期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
Composition regulates dissolved organic matter adsorption onto iron (oxy)hydroxides and its competition with phosphate: Implications for organic carbon and phosphorus immobilization in lakes
1
作者 ShuaiLong Wen JingJing Liu +6 位作者 YueHan Lu JiaRu Dai XiuLin Huang ShiLin An Erik Jeppesen ZhengWen Liu YingXun Du 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第10期159-171,共13页
Dissolved organicmatter(DOM)is a heterogeneous pool of compounds and exhibits diverse adsorption characteristics with or without phosphorous(P)competition.The impacts of these factors on the burial and mobilization of... Dissolved organicmatter(DOM)is a heterogeneous pool of compounds and exhibits diverse adsorption characteristics with or without phosphorous(P)competition.The impacts of these factors on the burial and mobilization of organic carbon and P in aquatic ecosystems remain uncertain.In this study,an algae-derived DOM(ADOM)and a commercially available humic acid(HA)with distinct compositions were assessed for their adsorption behaviors onto iron(oxy)hydroxides(FeOx),both in the absence and presence of phosphate.ADOM contained less aromatics but more protein-like and highly unsaturated structures with oxygen compounds(HUSO)than HA.The adsorption capacity of FeOx was significantly greater for ADOM than for HA.Protein-like and HUSO compounds in ADOM and humic-like compounds and macromolecular aromatics in HA were preferentially adsorbed by FeOx.Moreover,ADOM demonstrated a stronger inhibitory effect on phosphate adsorption than HA.This observation suggests that the substantial release of autochthonous ADOM by algae could elevate internal P loading and pose challenges for the restoration of restore eutrophic lakes.The presence of phosphate suppressed the adsorption of protein-like compounds in ADOM onto FeOx,resulting in an increase in the relative abundance of protein-like compounds and a decrease in the relative abundance of humic-like compounds in post-adsorption ADOM.In contrast,phosphate exhibited no discernible impact on the compositional fractionation of HA.Collectively,our results show the source-composition characters of DOM influence the immobilization of both DOM and P in aquatic ecosystems through adsorption processes.The preferential adsorption of proteinaceous compounds within ADOM and aromatics within HA highlights the potential for the attachment with FeOx to diminish the original source-specific signatures of DOM,thereby contributing to the shared DOM characteristics observed across diverse aquatic environments. 展开更多
关键词 algal dissolved organic matter Humic acid ADSORPTION PHOSPHATE Fractionation FT-ICR MS
原文传递
Decomposition of algal lipids in clay-enriched marine sediment under oxic and anoxic conditions
2
作者 吕冬伟 宋茜 王旭晨 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第1期131-143,共13页
A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period... A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions. During the 245-day incubation period, changes in the concentrations of TOC, major algal fatty acid components (14:0, 16:0, 16:1, 18:1 and 20:5), and n-alkanes (C16-C23) were quantified in the samples. Our results indicate that the organic matters were degraded more rapidly in oxic than anoxic conditions. Adsorption of fatty acids onto clay minerals was a rapid and reversible process. Using a simple G model, we calculated the decomposition rate constants for TOC, n-alkanes and fatty acids which ranged from 0.017-0.024 d^-1, 0.049-0.103 d^-1 and 0.011 to 0.069 d-l, respectively. Algal organic matter degraded in two stages characterized by a fast and a slow degradation processes. The addition of clay minerals montmorillonite and kaolinite to the sediments showed significant influence affecting the decomposition processes of algal TOC and fatty acids by adsorption and incorporation of the compounds with clay particles. Adsorption/association of fatty acids by clay minerals was rapid but appeared to be a slow reversible process. In addition to the sediment redox and clay influence, the structure of the compounds also played important roles in affecting their degradation dynamic in sediments. 展开更多
关键词 algal organic matter DECOMPOSITION marine sediments clay minerals
原文传递
Formation of regulated and unregulated disinfection byproducts during chlorination and chloramination: Roles of dissolved organic matter type, bromide, and iodide 被引量:4
3
作者 Yunsi Liu Keqiang Liu +2 位作者 Michael J.Plewa Tanju Karanfil Chao Liu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第7期151-160,共10页
Algal blooms and wastewater effluents can introduce algal organic matter(AOM) and effluent organic matter(Ef OM) into surface waters, respectively. In this study, the impact of bromide and iodide on the formation of h... Algal blooms and wastewater effluents can introduce algal organic matter(AOM) and effluent organic matter(Ef OM) into surface waters, respectively. In this study, the impact of bromide and iodide on the formation of halogenated disinfection byproducts(DBPs) during chlorination and chloramination from various types of dissolved organic matter(DOM, e.g., natural organic matter(NOM), AOM, and Ef OM) were investigated based on the data collected from literature. In general, higher formation of trihalomethanes(THMs) and haloacetic acids(HAAs) was observed in NOM than AOM and Ef OM, indicating high reactivities of phenolic moieties with both chlorine and monochloramine. The formation of haloacetaldehydes(HALs), haloacetonitriles(HANs) and haloacetamides(HAMs) was much lower than THMs and HAAs. Increasing initial bromide concentrations increased the formation of THMs, HAAs, HANs, and HAMs, but not HALs. Bromine substitution factor(BSF) values of DBPs formed in chlorination decreased as specific ultraviolet absorbance(SUVA) increased. AOM favored the formation of iodinated THMs(I-THMs) during chloramination using preformed chloramines and chlorination-chloramination processes. Increasing prechlorination time can reduce the I-THM concentrations because of the conversion of iodide to iodate, but this increased the formation of chlorinated and brominated DBPs. In an analogous way, iodine substitution factor(ISF) values of I-THMs formed in chloramination decreased as SUVA values of DOM increased. Compared to chlorination, the formation of noniodinated DBPs is low in chloramination. 展开更多
