The contents of soil/sediment organic carbon and clay minerals (i.e. montmorillonite, kaolinite, illite, gibbsite and 1.4nm minerals) for 21 natural soil/sediment samples and the sorption of Triton X-100 on these samples were determined. A multi-component statistic analysis was employed to investigate the importance of soil/sediment organic matters andclay minerals on their sorption of Triton X-100. The sorption power of soil/sediment composition for Triton X-100 conforms to an order of montmorillonite>organic carbon>illite>1.4nm minerals (vermiculite+chlorite+1.4nm intergrade mineral)bkaolinite. The sorption of Triton X-100 on a montmorillonite, a kaolinite anda humic acidwere also investigatedandconsistent with the result of multi-component statistic analysis. It is clear that the sorption of Triton X-100 on soils or sediments is the combined contribution of soil/sediment organic matters and clay minerals, which depended on both the contents of soil/sediment organic matters and the types and contents of clay minerals. The important influence of illite on the sorption of nonionic surfactants onto soils/sediments is suggested and demonstrated in this paper. Surfactants for aquifer remediation application may be more efficient for the contaminated soils/sediments that contain little clay minerals with 2:1 structure because of the less sorption of nonionic surfactants on these soils/sediments.

Uptake, accumulation and translocation of phenanthrene and pyrene by 12 plant species grown in various treated soils were comparatively investigated. Plant uptake and accumulation of phenanthrene and pyrene were correlated with their soil concentrations and plant compositions. Root or shoot accumulation of phenanthrene and pyrene in contaminated soils was elevated with the increase of their soil concentrations. Significantly positive correlations were shown between root concentrations or root concentration factors (RCFs) of phenanthrene and pyrene and root lipid contents. The RCFs of phenanthrene and pyrene for plants grown in contaminated soils with initial phenanthrene oncentration of 133 mgkg 1 and pyrene of 172 mgkg 1 were 0.05-0.67 and 0.23-4.44, whereas the shoot concentration factors of these compounds were 0.006-0.12 and 0.004-0.12, respectively. For the same soil-plant treatment, shoot concentrations and concentration factors of phenanthrene and pyrene were generally much lower than root. Translocations of phenanthrene and pyrene from shoots to roots were undetectable. However, transport of these compounds from roots to shoots usually was the major pathway of shoot accumulation. Plant off-take of phenanthrene and pyrene only accounted for less than 0.01% of dissipation enhancement for phenanthrene and 0.24% for pyrene in planted versus unplanted control soils, whereas plant-promoted biodegradation was the predominant contribution of remediation enhancement of soil phenanthrene and pyrene in the presence of vegetation.

enhanced in a linear fashion by each of Triton X-100 (TX100), Triton X-305 (TX305), Brij 35, and sodium dodecyl sulfate (SDS). Solubility enhancement efficiencies of surfactants above the critical micelle concentration (CMC) follow the order of TX100> Brij 35>TX305>SDS. PAHs are solubilized synergistically in mixed anionic-nonionic surfactant solutions, especially at low surfactant concentrations. The synergistic pwer of the mixed surfactants is SDS-TX305>SDS-Brij35>SDS-TX100. Synergistic effect of a given mixed-surfactant solution on different PAHs also appears to be linearly related to the solute logKow. The noted synergism for the mixed surfactants is attributed to the formation of mixed micelles, the lower CMC of the mixedsurfactant solutions, and the increase of the solute s molar solubilization ratio or micellar partition coefficients ðKmcÞ because of the lower polarity of the mixed micelles. Suitable quantity of inorganic cations can enhance the solubilization capacities of anionic–nonionic mixed urfactants, the effect being Mg2+>NH+4>Na+. The water solubility of pyrene was slightly increased by anthracene and significantly increased by 1,2,3-TCB in the presence of SDS-Brij 35. Mixed surfactants may mprove the performance of surfactant-enhanced remediation of soils and sediments by decreasing the applied surfactant level and thus the remediation cost.

Twelve polycyclic aromatic hydrocarbons, multi-ringed compounds known to be carcinogenic in air of six domestic kitchens and four commercial kitchens of China were measured in 1999-2000. The mean concentration of total PAHs in commercial kitchens was 17 lg/m3, consisting mainly of 3-and 4-ring PAHs, and 7.6 lg/m3 in domestic kitchens, where 2-and 3-ring PAHs were predominant, especially naphthalene. The BaP levels in domestic kitchens were 0:0061-0:024 lg/m3 and 0:15-0:44 lg/m3 in commercial kitchens. Conventional Chinese cooking methods were responsible for such heavy PAHs pollution. The comparative study for PAH levels in air during three different cooking practices: boiling, broiling and frying were conducted. It was found that boiling produced the least levels of PAHs. For fish, a low-fat food, frying it produced a larger amount of PAHs compared to broiling practice, except pyrene and anthracene. In commercial kitchens, PAHs came from two sources, cooking practice and oil-fumes, however the cooking practice had a more predominant contribution to PAHs in commercial kitchen air. In domestic kitchens, except for cooking practice and oil-fumes, there were other PAHs sources, such as smoking and other human activities in the domestic houses, where 3-4 ring PAHs mainly came from cooking practice. Naphthalene (NA, 2-ring PAHs) was the most predominant kind, mostly resulting from the evaporation of mothball containing a large quantity of NA, used to prevent clothes against moth. A fingerprint of oil-fumes was the abundance of 3-ring PAHs. Heating at the same temperature, the PAHs concentrations in different oil-fumes were lard>soybean oil>rape-seed oil. An increase in cooking temperature increased the levels of PAHs, especially acenaphthene.

Twelve polycyclic aromatic hydrocarbons were simultaneously measured in indoor and outdoor air of eight homes in Hangzhou, China in both summer and autumn in 1999. It was observed that the sum of PAHs concentrations in indoor air were ranged from 1.418 to 20.466 íg/m3 in summer and from 3.897 to 29.852 íg/m3 in autumn; the corresponding concentrations in outdoor air were between 1.380 and 20.468 íg/m3 in the summer and between 2.721 and 30.678 íg/ m3 in autumn. The PAHs concentrations in indoor air generally exceeded that in the corresponding outdoor air. It was indicated that the two-, three-, and four-ring PAHs were predominantly in vapor phase, while the fivering PAHs were primarily associated with the particulate phase. The fraction of PAHs in vapor phase will increase with the increase of temperature. Among the 12 PAHs, naphthalene was the most abundant PAHs found in indoor and outdoor air. Both in summer and autumn, it contributed more than 60% to the sum of PAHs. Because of the different functions and ventilation conditions, the concentrations of PAHs in the rooms were bedroom> kitchen>living room>balcony. By the contrast of BaP concentrations in smoker and nonsmoker’s homes, we know that smoking in indoors could contribute 67% of BaP to the homes.