1
|
Vazquez CI, Chang HM, Gong GC, Shiu RF, Chin WC. Impacts of polystyrene nanoplastics on microgel formation from effluent organic matter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 954:176209. [PMID: 39284446 DOI: 10.1016/j.scitotenv.2024.176209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2024] [Revised: 08/18/2024] [Accepted: 09/09/2024] [Indexed: 09/22/2024]
Abstract
Municipal effluents discharged from wastewater treatment plants (WWTPs) are considered major contributors of nanoplastics (NPs) and dissolved effluent organic matter (dEfOM) to environments. Due to their small sizes, NPs can travel easily in waterways and evade wastewater treatment processes, and may directly interact with dEfOM, altering their environmental fates. However, although much research has examined the impact of natural organic matter on NPs, the interactions between NPs and dEfOM remain unexplored. This study investigated the influences of NPs on the behavior and capacity of dEfOM aggregation and surface granularity, and identified the possible aggregation mechanism. We also adjusted the salinity of water samples to simulate scenarios based on WWTP-sea continuums. Our data suggest that dEfOM can self-assemble with 55 nm polystyrene NPs to form microgels, particularly under high salinity conditions. NPs accelerates the formation speed and number of dEfOM aggregates, but the sizes of the aggregates remain largely unchanged. The relative particle counts at a salinity of 34 psu increased by 300 % compared to the control group. The potential mechanism behind NPs-microgels aggregation is likely driven by the synergistic effect of the divalent ion crosslinking and hydrophobic interactions between EfOM and NPs. Notably, NPs incorporation into microgels decreases the surface granularity, thereby possibly affecting settling velocity and colonization of aggregates, as well as microbial attachment and community diversity. Overall, our findings demonstrate the potential influence of NPs on dEfOM assembly and surface properties following effluent discharge, and can inspire further relevant studies on microorganism interactions, removal technologies, and the environmental transport of NPs.
Collapse
Affiliation(s)
- Carlos I Vazquez
- Quantitative and Systems Biology, School of Natural Sciences, University of California at Merced, Merced 95343, CA, USA
| | - Hsiao-Ming Chang
- Quantitative and Systems Biology, School of Natural Sciences, University of California at Merced, Merced 95343, CA, USA
| | - Gwo-Ching Gong
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202301, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202301, Taiwan
| | - Ruei-Feng Shiu
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202301, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202301, Taiwan.
| | - Wei-Chun Chin
- Quantitative and Systems Biology, School of Natural Sciences, University of California at Merced, Merced 95343, CA, USA; Chemical and Materials Engineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA.
| |
Collapse
|
2
|
Temperature Effects on Effluent Microgel Formation. Polymers (Basel) 2022; 14:polym14224870. [PMID: 36432997 PMCID: PMC9695844 DOI: 10.3390/polym14224870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/20/2022] [Accepted: 11/08/2022] [Indexed: 11/15/2022] Open
Abstract
Wastewater treatment plant effluent is considered an important hotspot of dissolved organic matter. The behavior and transformation of dissolved effluent organic matter (dEfOM) regulate particle sedimentation, pollutant fate, microbial attachment, and biofilm formation. However, studies have so far focused on the transformation of marine and riverine organic matter, and the current knowledge of dEfOM behavior is still limited. Fluctuations in water conditions, especially temperature, may directly alter the size, assembly speed, and structure of microgels, thereby potentially disturbing fate and the transportation of organic matter. In this study, we firstly investigated the effects of temperature on the behavior and capacity of dEfOM assembly into microgels and the possible mechanism. The microgel size and granularity of dEfOM were monitored by flow cytometry. Our results suggest that, with regard to microgels, a higher temperature leads to a higher assembly capacity but also a decrease in the size distribution. By contrast, assembly at 4 °C reduces the relative assembly capacity but increases the microgel size and granularity. The size distribution of the formed microgels at the various temperatures was ordered as follows: 4 °C > 20 °C > 35 °C. The size reduction in dEfOM assembly may be closely tied to the enhancement of hydrophobic interactions. The reduction in microgel granularity in warm conditions (35 °C) in terms of the effluent water may be caused by thermally induced condensation. Overall, the findings demonstrate the effects of temperature on dEfOM assembly and can facilitate further relevant studies on aquatic organic particle formation during current global warming scenarios.
