Effects of humic acids and microorganisms on decabromodiphenyl ether, 4,4′-dibromodiphenyl ether and anthracene transportation in soil

Abstract

In this study, effects of humic acids (HA) and microorganisms on the migration of hydrophobic organic contaminants (HOCs), decabromodiphenyl ether (BDE-209), 4,4′-dibromodiphenyl ether (BDE-15) and anthracene, in soils were examined. More soil particles were dispersed into the colloidal phase (0.22-1 m) in the presence of HA and/or microorganisms as a result of increased erosion and friction. The study suggested that PBDEs (BDE-209 and BDE-15) and anthracene in soils would be transported to other places by soil colloids with surface and underground water flow given the high concentrations of HA and microorganisms in the natural environment.

Response to the Letter from Biesemeier et al.

“…So in our papers Zhang et al, 2011) the purity of BDE-209 was given as >98%. Additionally, we also noted that the purity of >98% BDE-209 in this commercial product has also been reported by other researchers (Deng et al, 2011;Yu et al, 2010). During our sample preparation the photolytically induced debromination of BDE-209 was avoided by some precautions such as that the samples were covered with aluminum foil and kept in the dark place when the samples were temporarily stored.…”

Response to comment on “Characterization of maternal transfer of decabromodiphenyl ether (BDE-209) administered to pregnant Sprague-Dawley rats” by Biesemeier et al.

“…So in our article the purity of BDE-209 was given as >98% [2]. In addition, we also noted that the purity of >98% BDE-209 in this commercial product has also been reported by other researchers [3,4].…”

Transport behaviors of humic acid, kaolin and kaolin–humic acid compound colloids on naphthalene in floating islands with biofilmed fillers

“…Influent tank (ng) 300.3 ± 2.3 300.2 ± 1.8 300.5 ± 2.1 0.0-50.0-cm island (ng) 618.9 ± 7.5 666.9 ± 7.1 679.7 ± 6.6 Effluent tank (ng) 158.9 ± 4.3 112.1 ± 3.8 99.7 ± 4.8 Sum (ng) 1078.1 ± 8.9 1079.2 ± 8.3 1079.9 ± 8.4 Initial addition (ng) 1080.2 ± 3.2 1080.7 ± 2.4 1080.2 ± 2.7 Sum/initial addition (%) 99.8 ± 0.4 99.9 ± 0.7 99.8 ± 0.6 in Table 4. It was indicated that naphthalene in complexes would undergo both the chemo-and bio-chemo-degradation and evaporation into the atmosphere because of the values of the log K OW and log K OC of naphthalene by nature (Yu et al 2010;Simarro et al 2011;Rao et al 2014).…”

“…It was known that the results of colloid transport behaviors in waters were not much clearer due to the complex constituents and structures (Yu et al 2010;Alem et al 2015). Naphthalene behaviors in waters were less detailed because of its properties by nature.…”

“…The first 0-cm to 30-cm areas in floating islands could be subdivided into the 0-cm to 20-cm areas where the significant changes of both the colloids and the naphthalene were appeared and paid much close attention, whereas the variables of those in 20-cm to 30-cm areas were not obvious. With the help of both humic acid supplying the organic carbons and kaolin engendering the hydration shells of silicon dioxide as well as absorbing the coagulating metal ions of Fe 3+ and Al 3+ (Yu et al 2010;Jung et al 2014), the biomass on fillers would be rapidly catch the kaolin-humic acid compounded colloids to decrease the naphthalene concentrations in waters at present of the first 0-cm to 20-cm areas in floating islands (kaolin-humic acid compounded colloids in Fig. 4).…”