Distribution characteristics of organochlorine pesticides in surface and vertical sediments from the Zha Long Wetland, China

Introduction

The Zha Long Wetland, the first water bird conservation area in China, lies on the northern bank of the Song Nen Plain with an area of 2,100 km². In many areas of the Zha Long Wetland, water pollution has led to a decrease in the wetland??s ecological function, vegetation degradation, a decrease in the number of bird species, and the depletion of fish resources.

Materials and methods

The sediments used in this study were collected from the surface sediment of seven sites and from different depths in three types of marshes in the Zha Long Wetland in northeast China in late October 2006. The levels and distribution patterns of 17 organochlorine pesticides (OCPs; ??-HCH, ??-HCH, ??-HCH, ??-HCH, p,p??-DDE, p,p??-DDD, p,p??-DDT, endosulfan I, endosulfan II, endosulfan sulfate, heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, endrin aldehyde, and methoxychlor) in surface sediments as well as hexachlorocyclohexane (HCH) and 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) in vertical sediments were investigated.

Results and discussion

The concentrations of HCHs, DDTs, endosulfans, heptachlors, aldrin, and methoxychlor in surface sediments ranged from 10.44 to 41.97 ng/g, nd (undetectable levels) to 211.88 ng/g, nd to 69.89 ng/g, nd to 28.10 ng/g, 9.81 to 623.83 ng/g, and from nd to 3.99 ng/g, respectively. The highest levels of OCPs were detected in Tangtugangzi at a total concentration of 727.72 ng/g, where the dominant compound was endrin at a concentration of 483.04 ng/g. In the vertical sediments, the HCHs and DDTs were in the ranges of nd?C136.00 and nd?C214.06 ng/g, respectively.

Conclusions

Different distributions of HCHs, DDTs, and other OCPs indicated that they originated from different contamination sources. Composition analyses in surface sediments indicated recent OCP usage or discharge at some sample sites in the Zha Long Wetland.     

Mercury distribution in seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system

Background and purpose  

More and more coal-fired power plants equipped with seawater flue gas desulfurization systems have been built in coastal areas. They release large amount of mercury (Hg)-containing waste seawater into the adjacent seas. However, very limited impact studies have been carried out. Our research targeted the distribution of Hg in the seawater, sediment, biota, and atmosphere, and its environmental transportation.     

2008年江苏持续性降雪中的水汽和动力抬升机制分析

2008年1月下旬江苏省出现了历史罕见的持续性暴雪过程,研究发现,降雪量的大小与低空急流的日变化相对应,暴雪过程中700 hPa西南急流对水汽的输送起着重要的作用,作为大尺度天气系统,700 hPa急流的加速发生在降雪量增大之前,其值阈大小与6 h降雪量之间没有对应关系,急流减弱在暴雪结束以后;降雪的发生和发展与南北风的增大和冷暖平流有关,低层偏北风作为冷垫对暖湿气流的抬升和水汽的凝结起到了一定的作用;江苏降雪过程中水汽主要来源于700～500 hPa,低层东风气流对黄海南部的水汽输送非常有限;强降雪的发生与700 hPa水汽通量散度相对应,水汽通量散度辐合增大,降雪量增大;在降雪过程中垂直运动对降雪量的大小有很好的指示意义。     

Assessing microbial and chemical exposure risks of Giardia in indoor swimming pool water disinfected by chlorine

Swimming pools adopt chlorination to ensure microbial safety. Giardia has attracted attention in swimming pool water because of its occurrence, pathogenicity, and chlorine resistance. To control Giardia concentrations in pool water and reduce the microbial risk, higher chlorine doses are required during disinfection. Unfortunately, this process produces carcinogenic disinfection byproducts that increase the risk of chemical exposure. Therefore, quantitatively evaluating the comparative microbial...     

Water-soluble matter in PM2.5 in a coastal city over China: Chemical components, optical properties, and source analysis

Although marine and terrestrial emissions simultaneously affect the formation of atmospheric fine particles in coastal areas, knowledge on the optical properties and sources of water-soluble matter in these areas is still scarce. In this work, taking Qingdao, China as a typical coastal location, the chemical composition of PM_2.5 during winter 2019 was analyzed.Excitation-emission matrix fluorescence spectroscopy was combined with parallel factor analysis model to explain the component...     

