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Li J, Liang E, Deng C, Li B, Cai H, Ma R, Xu Q, Liu J, Wang T. Labile dissolved organic matter (DOM) and nitrogen inputs modified greenhouse gas dynamics: A source-to-estuary study of the Yangtze River. WATER RESEARCH 2024; 253:121318. [PMID: 38387270 DOI: 10.1016/j.watres.2024.121318] [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: 10/15/2023] [Revised: 02/07/2024] [Accepted: 02/14/2024] [Indexed: 02/24/2024]
Abstract
Although rivers are increasingly recognized as essential sources of greenhouse gases (GHG) to the atmosphere, few systematic efforts have been made to reveal the drivers of spatiotemporal variations of dissolved GHG (dGHG) in large rivers under increasing anthropogenic stress and intensified hydrological cycling. Here, through a source-to-estuary survey of the Yangtze River in March (spring) and October (autumn) of 2018, we revealed that labile dissolved organic matter (DOM) and nitrogen inputs remarkably modified the spatiotemporal distribution of dGHG. The average partial pressure of CO2 (pCO2), CH4 and N2O concentrations of all sampling sites in the Yangtze River were 1015 ± 225 μatm, and 87.5± 36.5 nmol L-1, and 20.3 ± 6.6 nmol L-1, respectively, significantly lower than the global average. In terms of longitudinal and seasonal variations, higher GHG concentrations were observed in the middle-lower reach in spring. The dominant drivers of spatiotemporal variations in dGHG were labile, protein-like DOM components and nitrogen level. Compared with the historical data of dGHG from published literature, we found a significant increase in N2O concentrations in the Yangtze River during 2004-2018, and the increasing trend was consistent with the rising riverine nitrogen concentrations. Our study emphasized the critical roles of labile DOM and nitrogen inputs in driving the spatial hotspots, seasonal variations and annual trends of dGHG. These findings can contribute to constraining the global GHG budget estimations and controls of GHG emission in large rivers in response to global change.
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Affiliation(s)
- Jiarui Li
- College of Environmental Sciences and Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, PR China; State Environmental Protection Key Laboratory of All Materials Flux in River Ecosystems, Beijing 100871, PR China
| | - Enhang Liang
- College of Environmental Sciences and Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, PR China; State Environmental Protection Key Laboratory of All Materials Flux in River Ecosystems, Beijing 100871, PR China
| | - Chunfang Deng
- College of Environmental Sciences and Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, PR China; State Environmental Protection Key Laboratory of All Materials Flux in River Ecosystems, Beijing 100871, PR China
| | - Bin Li
- College of Environmental Sciences and Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, PR China; State Environmental Protection Key Laboratory of All Materials Flux in River Ecosystems, Beijing 100871, PR China
| | - Hetong Cai
- College of Environmental Sciences and Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, PR China; State Environmental Protection Key Laboratory of All Materials Flux in River Ecosystems, Beijing 100871, PR China
| | - Ruoqi Ma
- College of Environmental Sciences and Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, PR China; State Environmental Protection Key Laboratory of All Materials Flux in River Ecosystems, Beijing 100871, PR China; General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Resources, Beijing 100120, PR China
| | - Qiang Xu
- School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 15030, PR China
| | - Jiaju Liu
- Research Center for Integrated Control of Watershed Water Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China.
| | - Ting Wang
- College of Environmental Sciences and Engineering, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, PR China; State Environmental Protection Key Laboratory of All Materials Flux in River Ecosystems, Beijing 100871, PR China.
