• Journal of environmental and Sanitary engineering
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• v.16 no.3
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• pp.80-86
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• 2001

This research was carried out to investigate the effect of microscopic silica matrix coagulation on heavy metals and anion removal in mining wastewater. pH and alkalinity played an important role to coagulate heavy metals such as Al, and Fe and an anion such as ${SO_4}^{2-}$ with silica matrix as well as NaOH. However, the efficiency to form coagulates was much greater in silica matrix-treated wastewater than NaOH-treated one. Fe in wastewater formed coagulation with both silica matrix and NaOH treatments resulting in lowering Fe content in wastewater at above pH 9. For Al removal in wastewater, silica matrix-treated wastewater at above pH 12.3 formed stable coagulate with Al, while NaOH-treated one did not. Alkalinities of 89 and 220 mg/L were required to stabilize silica matrix treated coagulate with Fe and Al, respectively. Reaction time of ten minute was required to provide enough reaction for coagulation between heavy metals and silica matrix. Heavy metals and anion leachates were much lower in coagulate with silica matrix than that with NaOH, which indicates that silica matrix could be used to remove heavy metals efficiently.

• Resources Recycling
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• v.24 no.4
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• pp.61-66
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• 2015

Cyanidation has been used worldwide to recover gold from primary ore or concentrate. The use of cyanide is however becoming an emerging issue because of the toxic residue and wastewater made from the process. The cyanide-containing wastewater should be treated properly, obeying the environmental standard and regulations. In the present article, the domestic and international uses, regulations, and treatment technologies of cyanide in gold mining were investigated as a feasibility study to develop a cyanide treatment process as well as the cyanidation process. A biological cyanide treatment process to develop a zeroemission gold recovery and wastewater treatment process was also briefly introduced.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.131-138
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• 2014

While coupling wastewater treatment with microalgal bioenergy production is very promising, new approaches are needed to enhance microalgal growth and lipid accumulation in wastewater. Therefore, this study investigated the effect of iron on the growth, nutrient removal, and lipid accumulation of Scenedesmus sp. LX1 in both artificial wastewater and domestic secondary effluents. When increasing the iron concentration from 0 to 2 mg/l in the artificial wastewater, the biomass production of Scenedesmus sp. LX1 increased from 0.17 to 0.54 g/l; the nitrogen and phosphorus removal efficiency increased from 15.7% and 80.6% to 97.0% and 99.2%, respectively; and the lipid content was enhanced 84.2%. The relationship between the carrying capacity/maximal population growth rate of Scenedesmus sp. LX1 and the initial iron concentration were also in accordance with the Monod model. Furthermore, when increasing the iron concentration to 2 mg/l in four different domestic secondary effluent samples, the lipid content and lipid production of Scenedesmus sp. LX1 was improved by 17.4-33.7% and 21.5-41.8%, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.1
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• pp.63-77
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• 2019

Traditional wastewater research mainly focuses on 1) estimating the amount of waste entering sewage treatment facilities, 2) evaluating the treatment efficiency of sewage facilities, 3) investigating the role of sewage treatment effluent as a point source, and 4) designing and managing sewage treatment facilities. However, since wastewater contains a variety of chemical and biological substances due to the discharge of human excreta and material used for daily living into it, the collective constituents of wastewater are likely a reflection of a community's status. Wastewater-based epidemiology (WBE), an emerging and promising field of study that involves the analysis of substances in wastewater, can be applied to monitor the state of a defined community. WBE provides opportunities for exploiting indicators in wastewater to fulfill various objectives. The data analyzed under WBE are those pertaining to selected natural and anthropogenic substances in wastewater that are a result of the discharge of metabolic excreta, illicit or legal drugs, and infectious pathogens into the wastewater. This paper reviews recent progress in WBE and addresses current challenges in the field. It primarily discusses several representative applications including the investigation of drug consumption across different communities and the management of community disease and health. Finally, it summarizes established indicators for WBE.

