Economic Failures in French Recreational Fishing Management

In France, freshwater recreational fishing management does not sufficiently satisfy anglers. Fishing effort is too high creating congestion costs and environmental quality is low while there is a positive willingness-to-pay for improvements. These inefficiencies are explained by three phenomena. First, private property rights are attenuated under institutional pressure. Second, recreational fishing is managed as an open access resource over the whole territory. Finally, halieutic policies focus on the protection of environmental resources and are inefficient at maximizing the social rent provided by recreational fisheries. Fishing effort regulation and environmental services provision following the beneficiary-pays principle could improve collective welfare. Social pricing could ensure equity in access to the resource.     

利用白云石石灰去除与回收污泥厌氧消化液中氮和磷

以白云石石灰为实验材料去除与回收污泥厌氧消化液中的氮磷,通过小试实验研究不同投药固液比S/L、初始pH值、反应温度、搅拌速度及反应时间对去除与回收氮磷效果的影响。实验结果表明,在最佳投药固液比S/L为300mg/L,最佳初始pH值范围为8.5~9.5,反应温度为25.0℃,搅拌速度为150 r/min,反应时间为24 h条件下,氨氮(NH+4-N)和磷(PO3-4-P)的去除率分别为37.26%和89.60%。利用X射线衍射仪(XRD)、扫描电镜(SEM)对沉淀产物进行了表征,通过分析可知沉淀产物中含有磷酸铵镁(MAP),可实现废水中氮磷经济有效的回收。     

Mn/γ-Al2O3催化剂的制备及头孢合成废水的催化臭氧氧化法深度处理

对Mn/γ-Al₂O₃催化剂的制备条件及头孢合成废水的催化臭氧氧化法深度处理工艺条件进行了优化。实验结果表明：以Mn（NO₃）₂溶液为浸渍液，Mn/γ-Al₂O₃催化剂的最优制备条件为浸渍液浓度0.10 mol/L、浸渍时间9 h、焙烧温度400 ℃、焙烧时间2 h;在反应时间为30 min、废水pH为9.0、臭氧通量为4.6 mg/min、催化剂加入量为5 g/L的条件下，当进水COD、BOD₅、ρ（氨氮）和色度分别为220~250 mg/L，8~10 mg/L，10~12 mg/L和60~70倍时，出水COD、BOD₅、ρ（氨氮）和色度的平均去除率分别为53%，30%，33%和93%，出水水质满足GB 21904—2008《化学合成类制药工业水污染物排放标准》的要求。     

Cancer risk from gaseous carbonyl compounds in indoor environment generated from household coal combustion in Xuanwei,China

Airborne carbonyls were characterized from emitted indoor coal combustion. Samples were collected in Xuanwei (Yunnan Province), a region in China with a high rate of lung cancer. Eleven of 19 types of samples (58%) demonstrated formaldehyde concentrations higher than the World Health Organization exposure limit (a 30-min average of 100 μg m^?3). Different positive significant correlations between glyoxal/methylglyoxal and formaldehyde/acetaldehyde concentrations were observed, suggesting possible different characteristics in emissions between two pairs of carbonyl compounds. A sample in the highest inhalation risk shows 29.2 times higher risk than the lowest sample, suggesting different coal sampling locations could contribute to the variation of inhalation risk. Inhabitants in Xuanwei also tend to spend more time cooking and more days per year indoors than the national average. The calculated cancer risk ranged from 2.2–63 × 10^?5, which shows 13 types of samples at high-risk level. Cumulative effect in combination with different carbonyls could have contributed to the additive actual inhalation cancer risk. There is a need to explicitly address the health effects of environmentally relevant doses, considering life-long exposure in indoor dwellings.     

Permeability of hair to cadmium,copper and lead in five species of terrestrial mammals and implications in biomonitoring

The capacity of mammal hair to absorb toxic metals and its utility in biomonitoring has been broadly studied. Though these metal-binding properties has generally been attributed to the sulphur contained in cysteine, an amino acid that forms part of keratin, there are not many experimental studies that analyze the role of sulphur in the external deposition of potentially toxic metallic elements in order to better understand the potential of hair in biomonitoring and generate better tools for differentiating between internal and external deposition of contaminants. In this study, an experimental analysis is carried out using a scanning electron microscope on hairs of five terrestrial mammal species (Peromyscus furvus, P. maniculatus, Glossophaga soricina, Artibeus jamaicensis and Marmosa mexicana) treated with cadmium, copper and lead salts. We quantified absorbed metals as well as natural elements of the hair by energy dispersive X-ray spectroscopy (EDS) to analyze using simple statistics the role of sulphur in the absorption Cd, Cu and Pb. Given the lack of studies comparing the mechanisms of deposition of metal elements among different orders of Class Mammalia, external morphology was considered to be an important factor in the deposition of metallic particles of Cd, Cu and Pb. Bat species (Glossophaga soricina, Artibeus jamaicensis) showed a high concentration of particles in their scales, however, no between-species differences in metal absorption were observed, and during the exogenous deposition metal particles do not permeate the medulla. These results suggest that the sulphur in hair itself cannot bind metals to hair cuticle and that hair absorption capacity depends on a variety of factors such as aspects of hair morphology.     