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Zheng J, Wang XG, Sun Y, Wang YX, Sha HQ, He XS, Sun XJ. Natural and anthropogenic dissolved organic matter in landfill leachate: Composition, transformation, and their coexistence characteristics. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133081. [PMID: 38016321 DOI: 10.1016/j.jhazmat.2023.133081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 11/19/2023] [Accepted: 11/22/2023] [Indexed: 11/30/2023]
Abstract
A large number of natural and anthropogenic wastes were landfilled, and dissolved organic matter (DOM) were formed during landfill. However, the composition, transformation, and coexistence characteristics of natural and anthropogenic DOM in leachate remain unclear. Fourier transform ion cyclotron resonance mass spectrometry, size exclusion chromatography, gas chromatography coupled with mass spectrometry, and three-dimensional excitation-emission matrix spectrum were employed to clarify comprehensively the abovementioned question. The results showed that natural DOM in young leachate constituted mainly straight-chain organic acids, protein substances, and building blocks of humic substances (BB). Straight-chain organic acids vanished in old leachates, and the concentration of protein substances and BB decreased from 44% to 26% and from 47% to 12%, respectively, while CHON and CHONS were degraded to CHO and CHOS during the process. As to anthropogenic DOM, its types and relative content in leachate increased during landfill, and aromatic acids, terpenes, halogenated organics, indoles, and phenols became the main organic components in old leachate. Compared to natural DOM, anthropogenic DOM was degraded slowly and accumulated in leachate, and some of the natural DOM facilitated the dechlorination of dichlorinated organic compounds. This study demonstrates that landfill led to an increase in humic substances and halogenated organic compounds in old leachate, which was intensified with concentrated leachate recirculation.
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Affiliation(s)
- Jing Zheng
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541000, China
| | - Xian-Ge Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yue Sun
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yu-Xin Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Hao-Qun Sha
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xiao-Song He
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Xiao-Jie Sun
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541000, China
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Pi J, Gong T, He M, Zhu G. Aquatic plant root exudates: A source of disinfection byproduct precursors in constructed wetlands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 899:165590. [PMID: 37474067 DOI: 10.1016/j.scitotenv.2023.165590] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 07/13/2023] [Accepted: 07/15/2023] [Indexed: 07/22/2023]
Abstract
Aquatic plant-derived dissolved organic matter (DOM) in water bodies is an important source of disinfection byproduct (DBP) precursors. It is therefore very important to investigate DBP formation, and the main DBP precursors that enter drinking water during treatment processes. In this study, Lythrum salicaria root extract (LSRE) and Acorus calamus root extract (ACRE) were analyzed. The LSRE and ACRE were chlorinated and disinfected to generate trihalomethanes, haloacetic acids, haloketones, and haloacetaldehydes. The DBP formation potential of LSRE, dominated by humus, was higher than that of Suwannee River natural organic matter (SRNOM), and trichloroacetic acid was the main DBP. It was calculated that 2.09 % of the increased DOC brought by the surface flow wetland planted with emergent aquatic plants, and the contribution rates of TCMFP, DCAAFP and TCAAFP in effluent were 3.34 %, 3.23 % and 3.05 %, respectively. A total of 706 chlorinated-formula were detected by FTICR-MS, among which mono- and di-chlorinated formulae were the most abundant. Macromolecular hydrophobic organics and tannins were the main precursors for LSRE. Unlike LSRE, the DOM composition of ACRE was dominated by protein or aliphatic compounds; therefore, the risk of DBP formation was not as high as that for LSRE. This study is the first to determine the risk of DBP formation associated with aquatic plant root extracts, and confirmed that tannins in plant-derived DOM are more important DBP precursors than lignins.
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Affiliation(s)
- Jiachang Pi
- School of Energy and Environment, Southeast University, Nanjing 210096, China; State Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing 210096, China
| | - Tingting Gong
- School of Energy and Environment, Southeast University, Nanjing 210096, China; State Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing 210096, China
| | - Min He
- School of Energy and Environment, Southeast University, Nanjing 210096, China; State Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing 210096, China
| | - Guangcan Zhu
- School of Energy and Environment, Southeast University, Nanjing 210096, China; State Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Southeast University, Nanjing 210096, China.
