Arsenic removal from groundwater by acclimated sludge under autohydrogenotrophic conditions

Arsenic in the environment is attracting increasing attention due to its chronic health effects. Although arsenite(As(III)) is generally more mobile and more toxic than arsenate(As(V)), reducing As(V) to As(III) may still be a means for decontamination, because As(III) can be removed from solution by precipitation with sulfide or by adsorption or complexation with other metal sulfides. The performance of As(V) bio-reduction under autohydrogenotrophic conditions was investigated with batch experiments. The results showed that As(V) reduction was a biochemical process while both acclimated sludge and hydrogen were essential. Most of the reduced arsenic remained in a soluble form, although 20% was removed with no addition of sulfate, while 82% was removed when sulfate was reduced to sulfide. The results demonstrated that the reduced arsenic was re-sequestered in the precipitates, probably as arsenic sulfides. Kinetic analysis showed that pseudo first-order kinetics described the bio-reduction process better than pseudo second-order. In particular, the influences of pH and temperature on As(V) reduction by acclimated sludge under autohydrogenotrophic conditions and total soluble As removal were examined. The reduction process was highly sensitive to both pH and temperature, with the optimum ranges of pH 6.5–7.0 and 30–40°C respectively. Furthermore, Arrhenius modeling results for the temperature effect indicated that the As(V) reduction trend was systematic. Total soluble As removal was consistent with the trend of As(V) reduction.     

钦州湾无机氮入海通量及其富营养化症状分析

根据对环钦州湾区域的入海河流、直排海污染源及养殖废水无机氮入海通量的估算,2011年钦州湾无机氮入海通量约为7 655 t,其中入海河流无机氮入海通量占总量的96.4%,直排海污染源次之。入海无机氮占钦州湾无机氮总量的比重为36.7%,说明钦州湾已属中等强度人为影响海域。根据对钦州湾富营养化症状——叶绿素a含量的分析,钦州湾富营养化症状不明显,钦州湾整体的富营养化程度较低。因而仅以营养盐含量评价目标海域的富营养化程度,易失之偏颇,宜结合富营养化症状来判断目标海域的富营养化程度。     

低碳高氮污水处理应用技术研究

针对碳氮比小于7的污水,其碳源不能满足硝化与反硝化的要求这一问题,通过改变SBR工艺的运行方式、调解工艺参数等技术手段,使其能够达标处理此类工业废水,并通过某淀粉厂的工程实例进行了验证:采用改良的SBR工艺可以对低碳高氮污水进行有效的处理。     

内蒙古自治区机动车尾气污染监控体系初探

随着机动车大量开始进入普通家庭,内蒙古自治区机动车保有量快速增长,使得机动车排气污染已经成为城市大气污染的重要来源。因此,开展在用机动 车排气污染防治工作,建立切实有效的机动车排气污染监控体系刻不容缓。本文对内蒙古自治区在用机动车排气污染监控体系和保障好保障体系建设内容进行了初探。     

扬州市区水环境质量现状及防治对策

通过对扬州市区境内河流和地下水的环境质量进行调查分析,结果表明：河流水质较好,城区污水都排入污水处理厂且处理厂正常运行,水质达标排放,主要的污染物是有机污染物;地下水达到水质标准,由于地质原因,主要污染指标为总硬度和总矿化度。但仍应加大污染防治力度,针对水环境现状和问题,采取有效措施,坚持深入开展环境宣传教育,依靠科技进步,科学防治环境污染,控制污染源,实行达标制度,提高人们自身环保意识,促进水资源的可持续利用。     

上海市环保行政审批系统的设计与实现

上海市环保局行政审批系统采用流程控制和数据传输交换技术,构建了申报系统、审批系统、业务管理系统、跟踪监控系统四部分,实现了包括建设项目环评、固废、辐射等15项行政审批和23项非行政审批事项的“一口受理、一办到底”,通过信息技术实现了外网申报、内网审批,实现了环保审批流程优化再造和审批全过程公开透明,实现了“便民审批”、“高效审批”、“阳光审批”。     

陕西老厂铅锌矿床成矿流体特征及其地质意义

陕西老厂铅锌矿床是一个与海相火山岩有关的块状硫化物矿床。老厂铅锌矿床石英流体包裹体的均一温度为93.3~396.5℃,平均值为235.9℃;盐度为0.4~22.5wt%NaCl,平均值为9.9wt%NaCl。原生流体包裹体均一温度测定结果表明其具有近似正态分布的特点;石英流体包裹体的盐度表明,其不成正态分布,且盐度较低。老厂矿床δDV-SMOW‰和δ18 OH2O‰的组成关系反映了其成矿流体为混合热液来源。     

企业环境风险评估概述

绘制了企业环境风险评估程序图,根据程序图,企业环境风险评估包括分析计算化学物质数量与其临界量的比值(Q)、评估工艺过程与环境风险控制水平(M)以及环境风险受体敏感性(E)和风险等级划分4个步骤。     

中国石化炼油企业QHSE管理体系典型建过程研究

总结了中国石化炼油企业构建QHSE管理体系的典型步骤和内容,描述了体系构建各阶段的工作和要求,并提出了构建QHSE管理体系过程中的关注要点.     

油田联合站安全性评价模式研究

针对联合站生产过程复杂、安全影响因素多的特点,提出了二级模糊综合安全评价方法。以港东联合站的实际情况为基础,在系统分析联合站危险因素的基础上,选取储罐、管道、监控系统、其他系统4个因素作为联合站安全评价的主要关联因子,构建了针对港东联合站安全的二级综合模糊评估模型。运用层次分析法确定不同层次和因素的重要度,以加权法为运算准则,确定了联合站的安全等级。评估结果表明:该二级模糊综合评价方法提高了联合站安全现状评价的客观性,评估过程易于实现,评价结果更加客观、合理。