Direct Treatment of an Acidic and High-Strength Nitrate-Polluted Wastewater Containing Heavy Metals by Using a Bio-electrochemical Reactor

2008 ◽  
Vol 13 (5-6) ◽  
pp. 627-638 ◽  
Author(s):  
Tomohide Watanabe ◽  
Hong-Wei Jin ◽  
Kyung-Jin Cho ◽  
Masao Kuroda
Keyword(s):  
Heavy Metals ◽  
High Strength ◽  
Electrochemical Reactor ◽  
Direct Treatment ◽  
Polluted Wastewater

Application of a bio-electrochemical reactor process to direct treatment of metal pickling wastewater containing heavy metals and high strength nitrate

2004 ◽  
Vol 50 (8) ◽  
pp. 111-118 ◽  
Author(s):  
T. Watanabe ◽  
H.W. Jin ◽  
K.J. Cho ◽  
M. Kuroda
Keyword(s):  
Heavy Metals ◽  
Electric Current ◽  
Ph Value ◽  
Electrochemical Reactor ◽  
Hydrogen Gas ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Carbon Anode ◽  
Lead Removal ◽  
Direct Treatment

The fundamental performance of a bio-electrochemical reactor for the direct treatment of metal ickling wastewater was investigated experimentally. In the reactor, carbon anode and cathode were installed. On the cathode, denitrifying microorganisms were immobilized. Continuous experiments were carried out by feeding a synthetic wastewater containing nitrate and binary heavy metal ions, copper and lead, under different operating conditions. Acetate as well as the electric current was supplied at the minimum amount for stoichiometry of the dissimilatory denitrification reaction. The results indicated that the dissolved copper and lead removal, denitrification and neutralization could be achieved simultaneously in a single bio-electrochemical reactor. The dissolved heavy metals were removed by electrochemical deposition on cathode and by the other phenomena such as the formation of insoluble suspensions and the sorption on suspended bacterial sludge. Denitrification proceeded effectively with the utilization of both added acetate and hydrogen gas generated by electrolysis of water. The pH value increased up to around neutral due to the occurrence of denitrification in the reactor, although the influent pH was less than 3. The removal efficiencies of heavy metals and nitrate increased with increasing the current density. The applied electric current was indispensable for sustaining the stable treatment in the reactor.

Partitioning of heavy metals in sub-surface flow treatment wetlands receiving high-strength wastewater

2013 ◽  
Vol 68 (2) ◽  
pp. 486-493 ◽  
Author(s):  
Ewa Wojciechowska ◽  
Magdalena Gajewska
Keyword(s):  
Heavy Metals ◽  
Metal Removal ◽  
High Strength ◽  
Pilot Scale ◽  
Surface Flow ◽  
Treatment Wetlands ◽  
Treated Wastewater ◽  
Upward Movement ◽  
Below Ground ◽  
Co Precipitation

The retention of heavy metals at two pilot-scale treatment wetlands (TWs), consisting of two vertical flow beds (VSSF) followed by a horizontal flow bed (HSSF) was studied. The TWs received high-strength wastewater: reject waters from sewage sludge centrifugation (RW) and landfill leachate (LL). The concentrations of the metals Fe, Mn, Zn, Al, Pb, Cu, Cd, Co, and Ni were measured in treated wastewater, substrate of the beds and in plant material harvested from the beds (separately in above ground (ABG) parts and below ground (BG) parts). The TWs differed in metals retention. In the RW treating TW the metal removal efficiencies varied from 27% for Pb to over 97% for Fe and Al. In the LL treating system the concentrations of most metals decreased after VSSF-1 and VSSF-2 beds; however, in the outflow from the last (HSSF) bed, the concentrations of metals (apart from Al) increased again, probably due to the anaerobic conditions at the bed. A major removal pathway was sedimentation and adsorption onto soil substrate as well as precipitation and co-precipitation. In the LL treating facility the plants contained substantially higher metal concentrations in BG parts, while the upward movement of metals was restricted. In the RW treating facility the BG/ABG ratios were lower, indicating that metals were transported to shoots.