Collapse
|
3
|
Shiu RF, Chen LY, Lee HJ, Gong GC, Lee C. New insights into the role of marine plastic-gels in microplastic transfer from water to the atmosphere via bubble bursting. WATER RESEARCH 2022; 222:118856. [PMID: 35863277 DOI: 10.1016/j.watres.2022.118856] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/07/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
The pervasiveness of microplastics (MPs) in global oceans is raising concerns about their adverse impacts on ecosystems. The mechanistic understanding of MP transport is critical for evaluating its fate, flux, and ecological risks specifically. Currently, bubble bursting is believed to represent an important route for MP transfer from sea surfaces to the atmosphere. However, the detailed mechanisms of the complex physico-chemical interactions between MPs, water composition, and gel particles in the air-sea interface remain unknown. Our results suggested three steps for MP transfer between air-sea phases: (1) MPs incorporating into gel aggregates in the water column; (2) further accumulation of plastic-gel aggregate in the surface layer phase; finally (3) ejection of aggregates from the sea when bubbles of trapped air rise to the surface and burst. The water composition (e.g., high salinity, gel concentration and viscosity) can modulate plastic-gel aggregation and subsequent transport from water to the atmosphere. The possible mechanism may be closely tied to the formation of plastic-gel via cation-linking bridges, thereby enhancing plastic-gel ejection into air. Collectively, this work offers unique insights into the role of marine plastic-gels in determining MP fate and transport, especially at air-sea interfaces. The data also provide a better understanding of the corresponding mechanism that may explain the fates of missing plastics in the ocean.
Collapse
Affiliation(s)
- Ruei-Feng Shiu
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung City 202301, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung City 202301, Taiwan.
| | - Lu-Yi Chen
- Department of Microbiology, Immunology and Biopharmaceuticals, National Chiayi University, Chiayi City 60004, Taiwan
| | - Hui-Ju Lee
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung City 202301, Taiwan
| | - Gwo-Ching Gong
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung City 202301, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung City 202301, Taiwan
| | - Chuping Lee
- Department of Chemistry, Fu Jen Catholic University, New Taipei City 24205, Taiwan.
| |
Collapse
|
4
|
Duan Z, Wang P, Yu G, Liang M, Dong J, Su J, Huang W, Li Y, Zhang A, Chen C. Aggregation kinetics of UV-aged soot nanoparticles in wet environments: Effects of irradiation time and background solution chemistry. WATER RESEARCH 2021; 201:117385. [PMID: 34225234 DOI: 10.1016/j.watres.2021.117385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/13/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
Soot nanoparticles (SNPs) undergo aging processes in aqueous systems, altering their physicochemical properties and affecting their fate and transport. This study investigated the aging effects via ultraviolet irradiation on aggregation kinetics of SNPs in water. The results showed that, compared to fresh SNPs, those irradiated for 1 day aggregated more easily in NaCl and CaCl2 solutions, with reduction of critical coagulation concentrations by 72% and 40%, respectively. Similar phenomena were found in additional six electrolyte solutions, and SNPs irradiated for > 3 days had no measurable difference in aggregation rate. The aggregation-enhancement of irradiated SNPs was more prominent at low electrolyte concentrations and pH > 4. However, in the presence of macromolecules, irradiated SNPs could be stabilized against aggregation via steric hindrance with strength of bovine serum albumin > humic acid > alginate > fulvic acid, whereas alginate further destabilized aged SNPs via calcium bridging. The fitted Hamaker constant increased from 7.8 × 10-20 (fresh) to 1.2 × 10-19 J (7-day irradiated), suggesting that decarboxylation during irradiation may weaken electrical repulsion and enhance van der Waals attraction, promoting aggregation. These results demonstrated the vital role of UV-induced aging in fate and transport of SNPs in wet environments.
