环保型无氮自硬呋喃树脂砂粘结剂的制作应用

介绍了基本上不含游离甲醛及游离苯酚含量很低的无氮自硬呋喃树脂砂粘结剂的制作方法和应用。这种粘结剂仍然使用甲醛、糠醇(呋喃甲醇)、苯酚等原料作为其合成树脂的主要材料,使用一种低分子物作为合成改性剂,采用适当的工艺制作而成,不改变树脂的性能,且树脂制作成本基本不变。该粘结剂的使用可在很大程度上降低铸件生产过程的游离甲醛和游离苯酚对生产环境和操作人员的污染和损害。     

Water quality management of a stretch of river Yamuna: An interactive fuzzy multi-objective approach

This paper presents an Interactive Fuzzy Multi-Objective Linear Programming (IFMOLP) model for water quality management in a river basin. The IFMOLP model formulated will first evaluate dissolved oxygen (DO) concentrations or DO deficits at a point in different reaches depending on the overall Biochemical Oxygen Demand (BOD) concentration present in the respective drain. Subsequently, the model incorporates the aspirations and conflicting objectives of the decision maker (DM) by taking into consideration the aspects relevant for pollution control boards as well as dischargers responsible for generating wastewater. The uncertainty associated with specifying the water quality criteria (based on DO concentration or DO deficit) and treatment cost to remove pollution level is incorporated by interacting the decision maker. In this process DM is asked to specify the reference aspiration levels of achievement for the values of all membership functions generated with respect to each objective. This provides flexibility for the pollution control authorities and dischargers to specify their aspirations. IFMOLP model developed herein is then used in a case study for the evaluation of optimal BOD removal in different drains located across the river Yamuna at New Delhi, India. The presented model will simulate the allocation of waste load efficiencies with satisfactory results which will indicate usefulness of the model in managing more complex river basins along with better flexible policies of water management.     

某厂放射性废水排放口外江浅滩底质泥污染调查(二)

本文是对某钍水冶厂放射性废水造成江浅滩底质泥污染的第二篇报告。作者测定了底质泥表面上的γ照射量率,认为底质泥的污染可能是符合高斯分布的。根据深度为40厘米泥芯样的测量结果,表明最大污染层深度为20厘米左右。作者对1975—1979年期间的废水监测资料进行了统计分析,发现 pH 值呈正态分布((?)=8.0,(?)=2);钍、铀和镭的浓度呈对数正态分布。     

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压井是试油中经常采用的一项工艺技术，多年来对于压井暂闭通常是采用重泥浆压井，有时还在井内加注一个水泥塞。对于压井酸化、通常是在井底压降较大的情况下进行。过去的这种压井方法不仅对地层造成了较严重的污染，而且在些井还造成了严重的工程事故，耗费了大量的人力和财力。为了防止这些问题的发生，着重针对四川碳酸盐地层高压高产气井的压井暂闭、常规压井酸化增产措施中防止地层污染、防止工程事故的问题进行了研究。从实际     

钻井液添加剂生物降解性研究

采用OECD推荐的需氧性简易生物降解能力实验——带盖小瓶海水实验法,对7种钻井液添加剂的生物降解性进行了较为详细的研究。研究结果表明,7种钻井液添加剂在所研究的浓度(20mg/L)范围内均能发生生物降解,其降解难易程度与分子结构密切相关,生物可降解性顺序为:淀粉类产品>烯类单体聚合物>含芳香烃的添加剂     

Aqueous and vapor phase mercury sorption by inorganic oxide materials functionalized with thiols and poly-thiols

The objective of the study is the development of sorbents where the sorption sites are highly accessible for the capture of mercury from aqueous and vapor streams. Only a small fraction of the equilibrium capacity is utilized for a sorbent in applications involving short residence times (e.g., vapor phase capture of mercury from coal-fired power plant flue gases). So, dynamic capacity rather than equilibrium capacity is more relevant for these kinds of situations. Rapid sorption rates and higher dynamic capacity can be achieved by increasing the accessibility of active sites and decreasing the diffusional resistance to mass transport for the adsorbing species. This requires the use of open structured sorbent materials and attachment of functional groups on the external surface area of supports. The strong interaction of sulfur containing ligands (e.g., thiol) with mercury makes them suitable candidates for immobilization on these types of materials. In this study, inorganic oxide supports like alumina and silica are functionalized with thiol moieties like mercapto silane, cysteine and poly-cysteine for capturing mercury from aqueous and vapor phase. Aqueous phase Hg (II) sorption studies with cysteine/poly-cysteine functionalized silica showed that high dynamic capacity can be achieved by attaching active sites (thiol) on the external area of supports. Vapor phase Hg capture studies with thiol-functionalized mesoporous silica (Hg⁰ concentration = 3.37 mg/m³ with N₂ as the carrier, gas temperature = 70 ^°C) yielded a capacity of 143 g Hg/g for the sorbent. Although the sulfur content for the sorbent was low (0.80 wt. %) the molar ratio of Hg captured to sulfur was comparatively high (2.86×10^–3) pointing to the high accessibility of sulfur sites.     

浅谈液压系统污染物的控制

正确使用与维护液压系统,保证油液的清洁,是液压设备日常维护和使用中的一项重要工作。针对液压零件加工、液压元件、零件的清洗、液压件装配和液压件运输等各个过程讨论了液压系统的污染控制。     

有关电子俘获检测器污染后的判定、清洗及维修案例分析

电子俘获是气相色谱分析中常用的的检测器（ECD）。它最易出现的问题就是受污染,轻则灵敏度降低,重则没有响应。处于对放射源的恐惧,人们往往敬而远之,不知该如何处理。所以,了解污染源、判定污染程度、掌握有效的清洗方法,这对用好仪器有着很大的帮助。通过一个故障实例的分析,更清晰的展示了整个维修过程。包括防止污染的办法、判断污染的步骤、清洗管路的连接、操作中的注意事项和技巧等。     

我国城郊地区农用地重金属污染与农产品质量安全

本文综合分析了我国城郊地区农业生产的特点、土壤重金属污染现状和重金属污染物的主要来源,提出了加强管理、预防重金属污染和确保城郊农产品质量安全的措施。     

地下水硝酸盐迁移转化规律分析

地下水硝酸盐污染已日趋严重,已经在很大程度上影响了环境和人类健康。分析了地下水硝酸盐的迁移转化过程,并指出要从空间和时间两方面综合研究硝酸盐的迁移转化规律。最后,就今后地下水硝酸盐迁移转化规律的研究方向提出展望。