Emission control for precursors causing acid rain (V): Improvement of acid soil with the bio-briquette combustion ash

The bio-briquette technique which mixes coal, biomass and sulfur fixation agent and bio-briquettes under 3-5 t/cm^2 line pressure has aroused people‘s attention in view of controlling the air pollution and the acid rain. In this paper, the physicochemical properties of bio-briquette and its ash were investigated. And the acid soil was improved by the bio-briquette combustion ash, which contained nutritive substances such as P, N, K and had the acid-neutralizing capacity(ANC). The pH, EC, effective nutrient elements(Ca, Mg, K, P and N), heavy metal elements(AI, Cu, Cd, Cr, Zn and Mn) and acid-neutralizing capacity change of ash-added soils within the range of 0-10%, were also studied. Specially, when 5% bio-briquette combustion ash was added to the tested soil, the content of the effective elements such as Ca, Mg and K rose by 100 times, ? times and twice, respectively. The total nitrogen also increased by about twice. The results showed the oxyanions such as that of AI, Cu, Cd, Cr, Zn and Mn were not potentially dangerous, because they were about the same as the averages of them in Chinese soil. It is shown that the ANC became stronger, though the ANC hardly increases in the ash-added soil. On the basis of the evaluation indices, it is concluded that the best mixture ratio is to add 2.5%--8% of the bio-briquette combustion ash to the tested soil.     

Rapid treatment of atrazine-contaminated water by nickel/iron bimetallic system

The utility of nickel/iron in the remediation of atraz.ine-contaminated water was investigated. The experimental results showed that nickel/iron had effective catalytic activity in dechlorinating atraz.ine under acidic conditions. The dechlonnation reaction approximately followed the first-order kinetics under the experimental conditions( nickel/iron: 1.0 g/250 ml: Ca~r~ = 20.0 mg/L), the reaction rate increased with decreasing pH value of the reaction solution and increasing the proportion of Ni: Fe within 2.95 %. For condition with 2.95% nickel/iron, the reaction rate constants were 0.07518( R = 0.9927), 0.06212( R = 0.9846) and 0.00131 min^-1 ( R = 0.9.565) at pH = 2.0, 3.0 and 4.0, respectively. HPLC analysis was used to monitor the decline of atraz.ine concentration.     

高砷煤矿废水灌溉区土壤砷的分布特征探究

通过对贵州兴仁县交乐村高砷煤矿废水灌溉区土壤总砷的分布特征进行研究。文章对土壤总砷、pH值及有机质含量进行了分析,结果表明,污灌区土壤砷的含量最高达237.55mg/kg,最低为24.20mg/kg,平均As含量为85.62mg/kg,均高于世界、中国及贵州黄壤中的平均水平;pH平均值为5.12,属酸性土壤;有机质含量普遍偏高;高砷煤矿废水灌溉导致了灌区土壤中砷的累积。灌溉方式影响了土壤中砷的迁移与分布情况,土壤中砷的含量,随着与灌溉水源距离的增加而急剧降低。研究区土壤中砷的迁移较缓慢,但有向下游逐渐扩散的趋势。土壤总砷含量受到了pH值和有机质影响,但与两者的相关性并不明显。     

Biological removal of methanol from process condensate for the purpose of reclamation

The biological removal of methanol from condensate of ammonia manufacturing processes for the purpose of reclamation using contact type reactor was studied. Methanol of 60 mg/L was removed completely under an HRT of 1.12 h. Optimal inorganic nutrient dose was determined on evaluating methanol removal performance and dehydrogenase activities (DHA) under different nutrition doses. The optimal inorganic nutrient dose only gave an increase of conductivity of ca. 10μs/cm^2 in the effluent on treating synthetic condensate containing methanol of 30mg/L. The results demonstrated that biological removal of methanol was effective for the purpose of recovering the methanol-bearing condensate.     