Collapse
Affiliation(s)
- Zhihui Duan
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, 18 Shuangqing Road, Beijing 100085, China
| | - Ping Wang
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Guangwei Yu
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Miaoting Liang
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Jiawei Dong
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Jiana Su
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Weilin Huang
- Department of Environmental Sciences, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901, United States
| | - Yongtao Li
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, 18 Shuangqing Road, Beijing 100085, China
| | - Chengyu Chen
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong 510642, China.
| |
Collapse
|
5
|
Marine Gel Interactions with Hydrophilic and Hydrophobic Pollutants. Gels 2021; 7:gels7030083. [PMID: 34287300 PMCID: PMC8293255 DOI: 10.3390/gels7030083] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/16/2021] [Accepted: 06/27/2021] [Indexed: 02/07/2023] Open
Abstract
Microgels play critical roles in a variety of processes in the ocean, including element cycling, particle interactions, microbial ecology, food web dynamics, air-sea exchange, and pollutant distribution and transport. Exopolymeric substances (EPS) from various marine microbes are one of the major sources for marine microgels. Due to their amphiphilic nature, many types of pollutants, especially hydrophobic ones, have been found to preferentially associate with marine microgels. The interactions between pollutants and microgels can significantly impact the transport, sedimentation, distribution, and the ultimate fate of these pollutants in the ocean. This review on marine gels focuses on the discussion of the interactions between gel-forming EPS and pollutants, such as oil and other hydrophobic pollutants, nanoparticles, and metal ions.
Collapse
|
6
|
Chen CS, Shiu RF, Hsieh YY, Xu C, Vazquez CI, Cui Y, Hsu IC, Quigg A, Santschi PH, Chin WC. Stickiness of extracellular polymeric substances on different surfaces via magnetic tweezers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143766. [PMID: 33243507 DOI: 10.1016/j.scitotenv.2020.143766] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/08/2020] [Accepted: 11/08/2020] [Indexed: 06/11/2023]
Abstract
Organic particle dynamics in the surface ocean plays a critical part in the marine carbon cycle. Aggregation of marine organic particles drives their downward transport to support various marine organisms on their transit to the sediments. Extracellular polymeric substances (EPS) from various microbes are a major contributor to the oceanic organic particle pool. The stickiness of EPS is expected to play a determining role in the aggregation process of particles; however, stickiness parameters are usually indirectly estimated through data fitting without direct assessment. Here a magnetic tweezer method was developed to quantitatively assess the stickiness of three model EPS produced by: Amphora sp., (diatom), Emiliania huxleyi (coccolithophore), and Sagittula stellata (bacteria), under different in vitro environmental conditions (salinity or EDTA complexed cations) and surface matrices (EPS-EPS and bare glass). Our results showed the stickiness of three microbial EPS decreasing for S. stellata > E. huxleyi > Amphora sp., in line with their decreasing protein-to-carbohydrate (P/C) ratios (related to their relative hydrophobicity). The data not only emphasize the importance of hydrophobicity on EPS stickiness, but also demonstrates that salinity and the nature of the substrate surface can influence the stickiness. Furthermore, we investigated stickiness between various types of EPS, and the observed selective stickiness of EPS between species may shed light on the interactions among heterogeneous marine microorganisms. Overall, this newly developed system provides a platform to assess the EPS stickiness to advance our understanding of the aggregation and sedimentation process of organic particles that are critical for the fate of organic carbon as well as for biofilm formation and microbial colonization of surfaces in the ocean.
Collapse
Affiliation(s)
- Chi-Shuo Chen
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ruei-Feng Shiu
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Yu-Ying Hsieh
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chen Xu
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Carlos I Vazquez
- Department of Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Yujia Cui
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ian C Hsu
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA; Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Peter H Santschi
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX 77553, USA; Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Wei-Chun Chin
- Department of Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA.