High-Strength Solidification of Fly Ash/Carbide Slag and Its Fixing Ability for Heavy Metals

2017 ◽  
Vol 14 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Huiping Song ◽  
Lifang Wei ◽  
Yinglu Ji ◽  
Fangqin Cheng
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
High Strength ◽  
Carbide Slag

Effects of sorption, sulphate reduction, and Phragmites australis on the removal of heavy metals in subsurface flow constructed wetland microcosms

2007 ◽  
Vol 56 (3) ◽  
pp. 193-198 ◽  
Author(s):  
E. Lesage ◽  
D.P.L. Rousseau ◽  
A. Van de Moortel ◽  
F.M.G. Tack ◽  
N. De Pauw ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Phragmites Australis ◽  
Constructed Wetland ◽  
Metal Removal ◽  
Subsurface Flow ◽  
High Strength ◽  
Sulphate Reduction ◽  
Separate Experiment ◽  
Subsurface Flow Constructed Wetland ◽  
Removal Of Heavy Metals

The removal of Co, Ni, Cu and Zn from synthetic industrial wastewater was studied in subsurface flow constructed wetland microcosms filled with gravel or a gravel/straw mixture. Half of the microcosms were planted with Phragmites australis and half were left unplanted. All microcosms received low-strength wastewater (1 mg L−1 of Co, Ni, and Zn, 0.5 mg L−1 Cu, 2,000 mg L−1 SO4) during seven 14-day incubation batches. The pore water was regularly monitored at two depths for heavy metals, sulphate, organic carbon and redox potential. Sorption properties of gravel and straw were assessed in a separate experiment. A second series of seven incubation batches with high-strength wastewater (10 mg L−1 of each metal, 2,000 mg L−1 SO4) was then applied to saturate the substrate. Glucose was added to the gravel microcosms together with the high-strength wastewater. Sorption processes were responsible for metal removal during start-up, with the highest removal efficiencies in the gravel microcosms. The lower initial efficiencies in the gravel/straw microcosms were presumably caused by the decomposition of straw. However, after establishment of anaerobic conditions (Eh∼−200 mV), precipitation as metal sulphides provided an additional removal pathway in the gravel/straw microcosms. The addition of glucose to gravel microcosms enhanced sulphate reduction and metal removal, although Phragmites australis negatively affected these processes in the top-layer of all microcosms.

Research on Function Aggregate Prepared by Steel Wastewater Sludge

2010 ◽  
Vol 168-170 ◽  
pp. 1625-1630
Author(s):  
Qing Jun Ding ◽  
Xiu Lin Huang ◽  
Hua Sun ◽  
Kun Yang
Keyword(s):  
Heavy Metals ◽  
Optimization Design ◽  
High Strength ◽  
Radiation Shielding ◽  
Wastewater Sludge ◽  
Raw Material ◽  
Linear Attenuation Coefficient ◽  
System A ◽  
Zn Content ◽  
Novel Method

Industrial wastewater sludge contains a certain amount of heavy metals, which will cause environmental pollution. In this paper high Cr, Zn content wastewater sludge from steel plant was used as the main raw material, with Kaolin and other materials as adjustment materials. Through optimization design of raw mix composition and firing system, a kind of function aggregate was got, which had an apparent relative density of about 3.0 g/cm3, a vacuum water absorption between 16%~23%, and a linear attenuation coefficient more than 0.15cm-1. Use XRD and SEM to analyze the existence state of heavy metals in aggregates. The novel method for making function aggregates provides a technical support for resource utilization of steel wastewater sludge, which could be applied in the field of high strength concrete and radiation shielding concrete.

scholarly journals Removal of Heavy Metal Ions from Wastewaters: An Application of Sodium Trithiocarbonate and Wastewater Toxicity Assessment

