Intranasal administration of tetrabromobisphenol A bis(2-hydroxyethyl ether) induces neurobehavioral changes in neonatal Sprague Dawley rats

Tetrabromobisphenol A (TBBPA) and its derivatives are now being highly concerned due to their emerging environmental occurrence and deleterious effects on non-target organisms. Considering the potential neurotoxicity of TBBPA derivatives which has been demonstrated in vitro, what could happen in vivo is worthy of being studied. Tetrabromobisphenol A bis(2-hydroxyethyl ether) (TBBPA-BHEE), a representative TBBPA derivative, was selected for a 21-day exposure experiment on neonatal Sprague Dawley (SD) rats through intranasal administration. The neurobehavioral, histopathological changes, and differentially expressed genes based on RNA microarray were investigated to evaluate the neurological effects of this chemical. The results indicated that TBBPA-BHEE exposure significantly compromised the motor co-ordination performance and the locomotor activities (p < 0.05). The neurobehavioral phenotype could be attributed to the obvious histopathological changes in both cerebrum and cerebellum, such as neural cell swelling, microglial activation and proliferation. A total of 911 genes were up-regulated, whereas 433 genes were down-regulated. Gene set enrichment analysis showed multiple signaling pathways, including ubiquitin-mediated proteolysis and wingless-int (Wnt) signaling pathway etc. were involved due to TBBPA-BHEE exposure. The gene ontology enrichment analysis showed the basic cellular function and the neurological processes like synaptic transmission were influenced. The toxicological effects of TBBPA-BHEE observed in this study suggested the potential neuronal threaten from unintended exposure, which would be of great value in the biosafety evaluation of TBBPA derivatives.     

Persistence of fensulfothion in a sandy‐loam soil and uptake by rutabagas,carrots and radishes using microplots

Abstract

Field microplots were treated with 141 and 282 ppm fensulfothion and 37.1 and 74.2 ppm fensulfothion sulfone. These concentrations are equivalent to field treatment rates of 8.48 and 16.96 kg Al/ha, fensulfothion, and 2.23 and 4.47 kg Al/ha, fensulfothion sulfone, respectively, for banded application (10 cm wide, rows 80 cm apart). The half‐lives in a sandy loam soil were 30–39 and 14–23 days, respectively. Fensulfothion sulfone and sulfide were the main derivatives found in fensulfothion treated soil.

The maximum levels of these derivatives were 21.22 and 22.95 ppm, respectively for the 8.48 kg/ha treatment and 33.90 and 42.45 ppm, respectively, for the higher treatment, which occurred between 30–60 days.

Carrots appeared to take up more fensulfothion from soil than rutabagas or radishes. The residue levels at harvest decreased in the order carrot peel > pulp > rutabagas root > peel > pulp. Residue levels of fensulfothion and sulfone in radishes were similar to those found in rutabagas. The ratio sulfoxide/sulfone in rutabagas ranged from 0.4–1.5 and in carrots from 1.7–7.6. This phenomenon is thought to be due to oxidative enzyme systems present in rutabagas. Dimethyl phosphorothioic acid, but not dimethyl phosphoric acid was detected (max. 1.33 ppm) in some rutabagas samples but not in carrots.     

Isolation and Identification of Antialgal Compounds from the Leaves of Vallisneria spiralis L. by Activity-Guided Fractionation (5 pp)

Background, Aims and Scope

Vallisneria spiralis Linn., a common, submerged macrophyte, is widely available in quiet waters of lakes, ponds, marshes and streams in Southeast Asia. V. spiralis plays a significant role not only in decreasing eutrophication of water body for its productivity, but also in inhibiting the growth of blue-green algae? The aim of the paper involves the isolation and identification of allelochemicals from extracts of V. spiralis by activity-guided fractionation and column chromatography.

Methods

Leaves of V. spiralis was washed free of debris, air-dried and refluxed in 95% EtOH. The extract was isolated using column chromatography and fractionation with antialgal activity. Potential allelochemicals were analyzed by high-resolution gas chromatography-mass spectrometry (HRGC-MS).