| |
Collapse
|
7
|
Shiu RF, Vazquez CI, Chiang CY, Chiu MH, Chen CS, Ni CW, Gong GC, Quigg A, Santschi PH, Chin WC. Nano- and microplastics trigger secretion of protein-rich extracellular polymeric substances from phytoplankton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 748:141469. [PMID: 33113698 DOI: 10.1016/j.scitotenv.2020.141469] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/31/2020] [Accepted: 08/02/2020] [Indexed: 06/11/2023]
Abstract
The substantial increase in plastic pollution in marine ecosystems raises concerns about its adverse impacts on the microbial community. Microorganisms (bacteria, phytoplankton) are important producers of exopolymeric substances (EPS), which govern the processes of marine organic aggregate formation, microbial colonization, and pollutant mobility. Until now, the effects of nano- and micro-plastics on characteristics of EPS composition have received little attention. This study investigated EPS secretion by four phytoplankton species following exposure to various concentrations of polystyrene nano- and microplastics (55 nm nanoparticles; 1 and 6 μm microparticles). The 55 nm nanoparticles induced less growth/survival (determined on a DNA basis) and produced EPS with higher protein-to-carbohydrate (P/C) ratios than the exposure to microplastic particles. The amount of DNA from the four marine phytoplankton showed a higher negative linear correlation with increasing P/C ratios, especially in response to nanoplastic exposure. These results provide evidence that marine phytoplankton are quite sensitive to smaller-sized plastics and actively modify their EPS chemical composition to cope with the stress from pollution. Furthermore, the release of protein-rich EPS was found to facilitate aggregate formation and surface modification of plastic particles, thereby affecting their fate and colonization. Overall, this work offers new insights into the potential harm of different-sized plastic particles and a better understanding of the responding mechanism of marine phytoplankton for plastic pollution. The data also provide needed information about the fate of marine plastics and biogenic aggregation and scavenging processes.
Collapse
Affiliation(s)
- Ruei-Feng Shiu
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Carlos I Vazquez
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Chang-Ying Chiang
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Meng-Hsuen Chiu
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA; National Life Science, Inc., Sacramento, CA 95660, USA; Kaiser Biotech, Inc., Sacramento, CA 95660, USA
| | - Chi-Shuo Chen
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chih-Wen Ni
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Gwo-Ching Gong
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA; Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Peter H Santschi
- Department of Oceanography, Texas A&M University, College Station, TX 77843, USA; Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Wei-Chun Chin
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA.
| |
Collapse
|
8
|
Huang YJ, Lin BS, Lee CL, Brimblecombe P. Enrichment behavior of contemporary PAHs and legacy PCBs at the sea-surface microlayer in harbor water. CHEMOSPHERE 2020; 245:125647. [PMID: 31874320 DOI: 10.1016/j.chemosphere.2019.125647] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 06/10/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the sea-surface microlayer (SML) and sub-surface water (SSW) were analyzed in and around Kaohsiung Harbor. The results confirm SML enrichments for PAHs, but PCBs less significantly, since PAHs are still produced while PCBs had banned years ago. However, PCBs still leak to the environment from contaminated sites. The results showed the sources and transport of PAHs and PCBs were different, but both are enriched in the SML. Total particulate PAHs at most sites are below the toxicity thresholds, with a few individual PAHs between the effects range-low and effect range-median even higher than the effect range-median. Total particulate PCBs might cause occasionally adverse effects in sensitive species and pose a risk to the organisms. The particulate phase in the SML poses a higher risk to the marine ecosystem than in the SSW although not all organisms will make direct use of the microlayer. Principal component analysis (PCA) of PAHs indicated the important contribution of traffic engine emission in the particulate samples of the SML and SSW and revealed that probably the petroleum pollutants are a predominant source for the dissolved phase. Cluster analysis revealed that PAH-PCB patterns in the river and anchorage channels were different to those in the wetlands and open harbor. However, PCA of PCBs showed differences in the congener profiles for the two phases, with highly chlorinated PCBs more abundant in particles, while less chlorinated PCBs were more abundant in dissolved.
Collapse
Affiliation(s)
- Yun-Jie Huang
- Department of Marine Environment and Engineering, National Sun Yat-sen University, 80424, Kaohsiung, Taiwan, ROC
| | - Bing-Sian Lin
- Department of Marine Environment and Engineering, National Sun Yat-sen University, 80424, Kaohsiung, Taiwan, ROC
| | - Chon-Lin Lee
- Department of Marine Environment and Engineering, National Sun Yat-sen University, 80424, Kaohsiung, Taiwan, ROC; Department of Public Health, College of Health Sciences, Kaohsiung Medical University, 80708, Kaohsiung, Taiwan, ROC; Aerosol Science Research Center, National Sun Yat-sen University, 80424, Kaohsiung, Taiwan, ROC; Department of Applied Chemistry, Providence University, 43301, Taichung, Taiwan, ROC.
