基于资源环境承载力的全国造纸工业类型区划分研究

本文从造纸行业特征、资源消耗、污染物排放等方面入手,结合区域资源环境承载力,分析行业发展可能带来的环境污染问题.分析造纸行业发展与其所需主要资源间的空间布局关系,明确选定行业发展的资源、环境和生态制约条件.结合造纸行业特点,从环境约束、生态约束和资源约束入手,构建其环境管理类型区划分的指标体系;采用层次分析法、灰色定权聚类分析等方法对分区数据进行必要处理,采用二维判断矩阵法等方法进行环境管理类型区划分,对实施针对造纸行业分区域、分类别、差别化的环境管理提供了决策依据和方法基础.     

一起液氯泄漏事故的分析及预防对策

针对国内近年来氯气泄漏、爆炸事故频发的现状,选择其中具有典型性的江西某厂氯气泄漏事故,运用因果分析方法对其事故原因进行系统分析,根据分析结果,以降低事故发生概率和严重度为目标,从管理角度提出预防对策.     

The method for leakage detection of urban natural gas pipeline based on the improved ITA and ALO

To solve the problems of the difficulty in early leakage monitoring and larger positioning error for urban hazardous chemicals pipelines, the optimized method based on the improved Inverse Transient Analysis (ITA) and Ant Lion Optimizer (ALO) was proposed. Firstly, based on the obtained experiment's results of leakage of natural gas in the non-metallic pipeline, the segment classification method was incorporated into the pressure gradient calculation. The modified method can adapt to the multi-node characteristics of urban pipe networks and help to obtain the preliminary positioning calculation results after optimization. Then the calculation results were embedded in the ITA calculation model. The input parameters of the gas pipeline such as boundary conditions, leakage rate and friction coefficient were used to establish the characteristic linear equations. Then the objective function of the least-squares criterion was defined, and the improved ITA model suitable for leakage detection of urban natural gas pipeline networks was constructed. Finally, the ALO was used to optimize the calculation process of the improved ITA model, and iteratively optimize the optimal friction coefficient and its corresponding minimum objective function (OF) value. As a result, a more precise location of the leakage source was calculated. The validation of the modified method is conducted by comparing the calculated values with the experiment's results. The results show that the method can accurately predict the location where the pipeline leakage occurs. The minimum error is 3.17%. Compared with the traditional ITA, this method not only accelerates the convergence speed of the objective function, but also improves the accuracy of location calculation.     

高吸附性能芦苇活性炭的制备方法研究

为实现白洋淀芦苇的有效利用,以白洋淀淀区芦苇(白苇)为原料,以KOH、K2CO3为活化剂,综合考虑制备过程中的剂料比、浸渍时间、活化温度、活化时间等因素的影响,通过正交试验,以碘吸附值和亚甲蓝吸附值综合作为吸附性能高低的评价标准,进行活性炭制备方法研究。结果表明:在以KOH为活化剂、剂料比为4∶1、浸渍时间36 h、850℃下活化1 h的条件下,制备的芦苇基生物质活性炭碘吸附值最高,亚甲基蓝吸附值较高;以K2CO3为活化剂、剂料比为3∶1、浸渍时间12 h、900℃下活化2 h的条件下,制备的芦苇基生物质活性炭有最高的碘吸附值和对亚甲蓝具有良好的吸附性。制备的生物质活性炭碘吸附值均高于国家活性炭一级品标准(1 000 mg/g),具备一定的实用性。     

羊草草原碳循环过程的模拟与验证

根据内蒙古典型羊草草原碳通量和生物量观测数据,验证VIP(Vegetation Interface Proces-ses)模型,并模拟分析1958—2007年该生态系统碳循环特征及其与环境因子的相关关系。结果显示:VIP模型能够较准确地模拟地上生物量(R2=0.70)和净生态系统生产力NEP(R2=0.57)的变化趋势。羊草草原生态系统总初级生产力(GPP)、净初级生产力(NPP)和生态系统呼吸(Re)在1958—1973年间下降,1973—1993年间增长,1993年后又出现下降的趋势。与环境因子的相关性分析表明,GPP、NPP和Re随CO2和降水的增多而增大,随温度升高和降水的减少而降低,其中降水量与碳通量相关性最高,呼吸与温度、降水、CO2均存在一定程度的正相关关系。NEP年际变化较大,主要受控于年降水量,以228 mm为界,年降水量大于此值时,NEP为正的概率较大。     

锡林河流域典型草原碳素生物小循环研究

应用生物地球化学分室方法研究了内蒙古锡林河流域2个典型草原群落——羊草草原和大针茅草原的碳素生物小循环,研究表明:①生长季禁牧的羊草草原植物分室碳素净固定量为165.50 gC.m-2,土壤分室碳素净排放量为174.36 gC.m-2,系统碳素净固定量为-8.86 gC.m-2,基本处于平衡状态,植物分室的碳输入和碳输出也近于平衡状态;②生长季禁牧的大针茅草原植物分室碳素固定量为130.04 gC.m-2,土壤分室碳素净排放量为128.28 gC.m-2,系统碳素净固定量为1.76 gC.m-2,基本处于平衡状态,植物分室的碳输入和碳输出在降水量大的年份以输入为主,在降水量小的年份近于平衡状态;③水热等生境条件较适宜的羊草草原碳素周转量比大针茅草原要大得多,水分是典型草原碳素循环量的主要影响因素。     

