采用节水措施促进秦皇岛市水资源可持续发展

水资源是人类生存与发展最宝贵的自然资源,是任何其他资源都无法取代的、有限的资源.中国人均水资源量只有世界人均占有量的四分之一,是一个水资源贫乏的国家.秦皇岛市人均水资源量为597 吨/年,是全国平均值的1/4左右,属于缺水城市.在可供水不断减少的情况下,水资源需求量又在不断增加,因此,未来水资源的短缺形势将更为严峻,以水资源紧张为特征的水危机将会不断加剧.面对水资源短缺危机,节水成为秦皇岛市水资源可持续利用的根本出路.     

辽河表层沉积物重金属生态风险与综合毒性表征

采用ICP-MS测定了辽河26个支流表层沉积物间隙水中7种重金属(Pb、Cu、Cr、Zn、Ni、As、Cd)的含量,并应用间隙水毒性基准单位(IWCTU)和Nemeraw指数(NI)对间隙水重金属生态风险进行了评价;同时利用摇蚊幼虫活体生物毒性测试方法评估了辽河流域26个支流表层沉积物的综合毒性。研究结果显示,辽河支流表层沉积物间隙水7种重金属平均含量为:Pb 3.92μg·L-1,Cu 5.73μg·L-1,Cr 7.21μg·L-1,Zn 4.33μg·L-1,Ni 4.48μg·L-1,As 5.89μg·L-1,Cd 0.29μg·L-1,根据IWCTU值和NI值,柴河、养息牧、亮子河、凡河、付家窝堡、接官厅具有潜在的生态风险;综合毒性表征结果表明,柴河、长沟子河、付家窝堡、柳河、一统河、潮沟河表层沉积物对摇蚊幼虫具有较高毒性。结合重金属毒性和综合毒性分析,认为辽河流域支流表层沉积物毒性应该是由复合污染形成,而不仅仅是重金属污染。     

Identification of magnetic particulates in road dust accumulated on roadside snow using magnetic, geochemical and micro-morphological analyses

The aim of this study is to test the applicability of snow surveying in the collection and detailed characterization of vehicle-derived magnetic particles. Road dust extracted from snow, collected near a busy urban highway and a low traffic road in a rural environment (southern Finland), was studied using magnetic, geochemical and micro-morphological analyses. Significant differences in horizontal distribution of mass specific magnetic susceptibility (χ) were noticed for both roads. Multi-domain (MD) magnetite was identified as the primary magnetic mineral. Scanning electron microscope (SEM) analyses of road dust from both roads revealed: (1) angular-shaped particles (diameter ∼1-300 μm) mostly composed of Fe, Cr and Ni, derived from circulation of motor vehicles and (2) iron-rich spherules (d ∼ 2-70 μm). Tungsten-rich particles (d < 2 μm), derived from tyre stud abrasion were also identified. Additionally, a decreasing trend in χ and selected trace elements was observed with increasing distance from the road edge.     

煤基腐殖酸对外源砷胁迫下玉米生长及生理性状的影响简

为了筛选用于砷污染土壤治理的煤基腐殖酸,采用盆栽实验研究了施用不同种类和浓度的煤基腐殖酸及EDTA对外源砷胁迫下玉米株高、株鲜重、株干重、根干重、砷积累量、叶片抗氧化酶（POD,SOD和CAT）活性和脯氨酸含量的影响。结果表明,11种供试煤基腐殖酸均促进了玉米生长,提高了叶片POD、SOD和CAT活性。其中6和10号腐殖酸可降低土壤砷活性和显著抑制玉米吸收和积累砷,而8和9号腐殖酸增加了土壤活性砷和显著促进了玉米对砷的吸收和累积,且不同程度地强于EDTA。除8和9号外,其余腐殖酸均可明显降低玉米叶片脯氨酸的含量。EDTA可显著促进玉米吸收和积累砷,且加剧了砷对玉米的危害。因此,8和9号供试煤基腐殖酸可以替代EDTA活化土壤砷,与植物配合以提高砷污染土壤的植物修复速度和效果,而6和10号供试煤基腐殖酸则可用于土壤砷钝化剂,以保证作物产品的安全。     