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Liang E, Li J, Li B, Liu S, Ma R, Yang S, Cai H, Xue Z, Wang T. Roles of dissolved organic matter (DOM) in shaping the distribution pattern of heavy metal in the Yangtze River. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132410. [PMID: 37647662 DOI: 10.1016/j.jhazmat.2023.132410] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/24/2023] [Accepted: 08/24/2023] [Indexed: 09/01/2023]
Abstract
Dissolved organic matter (DOM) strongly influences the solid-liquid partitioning and migration characteristics of heavy metals, yet little is known about the metal distribution and risk with the participation of DOM in large riverine systems. This study investigated the spatiotemporal distribution of 14 heavy metals and DOM along the entire Yangtze River (over 6000 km), and highlighted the critical roles of DOM in regulating the environmental behaviors of heavy metals. Significant spatial variations of metal contents were observed, with the river source and lower reach remarkably different from the upper-middle reaches. Heavy metals in the Yangtze River were mainly from the natural sources with minor anthropogenic disturbance. We found DOM could promote the conversion of metals from solid to liquid phase and DOM with higher aromaticity showed higher metal affinities. Although low ecological risks were observed in the Yangtze River, potential risks of metal leaching warrant attention, especially for As, Cd and Sb in the middle-lower reaches with higher DOM content and aromaticity. This study established a source-to-sea investigative approach to evaluate the influences of DOM features on metal partitioning, which is crucial for the risk control and sustainable management of large rivers.
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Affiliation(s)
- Enhang Liang
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China
| | - Jiarui Li
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China
| | - Bin Li
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China
| | - Shufeng Liu
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China
| | - Ruoqi Ma
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China; General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Resources, Beijing 100120, PR China
| | - Shanqing Yang
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China
| | - Hetong Cai
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China
| | - Zehuan Xue
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China
| | - Ting Wang
- College of Environmental Sciences and Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, PR China.
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Xu J, Xu J, Tong Z, Yu S, Liu B, Mu X, Du B, Gao C, Wang J, Liu Z, Liu D. Impact of different classification schemes on discrimination of proteins with noise-contaminated spectra using laboratory-measured fluorescence data. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 296:122646. [PMID: 37003145 DOI: 10.1016/j.saa.2023.122646] [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: 12/02/2022] [Revised: 03/05/2023] [Accepted: 03/15/2023] [Indexed: 06/19/2023]
Abstract
Biological agents are important to detect and identify with respect to environmental contamination and public health. Noise contamination in fluorescent spectra is one of the contributors to the uncertainties of identification. In order to investigate the noise-tolerant capability provided by laboratory-measured excitation-emission matrix (EEM) fluorescence spectra that are used as a database, fluorescence properties of four proteinaceous biotoxin samples and ten harmless protein samples were characterized by EEM fluorescence spectra, and the predicting performance of models trained by laboratory-measured fluorescence data was tested and verified from validation data with noise-contaminated spectra. By means of peak signal of noise (PSNR) as an indicator of noise levels, the potential impact of noise contaminations on the characterization and discrimination of these samples was evaluated quantitatively. Different classification schemes utilizing multivariate analysis techniques of Principal Component Analysis (PCA), Random Forest (RF), and Multi-layer Perceptron (MPL) coupled with feature descriptors of differential transform (DT), Fourier transform (FT) and wavelet transform (WT) were conducted under different PSNR values. We systematically analyzed the performance of classification schemes by the case study at 20 PSNR and by statistical analysis from 1-100 PSNR. The results show that the spectral features with EEM-WT decreased the demanding number of input variables while retaining high performances in sample classification. The spectral features with EEM-FT presented the worst performance although having the largest number of features. The distributions of feature importance and contribution were found sensitive to noise contaminations. The classification scheme of PCA prior to MPL with EEM-WT as input presented an improvement in lower PSNR. These results indicate that robust features extracted by corresponding techniques are critical to enhancing the spectral differentiation capabilities among these samples and play an important role in eliminating the noise effect. The study of classification schemes for discriminating protein samples with noise-contaminated spectra presents tremendous potential for future developments in the rapid detection and identification of proteinaceous biotoxins based on three-dimensional fluorescence spectrometry.
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Affiliation(s)
- Jiwei Xu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Jianjie Xu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China.
