臭氧和Fenton试剂处理石化电脱盐废水研究

利用臭氧和Fenton试剂对某石化炼油厂电脱盐废水进行了处理.结果表明:经臭氧处理后COD去除率为51.10％;用Fenton试剂处理经臭氧氧化后的电脱盐废水,效果最好,COD去除率提高到84.61％;用臭氧和Fenton试剂联合处理时,COD去除率为77.95％;这3种方法都能减轻该种废水的后续处理压力,其中第2种方法效果最好.     

重庆市次级河流整治的主要举措、存在问题及建议研究

近年来,重庆市将次级河流综合整治工作作为一项“重过程、重民生、重实效”的系统工程来抓,次级河流整治取得明显成效.但也面临一些问题,如污水处理基础设施仍不完善,农村面源污染局面未根本扭转,水污染防治长效管理机制不健全等.在此基础上提出以下建议,一是加强流域规划控制和管理;二是统筹实施次级河流整治项目;三是建立完善跨界河流上、下游联动工作机制;四是探索建立生态补偿机制.     

中国城市污泥重金属区域分布特征及变化趋势

通过整理和统计国内外文献(2006—2013年)报道的中国城市污泥重金属含量,分析了近年来中国城市污泥重金属的区域分布特征和变化趋势.结果表明,城市污泥重金属Cu、Pb、Zn、Cd、Hg、As、Cr和Ni含量分别为182.5、65.3、729.6、2.1、1.4、11.5、97.5和44.9 mg·kg-1,与《城镇污水处理厂污染物排放标准》(GB18918-2002)规定的中碱性土壤污泥农用污染物控制标准限值比较,Cu、Pb、Zn、Cd、Hg、As、Cr和Ni的超标率分别为2.3%、0、5.9%、5.5%、2.9%、0、0和3.5%;与酸性土壤污泥农用污染物控制标准限值比较,Cu、Pb、Zn、Cd、Hg、As、Cr和Ni的超标率分别为7.1%、1.3%、10.3%、27.4%、20.0%、0、1.6%和12.1%.不同区域城市污泥重金属含量存在一定差异,城市污泥Hg和As在北方地区含量较高,而Cu、Pb、Zn、Cd、Cr和Ni在南方地区含量较高.与2006年城市污泥重金属含量相比,本研究城市污泥重金属Cu、Pb、Zn、Cd、Hg、As、Cr和Ni含量均呈下降趋势,降幅分别为29.0%、16.5%、40.9%、9.0%、29.8%、41.8%、5.3%和23.6%.     

灰场包气带环境影响预测方法研究——以新疆某电厂灰场为例

灰场在防渗不当或事故工况下,淋滤液的渗漏可能会对灰场包气带产生影响。以新疆某火电厂灰场的淋滤液渗漏情景为例,介绍了淋滤液渗漏对包气带影响的3种预测方法并进行对比分析。结果表明,两类解析法计算误差较大且存在各自适用条件,应优先采用数值法进行定量化预测。     

再生水—土壤—蔬菜体系中Zn的迁移

2011~2013年通过小区试验种植小白菜和萝卜,以再生水灌溉和污泥施肥,采用修正的BCR法测定了再生水、污泥、土壤、蔬菜中Zn的5种形态含量,分析Zn在再生水(污泥)-土壤-蔬菜体系中的迁移和累积特征。结果表明:2011~2013年水样中Zn含量均未超出国家《农田灌溉水质标准(GB5084—2005)》中Zn的标准。水样中水溶态B0比例较大。污泥中B0含量极少,残渣态B4含量较高。土壤中Zn的本底含量较少,经过3年的蔬菜种植和灌溉,土壤中Zn含量有增高的趋势。蔬菜中5种形态均有分布,地上部分中水溶态B0和可氧化态B3含量较高,地下部分中残渣态B4含量也较高。小白菜中Zn的含量高于萝卜。灌溉水中B0的含量对Zn在土壤和蔬菜中的迁移产生了较大影响。适当的再生水灌溉和污泥施肥可以改善土壤的缺Zn状况。     

低强度超声波强化低温SMBR脱氮的性能与机制研究

考察了低温条件下低强度超声波对SMBR脱氮的强化作用,并研究了对硝化细菌脱氢酶活性和细胞通透性的影响。结果表明,经超声波强化后,SMBR对NH3-N5的去除效果得到明显提高,总去除率由启动完成时的65.94%升至84.01%,且长期运行稳定,说明超声波解除了低温对硝化作用的抑制。0.28 W/L超声波辐照20 min,可使硝化细菌脱氢酶活性提高81.19%,0.14 W/L的超声波辐照10 min使脱氢酶活性提高43.18%。0.28 W/L的超声功率密度对脱氢酶的活性提高程度最大,因此是较合适的超声波参数。     