| | - Peter Brimblecombe
- School of Energy and Environment, City University of Hong Kong, Kowloon, Hong Kong, China
| |
Collapse
|
9
|
Shiu RF, Vazquez CI, Tsai YY, Torres GV, Chen CS, Santschi PH, Quigg A, Chin WC. Nano-plastics induce aquatic particulate organic matter (microgels) formation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 706:135681. [PMID: 31780163 DOI: 10.1016/j.scitotenv.2019.135681] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/19/2019] [Accepted: 11/19/2019] [Indexed: 06/10/2023]
Abstract
The pervasive presence of plastic waste in the aquatic environment is widely viewed as one of the most serious environmental challenges for current and future generations. Microplastics ultimately degrade into nano and smaller-sizes. In turn, their biological and ecological impacts become more complicated and ambiguous. Nano-plastic particles travel from freshwater systems to estuarine and oceanic regions, during which they can interact with dissolved organic matter (DOM) to form microgels. Microgel formation is ubiquitous in aquatic systems, serving as a shunt between DOM and particulate organic matter (POM), as well as playing key roles in particle aggregation/sedimentation and pollutant transport. Currently the influences and mechanisms of the aggregation behavior and environmental fate of nano-plastics in different aquatic environments is poorly understood. Here, we report that 25 nm polystyrene nano-particles in lake and river water can promote POM (microgel) formation and accelerate the DOM-POM transition. We also adjusted various salinities of water samples to simulate scenarios based on plastic transport in waters flowing from rivers to seas. The results indicate polystyrene nanoparticles can interact with organic matter to form large organic particles, which may undergo further settling in response to specific salinity levels. Polystyrene-induced microgel formation appears to involve the hydrophobic interactions between plastics and DOM. Our data provides much needed information for modeling and understanding the retention and sedimentation of nano-plastics. We show that nano-plastics alter the DOM-POM shunt to cause unanticipated perturbations in the functionality of aquatic ecosystems.
Collapse
Affiliation(s)
- Ruei-Feng Shiu
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA; Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Carlos I Vazquez
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Yi-Yen Tsai
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Gabriela V Torres
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Chi-Shuo Chen
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Peter H Santschi
- Department of Marine Science, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Wei-Chun Chin
- Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA.
| |
Collapse
|
10
|
Chen C, Wei J, Li J, Duan Z, Huang W. Influence of macromolecules on aggregation kinetics of diesel soot nanoparticles in aquatic environments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 252:1892-1901. [PMID: 31227348 DOI: 10.1016/j.envpol.2019.06.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 04/29/2019] [Accepted: 06/04/2019] [Indexed: 06/09/2023]
Abstract
Soot nanoparticles (SNPs) produced from incomplete combustion have strong impacts on aquatic environments as they eventually reach surface water, where their environmental fate and transport are largely controlled by aggregation. This study investigated the aggregation kinetics of SNPs in the presence of macromolecules including fulvic acid (FA), humic acid (HA), alginate polysaccharide, and bovine serum albumin (BSA, protein) under various environmentally relevant solution conditions. Our results showed that increasing salt concentrations induced SNP aggregation by suppressing electrostatic repulsion and that CaCl2 exhibited stronger effect than NaCl in charge neutralization, which is in agreement with the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The aggregation rates of SNPs were variously reduced by macromolecules, and such stabilization effect was the greatest by BSA, followed by HA, alginate, and FA. Steric repulsion resulting from macromolecules adsorbed on SNP surfaces was mainly responsible for enhancing SNP stability. Such steric repulsion appeared to be affected by macromolecular structure, as BSA having a more compact globular structure on SNP surfaces imparted long-range steric repulsive forces and retarded the SNP aggregation rate by 10-100 times. In addition, alginate was shown to enhance SNP aggregation by ∼10 times at high CaCl2 concentrations due to alginate gel formation via calcium bridging. The results may bear strong significance for the fate and transport of SNPs in both natural and controlled environmental systems.
