Sep 16, 2008· Feb. 7, 2017 High levels of selenium have been found in the tissues of fish in North Carolina lakes that receive coal ash effluents from power plants. Concentrations of selenium
Jan 22, 1998· Selenium-laden effluents from oil refineries are polluting San Francisco Bay, California. One environmentally friendly way of cleaning up selenium (Se) from effluents is by plant and microbial Se volatilization using constructed wetlands. Using mesocosms, we investigated the role of biological Se volatilization in a 36-ha constructed wetland located adjacent to San Francisco Bay. The
The effluent of the settling tank still contains variable concentrations of selenium, molybdenum and antimony and the overall removal efficiency is not reproducible for these elements. Laboratory experiments are presented for the removal by coprecipitation and the results are discussed.
Water Air Soil Pollut (2011) 221:301312 DOI 10.1007/s11270-011-0791-z Treatment of Selenium in Simulated Refinery Effluent Using a Pilot-Scale Constructed Wetland Treatment System Michael M. Spacil & John H. Rodgers Jr. & James W. Castle & Cynthia L. Murray Gulde & James E. Myers Received: 29 November 2010 / Accepted: 7 March 2011 / Published online: 2 April 2011 # Springer
Apr 01, 2017· Selenium (Se) removal from synthetic solutions and from real Flue Gas Desulfurization (FGD) wastewater generated by a coal-fired power plant was studied for the first time using a commercial iron oxide impregnated strong base anion exchange resin, Purolite® FerrIX A33E.
Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product. After treatment, the treated industrial wastewater (or effluent) may be reused or released to a sanitary sewer or to a surface water in the environment.. Most industries produce some wastewater.Recent trends have been to minimize such production or
Feb 24, 2007· Selenium finds extensive application in the manufacture of photocells, rectifiers, xerography equipment, paint, glass and insecticides. Selenium concentration in industrial effluents may vary from 1 to 7000 μg/L. This paper reviews various treatment technologies for the removal of selenium from water and wastewater such as sedimentation
REMOVAL OF SELENIUM FROM WASTEWATER USING ZVI AND HYBRID ZVI/IRON OXIDE PROCESS . A Thesis . by . ZHEN YANG . Submitted to the Office of Graduate Studies of . Texas A&M University . in partial fulfillment of the requirements for the degree of . MASTER OF SCIENCE . Approved by: Chair of Committee, Yongheng Huang. Committee Members, Binayak
Selenium (VI) removal to ppb level Much more difficult than Se (IV) FGD effluents have complex / variable matrices adaptation of the biomass does take time however biological treatment using MBBR is a viable treatment solution potential for combining with SeleniumZero
Novel Approach for Removing Selenium from Phillips 66 Ponca City, OK Refinery Effluent AFPM, Oct 19, 2015 3 Fe(OH)3, while selenate is difficult to remove with
Effluents of sour water strippers are difficult to treat for selenium removal because of the unpredictable nature and unpredictable quantities of contaminants that are present in the effluents. These contaminants often hinder irreversibly selenium removal processes that use membrane, ion exchange resins or inorganic adsorbents.
The present study includes two parts: (1) Acid mine drainage (AMD) sludge, a waste product from coal mine water treatment, was used as an adsorbent to develop a cost-effective treatment approach to phosphorus removal from municipal secondary effluents. (2) Synthesized nano-magnetite was used as an adsorbent to develop an innovative technology for selenium removal from aqueous solutions.
1 Start-Up of a Passive Remediation Bioreactor for Sulfate and Selenium Removal from Mine Tailings Water Susan Baldwin1, Parissa Mirjafari1, Maryam Rezahdebashi1, Gaurav Subedi1, Jon Taylor1, Luke Moger2, Katie McMahen2 and Art Frye2 1. Chemical and Biological Engineering, University of British Columbia, Canada
Selenium Removal by Constructed Wetlands: Role of Biological Volatilization DREW HANSEN, PETER J. DUDA, ADEL ZAYED, AND NORMAN TERRY* Department of Plant and Microbial Biology, University of California, Berkeley, California 94720-3102 Selenium-laden effluents from oil refineries are polluting San Francisco Bay, California. One environmentally
removal of residual mill organics; O A two-stage EBR system each with a 6 -hour HRT to remove the total selenium and other metals; O An anaerobic post-treatment system with a 6-hour HRT to polish the EBR system effluents and remove the residual nutrients prior to discharge; and O A 24-hour holding pond prior to discharge site specified.
3.3. Removal of selenium (Se) from smelter effluents Selenium is often present in effluents from zinc hydrometallurgy circuits. Various microorganisms have been found to be effective in the reduction of selenium oxyanions to elemental selenium. McCready et al. (1990) studied the removal of selenium
material will passivate through generation of iron oxide surface layers, reducing the selenium removal efficiency. In addition, the kinetics of selenate removal using iron-based sorbents is slow. Generally, sorbent materials have to be in contact with selenium containing water for a long time (2-12 hours) in order to remove selenium effectively.
