51
|
Kim IY, Lee JM, Hwang EH, Pei YR, Jin WB, Choy JH, Hwang SJ. Water-floating nanohybrid films of layered titanate–graphene for sanitization of algae without secondary pollution. RSC Adv 2016. [DOI: 10.1039/c6ra24140a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
A novel efficient and safe methodology to sanitize algae in natural water without secondary pollution is developed by fabricating floating graphene–inorganic hybrid films.
Collapse
Affiliation(s)
- In Young Kim
- Department of Chemistry and Nanoscience
- College of Natural Sciences
- Ewha Womans University
- Seoul 03760
- Korea
| | - Jang Mee Lee
- Department of Chemistry and Nanoscience
- College of Natural Sciences
- Ewha Womans University
- Seoul 03760
- Korea
| | - Eui-Ho Hwang
- Department of Chemistry and Nanoscience
- College of Natural Sciences
- Ewha Womans University
- Seoul 03760
- Korea
| | - Yi-Rong Pei
- Department of Chemistry and Nanoscience
- College of Natural Sciences
- Ewha Womans University
- Seoul 03760
- Korea
| | - Woo-Bin Jin
- Department of Chemistry and Nanoscience
- College of Natural Sciences
- Ewha Womans University
- Seoul 03760
- Korea
| | - Jin-Ho Choy
- Department of Chemistry and Nanoscience
- College of Natural Sciences
- Ewha Womans University
- Seoul 03760
- Korea
| | - Seong-Ju Hwang
- Department of Chemistry and Nanoscience
- College of Natural Sciences
- Ewha Womans University
- Seoul 03760
- Korea
| |
Collapse
|
52
|
Ma G, Pei H, Hu W, Xu X, Ma C, Pei R. Effects of glucose on microcystin-LR removal and the bacterial community composition through anoxic biodegradation in drinking water sludge. ENVIRONMENTAL TECHNOLOGY 2015; 37:64-73. [PMID: 26086866 DOI: 10.1080/09593330.2015.1063705] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
To enhance the degradation efficiency of microcystin (MC) in drinking water sludge (DWS), the underlying mechanisms between organic carbon (glucose) and the biodegradation of MC-LR under anoxic conditions were investigated by polymerase chain reaction-denaturing gradient gel electrophoresis technology. The addition of glucose reduced the rate of the MC-LR biodegradation indicating the occurrence of inhibition of degradation, and an increased inhibition was observed with increases in glucose concentration (0-10,000 mg/L). In addition, the community analysis indicated that the variety and the number of the microbes increased with the concentration of glucose amended (0 -1000 mg/L), but they decreased substantially with the addition of 10,000 mg/L of glucose. The phyla Firmicutes, Proteobacteria and Chloroflexi were found to be the dominant. Methylobacterium and Sphingomonas were MC-degrading bacteria and used glucose as a prior carbon source instead of MC, resulting in the decrease in the MC-LR biodegradation rate under anoxic conditions. Thus, reducing organic carbon could improve the anoxic biodegradation efficiency of MC in DWS.