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 655
Author(s):  
Maciej Thomas ◽  
Violetta Kozik ◽  
Andrzej Bąk ◽  
Krzysztof Barbusiński ◽  
Joanna Jazowiecka-Rakus ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Industrial Wastewater ◽  
Brachionus Plicatilis ◽  
Toxicity Assessment ◽  
Optimal Conditions ◽  
Rotifer Brachionus Plicatilis ◽  
Removal Of Heavy Metals ◽  
Central Composite ◽  
Polluted Wastewater

The synthesis and application of sodium trithiocarbonate (Na2CS3) for the treatment of real galvanic wastewater in order to remove heavy metals (Cu, Cd and Zn) was investigated. A Central Composite Design/Response Surface Methodology (CCD/RSM) was employed to optimize the removal of heavy metals from industrial wastewater. Adequacy of approximated data was verified using Analysis of Variance (ANOVA). The calculated coefficients of determination (R2 and R2adj) were 0.9119 and 0.8532, respectively. Application of Na2CS3 conjugated with CCD/RSM allowed Cu, Cd and Zn levels to be decreased and, as a consequence, ∑Cu,Cd,Zn decreased by 99.80%, 97.78%, 99.78%, and 99.69%, respectively, by using Na2CS3 at 533 mg/L and pH 9.7, within 23 min. Implementation of conventional metal precipitation reagents (NaOH, Ca(OH)2 and CaO) at pH 11 within 23 min only decreased ∑Cu,Cd,Zn by 90.84%, 93.97% and 93.71%, respectively. Rotifer Brachionus plicatilis was used to conduct the assessment of wastewater toxicity. Following the application of Na2CS3, after 60 min the mortality of B. plicatilis was reduced from 90% to 25%. Engagement of Na2CS3 under optimal conditions caused the precipitation of heavy metals from the polluted wastewater and significantly decreased wastewater toxicity. In summary, Na2CS3 can be used as an effective heavy metal precipitating agent, especially for Cu, Cd and Zn.

scholarly journals Devising technology for utilizing water treatment waste to produce ceramic building materials

2021 ◽  
Vol 1 (10 (109)) ◽  
pp. 14-22
Author(s):  
Larysa Spasonova ◽  
Іrіna Subota ◽  
Аnastasia Sholom
Keyword(s):  
Heavy Metals ◽  
Water Purification ◽  
Building Materials ◽  
Raw Materials ◽  
Copper Ion ◽  
High Strength ◽  
Ceramic Materials ◽  
Physicochemical Characteristics ◽  
Ceramic Technology ◽  
Ceramic Building

Based on the modern ideas about environmental protection, this paper reports a study into the utilization of water-treated waste from heavy metals (using copper(II) compounds as an example) for the manufacture of ceramic building materials. The examined clay minerals from local deposits and the optimal conditions for their heat treatment (at 1,100 °C) have been proposed for the sorption removal of pollutants of inorganic origin from wastewater. The use of wastewater after its treatment makes it possible to address several tasks at the same time: to protect the environment from pollution by technological wastewater, as well as to reuse wastewater in order to resolve the issue of water scarcity. Ceramic building materials were manufactured based on water purification waste (in the amount of 5 %) and clay raw materials. Their structural-mechanical and physicochemical characteristics have been comprehensively studied. Sintering processes begin at lower temperatures, which is why, with an increase in the annealing temperature to 1,000 °C and higher, their strength rapidly decreases. In the temperature range of 600‒1,100 °C, there are possibilities to apply ceramic technology to immobilize heavy metals in ceramic matrices. The prospect of utilizing water purification waste in the technological process of manufacturing inorganic ceramic materials has been shown. The safety of the building materials, manufactured by leaching pollutants from the ceramic samples using various aggressive environments (leaching to 6.4 %, 0.083 mg·cm2/day) has been investigated. The high strength and degree of the copper ion fixation in the structure of polymineral clay have been confirmed while secondary environmental pollution is almost absent

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