关键词 Disinfection byproducts Natural organic matter algal organic matter Effluent organic matter BROMIDE IODIDE CHLORINATION CHLORAMINATION
原文传递
The impact of preozonation on the coagulation of cellular organic matter produced by Microcystis aeruginosa and its toxin degradation 被引量:1
4
作者 Magdalena Barešová Jana Naceradská +2 位作者 Katerina Novotná LenkaCermáková Martin Pivokonský 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2020年第12期124-133,共10页
Ozonation pretreatment is typically implemented to improve algal cell coagulation. However, knowledge on the effect of ozonation on the characteristics and coagulation of associated algal organic matter, particularly ... Ozonation pretreatment is typically implemented to improve algal cell coagulation. However, knowledge on the effect of ozonation on the characteristics and coagulation of associated algal organic matter, particularly cellular organic matter(COM), which is extensively released during algal bloom decay, is limited. Hence, this study aimed to elucidate the impact of ozonation applied before the coagulation of dissolved COM from the cyanobacteria Microcystis aeruginosa. Additionally, the degradation of microcystins(MCs) naturally present in the COM matrix was investigated. A range of ozone doses(0.1–1.0 mg O3/mg of dissolved organic carbon – DOC) and ozonation pH values(pH 5, 7 and 9) were tested, while aluminium and ferric sulphate coagulants were used for subsequent coagulation. Despite negligible COM removal, ozonation itself eliminated MCs, and a lower ozone dose was required when performing ozonation at acidic or neutral pH(0.4 mg O3/mg DOC at pH 5 and 7 compared to 0.8 mg O3/mg DOC at pH 9). Enhanced MC degradation and a similar pattern of pH dependence were observed after preozonation-coagulation, whereas coagulation alone did not sufficiently remove MCs. In contrast to the benefits of MC depletion, preozonation using ≥0.4 mg O3/mg DOC decreased the coagulation efficiency(from 42%/48% to 28%–38%/41%–44% using Al/Fe-based coagulants), which was more severe with increasing ozone dosage. Coagulation was also influenced by the preozonation pH, where pH 9 caused the lowest reduction in COM removal. The results indicate that ozonation efficiently removes MCs, but its employment before COM coagulation is disputable due to the deterioration of coagulation. 展开更多
关键词 algal organic matter Coagulation MICROCYSTINS Microcystis aeruginosa Ozonation
原文传递
Impact of pre-oxidation on the formation of byproducts in algae-laden water disinfection:Insights from fluorescent and molecular weight 被引量:2
5
作者 Da Sheng Lingjun Bu +4 位作者 Shumin Zhu Yangtao Wu Jue Wang Nan Li Shiqing Zhou 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第7期21-27,共7页
Pre-oxidation has been reported to be an effective way to remove algal cells in water, but the released algal organic matter (AOM) could be oxidized and lead to the increment in disinfection by-product (DBP) formation... Pre-oxidation has been reported to be an effective way to remove algal cells in water, but the released algal organic matter (AOM) could be oxidized and lead to the increment in disinfection by-product (DBP) formation. The relationship between pre-oxidation and AOM-derived DBP formation needs to be approached more precisely. This study compared the impact of four pre-oxidants, ozone (O), chlorine dioxide (ClO), potassium permanganate(KMnO) and sodium hypochlorite (NaClO), on the formation of nitrogenous (N-) and carbonaceous (C-) DBPs in AOM chlorination. The characterization (fluorescent properties,molecular weight distribution and amino acids concentration) on AOM samples showed that the characterization properties variations after pre-oxidation were highly dependent on the oxidizing ability of oxidants. The disinfection experiments showed that Oincreased DBP formation most significantly, which was consistent with the result of characterization properties variations. Then canonical correspondent analysis (CCA) and Pearson’s correlation analysis were conducted based on the characterization data and DBP formation. CCA indicated that C-DBPs formation was highly dependent on fluorescent data. The formation of haloacetic acids (HAAs) had a positive correlation with aromatic protein-like component while trichloromethane (TCM) had a positive correlation with fulvic acid-like component.Pearson’s correlation analysis showed that low molecular weight fractions were favorable to form N-DBPs. Therefore, characterization data could provide the advantages in the control of DBP formation, which further revealed that KMnOand ClOwere better options for removing algal cells as well as limiting DBP formation. 展开更多
关键词 algal organic matters PRE-OXIDATION Disinfection by-products
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部