Collapse
Affiliation(s)
- Guangxiang Ma
- a School of Environmental Science and Engineering , Shandong University , 27 Shanda Nan Road, Jinan 250100 , People's Republic of China
| | - Haiyan Pei
- a School of Environmental Science and Engineering , Shandong University , 27 Shanda Nan Road, Jinan 250100 , People's Republic of China
- b Shandong Provincial Engineering Centre on Environmental Science and Engineering , 17923 Jingshi Road, Jinan 250061 , People's Republic of China
| | - Wenrong Hu
- a School of Environmental Science and Engineering , Shandong University , 27 Shanda Nan Road, Jinan 250100 , People's Republic of China
- b Shandong Provincial Engineering Centre on Environmental Science and Engineering , 17923 Jingshi Road, Jinan 250061 , People's Republic of China
| | - Xiangchao Xu
- a School of Environmental Science and Engineering , Shandong University , 27 Shanda Nan Road, Jinan 250100 , People's Republic of China
| | - Chunxia Ma
- a School of Environmental Science and Engineering , Shandong University , 27 Shanda Nan Road, Jinan 250100 , People's Republic of China
| | - Ruoting Pei
- c Department of Civil and Environmental Engineering , The University of Texas at San Antonio , San Antonio , TX 78249 , USA
| |
Collapse
|
53
|
Huo X, Chang DW, Tseng JH, Burch MD, Lin TF. Exposure of Microcystis aeruginosa to Hydrogen Peroxide under Light: Kinetic Modeling of Cell Rupture and Simultaneous Microcystin Degradation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:5502-5510. [PMID: 25821997 DOI: 10.1021/acs.est.5b00170] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effect of hydrogen peroxide on the cell integrity of a cyanobacterium, Microcystis aeruginosa, and on the release and degradation of microcystins (MCs) under simulated sunlight was investigated. The cyanobacterium was exposed to H2O2 in the range of 0-60 mg·L(-1) for 3.5 h. Production of OH radical in the solution was estimated by a chemical probe method. More than 99% (2 log) of the M. aeruginosa cells were ruptured or damaged by 3 h for all the treatments. Loss of cell integrity over time revealed two distinct phases. Cells retained their integrity during the initial lag phase and rapidly ruptured following first-order reaction afterward. A linear relationship was found between the duration of the lag phase and the steady-state concentration of OH radical. Release of MCs was closely correlated with the loss of cell integrity. Sequential reaction models were developed to simulate the release and degradation of MCs. These models were able to quantitatively describe the kinetics of all reactions under different H2O2 doses and extended exposure time. In particular, the models successfully predicted the concentration change of MCs using independently measured parameters. These models provide a simple and quantitative means to estimate the interaction of oxidants and cells and the consequent release of metabolites during oxidation treatment of cyanobacterium-laden waters.
Collapse
Affiliation(s)
- Xiangchen Huo
- †College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - De-Wei Chang
- ‡Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan
| | - Jing-Hua Tseng
- ‡Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan
| | - Michael D Burch
- §Australian Water Quality Centre, South Australian Water Corporation, Adelaide, South Australia 5000, Australia
| | - Tsair-Fuh Lin
- ‡Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan
| |
Collapse
|
54
|
Bownik A, Stępniewska Z. Protective effects of ectoine on behavioral, physiological and biochemical parameters of Daphnia magna subjected to hydrogen peroxide. Comp Biochem Physiol C Toxicol Pharmacol 2015; 170:38-49. [PMID: 25704915 DOI: 10.1016/j.cbpc.2015.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 12/24/2022]
Abstract
Ectoine (ECT) is an osmoprotectant produced by halophilic microorganisms inducing protective effects against various stressful factors. However, little is known about its influence on aquatic invertebrates subjected to hydrogen peroxide (H2O2)-a commonly used oxidative disinfectant. Therefore, the aim of our study was to determine the effects of H2O2 alone (at 5 and 10 mg/L) and in the combination with various concentrations of ECT (5, 10 and 25 mg/L) on behavioral, physiological and biochemical parameters of Daphnia magna. The following endpoints were determined: mortality, heart rate, thoracic limb movement, total glutathione (GSH)/oxidized glutathione (GSSG) ratio, catalase (CAT) activity and nitric oxide (NOx) level. The study showed that daphnids exposed to the combination of H2O2+ECT showed decreased mortality, attenuated inhibition of heart rate and thoracic limb activity, less decreased GSH/GSSG ratio, lower stimulation of CAT activity and NOx level when compared to the crustaceans exposed to H2O2 alone. The most pronounced alleviation of toxic effects was observed in the combination of 5 mg/L H2O2+25 mg/L ECT. The results suggest that protective effects of ECT in D. magna subjected to H2O2 may be related to antioxidative properties of the osmoprotectant.