Collapse
Affiliation(s)
- Chengyu Chen
- College of Natural Resources and Environment, South China Agricultural University, 483 Wushan Road, Guangzhou, Guangdong, 510642, People's Republic of China
| | - Jingyue Wei
- Department of Environmental Sciences, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, United States
| | - Jing Li
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, People's Republic of China
| | - Zhihui Duan
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, People's Republic of China
| | - Weilin Huang
- Department of Environmental Sciences, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, United States.
| |
Collapse
|
11
|
Chiu MH, Vazquez CI, Shiu RF, Le C, Sanchez NR, Kagiri A, Garcia CA, Nguyen CH, Tsai SM, Zhang S, Xu C, Santschi PH, Quigg A, Chin WC. Impact of exposure of crude oil and dispersant (Corexit) on aggregation of extracellular polymeric substances. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 657:1535-1542. [PMID: 30677919 DOI: 10.1016/j.scitotenv.2018.12.147] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 11/28/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
Spilled oil treated with Corexit dispersant can cause unintended impacts on marine environment systems including altering marine organic matter dynamics; however, impacts on microgels and marine oil snow (MOS) formation are still debated and remain to be fully understood. Extracellular polymeric substances (EPS) are a major source of marine organic carbon for MOS and microgel formation. EPS initial aggregation plays key roles in the oil degrading process and various biogeochemical reactions. Here we used four types of EPS with water accommodated fraction (WAF), chemically-enhanced WAF (CEWAF) and Corexit, to represent potential situations during oil spills and post-application of Corexit. We found that Corexit alone can inhibit EPS aggregation and disperse pre-existing microgels. CEWAF can enhance EPS aggregation with efficiency by up to 80%-100% and more aggregates accumulated within the air-water interface. Additionally, more hydrophobic EPS aggregates showed high resistance to Corexit dispersion while hydrophilic EPS were more sensitive. Effects of oil spills on marine gel particle formation are primarily determined by chemical characteristics (hydrophobicity and protein content) of the constituent EPS. This study offers unique insights for organic particle dynamics and identifies controlling factors for MOS or gel particles associated with oil spills and Corexit dispersant used.
Collapse
Affiliation(s)
- Meng-Hsuen Chiu
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA; National Life Science, Inc., Sacramento, CA 95660, USA; Kaiser Biotech, Inc., Sacramento, CA 95660, USA
| | - Carlos I Vazquez
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Ruei-Feng Shiu
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Clarence Le
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Nicole R Sanchez
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Agnes Kagiri
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Cynthia A Garcia
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Chanh H Nguyen
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Shih-Ming Tsai
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Saijin Zhang
- Department of Marine Sciences, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Chen Xu
- Department of Marine Sciences, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Peter H Santschi
- Department of Marine Sciences, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Wei-Chun Chin
- Bioengineering Program, School of Engineering, University of California at Merced, Merced, CA 95343, USA.
| |
Collapse
|
12
|
Shiu RF, Lee CL, Chin WC. Reduction in the exchange of coastal dissolved organic matter and microgels by inputs of extra riverine organic matter. WATER RESEARCH 2018; 131:161-166. [PMID: 29278788 DOI: 10.1016/j.watres.2017.12.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 11/25/2017] [Accepted: 12/14/2017] [Indexed: 06/07/2023]
Abstract
Rivers drive large amounts of terrestrial and riverine organic matter into oceans. These organic materials may alter the self-assembly of marine dissolved organic matter (DOM) polymers into microgels and can even affect the behavior of existing natural microgels. We used Suwannee River humic acid, fulvic acid, and natural organic matter as a model of riverine organic matter (ROM) to investigate the impacts of ROM input on DOM polymer and microgel conversion. Our results indicated that the release of extra ROM, even at low concentrations (0.1-10 mg L-1), into the marine organic matter pool decreased the size of self-assembled DOM polymers (from 4-5 μm to < 1 μm) and dispersed the existing natural microgels into smaller particles (from 4-5 μm to 2-3 μm). The particle size of the microgel phase was also less sensitive than that of the DOM polymers to external changes (addition of ROM). This size reduction in DOM aggregation and existing microgels may be closely tied to the surface chemistry of the organic matter, such as negative surface charge stabilization and Ca2+ cross-linking bridges. These findings reveal that ROM inputs may therefore impede the self-assembly of DOM polymers into particulate organic matter and reduce the sedimentation flux of organic carbon and other elements from surface water to the deep ocean, thereby disturbing the biological pump, the downward transportation of nutrients, and the marine organic carbon cycle.
