Occurrence Of Phonels In Soils Along A Receiving Stream And The Evaluation Of Phytotoxicity Of Chemicals

Environmental pollution and ecological effects of industrial chemicals such asphenols are of great concern in the world, and focusing on this problem, there havebeen developed lots of methods, but mainly developed for aquatic phase rather thanthe soil now. More important, chemical analysis alone is not adequate to assess thepotential ecological impact of contaminated soil considering the complexity of soilenvironment. Therefore, by optimizing the conditions of accelerated solventextraction (ASE) and analysis process of GC-MS, a fast and efficient detectionmethod for different kinds of phenols in soil was propsed in this study, used toanalyze the phenols in soil near to Dagu river in Tianjing. Meanwhile, to evaluate thetoxic effects of industrial chemicals such as phenols, the evaluation targets such asroot elongation of wheat and barley exposing to different concentrations wereinvestigated. The study can provide a scientific basis for the diagnosis ofcontaminated soil and the main conclusions were as follows:1. Established an analysis method for17kinds of phenols in soil. The recoveryrate, the limit of detection and the limit of quantitation were ranged from31.88-124.3%,1.57-4.13μg·L-1and4.99-13.1μg·L-1, respectively. The distribution ofphenols in soil from Tianjing Dagu river were analyzed, and the results showed thatthe total concentration of phenols was0.51-348.08μg·kg-1. The mean concentrationsof phenol and pentachlorophenol were higher than30μg·kg-1. For3-cresol,4-cresoland4-nitrophenol, the mean concentration were higher than10μg·kg-1with a range of0.86-5.53μg·kg-1for2-cresol and other chlorophenols.2. To evaluate the toxic effects of13phenols, six evaluation indicators includingroot elongation, shoot elongation, fresh root weight, dry root weight, fresh shootweight and dry shoot weight of wheat and barley exposing to different concentrationswere investigated. Results showed that:1) The root elongation of wheat and barleywas the most sensitive indicator, and was significantly inhibited with the increasing ofphenols.2) The IC50(half maximal inhibitory concentration of root elongation) valuesof root elongation ranged from12.92to231.76mg·kg-1for wheat and between7.15and478.31mg·kg-1for barley. For pyrocatechol significant inhibition of rootelongation for wheat was observed only under the highest concentration of500 mg·kg-1.3) Wheat was relatively more sensitive to3-cresol,4-chloro-3,5-dimethylphenol, bisphenol A,2-naphthol and nonylphenol, while barley was moresensitive to other phenols. In general, the rank of phenols toxicity on wheat wassimilar to that of barley.3. To evaluate the toxic effects of21industrial chemicals, root elongation andshoot elongation of barley exposing to different concentrations were investigated.Results showed that:1) Shoot elongation was relatively more sensitive tobenzophenone, while root elongation was more sensitive to other chemicals. Ingeneral, the root elongation of barley was significantly inhibited with the increasingof phenols.2) The rank of phytotoxicity of chemicals to barley showed that: forphthalate esters：diethyl phthalate (DEP)> dimethyl phthalate (DMP)> dibutylphthalate (DBP)> butyl benzyl phthalate (BBP); for halogenated flame-retardants:tetrachlorobisphenol A> tetrabromobisphenol A; for tannery chemicals: thioureadioxide> sodium hypophosphite; for textile auxiliaries:2,4-dinitro-phenol sulfurised> reactive brilliant red KE-3B>4,4’-methylenebis(N,N-dimethylaniline)> directblue71; for ultraviolet absorbe: benzothiazole> benzophenone> benzotriazole>5-methyl-1H-benzotriazole. The toxicity of di-(2-ethylhexyl) phthalate (DEHP),dinoctyl phthalate (DOP), pentacosafluorotridecanoic acid (PFTriDA),perfluorododecanoic acid (PFDoA) and direct blue71were lower, since nosignificantly inhibition of root and shoot elongation of barley was observed at thegiven concentrations of0-1000mg·kg-1.