Collapse
Affiliation(s)
- Adam Bownik
- Department of Physiology and Ecotoxicology, Faculty of Biotechnology and Environmental Sciences, The John Paul II Catholic University of Lublin, Kontstantynów 1 "I", 20-708 Lublin, Poland
| | - Zofia Stępniewska
- Department of Biochemistry and Enironmental Chemistry, Faculty of Biotechnology and Environmental Sciences, The John Paul II Catholic University of Lublin, Kontstantynów 1 "I", 20-708 Lublin, Poland.
| |
Collapse
|
55
|
Valero E, Álvarez X, Cancela Á, Sánchez Á. Harvesting green algae from eutrophic reservoir by electroflocculation and post-use for biodiesel production. BIORESOURCE TECHNOLOGY 2015; 187:255-262. [PMID: 25863202 DOI: 10.1016/j.biortech.2015.03.138] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/27/2015] [Accepted: 03/29/2015] [Indexed: 06/04/2023]
Abstract
Each year there are more frequent blooms of green algae and cyanobacteria, representing a serious environmental problem of eutrophication. Electroflocculation (EF) was studied to harvest the algae which are present in reservoirs, as well as different factors which may influence on the effectiveness of the process: the voltage applied to the culture medium, run times, electrodes separation and natural sedimentation. Finally, the viability of its use to obtain biodiesel was studied by direct transesterification. The EF process carried out at 10V for 1min, with an electrode separation of 5.5cm and a height of 4cm in culture vessel, obtained a recovery efficiency greater than 95%, and octadecenoic and palmitic acids were obtained as the fatty acid methyl esters (FAMEs). EF is an effective method to harvest green algae during the blooms, obtaining the greatest amount of biomass for subsequent use as a source of biodiesel.
Collapse
Affiliation(s)
- Enrique Valero
- AF4 Research Group, Department of Natural Resources and Environment Engineering, Forestry Engineering College, University of Vigo, Campus A Xunqueira s/n, 36005 Pontevedra, Spain.
| | - Xana Álvarez
- AF4 Research Group, Department of Natural Resources and Environment Engineering, Forestry Engineering College, University of Vigo, Campus A Xunqueira s/n, 36005 Pontevedra, Spain.
| | - Ángeles Cancela
- Chemical Engineering Department, Industrial Engineering College, University of Vigo, Campus Lagoas-Marcosende s/n, 36310 Vigo, Pontevedra, Spain.
| | - Ángel Sánchez
- Chemical Engineering Department, Industrial Engineering College, University of Vigo, Campus Lagoas-Marcosende s/n, 36310 Vigo, Pontevedra, Spain.
| |
Collapse
|
56
|
Gao L, Pan X, Zhang D, Mu S, Lee DJ, Halik U. Extracellular polymeric substances buffer against the biocidal effect of H2O2 on the bloom-forming cyanobacterium Microcystis aeruginosa. WATER RESEARCH 2015; 69:51-58. [PMID: 25463931 DOI: 10.1016/j.watres.2014.10.060] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/23/2014] [Accepted: 10/28/2014] [Indexed: 06/04/2023]
Abstract
H2O2 is an emerging biocide for bloom-forming cyanobacteria. It is important to investigate the H2O2 scavenging ability of extracellular polymeric substances (EPS) of cyanobacteria because EPS with strong antioxidant activity may "waste" considerable amounts of H2O2 before it kills the cells. In this study, the buffering capacity against H2O2 of EPS from the bloom-forming cyanobacterium Microcystis aeruginosa was investigated. IC50 values for the ability of EPS and vitamin C (VC) to scavenge 50% of the initial H2O2 concentration were 0.097 and 0.28 mg mL(-1), respectively, indicating the higher H2O2 scavenging activity of EPS than VC. Both proteins and polysaccharides are significantly decomposed by H2O2 and the polysaccharides were more readily decomposed than proteins. H2O2 consumed by the EPS accounted for 50% of the total amount of H2O2 consumed by the cells. Cell growth and photosynthesis were reduced more for EPS-free cells than EPS coated cells when the cells were treated with 0.1 or 0.2 mg mL(-1) H2O2, and the maximum photochemical efficiency Fv/Fm of EPS coated cells recovered to higher values than EPS-free cells. Concentrations of H2O2 above 0.3 mg mL(-1) completely inhibited photosynthesis and no recovery was observed for both EPS-free and EPS coated cells. This shows that EPS has some buffering capacity against the killing effect of H2O2 on cyanobacterial cells. Such a strong H2O2 scavenging ability of EPS is not favorable for killing bloom-forming cyanobacteria. The high H2O2 scavenging capacity means considerable amounts of H2O2 have to be used to break through the EPS barrier before H2O2 exerts any killing effects on the cells. It is therefore necessary to determine the H2O2 scavenging capacity of the EPS of various bloom-forming cyanobacteria so that the cost-effective amount of H2O2 needed to be used for killing the cyanobacteria can be estimated.
