Thiocyanate biodegradation: harnessing microbial metabolism for mine remediation

2018 ◽  
Vol 39 (3) ◽  
pp. 157 ◽  
Author(s):  
Mathew P Watts ◽  
John W Moreau
Keyword(s):  
Cost Effective ◽  
Microbial Metabolism ◽  
Biogeochemical Cycles ◽  
Energy Sources ◽  
Coking Wastewater ◽  
Sulfur Species ◽  
Environmentally Sustainable ◽  
Ore Processing ◽  
Mine Remediation ◽  
Reduced Sulfur

Thiocyanate (SCN–) forms in the reaction between cyanide (CN–) and reduced sulfur species, e.g. in gold ore processing and coal-coking wastewater streams, where it is present at millimolar (mM) concentrations1. Thiocyanate is also present naturally at nM to µM concentrations in uncontaminated aquatic environments2. Although less toxic than its precursor CN–, SCN– can harm plants and animals at higher concentrations3, and thus needs to be removed from wastewater streams prior to disposal or reuse. Fortunately, SCN– can be biodegraded by microorganisms as a supply of reduced sulfur and nitrogen for energy sources, in addition to nutrients for growth4. Research into how we can best harness the ability of microbes to degrade SCN– may offer newer, more cost-effective and environmentally sustainable treatment solutions5. By studying biodegradation pathways of SCN– in laboratory and field treatment bioreactor systems, we can also gain fundamental insights into connections across the natural biogeochemical cycles of carbon, sulfur and nitrogen6.

scholarly journals Gasification and Power Generation Characteristics of Rice Husk, Sawdust, and Coconut Shell Using a Fixed-Bed Downdraft Gasifier

2021 ◽  
Vol 13 (4) ◽  
pp. 2027
Author(s):  
Md. Emdadul Hoque ◽  
Fazlur Rashid ◽  
Muhammad Aziz
Keyword(s):  
Rice Husk ◽  
Fixed Bed ◽  
Cost Effective ◽  
Coconut Shell ◽  
Energy Sources ◽  
Airflow Rate ◽  
Gas Generation ◽  
Biomass Feedstocks ◽  
Downdraft Gasifier ◽  
Synthetic Gas

Synthetic gas generated from the gasification of biomass feedstocks is one of the clean and sustainable energy sources. In this work, a fixed-bed downdraft gasifier was used to perform the gasification on a lab-scale of rice husk, sawdust, and coconut shell. The aim of this work is to find and compare the synthetic gas generation characteristics and prospects of sawdust and coconut shell with rice husk. A temperature range of 650–900 °C was used to conduct gasification of these three biomass feedstocks. The feed rate of rice husk, sawdust, and coconut shell was 3–5 kg/h, while the airflow rate was 2–3 m3/h. Experimental results show that the highest generated quantity of methane (vol.%) in synthetic gas was achieved by using coconut shell than sawdust and rice husk. It also shows that hydrogen production was higher in the gasification of coconut shell than sawdust and rice husk. In addition, emission generations in coconut shell gasification are lower than rice husk although emissions of rice husk gasification are even lower than fossil fuel. Rice husk, sawdust, and coconut shell are cost-effective biomass sources in Bangladesh. Therefore, the outcomes of this paper can be used to provide clean and economic energy sources for the near future.

Kazakhstan: Assessment of Renewable Energy Support and a Green Economy

2021 ◽  
Vol 12 (3) ◽  
pp. 631
Author(s):  
Sergey BESPALYY
Keyword(s):  
Economic Growth ◽  
Renewable Energy ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
The State ◽  
Green Economy ◽  
Energy Sources ◽  
Environmentally Sustainable ◽  
The Government ◽  
The Impact

The growth of renewable energy sources (RES) shows the desire of the government of Kazakhstan to meet challenges that affect the welfare and development of the state. National targets, government programs, policies influence renewable energy strategies. In the future, renewable energy technologies will act as sources of a green economy and sustainable economic growth. The state policy in the field of energy in Kazakhstan is aimed at improving the conditions for the development and support of renewable energy sources, amendments are being made to provide for the holding of auctions for new RES projects, which replaces the previously existing system of fixed tariffs. It is expected that the costs of traditional power plants for the purchase of renewable energy will skyrocket, provided that the goals in the field of renewable generation are achieved. This article provides an assessment of international experience in supporting renewable energy sources, as well as analyzes the current situation in the development of renewable energy in Kazakhstan and the impact on sustainable development and popularization of the «green» economy. The study shows that by supporting the development of renewable energy sources, economic growth is possible, which is achieved in an environmentally sustainable way.

