Assessing the Self-Purification Capacity of Surface Waters in Lake Baikal Watershed

The removal of trace metals (TM), dissolved organic carbon (DOC), mineral nitrogen (Nmin.), and polycyclic aromatic hydrocarbons (PAHs) from the water of Lake Baikal and its tributaries was evaluated. The contaminant removal rate (CRR) and the contaminant removal capacity (CRC) were used as water self-purification parameters. The CRR was calculated as the difference between contaminant mass flow rates at downstream and upstream gauging stations. The CRC was calculated as the quotient of the CRR and the change in water discharge between downstream and upstream gauging stations. Whether the CRR and CRC have positive or negative values depends on whether contaminant release or removal occurs in the water body. The CRR depends on the size of the water body. The lowest and the highest CRRs observed for Baikal were equal to −15 mg/s (PAHs) to −7327 g/s (DOC), whereas the highest PAH and DOC removal rates observed for Selenga River (the major Baikal tributary) in summer were equal to −9 mg/s and −3190 g/s correspondingly. The highest PAH and DOC removal rates observed for small tributaries were equal to 0.0004 mg/s and −0.7 g/s respectively. The amplitude of annual CRR oscillations depends on contaminant abundance. The highest amplitude was typical for most abundant contaminants such as Nmin. and DOC. In unpolluted sections of the Selenga River the highest rates of N and C removal (−85 g/s and −3190 g/s, respectively) were observed in summer and the lowest rates (4 g/s and 3869 g/s, respectively) were observed in the spring. The lowest amplitude was typical for PAHs and some low-abundance TM such as V and Ni. The highest summer rates of V and Ni removal were equal to −378 mg/s and −155 mg/s respectively, whereas lowest spring rates are equal to 296 mg/s and 220 mg/s. The intermediate CRR amplitudes were typical for most abundant TM such as Sr, Al, and Fe. The spatial CRR variability depends on water chemistry and the presence of pollution sources. The lowest (up to 38 g/s) rates of Nmin. removal was observed for polluted lower Selenga sections characterized by low water mineralization and high DOC concentrations. The highest rates (−85 g/s) were observed for unpolluted upper sections. Seepage loss from the river to groundwater was also recognized as an important means of contaminant removal. The CRC values depend mostly on water residence time. The DOC removing capacity value of Baikal (−26 g/m3) were lower than those of Selenga in summer (−35 g/m3) but higher than the CRCs of all tributaries during the other seasons (from 30 mg/m3 to −10 g/m3).

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Floating wetland islands as a method of nitrogen mass reduction: results of a 1 year test

Water Science & Technology ◽

10.2166/wst.2015.235 ◽

2015 ◽

Vol 72 (5) ◽

pp. 704-710 ◽

Cited By ~ 4

Author(s):

Rafael Vázquez-Burney ◽

James Bays ◽

Ryan Messer ◽

Jeffrey Harris

Keyword(s):

Distribution System ◽

Removal Rate ◽

Reclaimed Water ◽

Hydraulic Residence Time ◽

Removal Capacity ◽

The Difference ◽

Pasco County ◽

Water Transmission ◽

And Control ◽

Transmission And Distribution

Floating wetland islands (FWIs) were tested in Pasco County, Florida, as a method of reducing total nitrogen (TN) in reclaimed water during reservoir storage. The Pasco County Master Reuse System (PCMRS) is a regional reclaimed-water transmission and distribution system providing wastewater effluent disposal for the county. Total daily mass loading from reclaimed water is limited by nitrogen content in the PCMRS watershed. To test TN reduction efficacy, 20 FWIs were constructed, installed, and monitored in a lined pond receiving PCMRS reclaimed water. In total, 149 m2 of FWIs were installed, distributed as a connected network covering 1,122 m2, or 7% of pond area. Pond hydraulic residence time averaged 15.7 days. Treatment performance was assessed during three consecutive periods: establishment (first 6 months of grow-in), performance (8 months immediately following grow-in), and control (3 months after the FWIs were removed from the pond). The FWIs enhanced pond nitrogen removal capacity by 32%. The primary effect of the FWIs was to decrease organic nitrogen in the pond outflow. By evaluating the difference between the performance and control periods, an incremental TN removal rate for the FWIs was calculated to be 4.2 kg N/m2 FWI per year.