• Advances in nano research
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• v.5 no.1
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• pp.27-34
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• 2017

One of the methods of removing cyanide from wastewater is surface adsorption. We simulated the removal of cyanide from a synthetic wastewater in the presence of Titanium dioxide nano-particles absorbent uses VISUAL MINTEQ 3.1 software. Our aim was to determine the factors affecting the adsorption of cyanide from synthetic wastewater applying simulation. Synthetic wastewater with a concentration of 100 mg/l of potassium cyanide was used for simulation. The amount of titanium dioxide was 1 g/l under the temperature of $25^{\circ}C$. The simulation was performed using an adsorption model of Freundlich and constant capacitance model. The results of simulation indicated that three factors including pH, nanoparticles of titanium dioxide and the primary concentration of cyanide affect the adsorption level of cyanide. The simulation and experimental results had a good agreement. Also by increasing the pH level of adsorption increases 11 units and then almost did not change. An increase in cyanide concentration, the adsorption level was decreased. In simulation process, rising the concentrations of titanium dioxide nanoparticles to 1 g/l, the rate of adsorption was increased and afterward no any change was observed. In all cases, the coefficient of determination between the experimental data and simulation data was above 0.9.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2192-2197
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• 2005

This paper describes how to diagnose SBR plant equipment using time-series data mining. It shows the equipment diagnostics based upon vibration signals that are acquired from each device for process control. Data transform techniques including two data preprocessing skills and data mining methods were employed in the data analysis. The proposed method is not only suitable for SBR equipment, but is also suitable for other industrial devices. The experimental results performed on a lab-scale SBR plant show a good equipment-management performance.

• 수도
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• v.25 no.1 s.88
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• pp.25-35
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• 1998

Factors controlling water quality, water-quality standards, and normal ranges of concentrations in unpolluted fresh water and the sources of elements were explained in this paper. In particular, the sources of groundwater contamination such as the disposal of domestic waste water, landfills, chemical spills and leaking underground tanks, and agricultural and mining activities were discussed.

• Nuclear Engineering and Technology
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• v.50 no.6
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• pp.886-889
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• 2018

This article presented two-staged chemical precipitation for radioactive wastewater decontamination by using chemical agents. The total amount of radioactive wastewater was $35m^3$, and main radionuclides were Cs-137, Cs-134, and Co-60. Initial radioactivity concentration of the liquid waste was 2264, 17, and 9 Bq/L for Cs-137, Cs-134 and Co-60, respectively. Potassium ferrocyanide, nickel nitrate, and ferrum nitrate were selected as chemical agents at high pH levels 8-10 according to the laboratory jar tests. After the process, radioactivity was precipitated as sludge at the bottom of the tank and decontaminated clean liquid was evaluated depending on discharge limits. By this precipitation method decontamination factors were determined as 66.5, 8.6, and 9 for Cs-137, Cs-134, and Co-60, respectively. By using the potassium ferrocyanide, about 98% of the Cs-137 was removed at pH 9. At the bottom of the tank, radioactive sludge amount from both stages was totally $0.98m^3$. It was transferred by sludge pumps to cementation unit for solidification. By chemical processing, 97.2% of volume reduction was achieved. The potassium ferrocyanide in two-staged precipitation method could be used successfully in large-scale applications for removal of Cs-137, Cs-134, and Co-60.

• Advances in nano research
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• v.15 no.5
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• pp.441-449
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• 2023

Heavy metals, widely present in the environment, have become significant pollutants due to their excessive use in industries and technology. Their non-degradable nature poses a persistent environmental problem, leading to potential acute or chronic poisoning from prolonged exposure. Recent research has focused on separating heavy metals, particularly from industrial and mining sources. Industries such as metal plating, mining operations, tanning, wood and chipboard production, industrial paint and textile manufacturing, as well as oil refining, are major contributors of heavy metals in water sources. Therefore, removing heavy metals from water is crucial, especially for safe water supply in swimming and water sports. Iron oxide nanoparticles have proven to be highly effective adsorbents for water contaminants, and efforts have been made to enhance their efficiency and absorption capabilities through surface modifications. Nanoparticles synthesized using plant extracts can effectively bind with heavy metal ions by modifying the nanoparticle surface with plant components, thereby increasing the efficiency of heavy metal removal. This study focuses on removing lead from industrial wastewater using environmentally friendly, cost-effective iron nanoparticles synthesized with Genovese basil extract. The synthesis of nanoparticles is confirmed through analysis using Transmission Electron Microscope (TEM) and X-ray diffraction, validating their spherical shape and nanometer-scale dimensions. The method used in this study has a low detection limit of 0.031 ppm for measuring lead concentration, making it suitable for ensuring water safety in swimming and water sports.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.2
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• pp.96-100
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• 2002

This study is aimed at prevention and countermeasurements of the mine wastewater pollution caused by a mineralized area using heavy metals. Objective of this study is selected to a high positive ion methathesis capacity of the environmental integrity character materials, as well as applied to the mine wastewater treatments. Also, the environmental integrity character materials is selected Kaolin. Silica, Zeolite, Fly ash. Thus, this environmental integrity character matters will be proved in the reduced heavy metals level and fine water quality of effluent.