retention of polyfluoroalkyl betaines than perfluoroalkyl carboxylic acids (PFCAs) of equivalent chain-length. Sorption edges (minimal and maximal logKoc values over a defined pH range) determined for three polyfluoroalkyl betaines are: 1.90-3.81 for perfluorooctaneamide betaine (PFOAB), 2.03-2.65 for perfluoroctane sulfonamide betaine (PFOSB), and < 3.04 for 6:2 fluorotelomer sulfonamide betaine (6:2 FTAB). Moreover, the increase in pH reduces the sorption of all PFASs to SOM. Increasing calcium ion (concentration ranges from 0.5 to 50 mM) has enhanced the sorption of anionic PFASs to SOM but decreased the sorption of the polyfluoroalkyl betaines. These findings are expected to improve the ability to anticipate and predict the possible subsurface locations (i.e., predominantly in groundwater or sorbed to soil) of both novel and legacy PFASs.}, journal={Science of the Total Environment}, author={Zhi, Y. and Liu, J.}, year={2019}, pages={480–488} }
 @article{zhi_liu_2018, title={Sorption and desorption of anionic, cationic and zwitterionic polyfluoroalkyl substances by soil organic matter and pyrogenic carbonaceous materials}, volume={346}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85045706158&partnerID=MN8TOARS}, DOI={10.1016/j.cej.2018.04.042}, abstractNote={The fraction of pyrogenic carbonaceous materials (PCMs) left in aqueous film-forming foams (AFFFs) source zones may strongly affect the persistence of perfluoroalkyl and polyfluoroalkyl substances (PFASs). To examine the hypothesis and gain an additional perspective on the potential contributions of different organic phases present in soil, we measured sorption and desorption of five AFFF relevant PFASs, one cationic (perfluoroctaneamido ammonium iodide, PFOAAmS), two anionic (perfluorooctane sulfonate, PFOS; perfluorooctanoic carboxylate, PFOA), and two zwitterionic (perfluorooctane amido betaine, PFOAB; 6:2 fluorotelomer sulfonamido betaine, 6:2 FTAB), by three types of PCMs (biochar, soot, and oil-free soot) and soil organic matter (SOM, presented by Pahokee peat) by single-solute batch sorption experiments. It was found that sorption to PCMs is substantially stronger and nonlinear than SOM, especially for the cationic PFOAAmS. Strong sorption to PCMs discovered in this study suggests that such phenomenon can lead to high retardation of PFASs in the AFFF source zone and decreased mobility of PFASs in groundwater, especially for the precursor compounds to the legacy perfluoroalkyl acids. Fouling of PCMs by unburnt oil would hinder the surface activity of PCMs and consequently lower the sorption of PFAS, thereby facilitating PFAS mobility. Moreover, sorption hysteresis was observed in all the systems with sorption of 6:2 FTAB by biochar being the most significant. This study for the first time provided the evidence that PCMs are potentially a significant sink of PFASs in AFFF-impacted sites.}, journal={Chemical Engineering Journal}, author={Zhi, Y. and Liu, J.}, year={2018}, pages={682–691} }
 @article{zhang_zhi_liu_ghoshal_2018, title={Sorption of Perfluoroalkyl Acids to Fresh and Aged Nanoscale Zerovalent Iron Particles}, volume={52}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85046541268&partnerID=MN8TOARS}, DOI={10.1021/acs.est.8b00487}, abstractNote={The sorption of perfluoroalkyl acids (PFAAs), particularly perfluorooctanesulfonic acid (PFOS), to freshly synthesized nanoscale zerovalent iron (nZVI) and aged (oxidized) and sulfidated nZVI, was investigated under anaerobic conditions. The sorption of PFAAs to nZVI was 2-4 orders of magnitude higher than what has been reported for sediments, soils, and iron oxides. The hydrophobicity of the perfluorocarbon chain dominated the sorption, although FTIR spectra indicated specific interactions between sulfonate and carboxylate head groups and nZVI. The contributions from electrostatic interactions depended on the surface charge and pH. Humic acids influenced sorption only at concentrations above 50 mg/L. nZVI aged in deoxygenated water up to 95 days showed similar sorption isotherms for PFOS to fresh nZVI, because Fe(OH)2 was the predominant phase on the nZVI surface independent of aging time. Sulfidation of nZVI reduced sorption of PFOS by 1 log unit owing to the FeS deposited, but the sorption affinity was restored after aging because of formation of Fe(OH)2. Oxidation of nZVI by water and dissolved oxygen also resulted in similar sorption of PFOS as fresh nZVI at environmentally relevant concentrations. The results suggest that injection of nZVI could reduce PFAA concentrations in groundwater despite changes to its surface chemistry with aging.}, number={11}, journal={Environmental Science and Technology}, author={Zhang, Y. and Zhi, Y. and Liu, J. and Ghoshal, S.}, year={2018}, pages={6300–6308} }