Collapse
Affiliation(s)
- Lei Gao
- Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Graduate University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiangliang Pan
- Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
| | - Daoyong Zhang
- Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
| | - Shuyong Mu
- Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Umut Halik
- College of Resource and Environment Sciences, Xinjiang Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi 830046, China
| |
Collapse
|
57
|
Lürling M, Meng D, Faassen EJ. Effects of hydrogen peroxide and ultrasound on biomass reduction and toxin release in the cyanobacterium, Microcystis aeruginosa. Toxins (Basel) 2014; 6:3260-80. [PMID: 25513892 PMCID: PMC4280534 DOI: 10.3390/toxins6123260] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 11/25/2014] [Accepted: 12/03/2014] [Indexed: 11/25/2022] Open
Abstract
Cyanobacterial blooms are expected to increase, and the toxins they produce threaten human health and impair ecosystem services. The reduction of the nutrient load of surface waters is the preferred way to prevent these blooms; however, this is not always feasible. Quick curative measures are therefore preferred in some cases. Two of these proposed measures, peroxide and ultrasound, were tested for their efficiency in reducing cyanobacterial biomass and potential release of cyanotoxins. Hereto, laboratory assays with a microcystin (MC)-producing cyanobacterium (Microcystis aeruginosa) were conducted. Peroxide effectively reduced M. aeruginosa biomass when dosed at 4 or 8 mg L-1, but not at 1 and 2 mg L-1. Peroxide dosed at 4 or 8 mg L-1 lowered total MC concentrations by 23%, yet led to a significant release of MCs into the water. Dissolved MC concentrations were nine-times (4 mg L-1) and 12-times (8 mg L-1 H2O2) higher than in the control. Cell lysis moreover increased the proportion of the dissolved hydrophobic variants, MC-LW and MC-LF (where L = Leucine, W = tryptophan, F = phenylalanine). Ultrasound treatment with commercial transducers sold for clearing ponds and lakes only caused minimal growth inhibition and some release of MCs into the water. Commercial ultrasound transducers are therefore ineffective at controlling cyanobacteria.
Collapse
Affiliation(s)
- Miquel Lürling
- Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
| | - Debin Meng
- Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
| | - Elisabeth J Faassen
- Aquatic Ecology and Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
| |
Collapse
|
58
|
Ma G, Pei H, Hu W, Xu X, Ma C, Li X. The removal of cyanobacteria and their metabolites through anoxic biodegradation in drinking water sludge. BIORESOURCE TECHNOLOGY 2014; 165:191-198. [PMID: 24726136 DOI: 10.1016/j.biortech.2014.03.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 03/12/2014] [Accepted: 03/15/2014] [Indexed: 06/03/2023]
Abstract
The effects of environmental factors on cyanobacteria damage and microcystin-LR degradation in drinking water sludge were investigated under anoxic conditions. The rates of microcystin-LR release and degradation increased rapidly with the increasing temperature from 15°C to 40°C and the highest degradation rate of 99% was observed at 35°C within 10days. Compared to acidic conditions, microcystin-LR degraded more rapidly in weak alkali environments. In addition, the microbial community structures under different anoxic conditions were studied. The sequencing results showed that four phyla obtained from the DGGE profiles were as follows: Proteobacteria, Acidobacteria, Firmicutes and Cyanobacteria. Proteobacteria containing nine genera were the most common species. Pseudomonas, Methylosinus and Sphingomona all showed stronger activities and had significant increase as microcystin-LR degraded, so they should be responsible for the microcystin-LR degradation. This is the first report of Pseudomonas, Methylosinus and Sphingomonas as the microcystins-degrading microorganisms in anoxic drinking water sludge.