Results

Two fractions with strong antialgal activity were isolated using column chromatography and activity-guided fractionation from the extract of V. spiralis. 2-Ethyl-3-methylmaleimide, dihydroactinidiolide and 4-oxo-β-Ionone were identified in the first fraction, and 3-hydroxy-5,6-epoxy-β-ionone, loliolide, 6-hydroxy-3-oxo-α-ionone and an unknown compound in the second fraction. They had strong inhibitory effects on Microcystis aeruginosa Kütz.

Discussion

2-Ethyl-3-methylmaleimide is a byproduct of photooxidation of chlorophyll, and five other compounds identified were derivatives of β-carotene. HRGC-MS and derivatization technology were used to identify and confirm their molecular structures. The formula of the unknown compound was C16H19NO4. Metabolites of plant pigments had strong inhibitory activities on growth of algae.

Conclusions

Six compounds had been identified in V. spiralis, among them, 2-ethyl-3-methylmaleimide was the main allelochemical, and derivatives of ionone were also potential allelochemicals.

Recommendations and Perspective

. The results of our research could help us to study further mechanisms of inhibitory effect on algae and develop new potential antialgal substances.     

硫酸铝废渣生产硅酸钠的研究

讨论以硫酸铝废渣经水洗，碱萃取生产硅酸钠的最佳工艺条件，所得硅酸钠产品，符合国家规定．本生产工艺不仅解决了环保问题，还综合利用了资源，具有可观的经济效益．     

Removal of Cinnamic Acid Derivatives from Aqueous Effluents by Fenton and Fenton-like Processes as an Alternative to Direct Biological Treatment

The removal of various phenolic acids (p-coumaric, caffeic and ferulic acids), typically found in wastewaters of agricultural origin, from model effluents by chemical and biological means has been investigated. Chemical oxidation processes comprising hydrogen peroxide and a homogeneous or heterogeneous copper or iron catalyst were employed over a wide range of experimental conditions. Chemical oxidation is capable of removing most of the total organic carbon initially present in the effluent at relatively mild treatment conditions (i.e. reaction times up to 120 min and temperatures up to 80°C), while removal rates generally increase with increasing temperature, H₂O₂ and catalyst concentrations. The anaerobic degradability and toxicity of p-coumaric acid has been assessed using the biochemical methane potential and anaerobic toxicity assay respectively. p-Coumaric acid, at concentrations below about 1 g/L, is not toxic against methanogens and slowly degrades over a period of about 35 days at 35°C. In light of this, chemical oxidation may provide a promising alternative to direct biological treatment for either the partial or complete removal of phenolic acids at reasonable treatment times; the implications for wastewater treatment are discussed.     

氧化石墨烯-零价铁-聚乙二醇-海藻酸钠凝胶球活化过硫酸钠降解水中的偏二甲肼

以海藻酸钠(SA)、聚乙二醇(PEG)、氧化石墨烯(GO)和零价铁(ZVI)为原料制备了氧化石墨烯-零价铁-聚乙二醇-海藻酸钠凝胶球(GZPS),用于活化过硫酸盐(PDS)降解水中的偏二甲肼(UDMH)。对GZPS进行了表征,并优化了GZPS的制备工艺。实验结果表明:对UDMH去除率影响因素的主次顺序为:w(PEG) w(SA)w(GO)w(ZVI);GZPS的最佳制备工艺为SA、PEG、GO、ZVI的质量分数分别为5%,3%,0.3%,2%;在UDMH质量浓度为100mg/L、PDS加入量为4mmol/L、GZPS加入量为60g/L、反应温度为35℃、反应时间为80 min的条件下,UDMH的去除率达85%以上。GZPS活化PDS降解UDMH的反应符合准一级动力学,Fe溶出量仅为Fe-GO-PDS体系的12.7%,重复使用4次后对UDMH的去除率仍在65%以上。     

Decomposition and oxidation of sodium 3,5,6-trichloropyridin-2-ol in sub- and supercritical water