Collapse
Affiliation(s)
- Ruei-Feng Shiu
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Chon-Lin Lee
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan; Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan; Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan; Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
| | - Wei-Chun Chin
- Bioengineering Program, School of Engineering, University of California, Merced, Merced, CA, USA.
| |
Collapse
|
13
|
Yang ZH, Dong CD, Chen CW, Sheu YT, Kao CM. Using poly-glutamic acid as soil-washing agent to remediate heavy metal-contaminated soils. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:5231-5242. [PMID: 28528500 DOI: 10.1007/s11356-017-9235-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/08/2017] [Indexed: 06/07/2023]
Abstract
The extraction efficiency of heavy metals from soils using three forms of gamma poly-glutamic acid (γ-PGA) as the washing agents was investigated. Controlling factors including agent concentrations, extraction time, pH, and liquid to soil ratio were evaluated to determine the optimum operational conditions. The distribution of heavy metal species in soils before and after extraction processes was analyzed. Up to 46 and 74% of heavy metal removal efficiencies were achieved with one round and a sequential extraction process using H-bonding form of γ-PGA (200 mM) with washing time of 40 min, liquid to solid ratio of 10 to 1, and pH of 6. Major heavy metal removal mechanisms were (1) γ-PGA-promoted dissolution and (2) complexation of heavy metal with free carboxyl groups in γ-PGA, which resulted in heavy metal desorption from soils. Metal species on soils were redistributed after washing, and soils were remediated without destruction of soil structures and productivity.
Collapse
Affiliation(s)
- Zong-Han Yang
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Cheng-Di Dong
- Department of Marine Environmental Engineering, National Kaohsiung Marine University, Kaohsiung City, Taiwan
| | - Chiu-Wen Chen
- Department of Marine Environmental Engineering, National Kaohsiung Marine University, Kaohsiung City, Taiwan
| | - Yih-Terng Sheu
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
- General Education Center, National University of Kaohsiung, Kaohsiung City, Taiwan
| | - Chih-Ming Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan.
| |
Collapse
|
14
|
Shiu RF, Lee CL. Role of microgel formation in scavenging of chromophoric dissolved organic matter and heavy metals in a river-sea system. JOURNAL OF HAZARDOUS MATERIALS 2017; 328:12-20. [PMID: 28073059 DOI: 10.1016/j.jhazmat.2016.12.064] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 12/30/2016] [Accepted: 12/31/2016] [Indexed: 06/06/2023]
Abstract
We use riverine and marine dissolved organic carbon (DOC) polymers to examine their aggregation behavior, and to evaluate the roles of microgel formation in scavenging of chromophoric dissolved organic matter (CDOM) and heavy metals in a river-sea system. Our results indicate that riverine and marine microgels did not exhibit very much difference in size and self-assembly curve; however, the assembly effectiveness ([microgel]/DOC) of marine samples was much higher than riverine. Instead of concentration of DOC, other factors such as types and sources of DOC polymers may control the microgel abundance in aquatic environments. After filtering water samples (microgels removed), the CDOM and selected metals (Cu, Ni, Mn) in the filtrate were quantified. CDOM and metals were concurrently removed to an extent via DOC polymer re-aggregation, which also suggested that the microgels had sequestering capability in CDOM and metals. This finding provides an alternative route for CDOM and heavy metals removal from the water column. As such the process of re-aggregation into microgels should then be considered besides traditional phase partitioning in the assessment of the ecological risk and fate of hazardous materials.
Collapse
Affiliation(s)
- Ruei-Feng Shiu
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Chon-Lin Lee
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan; Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan; Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan; Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
| |
Collapse
|
15
|
Shiu RF, Lee CL. Effects of anthropogenic surfactants on the conversion of marine dissolved organic carbon and microgels. MARINE POLLUTION BULLETIN 2017; 117:156-160. [PMID: 28162250 DOI: 10.1016/j.marpolbul.2017.01.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/19/2017] [Accepted: 01/25/2017] [Indexed: 06/06/2023]
Abstract
The possible impact of three types of anthropogenic surfactants on the ability of marine dissolved organic carbon (DOC) to form self-assembled microgels was evaluated. The behavior of existing native microgels was also examined in the presence of surfactants. These results reveal that the release of surfactants even at low concentrations into the aquatic environment could effectively hinder the self-assembly of DOC polymers. The extent of the size reduction had the following order: anionic, cationic, and non-ionic. Furthermore, charged surfactants can disrupt existing native microgels, converting large assemblies into smaller particles. One possible mechanisms is that surfactants are able to enhance the stability of DOC polymers and disrupt aggregates due to their surface charges and protein-denaturing activities. These findings suggest that the ecological system is altered by anthropogenic surfactants, and provide useful information for ecological assessments of different types of surfactants and raise warnings about surfactant applications.
