Environmental Comparison of Biochar and Activated Carbon for Tertiary Wastewater Treatment

Kyle A. Thompson, Kyle K. Shimabuku, Joshua P. Kearns, Detlef R. U. Knappe, R. Scott Summers, and Sherri M. Cook. “Environmental Comparison of Biochar and Activated Carbon for Tertiary Wastewater Treatment.” Environmental Science & Technology 2016 50 (20), 11253-11262. DOI: 10.1021/acs.est.6b03239

Abstract: Micropollutants in wastewater present environmental and human health challenges. Powdered activated carbon (PAC) can effectively remove organic micropollutants, but PAC production is energy intensive and expensive. Biochar adsorbents can cost less and sequester carbon; however, net benefits depend on biochar production conditions and treatment capabilities. Here, life cycle assessment was used to compare 10 environmental impacts from the production and use of wood biochar, biosolids biochar, and coal-derived PAC to remove sulfamethoxazole from wastewater. Moderate capacity wood biochar had environmental benefits in four categories (smog, global warming, respiratory effects, noncarcinogenics) linked to energy recovery and carbon sequestration, and environmental impacts worse than PAC in two categories (eutrophication, carcinogenics). Low capacity wood biochar had even larger benefits for global warming, respiratory effects, and noncarcinogenics, but exhibited worse impacts than PAC in five categories due to larger biochar dose requirements to reach the treatment objective. Biosolids biochar had the worst relative environmental performance due to energy use for biosolids drying and the need for supplemental adsorbent. Overall, moderate capacity wood biochar is an environmentally superior alternative to coal-based PAC for micropollutant removal from wastewater, and its use can offset a wastewater facility’s carbon footprint.

Effects of biochar and marble mud on mine waste properties to reclaim tailing ponds

M. A. Muñoz, J. G. Guzman, R. Zornoza, F. Moreno, A. Faz, andR. Lal (2016). “Effects of biochar and marble mud on mine waste properties to reclaim tailing ponds.” Land Degradation and Development online ahead of print. DOI: 10.1002/ldr.2521.

Abstract: The effects of biochar addition in improving soil physical properties are not clearly understood in mining tailings. The objective of this study was to determine the effects of 3 different types of biochars, in addition to marble mud (MM) and their mixtures, on the structural stability and water retention of mine wastes in Cartagena, Spain. Biochars were produced at 500 °C from pig manure (PM), cotton (Gossipium hirsutum L.) residues (CR) and municipal solid waste (MSW). Biochars were added to the mine waste along with marble mud and a control (no amendments added). These mixtures were incubated in cores for 90 days (25 °C). PM and CR mixed with MM decreased soil bulk density (from 0.98 g cm-3 to 0.89 and 0.84 g cm-3, respectively). Amendments had no significant effect on total porosity whereas they increased gas diffusion by 100%, except for MSW.Marble mud improved the plant available water from 0.59 to 2.56 cm as its combination with biochars, extremely relevant in water scarce climates. The micropores were likely replaced by mesopores when application of PM, CR, MM and biochars + MM and they improved water retention. Total carbon (TC) and total nitrogen (TN) increased by using biochars and MM and no significant effects were assessed on aggregates. In general, MM mixed with PM and CR derived biochar improved the structural stability and exhibited a strong impact in reclaiming physical quality on mine tailings.

Farms Harvest Cuts in Carbon Dioxide via Soil

Read the full story in Scientific American.

Increasingly more research shows that agricultural practices like cover cropping, no-till farming, composting or even the use of biochar can remove carbon dioxide from the atmosphere through photosynthesis, boosting the organic matter in the soil.

In Colorado, a green fleecing worth millions

Read the full story in High Country News.

At a 2009 conference in Centennial, Colorado, Wayde McKelvy, a former offensive lineman at the University of Northern Colorado stood in front of a room full of potential investors for a green startup called Mantria.

Mantria was building the country’s first “carbon-negative” housing development in rural Tennessee, powered entirely by renewable energy, investors heard. What’s more, it was developing a substance that turned garbage into usable materials and produced something called biochar, a carbon-negative fertilizer made from charcoal.

The company was “on the cusp of revolutionary technology that’s going to change the world,” McKelvy promised, “and you guys can benefit from it by putting money in and getting stinkin’ wealthy.”