Sodium 3,5,6-trichloropyridin-2-ol (STCP) is a necessary precursor compound for the production of chlorpyrifos and triclopyr, which are extensively used as pesticide and herbicide, respectively. In the process of STCP production, however, large amount of wastewater containing STCP is discharged, which causes increasingly environmental concerns. Therefore, it is of great significance to develop a rapid and effective method for the disposal of containing STCP contaminants. In this work, the thermal decomposition of STCP in sub- and supercritical water was investigated using a continuous tubular reactor. While STCP was stable below 280 °C, it could be effectively decomposed at elevated temperature. FT-IR spectra of the decomposition products indicated that the pyridine ring structure in the STCP molecule was stable even at temperatures up to 400 °C. The decomposition reaction was mainly caused by the substitution of Cl groups in the STCP molecule with OH groups, resulting in polyhydroxylated pyridines as the major decomposition product. Moreover, high pressure favored the substitution reaction. To completely decompose STCP into non-toxic or low toxic compounds, supercritical water oxidation (SCWO) was employed to evaluate the oxidation of STCP using H₂O₂ as an oxidant. It was found that STCP could be completely oxidized to H₂O, CO₂ and corresponding inorganic ammonium salts with an oxidation rate of 99%.     

包埋碳纳米管海藻酸钠凝胶球吸附苯酚的研究

研究了水溶液中碳纳米管及包埋固定于海藻酸钠凝胶球中的碳纳米管吸附苯酚的特性,测定了温度、pH值、转速等因素对吸附的影响,并对吸附剂进行了热脱附再生.绘制了吸附等温线,对吸附机理进行探讨.结果表明,碳纳米管及包埋于海藻酸钠凝胶球中的碳纳米管对苯酚的吸附平衡受pH和转速影响不显著,受温度影响显著,简单的热再生即有很好的再生效果.通过方程拟合,2种吸附剂对苯酚的吸附均符合Langmuir和Freundlich型吸附等温式.     

The use of respirometric measurements to determine the toxicity of textile dyes in aqueous solution and after oxidative decolourisation processes

Selected results from the degradation of reactive-dye hydrolysates after UV irradiation, ozonation and sodium peroxodisulphate (NaPS) treatment are presented. Reactive dyes with representative chromophores and anchor groups were chosen for the research project. Different stages of oxidative decolourisation were examined and determined by water parameters for biological degradation (BOD). The paper focuses on toxicity tests with Pseudomonas putida to consider whether the oxidative treatments result in products with a risk for the environment. Tests were performed with the AQUALYTIC^® Sensomat System, which measures biological oxygen demand (BOD). It was determined that the chosen oxidative treatments had as a rule no bearing on respiration of P. putida. Experiments with hydrolysates after short-term UV irradiation resulted in a slightly increased but not long-lasting toxicity in comparison with treatments with ozone or NaPS. Toxic effects were found in tests with hydrolysates of metalliferous dyes. During oxidative treatment, metals were liberated from the chromophores. This did cause complete inhibition of respiration of P. putida. Dye Blue E, a member of a dye class with chlorotriazine anchor groups, was itself found to be toxic, caused by the reactivity of the anchor group. The hydrolysate is only of minor toxicity.     

钢铁厂冷轧废水污泥中铬回收实验研究

钢铁厂冷轧废水污泥中含有10%以上的铬、20%以上的铁和1.5%以上的锌(均以质量分数计).为了从污泥中回收铬,首先研究了污泥中铬的形态,确定为Cr(Ⅲ);然后以碳酸钠为氧化助剂,将污泥与碳酸钠按一定比例混合后焙烧,再用水浸取.研究了碳酸钠的添加量、焙烧温度和时间、浸取时间和浸取方式对铬回收率的影响.研究表明,每克干污泥中添加0.6 g或以上碳酸钠,在固定床上700 ℃焙烧4 h以上,可实现60%以上的总铬浸出率,残渣为Fe2O3基脱硫剂原料.