Collapse
Affiliation(s)
- Ruei-Feng Shiu
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Chon-Lin Lee
- Department of Marine Environment and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan; Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan; Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan; Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
| |
Collapse
|
16
|
Chen C, Huang W. Aggregation Kinetics of Diesel Soot Nanoparticles in Wet Environments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2077-2086. [PMID: 28090765 DOI: 10.1021/acs.est.6b04575] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Soot produced during incomplete combustion consists mainly of carbonaceous nanoparticles (NPs) with severe adverse environmental and health effects, and its environmental fate and transport are largely controlled by aggregation. In this study, we examined the aggregation behavior for diesel soot NPs under aqueous condition in an effort to elucidate the fundamental processes that govern soot particle-particle interactions in wet environments such as rain droplets or surface aquatic systems. The influence of electrolytes and aqueous pH on colloidal stability of these NPs was investigated by measuring their aggregation kinetics in different aqueous solution chemistries. The results showed that the NPs had negatively charged surfaces and exhibited both reaction- and diffusion-limited aggregation regimes with rates depended upon solution chemistry. The aggregation kinetics data were in good agreement with the classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The critical coagulation concentrations (CCC) were quantified and the Hamaker constant was derived for the soot (1.4 × 10-20 J) using the colloidal chemistry approach. The study indicated that, depending upon local aqueous chemistry, single soot NPs could remain stable against self-aggregation in typical freshwater environments and in neutral cloud droplets but are likely to aggregate under salty (e.g., estuaries) or acidic (e.g., acid rain droplets) aquatic conditions or both.
Collapse
Affiliation(s)
- Chengyu Chen
- Department of Environmental Sciences, Rutgers, The State University of New Jersey , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Weilin Huang
- Department of Environmental Sciences, Rutgers, The State University of New Jersey , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| |
Collapse
|
17
|
He W, Chen M, Schlautman MA, Hur J. Dynamic exchanges between DOM and POM pools in coastal and inland aquatic ecosystems: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 551-552:415-428. [PMID: 26881732 DOI: 10.1016/j.scitotenv.2016.02.031] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 06/05/2023]
Abstract
Dynamic exchanges between dissolved organic matter (DOM) and particulate organic matter (POM) plays a critical role in organic carbon cycling in coastal and inland aquatic ecosystems, interactions with aquatic organisms, mobility and bioavailability of pollutants, among many other ecological and geochemical phenomena. Although DOM-POM exchange processes have been widely studied from different aspects, little to no effort has been made to date to provide a comprehensive, mechanistic, and micro-spatial schema for understanding various exchange processes occurring in different aquatic ecosystems in a unified way. The phenomena occurring between DOM and POM were explained here with the homogeneous and heterogeneous mechanisms. In the homogeneous mechanism, the participating components are only organic matter (OM) constituents themselves with aggregation and dissolution involved, whereas OM is associated with other components such as minerals and particulate colloids in the heterogeneous counterpart. Besides the generally concerned processes of aggregation/dissolution and adsorption/desorption, other ecological factors such as sunlight and organisms can also participate in DOM-POM exchanges through altering the chemical nature of OM. Despite the limitation of current analytical technologies, many unknown and/or unquantified processes need to be identified to unravel the complicated exchanges of OM between its dissolved and particulate states. Based on the review of several previous mathematical models, we proposed a unified conceptual model to describe all major dynamic exchange mechanisms on the basis of exergy theory. More knowledge of dynamic DOM-POM exchanges is warranted to overcome the potential problems arising from a simple division of OM into dissolved versus particulate states and to further develop more sophisticated mathematic models.
Collapse
Affiliation(s)
- Wei He
- Department of Environment and Energy, Sejong University, Seoul 143-747, South Korea
| | - Meilian Chen
- Department of Environment and Energy, Sejong University, Seoul 143-747, South Korea
| | - Mark A Schlautman
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC 29625-6510, United States
| | - Jin Hur
- Department of Environment and Energy, Sejong University, Seoul 143-747, South Korea.
| |
Collapse
|