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Results of multiyear studies on the dynamics of pollution of lake Baikal by polycyclic aromatic hydrocarbons in the area waste water discharge from the Baikal Pulp and Paper Plant

Doklady Earth Sciences ◽

10.1134/s1028334x12030075 ◽

2012 ◽

Vol 443 (1) ◽

pp. 361-364 ◽

Cited By ~ 3

Author(s):

A. M. Nikonorov ◽

A. A. Matveev ◽

S. A. Reznikov ◽

V. S. Arakelyan ◽

N. N. Luk’yanova

Keyword(s):

Waste Water ◽

Polycyclic Aromatic Hydrocarbons ◽

Lake Baikal ◽

Aromatic Hydrocarbons ◽

Water Discharge ◽

Pulp And Paper ◽

Polycyclic Aromatic

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Analysis of organic removal rates in the aerated submerged fixed film process

Water Science & Technology ◽

10.2166/wst.1998.0809 ◽

1998 ◽

Vol 38 (8-9) ◽

pp. 213-221 ◽

Cited By ~ 3

Author(s):

Mohamed F. Hamoda ◽

Ibrahim A. Al-Ghusain

Keyword(s):

Pilot Plant ◽

Removal Rate ◽

Domestic Wastewater ◽

Removal Rates ◽

Hydraulic Loading ◽

Organic Removal ◽

Wide Range ◽

Fixed Film ◽

Cod Removal Rate ◽

And Performance

Performance data from a pilot-plant employing the four-stage aerated submerged fixed film (ASFF) process treating domestic wastewater were analyzed to examine the organic removal rates. The process has shown high BOD removal efficiencies (> 90%) over a wide range of hydraulic loading rates (0.04 to 0.68 m3/m2·d). It could also cope with high hydraulic and organic loadings with minimal loss in efficiency due to the large amount of immobilized biomass attained. The organic (BOD and COD) removal rate was influenced by the hydraulic loadings applied, but organic removal rates of up to 104 kg BOD/ m2·d were obtained at a hydraulic loading rate of 0.68 m3/m2·d. A Semi-empirical model for the bio-oxidation of organics in the ASFF process has been formulated and rate constants were calculated based on statistical analysis of pilot-plant data. The relationships obtained are very useful for analyzing the design and performance of the ASFF process and a variety of attached growth processes.

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The comparison of trichloroethylene removal rates by methane- and aromatic-utilizing microorganisms

Water Science & Technology ◽

10.2166/wst.1998.0272 ◽

1998 ◽

Vol 38 (7) ◽

pp. 19-24 ◽

Cited By ~ 3

Author(s):

C.-J. Lu ◽

C. M. Lee ◽

M.-S. Chung

Keyword(s):

Cell Concentration ◽

Removal Rate ◽

Carbon Sources ◽

Batch Reactors ◽

Initial Cell Concentration ◽

Removal Rates ◽

Initial Cell ◽

Toluene Concentration ◽

Cell Source ◽

Removal Efficiencies

The comparison of TCE cometabolic removal by methane, toluene, and phenol utilizers was conducted with a series of batch reactors. Methane, toluene, or phenol enriched microorganisms were used as cell source. The initial cell concentration was about 107 cfu/mL. Methane, toluene, and phenol could be readily biodegraded resulting in the cometabolic removal of TCE. Among the three primary carbon sources studied, the presence of phenol provided the best cometabolic removal of TCE. When the concentration of carbon source was 3 mg-C/L, the initial TCE removal rates initiated by methane, toluene, and phenol utilizers were 1.5, 30, and 100 μg/L-hr, respectively. During the incubation period of 80 hours, TCE removal efficiencies were 26% and 96% with the presence of methane and toluene, respectively. However, it was 100% within 20 hours with the presence of phenol. For phenol utilizers, the initial TCE removal rates were about the same, when the phenol concentrations were 1.35, 2.7, and 4.5 mg/L. However, TCE removal was not proportional to the concentrations of phenol. TCE removal was hindered when the phenol concentration was higher than 4.5 mg/L because of the rapid depletion of dissolved oxygen. The presence of toluene also initiated cometabolic removal of TCE. The presence of toluene at 3 and 5 mg/L resulted in similar TCE removal. The initial TCE removal rate was about 95 μg/L-hr at toluene concentrations of 3 and 5 mg/L compared to 20 μg/L-hr at toluene concentration of 1 mg/L.

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Relations between carbon removal rates, biofilm size and density of a novel anaerobic reactor: the inverse turbulent bed

Water Science & Technology ◽

10.2166/wst.2000.0453 ◽

2000 ◽

Vol 41 (4-5) ◽

pp. 253-260 ◽

Cited By ~ 4

Author(s):

P. Buffière ◽

R. Moletta

Keyword(s):

