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Wang WH, Wang Y, Fan P, Chen LF, Chai BH, Zhao JC, Sun LQ. Effect of calcium peroxide on the water quality and bacterium community of sediment in black-odor water. Environ Pollut 2019; 248:18-27. [PMID: 30769226 DOI: 10.1016/j.envpol.2018.11.069] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/05/2018] [Accepted: 11/22/2018] [Indexed: 06/09/2023]
Abstract
This study investigated how efficiently CaO2 could treat black-odor landscape water caused by low dissolved oxygen (DO) in a field experiment of 600 m2. The study demonstrated that CaO2 could significantly elevate the DO concentration in waters and the oxidation-reduction potential (ORP) level in sediments (p = 0.003 and p = 0), which is conducive to improving the anoxic environment of landscape water. The concentrations of total chemical oxygen demand (TCOD) and S2- in overlying and interstitial waters were considerably decreased. The average concentrations of TCOD in the overlying and interstitial waters of the test zone (TZ) were 52.98% and 66.05% of those of the control zone (CZ), and the average concentrations of S2- in the overlying and interstitial waters of TZ were 29.63% and 39.79% of those of CZ. Meanwhile, CaO2 could obviously reduce turbidity but increase the transparency in the overlying water. The mean value of turbidity in the overlying water of TZ was 39.46% of that of CZ, whereas the transparency in the overlying water of TZ was 2.07 times that of CZ. Furthermore, CaO2 changed the microbial community structure in the sediments, where the relative abundance of anaerobic bacteria was decreased but that of the aerobic bacteria was increased with some functional bacteria. In summary, CaO2 could significantly increase the DO and ORP in black-odor landscape water, obviously inhibit the release of pollutants from sediment, and increase the diversity of microbial strains. Consequently, the black-odor phenomenon of landscape water could be alleviated effectively by adding CaO2.
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Affiliation(s)
- Wen-Huai Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, China
| | - Yi Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, China.
| | - Pan Fan
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, China
| | - Lin-Feng Chen
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, China
| | - Bao-Hua Chai
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, China
| | - Jing-Chan Zhao
- College of Chemistry & Materials Science, Northwest University, Xi'an, 710069, China
| | - Lu-Qin Sun
- Environmental Science Department, University of San Francisco, California, CA, 94117, USA
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Fan P, Wang Y, Wang WH, Chai BH, Lu XX, Zhao JC. Release characteristics of nitrogen and phosphorus from sediments formed under different supplemental water sources in Xi'an moat, China. Environ Sci Pollut Res Int 2019; 26:10746-10755. [PMID: 30778936 DOI: 10.1007/s11356-019-04537-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
The endogenous release of nutrients from sediments contributes to the eutrophication of landscape water to a certain degree, which depends on the characteristics of sediments. The study explored the characteristics of nitrogen (N) and phosphorus (P) released from two different sediments, which were deposited from reclaimed water (SRW) or surface water (SSW) respectively in Xi'an moat. This paper aimed to compare the effects of nutrient release from SRW and SSW on the water quality. Results showed that the maximum increase rates reached 1.21 mg TN/(L·day) and 0.11 mg TP/(L·day), respectively, in the overlying water of SRW, which were 1.6 and 2.8 times those of SSW. The released amounts of SRW were 0.192 mg TN/g and 0.038 mg TP/g, which were 4.1 and 12.7 times those of SSW. Meanwhile, the densities of benthic algae in SRW and SSW were 5.605 × 109 and 2.846 × 108 cells/L, respectively. Moreover, the species number and individual sizes of benthic algae in SRW were also larger than those in SSW, which played an important role in the nitrogen circulation. Unexpectedly, oxidation reduction potential (ORP) level of SRW was lower than that of SSW, although SRW has a higher dissolved oxygen level. Therefore, the N and P concentrations in the overlying water of SRW were considerably higher than those of SSW, which was mainly attributed to the higher nutrient contents and lower ORP in SRW.
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Affiliation(s)
- Pan Fan
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Beilin District, Xi'an, Shaanxi, China
| | - Yi Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Beilin District, Xi'an, Shaanxi, China.
| | - Wen-Huai Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Beilin District, Xi'an, Shaanxi, China
| | - Bao-Hua Chai
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Beilin District, Xi'an, Shaanxi, China
| | - Xin-Xin Lu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Beilin District, Xi'an, Shaanxi, China
| | - Jing-Chan Zhao
- College of Chemistry & Materials Science, Northwest University, Xi'an, 710069, China
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Nicholls JF, Henderson B, Chai BH. Accurate determination of the indices of refraction of nonlinear optical crystals. Appl Opt 1997; 36:8587-8594. [PMID: 18264406 DOI: 10.1364/ao.36.008587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Two techniques are described for measurement of the indices of refraction of novel optical crystals. First a modification is presented of the traditional measurement of the angle of minimum deviation of a refracted beam and applied to lead tetraborate (PTB). The second method applies polarized Michelson interferometry to the principal refractive indices of RbNbB(2)O(6) (RNB). Both PTB and RNB are nonlinear optical crystals that have been recently synthesized and grown for the first time.
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Möbert PE, Heumann E, Huber G, Chai BH. Green Er(3+):YLiF(4) upconversion laser at 551nm with Yb(3+) codoping: a novel pumping scheme. Opt Lett 1997; 22:1412-4. [PMID: 18188254 DOI: 10.1364/ol.22.001412] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report room-temperature continuous-wave upconversion laser emission on the green transition (4)S(3/2)?(4)I(15/2) in Er(1%), Yb(3%):YLiF(4) at 551nm. Green laser operation was obtained for titanium-sapphire pump wavelengths continuously tunable between 955 and 974.5nm. Codoping with Yb(3+) resulted in a more efficient excitation of the upper laser level by upconversion processes. The maximum green laser output power was 37mW at an incident titanium-sapphire pump power level of 1580mW at 966nm.