| | - Zhaoyang Tong
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Siqi Yu
- Department of Earth System Science, Tsinghua University, Beijing, 100084, China
| | - Bing Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Xihui Mu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Bin Du
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Chuan Gao
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Jiang Wang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Zhiwei Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Dong Liu
- Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
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Luo Y, Tan C, He Y, Chen Y, Wan Z, Fu T, Wu Y. Rhizosphere activity induced mobilization of heavy metals immobilized by combined amendments in a typical lead/zinc smelter-contaminated soil. CHEMOSPHERE 2023; 313:137556. [PMID: 36528153 DOI: 10.1016/j.chemosphere.2022.137556] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 12/04/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
The persistence of the stabilization effect of amendments on heavy metals (HMs) is of great concern when they are used for remediating HM-contaminated soil. Here, pot experiments were conducted to investigate the effects of two consecutive seasons of vegetable cultivation on the mobilization of HMs (Cu, Pb, Zn, and Cd) immobilized by different application ratios (0, 20, 40, and 80 g kg-1, labelled C0, C2, C4, and C8) of a combined amendments (lime: sepiolite: biochar: humic acid = 2:2:1:1). The results showed that HM bioavailability decreased with increasing application ratios of the combined amendments in control (CK) treatments. The DOC contents, HM bioavailability, and HM contents in the leaves of vegetables increased, but the pH decreased during two consecutive seasons of vegetable cultivation; however, the HM bioavailability in the C2, C4, and C8 treatments was lower than that in the C0 treatments with vegetables. Catalase, urease, alkaline phosphatase, and dehydrogenase activities in the combined amendment treatments with and without vegetables were decreased compared to those in the C0 treatments. The relative abundances of the dominant bacterial phyla in the different treatments were Actinobacteria > Proteobacteria > Chloroflexi > Acidobacteria > Gemmatimonadetes > Bacteroidetes for the first season and Proteobacteria > Actinobacteria > Chloroflexi > Acidobacteria > Bacteroidetes > Gemmatimonadetes for the second season. Correlations showed that the pH and DOM properties during two consecutive seasons of vegetable cultivation were important factors influencing HM bioavailability, enzyme activity, and bacterial community composition. The bacterial community composition shift indirectly influenced the mobilization of HMs immobilized by the combined amendments. Thus, rhizosphere activity induced the mobilization of HMs immobilized by combined amendments during two consecutive seasons of vegetable cultivation.
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Affiliation(s)
- Youfa Luo
- Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang, 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang, 550025, China.
| | - Chuanjing Tan
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Yu He
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Yulu Chen
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Zuyan Wan
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Tianling Fu
- The New Rural Development Research Institute, Guizhou University, Guiyang, 550025, China
| | - Yonggui Wu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang, 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang, 550025, China
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Koh KY, Chen Z, Lin S, Chandra Mohan K, Luo X, Chen JP. Leaching of organic matters and formation of disinfection by-product as a result of presence of microplastics in natural freshwaters. CHEMOSPHERE 2022; 299:134300. [PMID: 35288183 DOI: 10.1016/j.chemosphere.2022.134300] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 06/14/2023]
Abstract
Microplastics (MPs) are ubiquitous in the environment that may cause negative impacts on the aquatic organisms and human health. They exist in water and wastewater, which are from several sources, such as inappropriate disposal and littering. Therefore, it is important to evaluate the characteristics of MPs in different water types and oxidation processes and study dissolved organic carbon (DOC) leaching and chloroform formation. A commonly existing plastic matter, polyethylene (PE) was placed in different waters and gone through the Fenton-like reaction and the chlorination. The result showed that the PE leached nearly a similar amount of DOC (<1 mg L-1), which was regardless of the water types and under low-dosed irradiation/dark environment. The leached DOC caused the chloroform formation after the chlorination in the waters. During the Fenton-like reaction with the PE, a higher amount of leached DOC (∼3 mg L-1) was detected compared with that in the chlorination (∼0.8 mg L-1). The degree of DOC leaching from the PE caused by the oxidation processes was reflected by the degree of surface structural damage on the PE. However, the chlorination resulted in a higher chloroform formation from the PE (∼20 μg L-1) as the Fenton-like reaction degraded the chloroform. The higher the sodium hypochlorite concentration, the higher the chloroform concentration. When the chloroform existed in the water with the PE, adsorption of chloroform onto the PE was initially observed; however the rate of volatilization would be higher than the rate of adsorption eventually. This study offers useful information for the risk assessment of MPs in our fresh water and drinking water and possible mitigation strategies.
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Affiliation(s)
- Kok Yuen Koh
- Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore; NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, 117411, Singapore
| | - Zhihao Chen
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, 117411, Singapore
| | - Shihan Lin
- Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore
| | - Kishan Chandra Mohan
- Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore
| | - Xiaohong Luo
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, 117411, Singapore
| | - J Paul Chen
- Department of Civil and Environmental Engineering, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore; NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, 117411, Singapore.
