Persistence,Distribution, and Emission of Telone C35 Injected into a Florida Sandy Soil as Affected by Moisture,Organic Matter,and Plastic Film Cover

Abstract

With the phase-out of methyl bromide scheduled for 2005, alternative fumigants are being sought. This study of Telone C35, a mixture of (Z)- and (E)-1,3-dichloropropene (1,3-D) with chloropicirin (CP), focuses on its emissions, distribution, and persistence in Florida sandy soil in microplots with different soil–water and organic matter carbon (C) content with and without two different plastic film mulches. The addition of CP did not affect the physical behavior of the isomers of 1,3-D. Slower subsurface dispersion and longer residence time of the mixed fumigant occurred at higher water content. An increase in the percent organic carbon in the soil led to a more rapid decrease for chloropicirin than for 1,3-dichloropene isomers. The use of a virtually impermeable film (VIF) for soil cover provided a more even distribution and longer persistence under all the conditions studied in comparison to polyethylene (PE) film cover or no cover. The conditions of near field capacity water content, low organic matter, and a virtually impermeable film cover yielded optimum conditions for the distribution, emission control, and persistence of Telone C35 in a Florida sandy soil.     

TiO2镀膜电极光电催化降解酸性紫红

采用溶胶-凝胶法在钛片上涂覆TiO2薄膜为电极,自行设计组装光电催化反应器,对酸性紫红染料废水进行光电脱色处理,探讨了光电反应的协同性并研究了初始染料浓度、电压、pH和电解质浓度对脱色反应的影响。结果表明,光化学催化和电化学氧化具有协同效应,单一紫外光催化和单一电催化酸性紫红的脱色率分别为44.27%和13.12%,而光电催化(紫外、外加电压10 V)的脱色率达到77.18%。初始浓度较低、电压适中、pH偏碱性时,酸性紫红废水脱色率较高;电解质对脱色反应有促进作用,且浓度越高,酸性紫红脱色率越高。     

羽毛角蛋白海绵膜去除气溶胶简

通过添加一定含量增塑剂和冷冻干燥,将羽毛还原法产生的较少被利用的残渣制备成致密多孔具有一定柔韧性的角蛋白膜,不需预处理和交联剂,得率高。甘油添加量对膜的结构影响进行研究后表明,甘油含量5%时机械性能最佳,断裂强度为6.2 MPa,完整性和柔韧性最好,孔隙率最大,兼顾了较好的透气性和对气溶胶的较高去除率。该膜在18℃ 空气流速1 m/s下对大气气溶胶中PM₁₀去除率98%、PM_2.5去除率 39.28% 、PM_1.0去除率 32.97%,在制备口罩材料上具有一定应用潜力。     

Assessment of farmland sediments after flooding in Ubeji Land in Niger Delta of Nigeria

A study was conducted to evaluate ten heavy metals in dry sediment samples used to assess the contamination of farmland in Niger Delta after a protracted flooding. Eighteen sediment samples in six locations were collected. Niger Delta is a major industrial area where Nigeria petrochemical company is located. These sediments were subjected to analysis using standard methods for the examination of the soil samples. Results showed a trend toward induction of environmental contamination with Zn, Cu, Fe, Hg and Pb on the farmland. Mercury and Lead are disproportionately higher than other sediment elements. Concentrations of these sediment elements are above compliance limit for Nigeria and these may have long-term adverse effects on soil and vegetation.     

厌氧水解—高负荷生物滤池处理城镇污水的中试研究

厌氧水解 -高负荷生物滤池是一种利用附着在塑料模块填料上的微生物系统对城镇污水中的污染物质进行降解处理的绿色环保技术。厌氧水解池和高负荷生物滤池采用的塑料模块填料具有高空隙率、高附着面积、高布水性能和抗堵塞的优异性能 ,并无须回流。当厌氧水解池水力停留时间为 4h ,生物滤池水力负荷为 30m3/ (m2 ·d) ,该系统处理城镇污水的CODcr去除率达 75 % - 85 % ,BOD5去除率达 85 % - 95 % ,SS去除率达 85 % -95 % ,处理后出水的上述各项指标均可满足国家二级生物处理排放标准的要求。     

超声协同TiO2光催化降解4,4′-二溴联苯

以纳米TiO2膜为光催化剂,对4,4′-二溴联苯水溶液进行了超声光催化（US＋UV）、光催化（UV）和超声（US）降解,探讨了初始浓度、超声的声强和频率等对降解4,4′-二溴联苯的影响。结果表明,4,4′-二溴联苯的超声光催化降解存在协同效应,降解率随4,4′-二溴联苯初始浓度的增大而下降,随声强和频率的增大而增大。超声光催化过程符合一级动力学方程,反应数率常数为0.011 min^-1。超声光催化与光催化的降解产物不同。     