Removal Rate ◽

Removal Rates ◽

Carbon Removal ◽

Biofilm Growth ◽

Loading Rates ◽

Biomass Activity ◽

High Turbulence ◽

The One ◽

High Level ◽

Very High

An anaerobic inverse turbulent bed, in which the biogas only ensures fluidisation of floating carrier particles, was investigated for carbon removal kinetics and for biofilm growth and detachment. The range of operation of the reactor was kept within 5 and 30 kgCOD· m−3· d−1, with Hydraulic Retention Times between 0.28 and 1 day. The carbon removal efficiency remained between 70 and 85%. Biofilm size were rather low (between 5 and 30 μm) while biofilm density reached very high values (over 80 kgVS· m−3). The biofilm size and density varied with increasing carbon removal rates with opposite trends; as biofilm size increases, its density decreases. On the one hand, biomass activity within the reactor was kept at a high level, (between 0.23 and 0.75 kgTOC· kgVS· d−1, i.e. between 0.6 and 1.85 kgCOD·kgVS · d−1).This result indicates that high turbulence and shear may favour growth of thin, dense and active biofilms. It is thus an interesting tool for biomass control. On the other hand, volatile solid detachment increases quasi linearly with carbon removal rate and the total amount of solid in the reactor levels off at high OLR. This means that detachment could be a limit of the process at higher organic loading rates.

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Phosphorus in the Selenga river water and its input to Lake Baikal in conditions of low hydraulicity.

География и природные ресурсы ◽

10.21782/gipr0206-1619-2018-4(88-94) ◽

2018 ◽

Keyword(s):

River Water ◽

Lake Baikal ◽

Selenga River

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Enhanced Wastewater Treatment by Immobilized Enzymes

Current Pollution Reports ◽

10.1007/s40726-021-00183-7 ◽

2021 ◽

Author(s):

Jakub Zdarta ◽

Katarzyna Jankowska ◽

Karolina Bachosz ◽

Oliwia Degórska ◽

Karolina Kaźmierczak ◽

...

Keyword(s):

Wastewater Treatment ◽

Process Optimization ◽

Organic Pollutants ◽

Large Scale ◽

Removal Rate ◽

Immobilized Enzymes ◽

Future Research ◽

Process Conditions ◽

Removal Rates ◽

Catalytic Cycles

Abstract Purpose of Review In the presented review, we have summarized recent achievements on the use of immobilized oxidoreductases for biodegradation of hazardous organic pollutants including mainly dyes, pharmaceuticals, phenols, and bisphenols. In order to facilitate process optimization and achievement of high removal rates, effect of various process conditions on biodegradation has been highlighted and discussed. Recent Findings Current reports clearly show that immobilized oxidoreductases are capable of efficient conversion of organic pollutants, usually reaching over 90% of removal rate. Further, immobilized enzymes showed great recyclability potential, allowing their reuse in numerous of catalytic cycles. Summary Collected data clearly indicates immobilized oxidoreductases as an efficient biocatalytic tools for removal of hazardous phenolic compounds, making them a promising option for future water purification. Data shows, however, that both immobilization and biodegradation conditions affect conversion efficiency; therefore, process optimization is required to achieve high removal rates. Nevertheless, we have demonstrated future trends and highlighted several issues that have to be solved in the near-future research, to facilitate large-scale application of the immobilized oxidoreductases in wastewater treatment.

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Lubricant Removal, Degradation, and Recovery on Particulate Magnetic Recording Media

Journal of Tribology ◽

10.1115/1.2920869 ◽

1992 ◽

Vol 114 (1) ◽

pp. 61-67 ◽

Cited By ~ 20

Author(s):

V. J. Novotny ◽

T. E. Karis ◽

N. W. Johnson

Keyword(s):

Bulk Viscosity ◽

Magnetic Recording ◽

Photoelectron Spectroscopy ◽

Removal Rate ◽

Lateral Diffusion ◽

Recording Media ◽

Magnetic Recording Media ◽

Removal Rates ◽

Linear Chains ◽

Mechanical Durability

Lubrication of particulate magnetic recording media improves their mechanical durability in sliding and flying by several orders of magnitude compared with unlubricated media. Lubricant removal, degradation, and recovery were studied using microslit scanning Fourier transform infrared spectroscopy and microspot scanning X-ray photoelectron spectroscopy. These techniques measure the total and surface lubricant amounts in the porous film, respectively. Lubricant dynamics were compared for two physisorbed polyperfluoroalkylether lubricants of similar molecular weight but different molecular structure—Y with a CF3 side group and Z with linear chains. The bulk viscosity of Y was about ten times higher than the viscosity of Z. In sliding, the lubricant removal rate of Y was significantly higher than that of Z while in flying the removal rates were reversed. Removal rates in sliding were orders of magnitude higher than those in flying. Effective lateral diffusion coefficients estimated from the rate of lubricant reflow back to the depleted tracks were close to inversely proportional to the bulk viscosity. During sliding and flying both lubricants degraded as evidenced by chemically altered lubricant detected on the surfaces after dissolution of undegraded lubricant.

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