土壤污染的农业防治方法

随着人口的增加和人类活动的加强,土壤污染日益严重,对作物产量和质量的影响越来越大,并通过农产品进入食物链,影响人体健康,治理土壤污染刻不容缓。目前土壤污染治理的方法主要有物理法、化学法、生物法、农业防治法等多种,其中农业防治土壤污染,可操作性较强,利于推广。1土壤污染的途径造成土壤污染的物质主要有下列四种:化学污染物,如重金属、过量的氮、磷元素、农药等。物理污染物。

海洋污染基线研究的几个问题

所谓基线研究,即对指定污染物,在指定介质(这种介质能够对该污染物经指定路径的输入量进行估算)中的目前分布和浓度进行研究。对海洋来说,就是研究海洋环境中某些选择污染物的目前分布和浓度等。

Effects of Excessive Mg2+ on the Germination Characteristics of Crop Seeds

[ Objective ] The research aimed to reveal theeffects of excessive Mg^2＋ on the germination characteristics of maize and soybean. [ Method ] Eleven concentration gradients of Mg^2＋ including 0, 40, 80, 120, 160,200,240,280,320,360 and 400 mmol/L were set up to study the effects of different treatments on such indices as the germination potential, germination rate, fresh weight, dry weight, root length, plant height and stem diameter of maize and soybean. [ Result] With the increasing of Mg^2＋ concentration, the germination of maize delayed and the germination rate of soybean obviously decreased, reaching the significant difference at 0.05 level. When Mg^2＋ concentration increased, the fresh weight and dry weight of maize and soybean decreased, but maize and soybean showed some adaptability. The growth of radicles and seedlings in maize and soybean were obviously inhibited by Mg^2＋ , and atrophy and dysplasia phenomena appeared. [ Conclusion] Excessive Mg^2＋ stress has different effects on the germination potential and germination rate of different crops and has obvious poisoning effects on the root and stem growth of crops.

Some factors controlling diffusive transportof potassium ion through clayey soils

To investigate the potential use of two Japanese regional clayey soils, named Ariake clay and Akaboku soil, as soil barrier materials, a series of laboratory diffusion tests are presented. Using an available computer program Pollute V6.3, the effective diffusion coefficients of K^＋ of the soils were back-calculated from the diffusion tests. It is found that the Ariake clay has a larger effective diffusion coefficient than the Akaboku soil, indicating that the Ariake clay may provide a better diffusion barrier. A comparison of the effective diffusion coefficients between the single-salt solution condition and the multi-salt solution condition indicates that soils have higher effective diffusion coefficients under the former condition. It is suggested to use miscible solution close to landfill leachates for determining effective diffusion coefficients of specified chemical species for a practical design.

如何选购空气净化设备

目前,空气净化设备市场尚未成熟,以次充好的现象不在少数,消费者如何正确选购空气净化器呢？一、选购前要明确选购目标首先确定家中的主要污染源是什么？污染源一般分为物理污染物、化学污染物和生物污染物。物理污染物包括灰尘、PM2.5、PM0.3、烟雾、花粉等,化学污染物包括甲醛、苯、甲苯、二甲苯、VOC等,生物污染物包括细菌、病毒、霉菌、真菌、虫螨等。其次,明确使用空气净化器的房间面积,

如何生产安全优质的休闲食品

据2014年3月底的数据统计,全球休闲食品年销售额高达3740亿美元,年增长率为2%。如今,越来越多的人爱吃休闲食品,每个人平均每天吃的次数也更多。实际上,分析数据表明,我们每天摄入的卡路里含量有24%来自休闲食品。将近四分之一的卡路里是在正餐以外摄入的,休闲食品不再只是小食品,而已变成了第四顿正餐。

Bioremediation potential of spirulina:toxicity and biosorption studies of lead

This study examines the possibility of using live spirulina to biologically remove aqueous lead of low concentration (below 50 mg/L) from wastewater. The spirulina cells were first immersed for seven days in five wastewater samples containing lead of different concentrations, and the growth rate was determined by light at wavelength of 560 nm. The 72 h-EC50 (72 h medium effective concentration) was estimated to be 11.46 mg/L (lead). Afterwards, the lead adsorption by live spirulina cells was conducted. It was observed that at the initial stage (0–12 min) the adsorption rate was so rapid that 74% of the metal was bio- logically adsorbed. The maximum biosorption capacity of live spirulina was estimated to be 0.62 mg lead per 105 alga cells.

Ozonation with ultrasonic enhancement of p-nitrophenol wastewater

Synergetic effects for p-nitrophenol degradation were observed in the ozonation with ultrasonic enhancement. The enhancements of removal rate for p-nitrophenol and TOC were around 116% and 294% respectively in comparison with the individual ultrasound and ozonation systems. The synergetic phenomenon is attributed to two physicochemical mechanisms: (1) Ultrasound decomposes ozone causing augmentation of the activity of free radicals; (2) Ultrasonic wave increased the concen- tration of O3 in solution because of ultrasonic dispersion.

