SSR addition upgraded VFAs production from WAS.Structure modification by pretreatments led to performance distinctions.Distinctions in microbial community was observed by pretreatments selection.Up to 0.49‒0.65 billion €/year of market value potential was preliminary estimated. Conditioning of extra carbon sources has been widely reported to facilitate fermentation of waste activated sludge (WAS). Soy sauce residue (SSR) was a relatively untapped carbon source for sludge conditioning. This batch study aimed to evaluate the possible implementation of SSR for volatile fatty acids (VFAs) production from WAS. To upgrade the bioavailability of feedstock, three typical pretreatment methods were conducted, i.e., ammonium hydroxide (AH), sulfuric acids (SA) and thermal assisted alkaline (TA). AH pretreated test (AH-PT) outperformed due to a relatively strong structure decomposition of cellulosic materials as revealed by infrared spectroscopic analysis and crystal index. As a result, performed a high hydrolysis rate of 4449 mg COD/d, 1.12-1.23-fold higher than that in TA and SA pretreated tests (TA-PT and SA-PT), and 7.8-fold higher than that in the Control test. Meanwhile, a volatile fatty acids (VFAs) contribution of 401.2 mg COD/g SSR∙L and a maximum acidification rate of 3.59 d-1 was recorded, with a high sum proportion of mall molecular acetic and propionic 82.2%, 11% ‒70% increase over the other three tests. Besides, speciation process characterized with functional genus differentiation was identified by microbial diversity and distribution investigation and canonical correspondence analysis (CCA). Finally, a potential market value of 0.49‒0.65 Billion €/year was preliminary estimated, showing promise of resource recovery from both WAS and SSR instead of extensive disposal. 相似文献
Many studies have focused on environmental estrogen-related diseases. However, no consistent gene markers or signatures for estrogenicity have been discovered in mammals. This study investigated the estrogenic effects of 17β-estradiol on the prostate in immature male mice. Consistent U-shaped responses were seen in bodyweight, ventral prostate epithelial morphology, and miRNA expression levels. Specifically, most estradiol regulated miRNAs were downregulated at low doses of estradiol (0.2 and 2 mg·kg–1), and whose expression returned to the control level at a larger dose (200 mg·kg–1). The function of these regulated miRNAs is related to the prostate cancer and PI3K-Akt signaling pathways, which is consistent with the function of estradiol. Furthermore, the miRNA-processing machinery, Drosha, in the prostate was also regulated in a similar pattern, which could be a part of the U-shaped miRNA expression mechanism. All of these data indicate that the prostate is a reliable organ for evaluating estrogenic activity and that the typical nonmonotonic dose-response relationship could be used as a novel biomarker for estrogenicity.
Volatile organic compounds (VOCs) and carbonyl compounds were measured both indoors and outdoors in 50 residences of Beijing in heating (December, 2011) and non-heating seasons (April/May, 2012). SUMMA canisters for VOCs and diffusive samplers for carbonyl compounds were deployed for 24 h at each site, and 94 compounds were quantified. Formaldehyde, acetone and acetaldehyde were the most abundant carbonyl compounds both indoors and outdoors with indoor median concentrations being 32.1, 21.7 and 15.3 μg·m−3, respectively. Ethane (17.6 μg·m−3), toluene (14.4 μg·m−3), propane (11.2 μg·m−3), ethene (8.40 μg·m−3), n-butane (6.87 μg·m−3), and benzene (5.95 μg·m−3) showed the high median concentrations in indoor air. Dichloromethane, p-dichlorobenzene (p-DCB) and toluene exhibited extremely high levels in some residences, which were related with a number of indoor emission sources. Moreover, isoprene, p-dichlorobenzene and carbonyls showed median indoor/outdoor (I/O) ratios larger than 3, indicating their indoor sources were prevailing. Chlorinated compounds like CFCs were mainly from outdoor sources for their I/O ratios being less than 1. In addition, indoor concentrations between two sampling seasons varied with different compounds. Carbonyl compounds and some chlorinated compounds had higher concentrations in the non-heating season, while alkanes, alkenes, aromatic compounds showed an increase in the heating season. Indoor concentration of VOCs and carbonyls were influenced by locations, interior decorations and indoor activities, however the specific sources for indoor VOCs and carbonyls could not be easily identified. The findings obtained in this study would significantly enhance our understandings on the prevalent and abundant species of VOCs as well as their concentrations and sources in Beijing residences. 相似文献
Understanding the mechanism of arsenic (As) mobilization from sediments to groundwater is important for water quality management
in areas of endemic arsenic poisoning, such as the Datong basin in northern China. The bulk geochemistry analysis of sediment
samples from three 50-m boreholes drilled specifically for this study at As-contaminated aquifers, the groundwaters of which
have an As concentration up to 1060 μg/l, revealed that the average bulk concentrations of major and trace elements of the
samples are similar to those of the average upper continental crust. The average As content of the sediment samples (18.7 mg/kg)
is higher than that of modern unconsolidated sediments (5–10 mg/kg). Moreover, the abundance of elements varied with grain
size, with higher concentrations in finer fractions of the sediments, such as silt and clay. The concentration of NH2OH–HCl-extracted iron (Fe) strongly correlated with that of extracted As, suggesting that Fe oxyhydroxides may be the major
sink of As in the aquifer. The results of microcosm experiments showed that As mobilization from sediments to groundwater
is probably mainly related to changes in the redox conditions, with moderately reducing conditions being favorable for As
release from sediments into groundwater. 相似文献