Cu fractions, mobility and bioavailability in soil-wheat system after Cu-enriched livestock manure applications

Fertilization of crops with livestock manure (LM) is a common waste disposal option, but repeated application of LM containing high concentrations of heavy metals such as Cu could lead to crop toxicity and environmental risk. To examine the Cu availability and uptake by wheat in a Mollisol affected by Cu-enriched LM, pot experiments were conducted. LM (376 mg kg⁻¹ Cu originally) was spiked with different concentrations of Cu (0, 100, 200, 400, 600 and 800 mg kg⁻¹ soil, added as CuSO₄) to simulate soil Cu contamination by LM application. The results indicated that Cu was predominately distributed in organic bound fraction, while the most drastic increase was found in reducible fraction. Acid-extractable fraction played a more important role than other fractions in controlling the mobility and bioavailability of Cu. DTPA-extractable Cu may overestimate the Cu bioavailability since DTPA solution could extract soluble and part of stable forms. The application of LM at 1% level significantly decline the Cu mobility, but that at 3% level exhibited the opposite effect.Although the quantities of Cu in wheat was very low compared with the accumulation in soil, Cu concentrations in roots increased evidently from 12 to 533 mg kg⁻¹ and that in aerial parts were in a narrow range from 12.1 to 32.7 mg kg⁻¹, indicating the more sensitivity of roots to the Cu toxicity. The Cu concentrations in grains after 3% manure application did not approach the threshold for Cu toxicity (<20 mg kg⁻¹) even at higher Cu addition rates.     

城市环境承载力分析与评估——以湛江市为例

介绍了环境承载力的涵义以及城市环境承载力的评估方法,以PSR模型研究环境压力所对应的环境状态,以此评估城市环境承载状态,并以湛江市为对象,展开城市环境承载力的现状分析,在此基础上对未来不同发展阶段的环境承载力做情景分析,从减压—改善—优化层次上提出湛江市环境承载力提升的对策建议。     

A new and integrated hydro-economic accounting and analytical framework for water resources: a case study for North China

Water is a critical issue in China for a variety of reasons. China is poor of water resources with 2300m(3) of per capita availability, which is less than 13 of the world average. This is exacerbated by regional differences; e.g. North China's water availability is only about 271m(3) of per capita value, which is only 125 of the world's average. Furthermore, pollution contributes to water scarcity and is a major source for diseases, particularly for the poor. The Ministry of Hydrology [1997. China's Regional Water Bullets. Water Resource and Hydro-power Publishing House, Beijing, China] reports that about 65-80% of rivers in North China no longer support any economic activities. Previous studies have emphasized the amount of water withdrawn but rarely take water quality into consideration. The quality of the return flows usually changes; the water quality being lower than the water flows that entered the production process initially. It is especially important to measure the impacts of wastewater to the hydro-ecosystem. Thus, water consumption should not only account for the amount of water inputs but also the amount of water contaminated in the hydro-ecosystem by the discharged wastewater. In this paper we present a new accounting and analytical approach based on economic input-output modelling combined with a mass balanced hydrological model that links interactions in the economic system with interactions in the hydrological system. We thus follow the tradition of integrated economic-ecologic input-output modelling. Our hydro-economic accounting framework and analysis tool allows tracking water consumption on the input side, water pollution leaving the economic system and water flows passing through the hydrological system thus enabling us to deal with water resources of different qualities. Following this method, the results illustrate that North China requires 96% of its annual available water, including both water inputs for the economy and contaminated water that is ineligible for any uses.     

机场鸟击事故灾害的生态防治

从生态学角度分析了机场鸟击事故灾害发生的根源和特点，概述了鸟击灾害的生态防治措施，包括主动性防治和被动性防治，以及计算机和信息技术的应用。指出鸟击灾害已经成为机场飞行安全的主要威胁之一；生态综合防治是机场鸟击事故灾害防治的根本手段。     

中国安全防范产品行业协会第四届理事会第二次会议在南宁召开

中国安全防范产品行业协会于2005年12月14日,在广西南宁召开第四届理事会第二次全体会议.公安部科技委员会主任李润森,中国安全防范产品行业协会理事长柳晓川,公安部科技局副局长刘烁,中国安全防范产品行业协会副理事长廖晓村,中国安全防范产品行业协会副理事长司同军,公安部第一研究所副所长陈绍武,中国安全防范产品行业协会秘书长靳秀凤,中国安全防范产品行业协会副秘书长赵锡廷,中国安全防范产品行业协会副秘书长王俊生等领导出席会议.广西壮族自治区公安厅副厅长于娃宪出席会议,并代表公安厅向大会表示祝贺.……     

两相消化系统产酸相酸化特性模型

通过物料衡算建立产酸相的酸化特性分段模型 ,并求得本研究两相消化系统处理淀粉配制废水情况下产酸相动力学参数为 :产酸菌产率系数 Y=0 .2 8mg·mg^-1,产酸菌衰减系数 kd=0.054h^-1,产酸菌最大比增长率μm=3.1 h^-1,饱和系数 Ks=1866mg·L^-1.讨论了产酸相酸化率对整个系统运行状况的影响 ,表明高酸化率有利于提高系统的处理效率和沼气回收 .     

对某工地一起工伤事故的思考

根据某工地一名工人因开挖作业而被活埋致死这一事故 ,论述了作好安全工作防止事故的前提条件和必要的预防、检查、控制、措施及程序。     

生物-物化法治理稀黑液工艺

提出了以从自然界分离得来的组合菌CG、WD,结合物化法治理稀黑液的工艺方法.结果表明,1.5°Be′左右的稀黑液经本工艺处理,硫化物、挥发酚去除率均达99%以上,色度、CODcr和BOD     

垃圾站垃圾定量出料系统研究与设计

通过对垃圾站内垃圾出料现状的分析及不同出料方式的比较,确定了垃圾出料口出料系统的设计方案,提出了一种全新的出料方式,解决了垃圾站内垃圾定量出料问题。