生物膜生态浮床对城市尾水净化特征分析

为探究生物膜对城市尾水的净化特征,通过采用联合生物膜生态浮床技术,考察生物膜长度、水力停留时间(HRT)及生物膜覆盖面积对含氮尾水的净化特征.结果表明,生物膜为1/2水深长度时,NH₄⁺-N、NO₃^--N和TN的去除率分别可达到90. 82%、62. 7%和81. 96%,氮去除率较高,而生物膜长度为整个河道水深时,NH₄⁺-N的去除率最高只有22. 07%,NO₃^--N和TN的浓度变化不明显.在HRT为6 d时,NH₄⁺-N和TN的去除率最高分别可达到82. 01%和62. 88%,最低分别为55. 24%和46. 82%;当HRT为12 d时,NH₄⁺-N和TN的去除率最高分别可达81. 4%和79. 93%,但最低分别达到了8. 73%和17. 23%,对比发现,HRT为6 d时氮的去除效率较高且稳定.在生物膜覆盖面积为...     

Combined application of chemical fertilizer with green manure increased the stabilization of organic carbon in the organo-mineral complexes of paddy soil

Environmental Science and Pollution Research - The influence of the combined application of chemical fertilizer with green manure on the stabilization of organic carbon (C) was explored in the...     

农用土地价格评估——以新疆库尔勒市为例

根据农用土地的具体特征选择适当的方法和评估中具体的操作是本文探讨的重点。解决不同利用方式下农用土地收益差异的综合平衡计算是关键。结合库尔勒市农用土地分等定级的具体实践，建立一套较为完整的农用土地价格评估体系，为今后开展的工作提供范例。     

长江三角洲地区耕地质量变化的初步研究——以锡山市为例

长江三角洲地区耕地质量变化的监测是区土地可持续利用研究的重点领域。锡山市位于太湖平原北部，其耕地质量变化过程反映了长江三角洲腹地经济发展水平较高地区的耕地现状和发展趋势。本研究以锡山市为典型区，依据第二次土壤普查资料，多年土壤监测数据和有关耕地系统状态的统计数据，结合研究区耕地状况的调查分析，提出了支持压力－状态－响应模型的耕地质量评价指标体系，并据此指标体系分析了该区耕地质量变化趋势。结果表明，该区耕地系统的发展总体上是可控的、有序的、但是耕地系统产出能力的稳定性呈下降趋势，系统高水平投入的维持面临较大的压力。鉴于人口增加和耕地持续减少的态势在很长一段时间内难以逆转，耕地占补的质量差异因素，是该区能否实现耕地总量动态平衡的关键所在。     

壳聚糖吸附处理废水的研究进展

壳聚糖吸附处理废水的研究包括其对废水吸附性能和吸附机理的研究两个方面。壳聚糖表现出了良好的吸附废水中重金属离子、染料分子和其它易引起变异物质的能力;壳聚糖对金属离子和染料的吸附机理模型研究理论意义重大,它将进一步推动壳聚糖的实际工程应用。     

Combined effects of nitrogen addition and organic matter manipulation on soil respiration in a Chinese pine forest

The response of soil respiration (Rs) to nitrogen (N) addition is one of the uncertainties in modelling ecosystem carbon (C). We reported on a long-term nitrogen (N) addition experiment using urea (CO(NH₂)₂) fertilizer in which Rs was continuously measured after N addition during the growing season in a Chinese pine forest. Four levels of N addition, i.e. no added N (N0: 0 g N m⁻² year⁻¹), low-N (N1: 5 g N m⁻² year⁻¹), medium-N (N2: 10 g N m⁻² year⁻¹), and high-N (N3: 15 g N m⁻² year⁻¹), and three organic matter treatments, i.e. both aboveground litter and belowground root removal (LRE), only aboveground litter removal (LE), and intact soil (CK), were examined. The Rs was measured continuously for 3 days following each N addition application and was measured approximately 3–5 times during the rest of each month from July to October 2012. N addition inhibited microbial heterotrophic respiration by suppressing soil microbial biomass, but stimulated root respiration and CO₂ release from litter decomposition by increasing either root biomass or microbial biomass. When litter and/or root were removed, the “priming” effect of N addition on the Rs disappeared more quickly than intact soil. This is likely to provide a point of view for why Rs varies so much in response to exogenous N and also has implications for future determination of sampling interval of Rs measurement.