工业废水综合回用的实验研究

以保定市某渠工业废水为研究对象,调查了污水的主要来源和主要污染物,提出了处理方案:首先采用酸改性粉煤灰进行混凝,活性炭吸附,最后用臭氧进行氧化。同时探讨了酸改性粉煤灰的制备和最佳运行条件,活性炭的最佳运行条件和臭氧的最佳氧化时间,从而探索出一条适合于该渠工业废水的综合回用方法。     

含铬电镀废水回收铬黄实验

在含铬电镀废水中加入硫化钠、碳酸氢钠和双氧水去除铜及其它杂质,再利用氢氧化钠和盐酸调节pH值,最后加入过量的硝酸铅制成铬黄。实验结果表明,温度和硝酸铅加入量对铬黄的生成有显著的影响。当反应温度为60℃,硝酸铅的添加量为0.05g/mL时,铬黄的生成量最大。在此条件下,100mL废水中能回收4.8g铬黄,铬的回收率为97.1%。     

不同预处理对电镀污泥电动过程的影响

以风干电镀污泥为电动处理试验材料,水为阳极电解液,柠檬酸-柠檬酸铵缓冲液为阴极电解液,施加25 V直流电压条件下电动运行5 d,研究了水、低浓度木钙和硝酸等预处理对电镀污泥电动过程的影响。结果表明,各处理的阴极电解液pH值变化平稳,都维持在3-3.5较理想的范围。而1%木钙、1%硝酸饱和预处理电镀污泥,明显改变了电动过程中电渗流和电流密度的大小,对电镀污泥Cu、Ni的去除率也有明显增加。其中,木钙、硝酸预处理后对Cu的去除率由对照的13.24%分别提高到19.05%和25.55%,即去除量分别增大3 516.35 mg/kg和7 457.62 mg/kg;木钙、硝酸预处理后对Ni的去除率由对照的14.68%分别提高到16.47%和28.85%,即去除量分别增大800.91 mg/kg和6 359.92 mg/kg。     

城市水资源综合风险评价指标体系与模型构建

水资源是城市形成、发展的必要条件,在自然和人类活动影响下,城市旱涝、缺水及水环境污染现象时有发生,水资源问题已严重阻碍了当今城市发展。在城市水资源风险评价方面,国内外学者已进行了大量的理论探索和实证研究,但方法模型尚未统一。本文在系统论述前人关于自然灾害与城市水资源、水环境风险分析与评估研究成果的基础上,基于城市灾害风险系统论的角度,提出一套适合中国城市水资源综合风险评估的指标体系;同时,对城市水资源综合风险管理模式作了一定的探讨和分析,拟为城市水资源安全规划和管理提供科学的决策依据。     

浸出时间、H2SO和Fe^3＋浓度对硫脲浸金的影响

目前废旧电脑的产生量日益增加,废旧电脑主板中含有丰富的可回收金属资源,对其回收处理意义重大。本实验采用硫脲对电脑主板中的金进行浸取研究,在硫脲浸金过程中,主要通过调整时间、硫酸浓度、Fe^3＋浓度,考察对浸金的影响。研究结果表明：当t=60min、硫酸浓度为15％、Fe^3＋浓度为0.45％时,金的浸出最大,可达91.14％。因硫脲具有浸金速率快,试剂易再生,对环境污染小、反应条件易控制等优点适于应用于实际生产。     

呼伦贝尔市环境问题现状及对策初探

通过对呼伦贝尔市自然条件、资源储备、生态环境的调查,分析该市在水环境、大气环境、固体废物排放以及生态环境等方面的污染现状,指出该市在环境保护方面所面临的问题,并选择适当的预测方案,预测在未来五年各类环境污染所带来的压力;探讨该市在水、大气、固废、生态环境等方面的优势及劣势,并在此基础上提出了解决对策。在环境规划中应该把握好经济发展与环境保护并重的方向,明确地方环境问题,有针对性地开展规划工作,重点地解决环境污染问题,因地制宜地开展环境保护与规划工作。     

都市工业园区规划环评的实践与思考

通过对白沙洲都市工业园规划环评筹备、撰写、执行等环节的剖析,总结了该规划环评的特点,并指出基层环保组织在推动规划环评过程中所起的作用。对应用规划环评成果为园区和谐快速发展服务提出建议。着重探讨了基层环保部门该如何推动规划环评,促进城市中心老工业区改造,发展都市工业因,乃至生态工业园,实现城区经济又好又快发展。提出了法律赋予环保部门管理规划环评的职权不足、公众参与流于形式、规划环评法律约束不力等规刘环评实践过程中遇到的主要问题,并给出建议。     

Effects of disinfection efficiency on microbial communities and corrosion processes in drinking water distribution systems simulated with actual running conditions

The effects of disinfection efficiency on microbial communities and the corrosion of cast iron pipes in drinking water distribution systems (DWDSs) were studied. Two annular reactors (ARs) that simulated actual running conditions with UV/Cl₂ disinfection and chlorination alone were used. High chlorine consumption and corrosion rate were found in the AR with UV/Cl₂. According to functional genes and pyrosequencing tests, a high percentage of iron recycling bacteria was detected within the biofilm of the AR with Cl₂ at early running stage, whereas siderophore-producing bacteria were dominant in the biofilm of the AR with UV/Cl_2. At the early running stage, the sequential use of UV light and an initial high chlorine dosage suppressed the biomass and iron-recycling bacteria in both bulk water and biofilms, thereby forming less protective scales against further corrosion, which enhanced chlorine consumption. Non-metric multidimensional scaling analysis showed that the bacterial communities in the ARs shaped from within rather than being imported by influents. These results indicate that the initial high disinfection efficiency within the distribution system had not contributed to the accumulation of iron-recycling bacteria at the early running stages. This study offer certain implications for controlling corrosion and water quality in DWDSs.     

Historical trends of PCBs and PBDEs as reconstructed in a lake sediment from southern Tibetan Plateau

High-altitude lake sediment can be used as a natural archive to reconstruct the history of pollutants. In this work, the temporal distribution of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined using a high-resolution gas chromatography coupled with high-resolution mass spectrometer (HRGC/HRMS) in an alpine lake sediment core collected from the southern Tibetan Plateau (TP) to examine whether the expected decreasing trends due to the implementation of the international Conventions could be observed. The concentrations of PCBs and PBDEs in the sediment core were in the range of 11.8–142 pg/g dw and ND-457 pg/g dw, and their fluxes were in the range of 2.51–31.7 ng/(m²·yr) and ND-43.2 ng/(m²·yr), respectively. The prevalence of low-chlorinated (tri-CB) PCBs and low-brominated (tri- to tetra-) PBDEs in most sections of the sediment profiles was observed, suggesting that the light molecular weight PCBs and PBDEs have most likely reached lake sediments by long-range atmospheric transport from distant sources. Despite the restrictions on their applications, the sediment records for the concentrations and fluxes showed no corresponding decreasing trend with restrictions for PCBs, which suggested that these POPs (e.g., PCBs) were still emitted to the environment owing to the influence of primary or secondary emissions. To our knowledge, this is the first report on input history of atmospheric PCBs and PBDEs recorded in TP Lake sediment.