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Treatment of Sewage Sludge Compost Leachates on a Green Waste Biopile: A Case Study for an On-Site Application. Processes (Basel) 2022. [DOI: 10.3390/pr10061196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
This work proposes a suitable treatment for the leachates from a sewage sludge composting process using a specific windrow (biopile). The biopile’s evolution and organic content degradation were followed for 2 months with regular leachate spraying to assess the physico-chemical and biological impacts, and determine the risk of enrichment with certain monitored pollutants. The final objective was the valorization of the biopile substrates in the composting process, while respecting the quality standards of use in a circular economy way. Classical physico-chemical parameters (pH, conductivity, dissolved organic carbon (DOC), total dissolved nitrogen (TDN), etc.) were measured in the leachates and in the water-extractable and dry-solid fractions of the biopile, and the catabolic evolution of the micro-organisms (diversity and activities), as well as the enrichment with persistent organic pollutants (POPs) (prioritized PAHs (polycyclic aromatic hydrocarbons) and PCBs (polychlorinated biphenyls)), were determined. The results showed that the microbial populations that were already present in the biopile, and that are responsible for biodegradation, were not affected by leachate spraying. Even when the studied compost leachate was highly concentrated with ammonium nitrogen (10.4 gN L−1 on average), it significantly decreased in the biopile after 2 weeks. A study on the evolution of the isotopic signature (δ15 N) confirmed the loss of leachate nitrogen in its ammoniacal form. The bio-physico-chemical characteristics of the biopile at the end of the experiment were similar to those before the first spraying with leachate. Moreover, no significant enrichment with contaminants (metal trace elements, volatile fatty acids, or persistent organic pollutants) was observed. The results show that it would be possible for composting platforms to implement this inexpensive and sustainable process for the treatment of leachates.
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Li LP, Liu YH, Ren D, Wang JJ. Characteristics and chlorine reactivity of biochar-derived dissolved organic matter: Effects of feedstock type and pyrolysis temperature. WATER RESEARCH 2022; 211:118044. [PMID: 35033743 DOI: 10.1016/j.watres.2022.118044] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/18/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Increasing biochar application worldwide may release more biochar-derived dissolved organic matter (BDOM) to the source water for drinking water supply. However, it is unclear how feedstock types and pyrolysis temperatures for biochar production would affect the characteristics and chlorine reactivity of BDOM. Here, we studied the spectroscopic characteristics of BDOM pyrolyzed from pine needle, wheat straw, walnut shells, alfalfa, pig manure, and sludge derived biochars at 300, 500, and 700 °C, as well as the formation potential of disinfection byproducts (DBPs) and their bulk toxicity after BDOM chlorination. The N/C ratio of biochar was higher for N-rich than C-rich feedstocks. Optical analyses indicated that BDOM aromaticity was highest at 700 °C, while the impact of pyrolysis temperature on the molecular weight of BDOM varied greatly among feedstocks. Increasing pyrolysis temperature caused consistently decreased BDOM reactivity toward haloketone formation but did not show consistent impacts on the other DBPs. Among feedstocks, the N-rich sludge showed the highest specific haloacetonitrile formation potential of BDOM at any given pyrolysis temperature. The DBP formation potential from biochar was consistently highest at 300 °C and was higher for N-rich than C-rich feedstocks. The microtoxicity of DBP mixture was highest for the BDOM derived from sludge produced at 300 °C. This study highlights the high variations in characteristics and chlorination reactivity of BDOM with varying feedstocks and pyrolysis temperatures, which implies that more attention should be paid to the environmental impacts of the intensive application of low-temperature biochar from N-rich feedstock such as sludge.
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Affiliation(s)
- Li-Ping Li
- Research and Development Center for Watershed Environmental Eco-Engineering, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, Guangdong, 519087, China; Guangdong Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Yu-Hui Liu
- Guangdong Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Dong Ren
- College of Environmental Science and Engineering, China West Normal University, Nanchong, Sichuan, 637009, China; Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong, Sichuan, 637009, China
| | - Jun-Jian Wang
- Guangdong Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.
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