title: Suspension stability and aggregation of multi-walled carbon nanotubes as affected by dissolved organic matters extracted from agricultural wastes.
abstract: Dissolved organic matters (DOMs) extracted from wheat straw (SDOM) and cow manure (MDOM) were used to investigate their effects on the suspension stability and aggregation of multi-walled carbon nanotubes (MWCNTs). Two types of DOM can effectively disperse and stabilize the MWCNTs. At initial MWCNT concentration of 500 mg/L, suspended MWCNT concentration ranged from 8.0 to 17.9 mg/L as DOM were varied from 50 to 200 mg/L dissolved organic carbon (DOC). The critical coagulation concentration (CCC) values were estimated to be 41.4 mM NaCl and 5.3 mM CaCl2 in the absence of DOM. The presence of SDOM and MDOM significantly retarded the aggregation rate of MWCNTs. The CCC values increased to 120 mM NaCl and 14.8 mM CaCl2 at SDOM concentration of 20 mg/L DOC. Due to its higher aromaticity and molecular weight, MDOM showed higher ability to stabilize MWCNTs, with CCC values of 201 mM and 15.8 mM at 20 mg/L DOC. These findings revealed that DOMs originated from agricultural wastes will have great impact on the dispersion and stabilization of MWCNTs, thus their fate in the aquatic environment.
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan 250022, China; Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA. Electronic address: ujn_lihl@163.com.
authors.forename: Helian
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan 250022, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan 250022, China.
authors.forename: Xiaonuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan 250022, China.
authors.forename: Wenhao
authors.initials: W
authors.lastname: Liu
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA; Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Fuyang, Zhejiang 311400, China.
authors.forename: Guangcai
authors.initials: G
authors.lastname: Chen
authors.affiliation: School of Resources and Environment, University of Jinan, Jinan 250022, China; National Soil Fertility and Fertilizer Effects Long-term Monitoring Network, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA. Electronic address: bx@umass.edu.
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
mesh_terms: D000383:Agriculture; D000818:Animals; D002417:Cattle; D005260:Female; D008372:Manure; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry* / Q000302:isolation & purification; D013535:Suspensions; D014908:Triticum / Q000737:chemistry*; D014866:Waste Products
chemical_list: D008372:Manure; D037742:Nanotubes, Carbon; D009930:Organic Chemicals; D013535:Suspensions; D014866:Waste Products
keywords: Aggregation; Agricultural waste; Carbon nanotubes; Dissolved organic matter; Suspension