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721.
滇池流域水污染防治规划与富营养化控制战略研究 总被引:6,自引:5,他引:6
根据滇池水污染防治的决策需求,在系统分析滇池水环境演变趋势和评估演变诱因的基础上,以流域水环境承载力方案及容量总量控制方案为基础,提出了滇池流域水污染防治中长期规划研究的方法体系,包括:问题驱动、调查诊断、规划基础、规划方案、评估调控、规划战略;提出了源头控制、工程控制和末端控制相结合的污染减排对策;通过构建3个尺度、8个分区及4个规划重点的流域污染减排集成体系及情景方案,来实现在2个规划期、3类水质目标、4种社会经济发展情景下的规划目标.在此基础上,提出了滇池富营养化控制的战略思路. 相似文献
722.
Contents and sources of polycyclic aromatic hydrocarbons and organochlorine pesticides in vegetable soils of Guangzhou, China 总被引:36,自引:0,他引:36
We investigated contents, distribution and possible sources of PAHs and organochlorine pesticides (Ops) in 43 surface and subsurface soils around the urban Guangzhou where variable kinds of vegetables are grown. The results indicate that the contents of PAHs (16 US EPA priority PAHs) range from 42 to 3077 microg/kg and the pollution extent is classified as a moderate level in comparison with other investigations and soil quality standards. The ratios of methylphenanthrenes to phenanthrene(MP/P), anthracene to anthracene plus phenanthrene (An/178), benz[a]anthracene to benz[a]anthracene plus chrysene (BaA/228), indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (In/In+BP) suggest that the sources of PAHs in the soil samples are mixed with a dominant contribution from petroleum and combustion of fossil fuel. The correlation analysis shows that the PAHs contents are significantly related to total organic carbon contents (TOC) (R2=0.75) and black carbon contents (BC) (R2=0.62) in the soil samples. Dichlorodiphenyltrichloroethane and metabolites (DDTs) and hexachlorocyclohexanes and metabolites (HCHs) account largely for the contaminants of OPs. The concentrations of DDTs range from 3.58 to 831 microg/kg and the ratios for DDT/(DDD+DDE) are higher than 2 in some soil samples, suggesting that DDT contamination still exists and may be caused by its persistence in soils and/or impurity in the pesticide dicofol. The concentrations of HCHs are 0.19-42.3 microg/kg. 相似文献
723.
Mutual effects of cadmium and phosphate on their adsorption and desorption by goethite 总被引:4,自引:0,他引:4
Adsorption of cadmium (Cd) and phosphate by oxides or soils has been extensively studied, but the adsorption/desorption kinetics and mutual effects of these two species in co-existing systems has received little attention. In this study, a batch equilibration method was used to investigate the effect of phosphate and its application time on Cd adsorption and desorption on goethite. The influence of Cd and its application time on phosphate sorption and desorption kinetics was also determined. For Cd adsorption, phosphate was introduced into the system by two sequences: pre-treating goethite at 40 (degrees)C for 1 week, and applying with Cd simultaneously. Similarly, for phosphate sorption, Cd was applied by pre-treating goethite at 40 (degrees)C for 1 week or simultaneous addition with phosphate. Results demonstrated that phosphate added to goethite enhanced Cd adsorption, and facilitated Cd release as compared to untreated goethite. Cadmium had slightly higher adsorption, but a significantly faster desorption rate from the goethite simultaneously treated with phosphate and Cd, as compared to phosphate-pretreated goethite. Cadmium and its application time had little impact on phosphate sorption by goethite. However, phosphate desorption kinetics was affected by Cd application time. When the sorption time was short (15 min), phosphate desorption was faster from the goethite that was simultaneously treated with phosphate and Cd, as compared to Cd pretreated or untreated goethite. In contrast, a longer sorption time (4 weeks) resulted in a higher desorption rate of phosphate from Cd pretreated goethite than simultaneously phosphate-Cd treated goethite. This study provided useful information on adsorption/desorption kinetics in complicated Cd-phosphate-goethite systems. 相似文献
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726.
Guo Ting Bulin Chaoke Zhang Bangwen Ma Zeyu Xing Ruiguang Ge Xin Zhang Yanghuan Li Bo 《Journal of Polymers and the Environment》2022,30(2):569-584
Journal of Polymers and the Environment - Heavy metal pollution stems from the modern industry is a severe environmental problem. In this work, a highly efficient adsorbent based on starch-graphene... 相似文献
728.
729.
Chen Xing Daihui Yang Yan Zhang Tian Sun Junfei Duan Hussein A.Younus Shiguo Zhang 《绿色能源与环境(英文)》2022,7(1):43-52
Heteroatom-doped meso/micro-porous carbon materials are conventionally produced by harsh carbonization under an inert atmosphere involving specific precursors, hard/soft templates, and heteroatom-containing agents. Herein, we report a facile synthesis of N and O co-doped meso/micro-porous carbon (NOMC) by template-free carbonization of a small-molecule precursor in a semi-closed system. The semi-closed carbonizaiton process yields hydrophilic NOMCs with large surface area in a high yield. The porous structure as well as the elemental composition of NOMCs can be modulated by changing the holding time at a particular temperature. NOMCs as metal-free heterogeneous catalysts can selectively oxidize benzyl alcohol and its derivatives into aldehydes/ketones with>85%conversion in aqueous solution, which is much higher than that of the control sample obtained in tube furnace (21%conversion), mainly due to their high N content, high percentage of pyridinic N, and large surface area. The presence of O-containing moieties also helps to improve the hydrophilicity and dispersion ability of catalysts and thus facilitates the mass transfer process during aqueous oxidation. The NOMC catalysts also dispayed excellent activity for a wide range of substrates with a selectivity of>99%. 相似文献
730.
2015年8月,对秦山岛周边的10个站位进行大型底栖动物定量调查。采用生物多样性指数法和丰度生物量比较法对大型底栖动物群落健康状况进行评价。结果显示,共鉴定大型底栖动物7大类31种,其中软体动物、环节动物各10种,节肢动物5种,脊索动物和棘皮动物各2种,纽虫类和腔肠动物各1种;密度优势类群为软体动物,占总密度的35.00%,生物量优势类群为脊索动物,占总生物量的49.35%;优势种分别为红狼牙虾虎鱼(Odontamblyopus rubicundus)、棘刺锚参(Protankyra bidentata)、内卷原盒螺(Eocylichna involuta)和微角齿口螺(Odostomia subangulata)。大型底栖动物密度为站位St.6最大,为115 ind./m2,St.2最小,为20 ind./m2,平均值为70 ind./m2;生物量St.3最大,为197.25 g/m2,St.9最小,为2.56 g/m2,平均值为54.04 g/m2。秦山岛受污染压力、人为活动干扰和生境限制能因素影响,多样性偏低,优势种为耐污的软体动物、脊索动物和棘皮动物,但其主要为K对策种类,大型底栖动物群落受到了轻度干扰,但群落结构仍较为稳定。 相似文献