Radiation removal of synthetic estrogens in aqueous solution:influence of reduction or oxidation system and toxicity test

Estrogens as a kind of steroidal sex hormone are widely used in humans, especially quinestrol(QS),dienestrol(DS) and norethindrone(NET, 19-nor-17-alphaethinltestoster-one), which cannot be completely degraded after application. Steroidal estrogens at low concentration pulling into environment can disturb the normal biological function of wide life and thus lead to great threat to humans. So it is important to explore its degradation mechanism and its behavior in the environment. In this study, we investigated the oxidation or reduction system under gamma irradiation for reducing estrogenic activity in the aqueous solutions as well as degradation kinetics, its by-products and yield of transformation by different analytical methods such as GC–MS and HPLC. Gamma irradiation could effectively degrade estrogens in aqueous solution. The degradation reaction of estrogens could be depicted by first-order reaction kinetics. The total organic carbon of solution decreased with an increasing absorbed dose with the order: quinestrol [ norethindrone [ dienestrol. The toxicity of the three estrogens was declined after irradiation. Mono- and quadric-hydroxylated intermediates as well as organic acids were formed after gamma irradiation.

E-beam radiolysis of aqueous dimethyl phthalate solution

To investigate the influence of radiolysis on kinetics and factors of dimethyl phthalate(DMP),the aqueous DMP solution is degraded by 1.8 MeV E-beam,following pseudo-first-order kinetics.The rate constant of DMP degradation decreased exponentially with increasing initial DMP concentration.The DMP is favorably degraded by radical scavengers under its low concentration and alkaline condition.At high doses,the DMP is attacked by eaq-and ·OH,producing monomethyl phthalate,phthalate acid,and a series of aliphatic carboxylic acids,which are completelymineralized into H2O and CO2.

Distributions of Picophytoplankton and Phytoplankton Pigments Along a Salinity Gradient in the Changjiang River Estuary, China

We investigated the abundance of different picophytoplankton groups and the phytoplankton pigment ratio in relation to environmental factors such as nutrients and suspended solids along a salinity gradient in the Changjiang River Estuary.The average numbers of Synechococcus spp.（Syn） and picoeukaryotes （Euk） were （2.7 ±5.1）×l03 and （1.1±1.4）×l03 cells mL-1,respectively.Prochlorococcus spp.（Pro） was only found in the high-salinity brackish water with the concentration of 3.0× 10^3 cells mL-1.Syn and Euk numbers both tended to increase offshore and Syn showed a larger variation in cell abundance than Euk.The contribution of picophytoplankton to total phytoplankton biomass increased with increasing salinity and decreasing nutrient concentrations from the estuary to the open ocean.The response of different picophytoplankton groups to environmental variables was different.Water temperature was more important in its control over Euk than over Syn,while nutrients were more important in their influence over Syn than over Euk.Phytoplankton pigment ratios were different in the three different ecological zones along the salinity gradient （i.e.,freshwater zone with 0-5 range,fresh and saline water mixing zone with 5-20 range,and high-salinity brackish water zone with 20-32 range）,where three different phytoplankton communities were discovered,suggesting that phytoplankton pigment ratios can be considered as a complementary indicator of phytoplankton community structure in the Changjiang River Estuary.

A decade of variation of COD in the Changjiang River (Yangtze River) and its variation trend analysis

The average annual value of COD (chemical oxygen demand) fluxes of the Changjiang River (Yangtze River) and its main tributaries in the past decade (i.e., 1991–2000), has been evaluated. Based on the data from the Datong Hydrological Station (DHS), it was found that the Dongting Lake drainage basin contributed the greatest water discharge (35.8%) and COD flux (48.3%) among the main tributary drainage basins, followed by the Poyang Lake drainage basin with the contributions of 15.4% and 19.3%,respectively. By the end of the year of 2000, COD flux in the Changjiang River rose by almost 45% relative to that in the year of 1991, reaching about 1941000 ton/a at DHS. Statistical analysis revealed that industrial wastewater discharge, as well as COD in it, was found decreasing in the same period, due to the gradual reinforcement of environmental management. Moreover, correlation analysis indicated that non-point pollution from agriculture and increasing discharge of domestic sewages caused by rapid growth of population along the Changjiang River drainage valley should be responsible for the high COD. Furthermore, with the current trend of population growth and agricultural development in this basin, water quality of the Changjiang River, in terms of COD level, is going to deteriorate in the near future. Thus, the rational applications of fertilizers and pesticides in agriculture and the proper treatment of domestic sewages before they are discharged would be the most concerned controlling parameters.