Collapse
Affiliation(s)
- Guangxiang Ma
- School of Environmental Science and Engineering, Shandong University, 27 Shanda Nan Road, Jinan 250100, China
| | - Haiyan Pei
- School of Environmental Science and Engineering, Shandong University, 27 Shanda Nan Road, Jinan 250100, China; Shandong Provincial Engineering Centre on Environmental Science and Engineering, 17923 Jingshi Road, Jinan 250061, China
| | - Wenrong Hu
- School of Environmental Science and Engineering, Shandong University, 27 Shanda Nan Road, Jinan 250100, China; Shandong Provincial Engineering Centre on Environmental Science and Engineering, 17923 Jingshi Road, Jinan 250061, China.
| | - Xiangchao Xu
- School of Environmental Science and Engineering, Shandong University, 27 Shanda Nan Road, Jinan 250100, China
| | - Chunxia Ma
- School of Environmental Science and Engineering, Shandong University, 27 Shanda Nan Road, Jinan 250100, China
| | - Xiuqing Li
- School of Environmental Science and Engineering, Shandong University, 27 Shanda Nan Road, Jinan 250100, China
| |
Collapse
|
59
|
Zhang H, Yang L, Yu Z, Huang Q. Inactivation of Microcystis aeruginosa by DC glow discharge plasma: Impacts on cell integrity, pigment contents and microcystins degradation. JOURNAL OF HAZARDOUS MATERIALS 2014; 268:33-42. [PMID: 24468526 DOI: 10.1016/j.jhazmat.2014.01.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 12/14/2013] [Accepted: 01/01/2014] [Indexed: 06/03/2023]
Abstract
We proposed a method to inactivate M. aeruginosa by using discharge plasma taking at the gas-solution interface supplied by DC power. Multiple analysis techniques including fluorescence excitation-emission matrix (EEM) and flow cytometry (FCM) were used to reveal the inactivation mechanism of M. aeruginosa. The photosynthetic pigment contents including phycocyanin, chlorophyll and metabolites were examined quantitatively. The DC glow discharge plasma caused an increased level of reactive oxygen species (ROS), and the damage of M. aeruginosa cells are mainly attributed to the oxidative stress including OH attack and H2O2 oxidation. Our findings demonstrate that plasma oxidation is a promising technology for inactivation of M. aeruginosa cells with simultaneous removal of microcystins and so it may lead us to a new route to efficient treatment of cyanobacterial blooms.
Collapse
Affiliation(s)
- Hong Zhang
- Key Laboratory of Ion Beam Bioengineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, PR China
| | - Linfang Yang
- Key Laboratory of Ion Beam Bioengineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, PR China
| | - Zengliang Yu
- Key Laboratory of Ion Beam Bioengineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, PR China
| | - Qing Huang
- Key Laboratory of Ion Beam Bioengineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, PR China; University of Science & Technology of China, Hefei, Anhui, 230026, PR China.