The influence of a voluntary fee in the consumption of plastic bags on supermarkets from Madeira Island (Portugal)

Since 2007, some supermarkets in Portugal have voluntarily abolished the free distribution of plastic bags, implementing a symbolic charge of €0.02 each at the same time that others still offer free plastic bags. This study assesses the influence of this voluntary measure on the reduction of plastic bags consumption, comparing clients from supermarkets that have adopted it with others who have free distribution. The reutilisation of bags reached 37% in supermarkets where customers pay a fee and was absent in supermarkets where plastic bags are free. Even the abstention of using bags, when clients buy only few products, is significantly higher in supermarkets where there are charges for plastic bags. The 2 cents charged has also induced a significant increase in optimal use of plastic bags since 52% of clients that pay for plastic bags use them so they are almost full, but only 17% do the same when they are free. Taken together, the different effects of charging for plastic bags represents a potential reduction of 64%. A mandatory tax on plastic bags is an important measure to reduce substantially the number of plastic bags consumed and to improve sustainability through the reduction of environmental, economic and social costs of pollution and waste management.     

Viscosity of Soy Protein Plastics Determined by Screw-Driven Capillary Rheometry

Soy protein plastics are a renewable, biodegradable alternative to fossil fuel-based plastic resins. Processing of soy protein plastics using conventional methods (injection molding, extrusion) has met with some success. Viscosities of processable formulations that contain soy protein along with the necessary additives, such as glycerol and cornstarch, have not been reported, but are necessary for extrusion modeling and the design of extrusion dies. Resins consisting of soy protein isolate-cornstarch ratios of 4:1, 3:2, and 2:3 were plasticized with glycerol and soy oil, compounded in a twin screw extruder and adjusted to 10% moisture. The effects on viscosity of added sodium sulfite, a titanate coupling agent and recycling were evaluated using a screw-driven capillary rheometer at shear rates of 100–800/s. The viscosities fit a power-law model and were found to be shear thinning with power-law indices, n, of 0.18–0.46 and consistency indices, m, of 1.1 × 10⁴–1.0 × 10⁵. Power-law indices decreased and consistency indices increased with increasing soy protein-to-cornstarch ratio and in the absence of sodium sulfite. Addition of the titanate coupling agent resulted in increased power-law index and decreased consistency index. Viscosities at a shear rate of 400/s decreased with recycling, except for the 4:1 soy protein isolate to cornstarch formulation, which displayed evidence of wall slip. Power-law indices were unaffected by recycling. Viscosities in the tested shear rate range were comparable to polystyrene and low-density polyethylene indicating soy protein plastics are potential drop-in replacements for commodity resins on conventional plastics processing equipment.     

Cloud point extraction coupled with HPLC-UV for the determination of phthalate esters in environmental water samples

A method based on cloud point extraction was developed to determine phthalate esters including di-ethyl-phthalate （DEP）, di- （2-ethylhexyl）-phthalate （DEHP） and di-cyclohexyl-phthalate （DCP） in environmental water samples using high-performance liquid chromatography separation and ultraviolet detection （HPLC-UV）. The non-ionic surfactant Triton X-114 was chosen as extraction solvent. The parameters affecting extraction efficiency, such as concentrations of Triton X-114 and Na2SO4, equilibration temperature, equilibration time and centrifugation time were evaluated and optimized. Under the optimum conditions, the method can achieve preconcentration factors of 35, 88, 111 and detection of limits of 2.0, 3.8, 1.0 ng/ml for DEP, DEHP and DCP in 10-ml water sample, respectively. The proposed method was successfully applied to the determination of trace amount of phathalate esters in effluent water of the wastewater treatment plant and the lixivium of plastic fragments.     

Semi-natural habitats in the European boreal region: Caught in the socio-ecological extinction vortex?

We propose to consider semi-natural habitats—hotspots for biodiversity—being caught in a socio-ecological extinction vortex, similar to the phenomenon described for species threatened with extinction. These habitats are essentially socioecological systems, in which socioeconomic drivers are interlinked with ecological processes. We identify four highly interlinked and mutually reinforcing socio-economic processes, pertaining to the importance of semi-natural habitats for (i) agricultural production, (ii) policy, research and development; (iii) vocational education in the fields of agricultural sciences and (iv) public’s experiences with semi-natural habitats. Evidence from six countries in the boreal region demonstrates that recent slowing down or even reversal of two processes are insufficient to stop the extinction vortex phenomenon. We suggest research directions to ascertain the phenomenon, monitor its development and develop proactive actions to weaken the vortex. It is highly plausible that interventions directed at most, if not all, of the key vortex processes are needed to reverse the overall deteriorating trends of a socio-ecological system.