基于稳定同位素示踪的流域颗粒有机物质来源辨析

为有效控制流域水质污染,保证饮用水水源的水质安全,通过采集和测定流域内土壤、植物以及河流断面水体悬浮颗粒有机质(POM)在枯水期和丰水期的碳、氮稳定同位素值和C/N比值,对石头口门水库汇水流域水体POM的来源进行研究.结果表明,水体中POM主要来源于土壤有机质,其贡献为69.2%,藻类等大型水生生物和浮游植物的贡献分别为23.1%和7.7%.流域水体中POM的来源存在时空差异.丰水期,浮游植物和藻类等大型水生植物的贡献均为15.4%,而枯水期后者的贡献提高到了30.8%.水体POM主要来源于双阳河和饮马河下游的土壤有机质,说明该区域土壤侵蚀较重,易发生非点源污染;岔路河和饮马河上游支流小黄河,水体POM以浮游植物的贡献占主导,其贡献分别为86.3%和94.8%,这些区域侵蚀较弱,非点源污染发生的风险小;大中型水库区域的POM主要由藻类等大型水生植物贡献,表明悬浮颗粒物在进入水库后可能发生了明显沉积.     

海藻酸钠包埋活性炭与细菌的条件优化及其对Pb~(2+)的吸附特征研究

利用海藻酸钠固定化包埋活性炭与多黏类芽孢杆菌GA1,通过正交试验研究海藻酸钠溶液浓度、包炭量及包菌量吸附Pb2+的最佳配比,并研究了这种新型的固定化小球对Pb2+的吸附特征.结果表明,固定化活性炭与多黏类芽孢杆菌GA1小球最佳制备条件为海藻酸钠质量分数2.5%、包炭量1:20和包菌量1:2,在该制备条件下吸附率达到93.74%.固定化小球的最佳吸附条件为pH5、温度30℃和Pb2+初始浓度300mg·L-1,活性炭与GA1经固定后对pH、温度和Pb2+初始浓度适应范围扩大.吸附平衡曲线表明,对Pb2+的吸附在30min内是一个快速的过程,在2h时基本趋于平衡,且平衡曲线能较好地用Langmuir模型和Freundlich模型来描述,其吸附过程主要为单分子层吸附,最大单分子层吸附量为370.37mg·g-1.解吸结果表明固定化小球能有效地循环利用.     

Influence of Indian mustard （Brassicajuncea） on rhizosphere soil solution chemistry in long-term contaminated soils： A rhizobox study

This study investigated the influence of Indian mustard (Brassica juncea) root exudation on soil solution properties (pH, dissolved organic carbon (DOC), metal solubility) in the rhizosphere using a rhizobox. Measurement was conducted following the cultivation of Indian mustard in the rhizobox filled four di erent types of heavy metal contaminated soils (two alkaline soils and two acidic soils). The growth of Indian mustard resulted in a significant increase (by 0.6 pH units) in rhizosphere soil solution pH of acidic soils and only a slight increase (< 0.1 pH units) in alkaline soils. Furthermore, the DOC concentration increased by 17–156 mg/L in the rhizosphere regardless of soil type and the extent of contamination, demonstrating the exudation of DOC from root. Ion chromatographic determination showed a marked increase in the total dissolved organic acids (OAs) in rhizosphere. While root exudates were observed in all soils, the amount of DOC and OAs in soil solution varied considerably amongst di erent soils, resulting in significant changes to soil solution metals in the rhizosphere. For example, the soil solution Cd, Cu, Pb, and Zn concentrations increased in the rhizosphere of alkaline soils compared to bulk soil following plant cultivation. In contrast, the soluble concentrations of Cd, Pb, and Zn in acidic soils decreased in rhizosphere soil when compared to bulk soils. Besides the influence of pH and DOC on metal solubility, the increase of heavy metal concentration having high stability constant such as Cu and Pb resulted in a release of Cd and Zn from solid phase to liquid phase.     

Particle properties in granular activated carbon filter during drinking water treatment

The elemental composition and bacteria attached in particles were investigated during granular activated carbon (GAC) filtration.The experimental results showed that trapped influent particles could form new,larger particles on GAC surface.The sloughing of individuals off GAC surface caused an increase in effluent particles in the size range from 5 to 25 μm.The selectivity for element removal in GAC filters caused an increasing proportion of metallic elements in the effluent particles.The distribution of molar ratio indicated a complicated composition for large particles,involving organic and inorganic substances.The organic proportion accounted for 40% of total carbon attached to the particles.Compared with dissolved carbon,there was potential for the formation of trihalomethanes by organic carbon attached to particles,especially for those with size larger than 10 μm.The pure carbon energy spectrum was found only in the GAC effluent and the size distribution of carbon fines was mainly above 10 μm.The larger carbon fines provided more space for bacterial colonization and stronger protection for attached bacteria against disinfection.The residual attached bacteria after chorine disinfection was increased to 10 2-10 3 CFU/mL within 24 hours at 25°C.