Hydrogen bonds of interfacial water in human breast cancer tissue compared to lipid and DNA interfaces

The paper presents the results for water confined in a human breast cancerous tissue, a single stranded DNA, a double stranded DNA and in phospholipids (DPPC - D-a-Phosphati dylcholine, dipalmitoyl). The interfacial water in DNA and lipids is represented by a double band in the region of the OH stretching mode of water corresponding to the symmetric and asymmetric vibrational modes, in contrast to water confined in the cancerous breast tissue where only one band at 3311 cm-1 has been recorded. The marked red-shift of the maximum peak position of the OH stretching mode confirms that the vibrational properties of the interfacial water observed in restricted biological environment differ drastically from those in bulk water. The change of vibrational pattern of behavior may be due to the decoupling of the vibrations of the OH bonds in water molecule or change of the vibrational selection rules at biological interfaces. According to our knowledge Raman vibrational properties of water confined in the normal and cancerous breast tissue of the same patient have not been reported in literature yet. Here we have also presented the first Raman ‘optical biopsy’ images of the non-cancerous and cancerous (infiltrating ductal cancer) human breast tissues.

MoS2/ZIF-8 Hybrid Materials for Environmental Catalysis:Solar-Driven Antibiotic-Degradation Engineering

Photocatalytic water purification is an efficient environmental protection method that can be used to eliminate toxic and harmful substances from industrial effluents.However,the TiO2-based catalysts currently in use absorb only a small portion of the solar spectrum in the ultraviolet(UV)region,resulting in lower efficiency.In this paper,we demonstrate a molybdenum disulfide/zeolitic imidazolate framework-8(MoS2/ZIF-8)composite photocatalyst that increases the photocatalytic degradation of ciprofloxacin(CIP)and tetracycline hydrochloride(TC)by factors of 1.21 and 1.07,respectively.The transformation products of CIP and TC from the catalysis processes are tentatively identified,with the metal-organic framework(MOF)being considered to be the main active species with holes being considered as the main active species.The hydrogen production rate of the MoS2/ZIF-8 nanocomposites is 1.79 times higher than that of MoS2.This work provides a novel perspective for exploring original and efficient 1T/2H-MoS2/MOF-based photocatalysts by optimizing the construction of surface nano-heterojunction structures.The composite photocatalyst is found to be durable,with its catalytic performance being preserved under stability testing.Thus,1T/2H-MoS2/MOF-based photocatalysts have excellent prospects for practical antibiotic-degradation engineering.

Dissolved inorganic carbon and its isotopic differentiation in cascade reservoirs in the Wujiang drainage basin

Three cascade reservoirs,built in different periods of time in the Wujiang drainage basin,were inves-tigated in this study.Samples were taken at the surface and also at 20,40,60,80 m depths in front of the dams in April,July,October of 2006 and January of 2007.Chemical parameters were calculated and the concentrations of dissolved inorganic carbon DIC and its isotopic composition(δ13CDIC) were de-termined.In surface waters,the δ13CDIC values are high in summer and autumn and low in winter and spring,while the DIC concentrations are relatively low in summer and autumn and relatively high in winter and spring.In the water column,the DIC concentrations increase while δ13CDIC values decrease with water depth.DIC in various reservoirs is significantly different in isotopic composition from that in natural rivers,but is close to that in natural lakes.In addition,in surface waters,the δ13CDIC values tend to become lower whereas the nutrition level tends to become higher with increasing age of the reser-voirs.The conclusion is that after dam blocking,changes took place in the hydrochemical properties of river water,and the impounding rivers developed toward lakes and swamps.In addition,differentiation in DIC isotopic composition may be used to some extent to trace the evolution process of a reservoir.