McKelvy was the pitchman for a green utopic offered by Mantria’s two founders, Troy Wragg and Amanda Knorr. And if Mantria’s promise sounded too good to be true, that’s because it was: a few months after the conference in Centennial, the Securities and Exchange Commission shut down the company, alleging Mantria had bilked investors out of tens of million of dollars in a widespread ponzi scheme. Now, after years of legal delays, federal prosecutors have indicted McKelvy, Wragg, and Knorr with wire and securities fraud and conspiracy.

Stanford’s Global Climate and Energy Project awards $9.3 million for innovative energy research

The Global Climate and Energy Project (GCEP) at Stanford University has awarded $9.3 million for six new research projects on energy. The funding will be shared by scientists at Stanford and four other universities to develop a suite of promising energy technologies, from a device that extracts power from the night sky to a charcoal-like soil amendment that removes carbon dioxide from the air.

“For more than a decade, GCEP has supported bold ideas for new technologies that significantly reduce greenhouse gas emissions,” said GCEP Director Sally Benson, a professor of energy resources engineering at Stanford. “These six projects are potential game changers that could help transform our global energy system in the future.”

The six awards bring the total number of GCEP-supported research programs to 127 since the project’s launch in 2002. In total, GCEP has awarded $170 million for energy research and other technical activities.

“The projects funded this cycle include a unique mix of energy technologies,” said GCEP management committee member Peter Trelenberg, manager of environmental policy & planning at Exxon Mobil. “These promising research efforts have the potential to open up pathways for applying innovative clean-energy approaches in the future.”

Stanford awards

The following Stanford faculty members will receive funding to develop new techniques for cooling buildings, improving engine efficiency and generating renewable fuels:

Nighttime radiative cooling: Harvesting the darkness of the universe. Researchers will create a device that generates electricity at night by radiating heat into outer space. This passive energy source, which exploits the large temperature difference between space and Earth, could provide nighttime lighting without batteries or other electrical inputs. Investigator: Shanhui Fan, professor, Department of Electrical Engineering.

Use of mixed combustion/electrochemical energy conversion to achieve efficiencies in excess of 70 percent for transportation-scale engines. This project will demonstrate how engines for transportation can be made at efficiencies above 70 percent, exceeding conventional internal combustion engines and fuel cells used today. Investigator: Chris Edwards, professor, Mechanical Engineering.

Electrochemical tuning of electronic structures for highly active electrocatalysts. The goal of this project is to identify efficient, low-cost metal catalysts that can split water into oxygen and clean-burning hydrogen fuel. Researchers will conduct experiments on several promising catalytic materials using lithium to enhance hydrogen production. Investigators: Yi Cui, associate professor, Materials Science and Engineering; Harold Hwang, professor, Applied Physics.

Sustainable fuel production from carbon dioxide and carbon monoxide. The aim of this research is to discover metal catalysts capable of converting carbon dioxide and its byproducts into methanol and other alcohols for use in sustainable fuels and chemicals. Investigators: Professor Jens Nørskov, Associate Professor Thomas Jaramillo and Professor Stacey Bent, Chemical Engineering; Anders Nilsson, professor, SLAC National Accelerator Laboratory.

Negative-emissions awards

In 2012, GCEP conducted a workshop on the feasibility of removing carbon dioxide from the atmosphere. That workshop resulted in a worldwide call for proposals to develop new carbon-negative technologies. Two research teams outside of Stanford will receive funding in this category:

The pyrolysis-bioenergy-biochar pathway to carbon-negative energy. Heating plant material slowly without oxygen – a process called pyrolysis – produces a carbon-rich material called biochar. Researchers will study the production of biochar for use as a soil amendment that stores carbon underground instead of allowing carbon dioxide to re-enter the atmosphere as the plant decomposes. Investigators: David Laird, Bruce Babcock, Robert Brown and Dermot Hayes (Iowa State University); David Zilberman (University of California, Berkeley).

Sustainable transportation energy with net-negative carbon emissions. Researchers will conduct an integrated ecological and engineering systems analysis to identify promising transportation fuels with negative carbon emissions. The project will include field studies of potential grassland resources in the United States. Investigators: Eric Larson, Princeton University; Clarence Lehman and David Tilman, University of Minnesota.

GCEP is an industry partnership that supports innovative research on energy technologies to address the challenge of global climate change by reducing greenhouse gas emissions. The project includes five corporate sponsors: ExxonMobil, GE, Schlumberger, DuPont and Bank of America.


A ‘Third Way’ to Fight Climate Change

Read the full opinion piece in the New York Times.

