Occurrence and risk evaluation of organophosphorus pesticides in typical water bodies of Beijing,China

Environmental Science and Pollution Research - Abstract Human activities, particularly in large cities, can lead to pollution caused by micropollutants such as pesticides in water bodies, which...     

Effects of high dose copper on plant growth and mineral nutrient (Zn,Fe, Mg,K, Ca) uptake in spinach

Loessal soil is one of the main cultivated soils in northwest China. Part of its distribution area was irrigated with industrial wastewater in past three decades. This caused heavy metal contamination in the soil. It had induced toxicity on crops and also threatened local human health for now. Based on a field plot experiment, effects of different Cu concentrations (from 45 to 2000 mg kg^?1) in loessal soil on spinach plant growth and uptake of mineral nutrients (Zn, Fe, Mg, K, and Ca) by spinach were investigated. The Cu addition increased available concentrations of mineral nutrients in loessal soil and concentrations of Cu, Zn, Mg, and Ca in roots. The translocation of mineral nutrients from roots to leaves was inhibited under Cu addition, inducing their decrease in leaves. The EC₁₀ and EC₅₀ of soil Cu in relative dry weights of leaves were 240.33 mg kg^?1 and 1205.04 mg kg^?1, respectively. The PLS-PM analysis showed that available concentrations of nutrients in soil were only affected by Cu in soil positively, nutrients in roots were mainly affected by Cu in soil and Cu in leaves positively, nutrients in leaves were mainly affected by Cu in roots negatively, translocation of nutrients in spinach and plant growth were principally affected by Cu in leaves negatively, and the total effect of Cu in leaves on nutrients in roots and leaves, translocation of nutrients in spinach, and plant growth was the highest. Our results indicated that the phytotoxicity of Cu including spinach growth inhibition and mineral disorder in spinach was mainly affected by the Cu concentrations in leaves.

     

Evaluation of toxic effects induced by arsenic trioxide or/and antimony on autophagy and apoptosis in testis of adult mice

Environmental Science and Pollution Research - Arsenic trioxide (ATO) and antimony (Sb) are well-known ubiquitous environmental contaminants and cause unpromising male reproductive effects in...     

美丽城市内涵与美丽杭州建设战略研究

城市是环境、经济、社会的复合体与基本单元,美丽城市建设是美丽中国的重要基础和途径。本文在城市系统、城市形象、城市美学和生态文明建设理论的基础上,研究提出美丽城市建设的自然、环境、人居、经济、人文、生活等六大系统框架,提出评价指标体系构建思路原则。结合美丽杭州建设战略研究,提出了三大战略重点、四大战略途径和六大战略任务的总体框架。提出美丽城市建设需要重视格局、结构、质量的内在约束引导机制、区域分类指导机制以及差异化的评价指标体系建设的建议．为姜丽城市建设提供券者．     

全国环境规划院（所）建设现状、问题及思考分析

通过对全国各省环境规划院所的建设情况,如机构设立情况和业务领域及主要工作内容的了解,在此基础上,对比分析了城市规划和土地规划院所的建设与发展情况,并对环保系统的规划院所建设存在的问题进行了分析,认为现阶段中国环境规划院所能力建设存在职能定位尚不清晰、全国建设未形成规模效应、人员队伍力量薄弱、资质等硬件水平竞争力差以及基础保障不足等问题。结合中国环境保护工作面临的形势,提出中国环境规划院所的建设与完善的可行性建议。     

基于低碳经济的城市建设发展研究

随着全球变暖的进一步加剧,低碳经济的概念逐渐进入人们的视野。文章主要介绍了城市发展低碳经济的必要性,低碳经济的内涵,城市发展低碳经济的主要途径,最后提出了在中国发展低碳经济的愿景。     

Photocatalytic degradation of C. I. Reactive Red 24 solution with K6SiW11O39SnⅡ

Environmental friendly materials, K₆SiW₁₁O₃₉Sn (SiWSn), was synthesized. SiWSn photocatalytic decomposition of C. I. Reactive Red 24 (RR24) with the UV-lamp (253.7 nm, 20 W), Xenon lamp filtered less than 390 nm light (500 W) and sun light was investigated. The results showed that RR24 solution could be effectively decolorized with the SiWSn photocatalyst. The photocatalytic degradation efficiency of RR24 with SiWSn was affected by the initial concentration of RR2 solution, the amount of SiWSn and the photolysis time. It is demonstrated that the process of photodegradation of RR24 with SiWSn is a pesudo first-order reaction, which can be described by Langmuir-Hinshelwood equation. Hydroxyl radicals and holes are both the main oxidants in the photocatalytic reaction of RR24 with SiWSn.     