Assessing China’s Ecological Restoration Programs: What’s Been Done and What Remains to Be Done?

This article surveys the recent literature that has assessed China’s ecological restoration programs, including the Sloping Land Conversion Program (SLCP) and the Natural Forest Protection Program (NFPP). Our presumption is that the performance of these programs should be determined by their effectiveness of implementation and significance of impact. Implementation effectiveness can be measured with such indicators as land area converted or conserved, and survival and stocking rates of restored vegetation, while impact significance can be gauged by the induced changes in ecosystem functionality and stability (erosion control, biodiversity protection, etc.) and socioeconomic conditions. Coupling this matrix with an exhaustive search of the publications, we find that: (1) the implementation effectiveness has not been examined as extensively as the impact significance; (2) efforts to assess the impact significance have concentrated on the SLCP, particularly its socioeconomic effects: growth of income, alternative industry, and employment, and likelihood of re-conversion; and (3) most of the socioeconomic studies are based on rural household surveys and discrete choice and difference in differences models. While much has been learned from previous studies, a lot more needs to be done in improving our understanding of the program execution and impacts. Future work should pay more attention to the NFPP and other programs, and the environmental impacts and the implementation effectiveness of all of them. To these ends, analysts must gather more field data regarding the evolving ecosystem conditions and socioeconomic information of higher aggregation, and conduct their research across scales and disciplines, with better application of geospatial technology and more effective modeling.     

课外环境调查能培养学生的创新思维

新高中地理教学大纲的内容是为面向 21世纪的高中学生制定的。它明确要求：增强学生的环境意识，培养他们对环境负责的观念和行为。为此我校开展了丰富多彩的环境教育活动。既丰富学生的精神生活，扩大视野、陶冶情操，也使学生不受教材、教师倾向的束缚，展开智慧的翅膀去动脑、动手、多思、多做。从中受到激励、启发，产生联想、灵感，激活学生创新思维的潜能。如组织高一地理课外活动小组同学，对齐齐哈尔市“劳动湖”的水质污染情况进行了调查。关于“劳动湖”水质现状如何改变问题，一些同学多次与有关专家咨询、探讨、研究、综合分…     

Sublethal impact of paraquat on the life span and parasitic behavior of Diaeretiella rapae M’Intosh

This study focuses on assessing the impact of sublethal doses of paraquat on the survival, the emergence, the life span and the parasitic behavior of Diaeretiella rapae M’Intosh (Hymenoptera: Braconidae). The impact of sublethal doses was measured at room temperature using different densities of the cabbage aphid Brevicoryne brassicae. The results reveal that the field dose of paraquat caused 100% mortality in D. rapae. The percentage emergence of D. rapae decreased from 80.5% in the control group to 71.5% when treated with the lowest concentration of paraquat. Similarly, the life span of parasitoids that emerged from the mummy treated with paraquat also decreased significantly. Oviposition capability and ovipositor thrusting frequency of D. rapae also treated with sublethal dose paraquat decreased significantly along with a shortened patch residence time in the foraging area.     

Willingness and behavior towards e-waste recycling for residents in Beijing city,China

This paper is to investigate the behavior of residents towards electrical and electronic waste (e-waste) recycling in Beijing. For this purpose a large sample questionnaire survey was performed to explore the residents’ characteristics of recycling behavior and preference of e-waste recycling pattern. Besides, the willingness of residents to participate in e-waste recycling was also assessed in our study. For this a logistic regression model was developed to estimate and explain residents’ willingness in e-waste recycling. The model showed that Convenience of recycling facilities and service, Residential conditions, Recycling habit and Economic benefits are four determinants of Beijing residents’ willingness and behavior in e-waste recycling. And centralized recycling pattern by professional recovery spots would have a broad prospect if various kinds of channels can be provided to make the residents feel more convenient in e-waste recycling.