Two options for dealing with climate change — reducing greenhouse gas emissions through a global agreement, and geoengineering proposals such as injecting sulfur into the stratosphere — tend to dominate current thinking. But there is a “third way” that is almost entirely neglected in political negotiations and public debate. It involves capturing carbon dioxide from the atmosphere and storing it or using it to create things we need. Because of the scale of the climate problem, I believe that in coming decades third-way technologies will become a major focus of activity.

Three recent biochar research articles

“Biochar Supported Nanoscale Iron Particles for the Efficient Removal of Methyl Orange Dye in Aqueous Solutions.” PLOS One, July 23, 2015. http://dx.doi.org/10.1371/journal.pone.0132067.

Abstract: The presence of organic contaminants in industrial effluents is an environmental concern of increasing global importance. One innovative technology for treating contaminated industrial effluents is nanoscale zero-valent iron supported on biochar (nZVI/BC). Based on Transmission Electron Microscopy, X-Ray Diffraction, and Brunauer-Emmett-Teller characterizations, the nZVI was well dispersed on the biochar and aggregation was dramatically reduced. Methyl orange (MO) served as the representative organic contaminant for verifying the effectiveness of the composite. Using decolorization efficiency as an indicator of treatment effectiveness, increasing doses of nZVI/BC yielded progressively better results with 98.51% of MO decolorized by 0.6 g/L of composite at an nZVI/BC mass ratio of 1:5. The superior decolorization efficiency of the nZVI/BC was attributed to the increase in the dispersion and reactivity of nZVI while biochar increasing the contact area with contaminant and the adsorption of composites. Additionally, the buffering function of acid-washed biochar could be in favor of maintaining the reactivity of nZVI. Furthermore, the aging nZVI/BC for 30 day was able to maintain the removal efficiency indicating that the oxidation of nZVI may be delayed in the presence of biochar. Therefore, the composite of nZVI/BC could represent an effective functional material for treating wastewater containing organic dyes in the future.

“Sorption of arsenate onto magnetic iron-manganese (Fe-Mn) biochar composites.” RSC Advances Accepted 28 Jul 2015. http://dx.doi.org/10.1039/C5RA12137J.

Abstract: Bimetal adsorbents attract much attention because of their good sorption ability to arsenate (As(V)). In this work, biochar-supported bimetal adsorbents were prepared through either direct pyrolysis of Fe and Mn ions treated pinewood biomass (FMM) or co-precipitation of Fe and Mn ions onto pinewood biochar (FMB). The two Fe-Mn biochar composites were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDS) analyses. Characterization results suggest that maghemite (γ-Fe2O3) and manganosite (MnO) are dominant metal crystals in FMM, while manganese ferrite (MnFe2O4) is the dominant bimetal crystal in FMB. Batch sorption experiments showed that maximal As(V) sorption of FMB and FMM were 3.44 and 0.50 g kg-1 respectively, which were higher than that of the unmodified biochar. As(V) sorption by FMM and FMB decreased with increasing solution pH (between 3-9). Results of this work suggest that co-precipitation is more effective in preparing magnetic Fe-Mn biochar composites for As(V) removal.

“The effect of paper sludge and biochar addition on brown peat and coir based growing media properties.” Scientia Horticulturae 193, 225–230. http://dx.doi.org/10.1016/j.scienta.2015.07.032.

Abstract: Peatlands are crucial sinks for carbon in the terrestrial ecosystem, but they are jeopardized by their use as fuel or as growing media. Much research has been performed aiming to find high quality and low cost substrates from different organic wastes, such as coir, compost, sewage or paper sludges, and thus decrease peat consumption. The main objective of this work is to study the effect on peat and coir-based growing media of deinking sludge (R) and biochar obtained by pyrolysis of deinking sludge at 300 °C (B300). For this reason, mixtures of peat or coir with deinking sludge and corresponding biochar were prepared mixing them at 50/50 v/v ratios. The results showed that it is possible to improve the chemical and hydrophysical properties of peat and coir with addition of biochar and deinking sludge. Indeed, biochar increased air space, water holding capacity and total porosity of peat-based growing media whereas for coir, the best hydrophysical properties were obtained after deinking sludge addition. Finally, the use of biochar plus peat as growing media can increase lettuce yield by more than 100% with respect to peat growing media, which can be related with the improvement of hydrophysical growing media properties. This yield increment along with the reduction of the over-exploitation of peat can justify the use of biochar as growing media in spite of the cost associated to the pyrolysis process.