Effect of Reduced Sulfur Species on Chemolithoautotrophic Pyrite Oxidation with Nitrate

2018 ◽  
Vol 36 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Ruiwen Yan ◽  
Andreas Kappler ◽  
E. Marie Muehe ◽  
Klaus-Holger Knorr ◽  
Marcus A. Horn ◽  
...  
Keyword(s):  
Pyrite Oxidation ◽  
Sulfur Species ◽  
Reduced Sulfur

scholarly journals Atjaunojamo energoresursu tiesiskuma nodrošinājums

2015 ◽  
Vol 1 (1) ◽  
pp. 55-63
Author(s):  
Kristīne Šeļepova
Keyword(s):  
Renewable Energy ◽  
Power Supply ◽  
Electricity Market ◽  
Renewable Resources ◽  
Renewable Energy Sources ◽  
Cost Effective ◽  
Energy Industry ◽  
Energy Sources ◽  
Power Base ◽  
Investment Priority

Raksta mērķis ir apzināt atjaunojamo energoresursu tiesisko regulējumu, tā atbalsta shēmas un problemātiku. Raksta autore skaidro, vai šo tiesību aizsardzības līmenis ir pietiekams, vai ir pieņemtas nepieciešamās materiālo tiesību normas, kā arī vai ir pietiekoši tiesiskie līdzekļi, kas nodrošina šo tiesību aizsardzības ievērošanu, kā arī nākamos soļus energoresursu liberalizācijas posmos. Use of renewable energy increases independence from imported energy, reduces greenhouse gas emissions, as well as increases security of energy supply. However, energy industry concedes that power becomes more vulnerable because of historical paradigms; independent power base is replaced with production from renewable energy sources. This is due to subsidies in the investment priority being cost-effective renewable resources projects. Thus, it is necessary to develop a solution defining how volatile and unpredictable renewable energy sources integrated into the European electricity market can be, while ensuring safe and uninterrupted power supply.

scholarly journals Biomass Valorization to Produce Porous Carbons: Applications in CO2 Capture and Biogas Upgrading to Biomethane—A Mini-Review

2021 ◽  
Vol 9 ◽  
Author(s):  
Maria Bernardo ◽  
Nuno Lapa ◽  
Isabel Fonseca ◽  
Isabel A. A. C. Esteves
Keyword(s):  
Circular Economy ◽  
Gas Adsorption ◽  
Activated Carbons ◽  
Textural Properties ◽  
Cost Effective ◽  
Attractive Alternative ◽  
Porous Carbons ◽  
Environmentally Sustainable ◽  
Gas Phases ◽  
Metal Organic

Porous carbon materials, derived from biomass wastes and/or as by-products, are considered versatile, economical and environmentally sustainable. Recently, their high adsorption capacity has led to an increased interest in several environmental applications related to separation/purification both in liquid- and gas-phases. Specifically, their use in carbon dioxide (CO2) capture/sequestration has been a hot topic in the framework of gas adsorption applications. Cost effective biomass porous carbons with enhanced textural properties and high CO2 uptakes present themselves as attractive alternative adsorbents with potential to be used in CO2 capture/separation, apart from zeolites, commercial activated carbons and metal-organic frameworks (MOFs). The renewable and sustainable character of the precursor of these bioadsorbents must be highlighted in the context of a circular-economy and emergent renewable energy market to reach the EU climate and energy goals. This mini-review summarizes the current understandings and discussions about the development of porous carbons derived from bio-wastes, focusing their application to capture CO2 and upgrade biogas to biomethane by adsorption-based processes. Biogas is composed by 55–65 v/v% of methane (CH4) mainly in 35–45 v/v% of CO2. The biogas upgraded to bio-CH4 (97%v/v) through an adsorption process yields after proper conditioning to high quality biomethane and replaces natural gas of fossil source. The circular-economy impact of bio-CH4 production is further enhanced by the use of biomass-derived porous carbons employed in the production process.