丹江口水库表层沉积物不同形态氮的赋存特征及其生物有效性

为了揭示丹江口水库沉积物氮空间分布特征及其生物有效性,采用连续分级提取法研究了表层沉积物中可交换态氮(Exchangeable nitrogen,EN)、酸解态氮(Acid hydrolysable nitrogen,HN)及残渣态氮(Residue nitrogen,RN)的赋存特征,同时结合生物可利用态氮的含量,探讨了各形态氮对生物可利用态氮的贡献。结果表明,丹江口水库沉积物中总氮(Total nitrogen,TN)在425~5796 mg/kg之间,平均为1 319.32 mg/kg,其中EN、HN和RN的平均值相对比例为2.15∶1.95∶1,且各形态氮含量的空间分布呈入库河流大于库区开阔区域的特征,尤其在丹江、老灌河以及犟河-堵河入库口的含量较大。潜在矿化氮(Potential mineralized nitrogen,PMN)含量在40.20~1 468.95 mg/kg之间,平均为275.06 mg/kg,其中EN对丹江口水库沉积物PMN的贡献较大,比例在19.85%~90.80%之间,平均为63.47%。各形态氮在不同的水环境条件下发生迁移转化,保持着水-沉积物界面氮的动态平衡。     

The effectiveness and risk comparison of EDTA with EGTA in enhancing Cd phytoextraction by Mirabilis jalapa L.

In the previous study, Mirabilis jalapa L. had revealed the basic Cd hyperaccumulator characteristics, but the accumulation ability was not as strong as that of other known Cd hyperaccumulators. In order to improve the accumulation ability of this ornamental plant, the chelants were used to activate the Cd in soil. As a substitute, ethylene glycol bis(2-aminoethyl) tetraacetic acid (EGTA) was selected to testify whether it has better effectiveness and can bring lesser metal leaching risk than EDTA. The data showed that the growth of M. jalapa was inhibited, while the Cd concentration of the plant was significantly increased under the treatments containing EDTA or EGTA. The Cd translocation ability under the EGTA treatments was higher than that under the EDTA treatments. The available Cd resulted from the application of chelant EGTA to the contaminated soils can be limited to the top 5 cm, while the application of chelant EDTA to the contaminated soils can be limited to the top 10 cm. In a word, EGTA showed better effectiveness than EDTA in enhancing Cd phytoextraction of M. jalapa. As an ornamental plant, M. jalapa has the potential to be used for phytoextraction of Cd-contaminated soils and it can beautify the environment at the same time.     

Human factors and tidal influences on water quality of an urban river in Can Tho, a major city of the Mekong Delta, Vietnam

In this study, we focused on water quality in an urban canal and the Mekong River in the city of Can Tho, a central municipality of the Mekong Delta region, southern Vietnam. Water temperature, pH, electrical conductivity, BOD₅, COD_Cr, Na⁺, Cl^?, NH₄ ⁺?N, SO₄ ^2??S, NO₃ ^??N, and NO₂ ^??N for both canal and river, and tide level of the urban canal, were monitored once per month from May 2010 to April 2012. The urban canal is subject to severe anthropogenic contamination, owing to poor sewage treatment. In general, water quality in the canal exhibited strong tidal variation, poorer at lower tides and better at higher tides. Some anomalies were observed, with degraded water quality under some high-tide conditions. These were associated with flow from the upstream residential area. Therefore, it was concluded that water quality in the urban canal changed with a balance between dilution effects and extent of contaminant supply, both driven by tidal fluctuations in the Mekong River.     

Distribution,sources, and ecological risk assessment of SVOCs in surface sediments from Guan River Estuary,China

The contamination of semi-volatile organic compounds (SVOCs) in the surface sediments of the Guan River Estuary, China was fully investigated. Total concentrations of 56 species of SVOCs ranged from 132 to 274 ng/g with an average of 186 ng/g (dry weight). Polycyclic aromatic hydrocarbon (PAH) concentrations were positively correlated with clay content and negatively correlated with sediment grain size. Source identification indicated that PAHs originated mainly from pyrolytic sources. However, intense ship traffic in the estuary may provide sources of petrogenic PAHs. Organochlorine pesticides (OCPs) mainly originated from direct input of dichlorodiphenyltrichloroethanes (DDTs) during some industrial processes. The SVOC concentrations were also compared with International Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated that negative biological impacts may originate from high concentrations of FLO, p,p′-DDE, and total DDTs.