scholarly journals The identification of heavy metal accumulator ferns in abandoned mines in the Philippines with applications to mine rehabilitation and metal recovery

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Rene Juna R. Claveria ◽  
Teresita R. Perez ◽  
Ian A. Navarrete ◽  
Rubee Ellaine C. Perez ◽  
Brian Christian C. Lim
Keyword(s):  
Heavy Metal ◽  
The Philippines ◽  
Metal Recovery ◽  
Abandoned Mines ◽  
Mine Rehabilitation

Thermal stability and heavy metal (As5+, Cu2+, Ni2+, Pb2+ and Zn2+) ions uptake of the natural zeolites from the Philippines

2019 ◽  
Vol 6 (8) ◽  
pp. 085204 ◽  
Author(s):  
Eleanor Olegario ◽  
Christian Mark Pelicano ◽  
Jenichi Clairvaux Felizco ◽  
Herman Mendoza
Keyword(s):  
Thermal Stability ◽  
Heavy Metal ◽  
The Philippines ◽  
Natural Zeolites

Adsorptive catalysis of hierarchical porous heteroatom-doped biomass: from recovered heavy metal to efficient pollutant decontamination

2018 ◽  
Vol 6 (34) ◽  
pp. 16690-16698 ◽  
Author(s):  
Jing Wang ◽  
Qingfeng Yang ◽  
Weixia Yang ◽  
Hanna Pei ◽  
Liang Zhang ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Selective Adsorption ◽  
Metal Recovery ◽  
Hierarchical Porous ◽  
Recovery And Reuse

Hierarchical porous heteroatom-doped biomass integrates enhanced selective adsorption for heavy metal recovery and reuse in catalytic pollutant decontamination.

scholarly journals The Borax Method of Gold Extraction for Small-Scale Miners

2012 ◽  
Vol 2 (3) ◽  
pp. 5-10 ◽  
Author(s):  
Peter W.U. Appel ◽  
Leoncio Na-Oy
Keyword(s):  
Heavy Metal ◽  
Melting Point ◽  
Scientific Research ◽  
The Philippines ◽  
Toxic Element ◽  
Heavy Mineral ◽  
Small Scale ◽  
Gold Extraction ◽  
Reducing Costs ◽  
Capture Rates

Background. More than ten million small-scale miners (SSM) worldwide use mercury to extract gold, releasing large amounts of the toxic element into the environment. Alternatives to mercury have been suggested over the years to little avail. A group of miners in the Philippines has demonstrated that borax, when used as a flux for smelting gold out of heavy mineral concentrates, is an effective and safer substitute for mercury. Objectives. To present a basic comparison of the mercury amalgamation and borax methods of gold extraction for SSM. Methods. Borax was added to milled ore to reduce the melting point of gold to a level accessible to SSM. The amount of gold captured, and the amount of mercury released into the environment, was compared to two common amalgamation methods: whole ore and heavy metal. Discussion. The borax method appears to capture more gold, as well as eliminate the use of mercury. It is also less expensive. It is important to stop the use of mercury amongst SSM. However, health and environmental arguments alone are not enough to convince miners to switch. The argument of improving gold-capture rates while reducing costs is more compelling, and may help propagate the technique among small-scale miners. Conclusions. Scientific research should continue in order to further establish the uses and limitations of the borax method.

scholarly journals Heavy metal contamination of soils from abandoned mines: The case of Aouli-Mibladen-Zeïda mines in Morocco

2014 ◽  
Vol 23 (3) ◽  
pp. 213-219 ◽  
Author(s):  
Moulay Laârabi El Hachimi ◽  
Mohamed Fekhaoui ◽  
Abdellah El Abidi ◽  
Ali Rhoujatti
Keyword(s):  
Heavy Metal ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Abandoned Mines ◽  
Contamination Of Soils

Levels and Potential Sources of Heavy Metals in Major Irrigated Rice Areas of the Philippines

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Jehru C. Magahud ◽  
Rodrigo B. Badayos ◽  
Pearl B. Sanchez ◽  
Pompe C. Sta. Cruz
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Irrigation Water ◽  
The Philippines ◽  
Rice Soils ◽  
Rice Plants ◽  
Metal Levels ◽  
Farm Inputs ◽  
Soil Metal ◽  
Very High

Industrialization, urbanization and intensive use of farm inputs can pollute agricultural areas. The study was then conducted to assess the levels of chromium (Cr), nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), arsenic (As), molybdenum (Mo), cadmium (Cd), mercury (Hg), and lead (Pb) in the country’s major rice areas. The study also determined the contributions of soil properties, land uses, irrigation water, and farm inputs to the metal levels. Strategic collections of soil, plant and water samples in the country’s major soil series planted to rice, analyses of samples using x-ray fluorescence or atomic absorption spectroscopy, and farmer interviews were done. Metal levels were very high in Zambales and Negros Occidental soils due to deposition or use of metal-enriched mine tailings and irrigation water. Soil metal concentrations in Zambales far exceeded the intervention values of 180 mg/kg for Cr and 100 mg/kg for Ni. Soil metal levels in Negros Occidental exceeded the intervention value of 190 mg/kg for Cu and Mo. Rice plants in Negros Occidental exceeded the toxic levels of 30 mg/kg for Cu and 10-50 mg/kg for Mo due to the very high soil Cu and Mo concentrations in the area. Molybdenum concentrations of rice plants in Sultan Kudarat and Camarines Sur exceeded the toxic level due to the high amounts of foliar chemicals applied at >66 sprayer loads per year. The study implies that rice areas deposited with mine wastes have high heavy metal levels, and foliar chemicals can increase metal levels in rice.   Keywords - Environmental toxicology, heavy metals, heavy metal sources, rice soils, Philippines

Biological treatment of heavy metals in acid mine drainage using sulfate reducing bioreactors

2006 ◽  
Vol 54 (2) ◽  
pp. 179-185 ◽  
Author(s):  
R. Sierra-Alvarez ◽  
S. Karri ◽  
S. Freeman ◽  
J.A. Field
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Acid Mine Drainage ◽  
Biological Treatment ◽  
Mine Drainage ◽  
Metal Removal ◽  
Abandoned Mines ◽  
Synthetic Wastewater ◽  
Sulfate Reducing ◽  
Acid Mine

The uncontrolled release of acid mine drainage (AMD) from abandoned mines and tailing piles threatens water resources in many sites worldwide. AMD introduces elevated concentrations of sulfate ions and dissolved heavy metals as well as high acidity levels to groundwater and receiving surface water. Anaerobic biological processes relying on the activity of sulfate reducing bacteria are being considered for the treatment of AMD and other heavy metal containing effluents. Biogenic sulfides form insoluble complexes with heavy metals resulting in their precipitation. The objective of this study was to investigate the remediation of AMD in sulfate reducing bioreactors inoculated with anaerobic granular sludge and fed with an influent containing ethanol. Biological treatment of an acidic (pH 4.0) synthetic AMD containing high concentrations of heavy metals (100 mg Cu2+l−1; 10 mg Ni2+l−1, 10 mg Zn2+l−1) increased the effluent pH level to 7.0–7.2 and resulted in metal removal efficiencies exceeding 99.2%. The highest metal precipitation rates attained for Cu, Ni and Zn averaged 92.5, 14.6 and 15.8 mg metal l−1 of reactor d−1. The results of this work demonstrate that an ethanol-fed sulfidogenic reactor was highly effective to remove heavy metal contamination and neutralized the acidity of the synthetic wastewater.

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