scholarly journals Electrochemical Evidence of non-Volatile Reduced Sulfur Species in Water-Soluble Fraction of Fine Marine Aerosols

Atmosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 674 ◽  
Author(s):  
Ana Cvitešić Kušan ◽  
Sanja Frka ◽  
Irena Ciglenečki
Keyword(s):  
Natural Waters ◽  
Soluble Fraction ◽  
Mercury Electrode ◽  
Water Soluble ◽  
Organic Carbon Content ◽  
Marine Aerosols ◽  
Sulfur Species ◽  
Water Soluble Fraction ◽  
Enhanced Solubility ◽  
Reduced Sulfur

The traditional voltammetric method at the mercury electrode, and an acidification step developed for the determination of reduced sulfur species (RSS) in natural waters, was for the first time used for the quantification of RSS in the water-soluble fraction of fine marine aerosols collected at the Middle Adriatic location (Rogoznica Lake). The evidence of two types of non-volatile RSS that have different interaction with the Hg electrode was confirmed: mercapto-type which complexes Hg as RS–Hg and sulfide/S0-like compounds which deposits HgS. The analytical protocol that was used for RSS determination in aerosol samples is based on separate voltammetric studies of a methyl 3-mercaptopropionate (3-MPA) as a representative of mercapto-type compounds and sulfide as a representative of inorganic RSS. Our preliminary study indicates the presence of mainly RS–Hg compounds in spring samples, ranging from 2.60–15.40 ng m−3, while both, the mercapto-type (0.48–2.23 ng m−3) and sulfide and/or S0-like compounds (0.02–0.26 ng m−3) were detected in early autumn samples. More expressed and defined RS–Hg peaks recorded in the spring potentially indicate their association with biological activity in the area. Those samples were also characterized by a higher water-soluble organic carbon content and a more abundant surface-active fraction, pointing to enhanced solubility and stabilization of RSS in the aqueous atmospheric phase.

Ceramic Composites for Aerospace Applications

2019 ◽  
Vol 23 ◽  
pp. 31-39
Author(s):  
Bhasha ◽  
Sanjeev Gautam ◽  
Parul Malik ◽  
Purnima Jain
Keyword(s):  
Cost Effective ◽  
Ceramic Composites ◽  
Jet Engines ◽  
Promising Candidate ◽  
Environmentally Sustainable ◽  
Aerospace Applications ◽  
Harmful Emissions ◽  
Temperature Application ◽  
Shock Resistance ◽  
Commercial Aircrafts

Ceramic composites is playing crucial role to accomplish highly efficiently and cost effective equipment for aerospace industry. The instigation of ceramics into aircraft industry is a promising step towards virtuous future. Ceramics has a key role in innovation of highly competent material for space travel which is highly economical and environmentally sustainable. Advancement in making fuel efficient engines are necessity in present scenario due to the harmful emissions releases in the environment by burning of fuel to power up engine. The high temperature application of composites makes it very attractive for aerospace applications. This light weight material has potential to thrust spacecraft upto ten times quicker with the identical fuel consumption, therefore significantly depreciating size of vehicle and increasing travel distance. The implementation of ceramics into jet engines and turbines increase the efficiency of engine due to its lighter weight and better thermal capabilities. A jet engine employing ceramic composites has manifest 15% more fuel saving when compared to the simple nickel based alloys. Hence, ceramic composites can replace nickel based alloys which has been a promising candidate for the engines of commercial aircrafts. Some disadvantages has been also discussed that is brittle failure and limited thermal and shock resistance.

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