The formation kinetics and control of biofilms by three dominant fungi species isolated from groundwater

Filamentous fungi can enter drinking water supply systems in various ways, and exist in suspended or sessile states which threatens the health of individuals by posing a high risk of invasive infections. In this study, the biofilms formation kinetics of the three genera of fungal spores, Aspergillus niger (A. niger), Penicillium polonicum (P. polonicum) and Trichoderma harzianum (T. harzianum) isolated from the groundwater were reported, as well as the effects of water quality parameters were evaluated. In addition, the efficiency of low- concentrations of chlorine-based disinfectants (chlorine, chlorine dioxide and chloramine) on controlling the formation of fungal biofilms was assessed. The results showed that the biofilms formation of the three genera of fungi could be divided into the following four phases: induction, exponential, stationary and sloughing off. The optimum conditions for fungal biofilms formation were found to be neutral or weakly acidic at 28 °C with rich nutrition. In fact, A. niger, P. polonicum, and T. harzianum were not observed to form mature biofilms in actual groundwater within 120 hr. Carbon was found to have the maximum effect on the fungal biofilms formation in actual groundwater, followed by nitrogen and phosphorus. The resistance of fungal species to disinfectants during the formation of biofilms decreased in the order: A. niger > T. harzianum > P. polonicum. Chlorine dioxide was observed to control the biofilms formation with maximum efficiency, followed by chlorine and chloramine. Consequently, the results of this study will provide a beneficial understanding for the formation and control of fungal biofilms.     

Alternating nitrogen feeding strategy induced aerobic granulation: Influencing conditions and mechanism

Effective cultivation of stable aerobic granular sludge (AGS) is a crucial step in the successful application of this technology, and the formation of AGS could be facilitated by some environmental stress conditions. Four identical sequencing batch reactors (SBRs) were established to investigate the aerobic granulation process under the same alternating ammonia nitrogen feeding strategy superimposed with different environmental conditions (inorganic carbon source, temperature, N/COD). Although various superimposed conditions induced a significant difference in the size, settling velocity, mechanic strength of AGS, mature aerobic granules could be successfully obtained in all four reactors after 70 days' operation, indicating the alternating ammonia nitrogen feeding strategy was the most critical factor for AGS formation. Based on the results of redundancy analysis, the presence of an inorganic carbon source could facilitate the cultivation of AGS with nitrification function, while the moderate temperature and fluctuant N/COD might benefit the cultivation of more stable AGS. In addition, superimposed stress conditions could result in the difference in the microbial population between four reactors, but the population diversity and abundance of microorganisms were not the determinants of AGS formation. This study provided an effective method for the cultivation of AGS by using alternating ammonia nitrogen feeding strategy.     

Theory and Model of Agricultural Insurance Subsidy

Abstract

The issue of agricultural insurance subsidy is discussed in this paper aiming to make it provided more rationally and scientifically. It is started with the connection between agricultural insurance and financial subsidy. It is really necessary and crucial to implement the financial insurance due to the bad operational performance, especially in the developing countries. But the subsidy should be provided more rationally because financial subsidy has lots of negative effects. A model in competitive insurance markets developed by Ahsan et al (1982) and a farmers' decision model are developed to solve the optimal subsidized rate. Finally, the equation is got to calculate it. But a quantitative subsidized rate is not made here because the calculation should be under some restricted conditions, which are always absent in the developing countries. So the government should provide some subsidy for the ex ante research and preparation to get the scientific probability and premium rate.