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Sutherland JM, French PM, Taylor JR, Chai BH. Visible continuous-wave laser transitions in Pr(3+):YLF and femtosecond pulse generation. Opt Lett 1996; 21:797-799. [PMID: 19876162 DOI: 10.1364/ol.21.000797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fourteen new cw, visible laser transitions have been observed in Pr(3+):YLF, several of which have exhibited modest tunability. The (3)P(0) - (3)H(6) transition near 613 nm has been shown to have a tunable linewidth of ~1 nm, which, for the first time to our knowledge, has permitted the direct production of femtosecond pulses in the visible from a cw solid-state laser by Kerr-lens mode locking.
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Tong YP, Sutherland JM, French PM, Taylor JR, Shestakov AV, Chai BH. Self-starting Kerr-lens mode-locked femtosecond Cr(4+):YAG and picosecond Pr(3+):YLF solid-state lasers. Opt Lett 1996; 21:644-646. [PMID: 19876111 DOI: 10.1364/ol.21.000644] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have observed true self-starting Kerr-lens mode locking in two distinct solid-state laser systems operating at room temperature by optimizing the cavity geometry to maximize the amplitude modulation with respect to the intracavity power variation. Pulses of 15 ps have been obtained from a Pr(3+):YLF laser system operating at 607 nm, and 53-fs pulses have been obtained from Cr(4+):YAG at 1.54 microm.
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Jensen T, Diening A, Huber G, Chai BH. Investigation of diode-pumped 2.8-microm Er:LiYF(4) lasers with various doping levels. Opt Lett 1996; 21:585-587. [PMID: 19876091 DOI: 10.1364/ol.21.000585] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report on efficient lasers emission of Er:LiYF(4) at 2.8 microm. The crystals were pumped by InGaAs semiconductor laser emitting near 970 nm. The laser performance was investigated for different doping levels and yielded an optimum doping level of ~15%. At this Er(3+) concentration we achieved a slope efficiency of 35%, which is identical to the quantum defect. Pumping at high power levels permits a true cw output power of 1.1 W at 2.8 microm, which is of interest for several applications based on the strong water absorption in this wavelength range.
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Ruan S, Sutherland JM, French PM, Taylor JR, Chai BH. Kerr-lens mode-locked visible transitions of a Pr:YLF laser. Opt Lett 1995; 20:1041. [PMID: 19859417 DOI: 10.1364/ol.20.001041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Zhang XX, Hong P, Bass M, Chai BH. Blue upconversion with excitation into Tm ions at 780 nm in Yb- and Tm-codoped fluoride crystals. Phys Rev B Condens Matter 1995; 51:9298-9301. [PMID: 9977572 DOI: 10.1103/physrevb.51.9298] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Payne SA, Smith LK, Beach RJ, Chai BH, Tassano JH, Deloach LD, Kway WL, Solarz RW, Krupke WF. Properties of Cr:LiSrAIF(6) crystals for laser operation. Appl Opt 1994; 33:5526-5536. [PMID: 20935948 DOI: 10.1364/ao.33.005526] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We have performed several physical and optical measurements on the Cr:LiSAF (LiSrAlF(6)) laser material that are relevant to its laser performance, including thermal and mechanical properties, water durabilities, and Auger upconversion constants. The expansion coefficient, Young's modulus, fracture toughness, thermal conductivity, and heat capacity are all used to determine an overall thermomechanical figure of merit for the crystal. An investigation of the water durability suggests that the cooling solution should be maintained at pH = 7 to ameliorate problems associated with water dissolution. The Auger constant was found to become much more significant at higher Cr doping, in which excited-state migration leads to a substantial increase in the upconversion rate. We propose a design for a 50-W Cr:LiSAF laser system that is based on a detailed knowledge of all the relevant material parameters.
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Abstract
A new congruent melting compound intermediate between the solid solutions of LiCaAIF(6) and LiSrAlF(6) is reported. When doped with Cr(3+) ion, the new compound (Cr:LiSr(0.8)Ca(0.2)AlF(6)) has demonstrated roomtemperature lasing in the spectral region from 750 to 950 nm. This material has mechanical properties similarto those of Cr:LiCaAlF(6) and a broadband laser tuning range similar to that of Cr:LiSrAlF(6). Long-pulse, flash-lamp-pumped lasing with 1.25% overall efficiency is reported by using a rod cut from an earlier boule.
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Evans JM, Spence DE, Sibbett W, Chai BH, Miller A. 50-fs pulse generation from a self-mode-locked Cr:LiSrAlF6 laser. Opt Lett 1992; 17:1447. [PMID: 19798209 DOI: 10.1364/ol.17.001447] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Abstract
Small-signal gain properties of Cr(3+)-doped LiSrAlF(6) are measured for the first time to our knowledge. Maximum small-signal gain values of 0.17 cm(-1) are reported for pi-polarized light. For sigma polarization, the gain is significantly suppressed by excited-state absorption.
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Abstract
With a liquid-crystal-based birefringent tuner in a coupled resonator, an AlGaInP diode-laser-pumped Cr:LiSrAlF(6) cube laser has been electronically tuned from 858 nm to beyond 920 nm. At an incident pump power of 42 mW, an output power in excess of 4.3 mW was observed near the peak of the tuning curve at 870 nm.
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