Effect of nitrogen and phosphorus on the water quality in the Three Gorges Reservoir Area during and after its construction

A survey concerning the concentration of the nutrients in the Three Gorges Reservoir Area was carried out. This paper presents the parameters(NO3^- -N, NO2^- -N, KjeldahI-N, non-ionic ammonia, P-PO4 and TP)determined at 16 sampling sites from 1997 to 1999. The dominant soluble nitrogen form was NO3^- -N followed by KjeldahI-N, NO2^- -N and non-ionic ammonia. Mean values of NO3^- -N, NO2^- -N, Kjeldahl-N and non-ionic ammonia ranged from 0.50 to 2.37 mg/L, 0.022 to 0.084 mg/L, 0.33 to 0.99 mg/L and 0.007 to 0.092 mg/L respectively.Mean values of P-PO4 at most sampling sites were higher than 0.1 mg/L for subject to eutrophication. The major factors influencing the concentrations of N and P might be agricultural runoff, municipal and industrial effluents. In addition, 6 kinds of soil were sampled at the area where would inundated after the dam completed. Two approaches were adopted to simulate the N and P release from the inundated soils. The results showed that the soils would release nitrogen and phosphorus to the overlying water when the soils were inundated. The characteristics of soil affected the equilibrium concentrations of N and P between the soil and the overlying water.     

如何有效规避管道交叉点施工风险

采气一厂管辖各类管线6000余km,随着国家和地方基础设施建设不断完善,天然气管道安全范围内的各类施工逐年增多。由于施工队伍水平参差不齐,管线安全范围内的施工对气田已建集输管网构成较大的安全风险。总结了采气一厂近年来在管线交叉施工管理过程中摸索出的各类经验,同时对实施效果进行评价,旨在为同行提供参考和借鉴。     

原料转运站除尘系统设计及应用

针对原料转运站除尘系统常见问题,结合工程实例,从管网系统设计、除尘器选型、系统控制及日常维护等方面阐述解决方法。     

基于GIS技术的工业危险废物排放信息管理系统研究

研究运用C#语言与地理信息系统(GIS)二次开发组件MapObjects相结合的技术,建立工业危险废物排放信息管理系统。该系统将危险废物排放信息与地理坐标有效地结合起来,准确定位工业危险废物的排放地点及其相关的排放信息,对工业危险废物的排放信息进行查询和处理,使申请排放单位和接纳单位通过环境保护部门进行良好的沟通,便于工业危险废物的分类、管理及回收再利用。     

纵向通风隧道内火灾温度场分布规律研究

以狮子洋水下特长隧道为工程背景,利用CFD数值模拟软件FDS 4.01,建立隧道实体物理模型,进行火灾数值模拟分析。研究了列车火灾热释放功率为15 MW、不同坡度、不同纵向通风风速下,该类隧道内拱顶附近和2 m高处温度场的纵向分布规律,以及各工况下拱顶的最高温度,并分析其对隧道结构防火和人员疏散救援的影响。结果表明:随隧道坡度的增大,在同一通风速率下的烟气回流长度逐渐减小,但随着风速的加大,坡度对烟气回流的影响逐渐减弱;随着通风风速的增大,火区附近的温度下降,而沿程温度上升,纵向通风速率越大,拱顶温度越低。     

基于化工发展胁迫的连云港生态风险预警研究

以区域生态风险预警为目的的区域生态风险评价工作,可以为政府实现有效的生态风险管理提供良好的决策依据.构建了包括化工风险压力指数、区域环境状态指数、区域生态风险管理指数的区域化工生态风险的评价指标体系,提出了根据区域生态风险评价结果进行生态风险状态以及趋势预警的具体方法.并据此对连云港地区进行了区域生态风险综合评价及状态预警.结果表明,研究区域多数镇化工总体而言风险不大,处于无警和轻警状态,分别占总数的11.1%和71.4%;中警状态占15.9%,包括人口稠密的连云港市区,云台乡和花果山等自然保护区以及灌河入海口;堆沟港镇属于重警区域,占总数的0.02%;无巨警区域.