 @article{zhi_liu_2016, title={Surface modification of activated carbon for enhanced adsorption of perfluoroalkyl acids from aqueous solutions}, volume={144}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84953791076&partnerID=MN8TOARS}, DOI={10.1016/j.chemosphere.2015.09.097}, abstractNote={The objective of the research was to examine the effect of increasing carbon surface basicity on uptake of perfluorooctane sulfonic (PFOS) and carboxylic acids (PFOA) by activated carbon. Granular activated carbons made from coal, coconut shell, wood, and phenolic-polymer-based activated carbon fibers were modified through high-temperature and ammonia gas treatments to facilitate systematical evaluation of the impact of basicity of different origins. Comparison of adsorption isotherms and adsorption distribution coefficients showed that the ammonia gas treatment was more effective than the high-temperature treatment in enhancing surface basicity. The resultant higher point of zero charges and total basicity (measured by total HCl uptake) correlated with improved adsorption affinity for PFOS and PFOA. The effectiveness of surface modification to enhance adsorption varied with carbon raw material. Wood-based carbons and activated carbon fibers showed enhancement by one to three orders of magnitudes while other materials could experience reduction in adsorption towards either PFOS or PFOA.}, journal={Chemosphere}, author={Zhi, Y. and Liu, J.}, year={2016}, pages={1224–1232} }
 @article{zhi_liu_2015, title={Adsorption of perfluoroalkyl acids by carbonaceous adsorbents: Effect of carbon surface chemistry}, volume={202}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84925878084&partnerID=MN8TOARS}, DOI={10.1016/j.envpol.2015.03.019}, abstractNote={Adsorption by carbonaceous sorbents is among the most feasible processes to remove perfluorooctane sulfonic (PFOS) and carboxylic acids (PFOA) from drinking and ground waters. However, carbon surface chemistry, which has long been recognized essential for dictating performance of such sorbents, has never been considered for PFOS and PFOA adsorption. Thus, the role of surface chemistry was systematically investigated using sorbents with a wide range in precursor material, pore structure, and surface chemistry. Sorbent surface chemistry overwhelmed physical properties in controlling the extent of uptake. The adsorption affinity was positively correlated carbon surface basicity, suggesting that high acid neutralizing or anion exchange capacity was critical for substantial uptake of PFOS and PFOA. Carbon polarity or hydrophobicity had insignificant impact on the extent of adsorption. Synthetic polymer-based Ambersorb and activated carbon fibers were more effective than activated carbon made of natural materials in removing PFOS and PFOA from aqueous solutions.}, journal={Environmental Pollution}, author={Zhi, Y. and Liu, J.}, year={2015}, pages={168–176} }
 @article{li_zhai_he_zhi_xiao_rong_2014, title={Phytoremediation of levonorgestrel in aquatic environment by hydrophytes}, volume={26}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84906942147&partnerID=MN8TOARS}, DOI={10.1016/j.jes.2014.06.030}, abstractNote={Adsorption and degradation of levonorgestrel (LNG) by two hydrophytes, Cyperus alternifolius (CA) and Eichhornia crassipes (EC), were investigated under light-shielding conditions in the water column. Variations of LNG concentrations in water, plant root epidermis, root, stem and leaf of the plants were analyzed. The results indicated that the removal efficiency of LNG by hydrophytes over the period of 50 days was significantly greater than the blank control (p < 0.05), with the removal rates of 79.80% ± 3.10% and 78.86% ± 2.55% for CA and EC, respectively. Compared with bio-adsorption, bio-conversion of LNG was found to be the dominant elimination pathway, evidenced by relatively high conversion rates (77.31% ± 2.68% for CA and 77.82% ± 2.95% for EC), while the adsorption rates were lower (1.77% ± 0.90% for CA and 1.05% ± 0.40% for EC). The bio-adsorption and conversion of LNG showed no significant differences between the two hydrophytes. Additionally, the mineralization on root epidermis played an important role in the reduction of LNG in water.}, number={9}, journal={Journal of Environmental Sciences (China)}, author={Li, G. and Zhai, J. and He, Q. and Zhi, Y. and Xiao, H. and Rong, J.}, year={2014}, pages={1869–1873} }
 @article{wu_zhi_he_tang_ling_pan_2013, title={Development of integrated reactors for domestic garbage and town sludge}, volume={36}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84874961358&partnerID=MN8TOARS}, number={1}, journal={Chongqing Daxue Xuebao/Journal of Chongqing University}, author={Wu, Z. and Zhi, Y. and He, Q. and Tang, S. and Ling, J. and Pan, M.}, year={2013}, pages={127–132} }