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Water Quality Monitoring in a Lake for Improving a Drinking Water Treatment Process
Published in Ni-Bin Chang, Kaixu Bai, Multisensor Data Fusion and Machine Learning for Environmental Remote Sensing, 2018
The Total Organic Carbon (TOC) content is the measure of organic molecules of carbon in water or sediment or both. TOC is the sum of Dissolved Organic Carbon (DOC), Particulate Organic Carbon (POC) or Suspended Organic Carbon (SOC), and colloids, which serves as a key water quality parameter in lakes, rivers, and reservoirs that the water supply industry is required to monitor. TOC is introduced to surface waters from both natural and anthropogenic sources. The headwater lakes in peat-rich areas have high organic matter concentration commonly. The level of TOC concentrations in surface waters also affects pH, redox reactions, bioavailability of metals, and the sorption capacity of suspended solids with regards to hydrophobic organic chemicals (Thurman, 1985; Parks and Baker, 1997). Whereas naturally occurring sources of TOC include humic substances, as well as degraded vegetation and animal matter flushed out by stormwater runoff in a watershed (Thurman, 1985; GEAS, 1994; Bayram et al., 2011), anthropogenic sources include fertilizers captured by stormwater runoff and irrigation return flows, a release of contaminants from a spill or improper usage in the watershed, as well as pesticides, surfactants, and solvents from sewage treatment plants (Visco et al., 2005).
Aquatic Remote Sensing in Regional and Global Environmental Monitoring
Published in Robert P. Bukata, John H. Jerome, Kirill Ya. Kondratyev, Dimitry V. Pozdnyakov, of Inland and Coastal Waters, 2018
Robert P. Bukata, John H. Jerome, Kirill Ya. Kondratyev, Dimitry V. Pozdnyakov
Thus, climate change impacts will be strongly influenced by basin hydrology Hydrology also plays a determinant role in the DOC concentrations of inland and coastal waters. Aquatic DOC originates largely in wet soils and wetlands, and is generally transported into the water column and bottom sediments by surface runoff and/or groundwater leaching. As streamflow decreases, the sources of DOC become less effective, and the corresponding increases in lake residence times result in accentuated DOC degradation. Thus, decreases in streamflow can manifest as decreases in aquatic DOC. Similarly, increases in streamflow can manifest as increases in aquatic DOC. Also, under warmer, drier climates, concentrations of DOC in inland waters can decline due to the combined effects of decreased carbon sources, possible increased degassing, and increased exposure to ultraviolet light and bacterial action.
Emerging disinfection by-products’ formation potential in raw water, wastewater, and treated wastewater in Thailand
Published in Journal of Environmental Science and Health, Part A, 2019
Warangkana Na Phatthalung, Charongpun Musikavong
DOC concentrations in water samples were determined by a combustion method (Standard Method 5310D)[21] on a total organic carbon analyzer (TOC-V CSN, Shimadzu, Japan). The DOC is usually represented as a complex mixture of aromatic and aliphatic carbon-rich compounds of natural DOM in water.[22] UV-254 was measured by the Standard Method 5910B using a Genesys 10S UV/VIS spectrophotometer (Thermo Electron Corp. Madison, WI, USA). UV-254 can be used as a quantitative indicator of the DOM with aromatic rings in the water.[23] SUVA was calculated using the UV-254 absorbance normalized to the mg/L DOC concentration. The SUVA is a useful surrogate for DOC aromaticity in the natural organic matter of water.[24]
Role of multiple substrates (spent mushroom compost, ochre, steel slag, and limestone) in passive remediation of metal-containing acid mine drainage
Published in Environmental Technology, 2019
Verma Loretta M. Molahid, Faradiella Mohd Kusin, Zafira Madzin
The characteristics of the treatment substrates are given in Table 3. Generally, it can be seen that SMC has the highest TDS, conductivity, alkalinity, TOC, TVS, and water content compared to other substrates. TVS are measured to indicate organic matter content [11]. Based on the TVS value, SMC consisted of more than 58% of volatile solids and this was consistent with previous findings [12]. Whereas, limestone and steel slag had less than 1% TVS, and ochre consisted of more than 16% TVS. This indicates that these three substrates had low organic matter compared to SMC. Similarly, SMC had the highest amount of TOC, which was the measure of total amount of organic matter content in the media. In addition, previous study has also stated that SMC had the highest amount of dissolved organic carbon, DOC [10]. DOC is the amount of available dissolved organic carbon released in the water for bacterial consumption.
A novel ecological state at Bear Pond (Adirondack Mountains, NY, USA) following acidification and partial recovery
Published in Lake and Reservoir Management, 2019
J. Curt Stager, Brendan Wiltse, Brian F. Cumming, Thomas M. Holsen, Jonathan Stetler, Corey Laxson, Cristina E. Marcillo, Donald F. Charles
The diatom record of Bear Pond shows that the lake first began to acidify during the mid 1800s and reached a minimum pH range roughly 1 unit lower than the pre-acidified condition by 1995–2010. Since 2010, pH values thus far have risen by ∼0.5 units, most likely due to the increasing pH of regional precipitation. However, full re-establishment of the lake's pre-acidification ecosystem may not be possible. Changes in precipitation chemistry and climate have increased DOC concentrations, altered the phytoplankton community, and reduced the clarity of the lake. In addition, fisheries management activities have altered the fish community and left toxic residues in the sediments. Microfossil assemblages suggest that the recent environmental changes in Bear Pond exceed the natural range of variability over several centuries, and possibly much longer. We conclude that although certain species, ecological niches, or chemical conditions may return to an impacted lake following efforts to restore or "reclaim" it (NRC 1992, Harig and Bain 1995, Gunn and Mills 1998, NOAA 2018; Huang et al. 2019), complete recovery of all aspects of such altered systems may be impossible in this Anthropocene epoch, when humans have become a powerful global force of nature. In that context, even remote lakes such as Bear Pond are likely to evolve into novel ecosystems under the influence of changing atmospheric chemistry, anthropogenic climate change, and aggressive fisheries management practices (Morse et al. 2014, Stager 2018).