Selenium compounds present in aqueous liquids containing sulfate and or chloride anions can be effectively removed by passing the liquid through a thiouronium modified anion ion exchange resin.
concentrations in EBR effluents ranged from 0.5 µg/L to 1.4 µg/L, while reducing sulfate concentrations. The test data demonstrate that the EBR technology is an effective Se removal option for British Columbias coal-mining wastewaters. Introduction Selenium in Mining Selenium (Se) is
cost-effective treatment approach to phosphorus removal from municipal secondary effluents. (2) Synthesized nano-magnetite was used as an adsorbent to develop an innovative technology for selenium removal from aqueous solutions. Each case involved a series of batch adsorption experiments conducted to evaluate adsorption kinetics,
Oct 08, 1992· The present invention relates to a process for the removal of selenium from aqueous media. 2. Description of the Prior Art . Selenium is a naturally occurring group VIA element found in rocks and soil with the average concentration in the earth's crust being about 0.7 ppm.
Jan 15, 2016· Biological treatment of mine effluents with MBBR technology is a viable solution to meet stringent discharge limits In combination with SeleniumZero®, complete selenium removal can be achieved, even at very low temperature 24 Conclusions
The removal of selenium from aqueous medium is complex and expensive, because of the high wastewater volumes generated, low discharge limits (even in μg/L) and the presence of Se(IV) and Se(VI) species (Santos et al. 2015).As regulatory limits are becoming stricter, selenium removal from wastewater has become more and more challenging.
The results show that MBBR can be a viable solution for biological selenium removal as well as nitrate removal from FGD and mine effluents. By combining the MBBR with traditional chemical treatment, very low effluent selenium concentrations can be reached.
selenium removal. Selenium removal is accomplished by using a strong base anion ion exchange resin. Selenium (VI) is extracted much more effectively than Se(IV). The extraction of Se(VI) is decreased by sulfate. Tailored resins show good selectivity for selenium in the presence of sulfate but only laboratory studies have been performed.
----- EPA-600/2-80-153 August 1980 SELENIUM REMOVAL FROM GROUND WATER USING ACTUATED ALUMINA BY R. Rhodes Trussell, Albert Trussell and Peter Kreft Oames M. Montgomery, Consulting Engineers, Inc. Pasadena, California 91101 Contract No. 68-03-1515 Project Officer Richard Lauch Drinking Water Research Division Municipal Environmental Research Laboratory Cincinnati,
Jan 15, 2016· Selenium, present in mine effluents as selenate and selenite, has recently become a concern. Selenium is highly toxic to aquatic life and the discharge limitations for total selenium are becoming increasingly stringent. Some discharge criteria for release of mine effluent into fresh water systems have been set to < 4.7 µg/l Total Se.
Amongst the first group it is easy to find processes based on the reduction of selenium ions using reagents such as zero-valent iron (6, 7) or sodium sulfide (8). Although relatively cost-effective techniques, they are extremely dependent on pH and temperature conditions and require vast quantities of non-reusable reactants.
Remove heavy metals from wastewater over a wide pH range Use chemical solutions for soluble and/or particulate heavy metals, such as lead, copper, chromium, iron, manganese, mercury, nickel and zinc Remove selenium with advanced biological treatment
Jan 17, 2014· The results show that MBBR can be a viable solution for biological selenium removal as well as nitrate removal from FGD and mine effluents. By combining the MBBR with traditional chemical treatment, very low effluent selenium concentrations can be reached. With so much focus on the selenium regulations, having a biological solution offers
The ratio of outflow to inflow selenium concentration ranged from 0.25 to 0.68 (a small ratio indicates high selenium removal). The ratio of outflow to inflow selenium
pollutants such as selenium, boron, and magnesium, are present mostly in soluble form and are not effectively and reliably removed by wastewater settling ponds. For metals present in both soluble and particulate forms (such as mercury), the settling pond will not effectively remove the dissolved fraction.
Processes for treating aqueous solutions to remove dissolved selenium species, for example in the presence of an excess of sulphate anions, which include the use of strongly basic anion exchange resins, or co-precipitation and adsorption of the selenate (and selenite) with mixed ferrous and ferric iron, or combinations thereof. Co-precipitation and adsorption of selenate may take place in an
Describe successful case studies of Se removal applied to aqueous effluents at the commercial or pilot stage, as well as cases of scaling up to full scale for these industry sectors: Power generation Mining and agriculture Oil and gas Treatment is only one of three approaches for selenium removal: Prevention Source
The coprecipitation of selenium (IV) (Se) with iron (III) (Fe) is a widely practiced method for the removal of Se from mineral processing effluents, but the effect of gypsum as a major secondary mineral on the iron-selenium coprecipitation process is still of concern. In our work we first investigated the effects of pH, Fe/Se molar ratio and the neutralizing agent on the removal efficiency of
While existing regulations limit selenium concentrations in water to 50 parts-per-billion, industrial effluents (e.g. flue gas desulfurization, mining wastewater, coal power plants) are often required to achieve levels below 10 parts-per-billion.