THE DIFFERENT FACES OF BIOCHAR: CONTAMINATION RISK VERSUS REMEDIATION TOOL

This article reviews the different aspects of biochar as source and sink of organic and inorganic contaminants. Biochar can contain organic contaminants such as polycyclic aromatic hydrocarbons or heavy metals. As the distribution coefficients of the biochar especially for contaminants are high, the freely dissolved concentrations are low and with that also the bioavailability. The link between biochar’s inherent contaminants and toxicity to soil meso– and macro–fauna remains unclear, with data being often contradictory and influenced by feedstock and pyrolysis conditions. The biochar’s potential to remediate contaminated soils has mainly been addressed in lab studies, but rarely in the field. This far, results have been contradicting. Many studies reported successful immobilization of contaminants but some not. In summary, the ambivalent face of the biochar with regard to contaminants prevails. In future, long term field studies are needed to properly address the sustainability of biochar in this respect.

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Variation in soil aggregate–size distribution affects the dissipation of polycyclic aromatic hydrocarbons in long-term field-contaminated soils

Environmental Science and Pollution Research ◽

10.1007/s11356-017-9919-z ◽

2017 ◽

Vol 24 (28) ◽

pp. 22332-22339 ◽

Cited By ~ 1

Author(s):

Ran Wei ◽

Jinzhi Ni ◽

Weifeng Chen ◽

Yusheng Yang

Keyword(s):

Polycyclic Aromatic Hydrocarbons ◽

Size Distribution ◽

Aromatic Hydrocarbons ◽

Contaminated Soils ◽

Aggregate Size ◽

Soil Aggregate ◽

Aggregate Size Distribution ◽

Polycyclic Aromatic ◽

Term Field

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Dissipation and phytoremediation of polycyclic aromatic hydrocarbons in freshly spiked and long-term field-contaminated soils

Environmental Science and Pollution Research ◽

10.1007/s11356-017-8459-x ◽

2017 ◽

Vol 24 (9) ◽

pp. 7994-8003 ◽

Cited By ~ 9

Author(s):

Ran Wei ◽

Jinzhi Ni ◽

Xiaoyan Li ◽

Weifeng Chen ◽

Yusheng Yang

Keyword(s):

Polycyclic Aromatic Hydrocarbons ◽

Aromatic Hydrocarbons ◽

Contaminated Soils ◽

Polycyclic Aromatic ◽

Term Field

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Bioremediation of Heavy Metals and Organic Toxicants by Composting

The Scientific World JOURNAL ◽

10.1100/tsw.2002.91 ◽

2002 ◽

Vol 2 ◽

pp. 407-420 ◽

Cited By ~ 67

Author(s):

Allen V. Barker ◽

Gretchen M. Bryson

Keyword(s):

Organic Matter ◽

Aromatic Hydrocarbons ◽

Organic Contaminants ◽

Contaminated Soils ◽

Native Plants ◽

Organic Complexes ◽

Soils And Sediments ◽

Polycyclic Aromatic ◽

By Products ◽

Metallic Pollutants

Hazardous organic and metallic residues or by-products can enter into plants, soils, and sediments from processes associated with domestic, municipal, agricultural, industrial, and military activities. Handling, ingestion, application to land or other distributions of the contaminated materials into the environment might render harm to humans, livestock, wildlife, crops, or native plants. Considerable remediation of the hazardous wastes or contaminated plants, soils, and sediments can be accomplished by composting. High microbial diversity and activity during composting, due to the abundance of substrates in feedstocks, promotes degradation of xenobiotic organic compounds, such as pesticides, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). For composting of contaminated soils, noncontaminated organic matter should be cocomposted with the soils. Metallic pollutants are not degraded during composting but may be converted into organic combinations that have less bioavailability than mineral combinations of the metals. Degradation of organic contaminants in soils is facilitated by addition of composted or raw organic matter, thereby increasing the substrate levels for cometabolism of the contaminants. Similar to the composting of soils in vessels or piles, the on-site addition of organic matter to soils (sheet composting) accelerates degradation of organic pollutants and binds metallic pollutants. Recalcitrant materials, such as organochlorines, may not undergo degradation in composts or in soils, and the effects of forming organic complexes with metallic pollutants may be nonpermanent or short lived. The general conclusion is, however, that composting degrades or binds pollutants to innocuous levels or into innocuous compounds in the finished product.

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