A Method and a Surface Treatment Agent for Preventing Biofouling on Surfaces under Water

This paper presents an environm centally friendly method of inhibiting biofouling especially acorn barnacles on surfaces under water by using nicotine and selenium in the form of Se（0）, or such a substance which can be converted into them. Both of the substances are necessary to oxygen dependent organisms and will be used after conversion, but are toxic in high doses. By adding the substances to paint or other surface treatment agent which marine surfaces are treated with, organisms which are trying to establish themselves on the surfaces will be exposed to so high doses, the reactions which the settling is based on are disturbed. When the substances leak out into the seas, they will act as environment protectors, as they promote the development of organisms. Nicotine is transformed to nicotine amid which is the reactive part in NADH and one of the most important substances for the transference of hydrogen. Selenite is reduced to Se（0）, also involved in the transport chain of hydrogen to reducible oxygen. However, large quantities Se（0） may disturb the reactions of sulphur b＇./binding to it and impairing the formation of S-S-bridges.

Characteristics of integrated biological aerated filter in municipal wastewater treatment

In this paper, the characteristics of integrated biological aerated filter (IBAF) applied to municipal wastewater treatment were studied in a pilot scale experiment. The experimental results showed that IBAF has high efficiencies in removing organic pollutants, such as CODCr and SS, in municipal wastewater. The removal rates of CODCr and SS can reach over 90% and 80%, respectively, when COD and SS in the influent are 234 mg L1 and 112 mg L1, hydraulic retention time (HRT) is 8 h, and the aerated intensity is in the range of (0.5 to 0.6) L m2 s1.

Dyeing wastewater treatment with a complex adsorption-coagulation agent

To remove effectively the pollutants from printing and dyeing wastewater, a new complex adsorption-coagulation agent was developed and employed in dyeing wastewater treatment. The experimental results showed that better removals of COD, turbidity and color could be efficiently realized under the operating conditions of mixing at 150 r/min, reacting within 5 min and dosing at 15 g/L and 20 g/L, respectively. Combined with the settled sludge, the agent could be recycled for further adsorption and coagulation within 10 times. Compared to the conventional coagulants, the newly-developed agent had such merits as suitability for wide pH range of wastewater, less sludge production, reutilization of the condensed sludge and low operation cost.

Physicochemical Characterization of Water of Bir M＇Cherga Reservoir and Its Effluents

This study aims the physico-chemical characterization of surface water of the Bir M＇Cherga reservoir and its effluents which are located in Zaghouan governorate of Tunisia. It required measures in situ of physicochemical parameters and chemical analysis at laboratory of major element and nutritive salts. The results of this study revealed the presence of pollutants in the Miliane river at El Fahs area and the eutrophication of water in the Bit M＇Cherga reservoir. According to the classification of Stuyfzand and Piper, water in the wadis of Melah, Hdada, Miliane and Boudebbane respectively is brackish, salty, extremely hard, chlorinated, sulphated, calcic, and magnesic. Water in the Bir M＇Cherga reservoir is characterized by calcic facies chlorinated sulphated and sodic. Thus, the Bir M＇Cherga reservoir presents a worrying situation and a risk of qualitative degradation of its water.

Assessment of Risk to Human Health from Landfill Gas at Sharra Landfill, Tirana--Albania

Urban waste management and particularly dumpsites represents one of the most significant problems tot the long term protection of public health and environment in Albania. All waste management options, including landfilling, involve an element of risk to human health. This article addresses the question, if sources of emissions from Sharra landfill lead theoretically to public exposures exceeding health criteria？ This question is approached using an exposure pathway analysis framework, which link a source of one or more harmful pollutants at a site with a human receptor that inhales the pollutant. The risk posed to human health from HCHO （formaldehyde） and dioxin is estimated for on-site and off-site receptors in Sharra landfill. For on-site receptors, the average risk to get harm through the inhalation pathway from HCHO is in the range of 20 times to 300 times greater than allowed risk value, while for off-site receptors the average risk is in the range of 10 times to 180 times greater. While for dioxin the risk is in the range from 50 to 600 for on-site receptors and 10 to 35 for off-site receptors, times greater than often allowed risk.

A Review of Chemical Industry Wastewater Treatment

With the development of China＇ s industry, the domestic industrial parks greatly emerge and thus give rise to the diversity of pollutants in chemical wastewater. In this paper, the main sources of China＇ s chemical industry wastewater, main pollutants types and the wastewater characteristics of the chemical industry＇ s different branches are introduced, the related technologies and methods mainly applied to chemical industry wastewater treatment at home and abroad are analyzed and the application of different chemical wastewater treatment process is explained, and also all sorts of treatment technologies, methods, and processes are reviewed, and finally the study achievements and problems of all technol^ogies are concluded.

Impacts of climate change on the ecotoxicology of chemical contaminants in estuarine organisms

Global climate change effects will vary geographically, and effects on estuaries should be independently considered. This review of the impacts of climate change on the ecotoxicology of chemical contaminants aims to summarize responses that are specific to estuafine species. Estuarine organisms are uniquely adapted to large fluctuations in temperature, salinity, oxygen, and pH, and yet future changes in climate may make them more susceptible to chemical contaminants. Recent research has hig- hlighted the interactive effects of chemical and nonchemical stressors on chemical uptake, metabolism, and organism survival. Assessments have revealed that the nature of the interaction between climate variables and chemical pollution will depend on es- tuarine species and life stage, duration and timing of exposure, prior stressor exposure, and contaminant class. A need for further research to elucidate mechanisms of toxicity under different abiotic conditions and to incorporate climate change factors into toxicity testing was identified. These efforts will improve environmental risk assessment of chemical contaminants and manage- ment capabilities under changing climate conditions [Current Zoology 61 （4）： 641-652, 2015].