江西省某冶炼厂遗留尾砂场重金属污染特征

以江西省某冶炼厂生产过程中遗留在厂内各尾砂池中的废渣为研究对象,利用单因子污染指数法和内梅罗综合污染指数法相结合的方法对其重金属污染状况进行评价。结果表明:各尾砂池土壤中铜、锌、镍、砷超标倍数高,且除尾砂池2深层土壤外,其他样点重金属内梅罗综合污染指数均远大于1,显示各尾砂池土壤均为重污染土壤。     

疏浚过程中的环境影响分析及其对策研究

环保疏浚因能将水体的污染底泥彻底去除,消除影响水质的潜在因素,从而成为治理水体的一项重要措施。但是,环保疏浚工程中扰动污染底泥、污染底泥处置不当等会导致环境的二次污染。各项减少底泥扰动以及底泥的资源化利用技术成为研究热点。减少污染底泥扰动主要是通过改进疏浚设备工艺来实现,目前国内主要采用的环保疏浚设备是绞吸式挖泥船与环保绞刀。底泥的资源化利用不但可以改善其对环境的二次污染,而且可变废为宝,增加资源,目前资源化利用途径主要有土地利用、建筑材料、填方材料、污水处理材料、制氢技术等。     

Assessment of the sources and transformations of nitrogen in a plain river network region using a stable isotope approach

The great spatial and temporal variability in hydrological conditions and nitrogen(N)processing introduces large uncertainties to the identification of N sources and quantifying N cycles in plain river network regions. By combining isotopic data with chemical and hydrologic measurements, we determined the relative importance of N sources and biogeochemical N processes in the Taige River in the East Plain Region of China. The river was polluted more seriously by anthropogenic inputs in winter than in summer. Manure and urban sewage effluent were the main nitrate(NO-3) sources, with the nitrification of N-containing organic materials serving as another important source of NO-3. In the downstream, with minor variations in hydrological conditions, nitrification played a more important role than assimilation for the decreasing ammonium(NH+4-N) concentrations.The N isotopic enrichment factors(ε) during NH+4utilization ranged from- 13.88‰ in March to- 29.00‰ in July. The ratio of the increase in δ18O and δ15N of river NO-3in the downstream was 1.04 in January and 0.92 in March. This ratio indicated that NO-3assimilation by phytoplankton was responsible for the increasing δ15N and δ18O values of NO-3in winter. The relationships between δ15N of particulate organic nitrogen and isotopic compositions of dissolved inorganic nitrogen indicated that the phytoplankton in the Taige River probably utilized NH+4preferentially and mainly in summer, while in winter, NO-3assimilation by phytoplankton was dominant.     

Continuous desulfurization and bacterial community structure of an integrated bioreactor developed to treat SO2 from a gas stream

Sulfide dioxide(SO2) is often released during the combustion processes of fossil fuels. An integrated bioreactor with two sections, namely, a suspended zone(SZ) and immobilized zone(IZ), was applied to treat SO2 for 6 months. Sampling ports were set in both sections to investigate the performance and microbial characteristics of the integrated bioreactor. SO2 was effectively removed by the synergistic effect of the SZ and IZ, and more than 85%removal efficiency was achieved at steady state. The average elimination capacity of SO2 in the bioreactor was 2.80 g/(m3·hr) for the SZ and 1.50 g/(m3· hr) for the IZ. Most SO2 was eliminated in the SZ. The liquid level of the SZ and the water content ratio of the packing material in the IZ affected SO2 removal efficiency. The SZ served a key function not only in SO2 elimination, but also in moisture maintenance for the IZ. The desired water content in IZ could be feasibly maintained without any additional pre-humidification facilities. Clone libraries of 16 S r DNA directly amplified from the DNA of each sample were constructed and sequenced to analyze the community composition and diversity in the individual zones.The desulfurization bacteria dominated both zones. Paenibacillus sp. was present in both zones, whereas Ralstonia sp. existed only in the SZ. The transfer of SO2 to the SZ involved dissolution in the nutrient solution and biodegradation by the sulfur-oxidizing bacteria.This work presents a potential biological treatment method for waste gases containing hydrophilic compounds.