| |
Collapse
|
60
|
Lürling M, van Oosterhout F. Controlling eutrophication by combined bloom precipitation and sediment phosphorus inactivation. WATER RESEARCH 2013; 47:6527-6537. [PMID: 24041525 DOI: 10.1016/j.watres.2013.08.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 08/12/2013] [Accepted: 08/17/2013] [Indexed: 06/02/2023]
Abstract
The hypothesis that the combination of the flocculent polyaluminium chloride (PAC) with the lanthanum-modified bentonite Phoslock(®) (Flock & Lock) could sink effectively a water bloom of cyanobacteria and could shift a turbid, cyanobacteria infested lake to a clear water lake was tested in a controlled laboratory experiment and a whole lake experiment. In the laboratory, a relatively low dose of the flocculent PAC (2.2 and 4.4 mg Al l(-1)) was insufficient to sediment positively buoyant cyanobacteria (Microcystis aeruginosa). Similarly, the lanthanum modified clay (dosed at 390 mg l(-1)) was insufficient to sediment the positively buoyant cyanobacteria. However, the combination of PAC and Phoslock(®) effectively sedimented cyanobacteria flocks. Likewise, a combined treatment of 2 tons PAC and 18 tons Phoslock(®) in Lake Rauwbraken in April 2008 effectively sedimented a developing cyanobacteria bloom of Aphanizomenon flos-aquae. The average chlorophyll-a concentration in the two years prior to this Flock & Lock treatment was 19.5 (±36.5) μg l(-1), while it was as low as 3.7 (±4.5) μg l(-1) in the years following the treatment. The combined treatment effectively reduced the amount of total phosphorus (TP) in the water column from on average 169 (±126) μg P l(-1) before the application to 14 (±15) μg P l(-1) after the treatment. Based on mean summer chlorophyll-a and TP concentrations, the lake was shifted from a eutrophic/hypertrophic state to an oligo/mesotrophic state. From directly after treatment in April 2008 until and including 2013, Lake Rauwbraken remained in an oligo-mesotrophic clear water state with TP reduced to less than 10% of the pre-treatment. This result shows that eutrophication in relatively small, isolated, stratifying lakes can be restored by targeting both water column and sediment P using a combination of flocculent and solid phase P-sorbent.
Collapse
Affiliation(s)
- Miquel Lürling
- Aquatic Ecology & Water Quality Management Group, Department of Environmental Sciences, Wageningen University, P.O. Box 47, 6700 AA Wageningen, The Netherlands; Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands.
| | | |
Collapse
|
61
|
Seckler FFS, Margarida M, Rosemeire AL. Interference of iron as a coagulant on MIB removal by powdered activated carbon adsorption for low turbidity waters. J Environ Sci (China) 2013; 25:1575-1582. [PMID: 24520695 DOI: 10.1016/s1001-0742(12)60231-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Powered activated carbon (PAC) is widely used in water treatment plants to minimize odors in drinking water. This study investigated the removal of 2-methylisoborneol (MIB) by PAC adsorption, combined with coagulation using iron as a coagulant. The adsorption and coagulation process were studied through different case scenarios of jar tests. The analysis evaluated the effect of PAC dosing in the liquid phase immediately before or after the coagulant addition. Ferric sulphate was used as the coagulant with dosages from 10 to 30 mg/L, and PAC dosages varied from 10 to 40 mg/L. The highest MIB removal efficiency (about 70%) was achieved without the coagulant addition and with the highest PAC dosage (40 mg/L). Lower MIB removal efficiencies were observed in the presence of coagulant, showing a clear interference of the iron precipitate or coagulant in the adsorption process. The degree of interference of the coagulation process in the MIB removal was proportional to the ratio of ferric hydroxide mass to the PAC mass. For both cases of PAC dosing, upstream and downstream of the coagulant injection point, the MIB removal efficiency was similar. However, MIB removal efficiency was 15% lower when compared with experiments without the coagulant application. This interference in the MIB adsorption occurs potentially because the coagulant coats the surface of the carbon and interferes with the MIB coming in contact with the carbon's surface and pores. This constraint requires an increase of the PAC dosage to provide the same efficiency observed without coagulation.
Collapse
Affiliation(s)
| | - Marchetto Margarida
- Department of Sanitary and Environmental Engineering, University of Mato Grosso, Brazil
| | | |
Collapse
|