Combination of the direct electro-Fenton process and bioremediation for the treatment of pyrene-contaminated soil in a slurry reactor

A combined treatment technology (DEF-BIO) using the direct electro-Fenton (DEF) process and bioremediation (BIO) was established in this study. The performance of the DEF-BIO process on the remediation of a pyrene (PYR)-contaminated soil was evaluated in a slurry reactor. The appropriate order of application was to conduct the DEF process followed by BIO, evaluated through analysis of the degradation characteristics of each process individually. In addition, the application time of the DEF process affected the efficiency of the combined process. The optimum time to apply the DEF process was determined through an analysis of the induced changes in PYR intermediates, pH, soil organic matter (SOM) and bacteria. The optimum application time of the DEF process was 6 h. All the induced changes were beneficial for the BIO phase. The removal of PYR was 91.02% for DEF–BIO after 72 h, and the efficiency was almost 50% increased, compared with the individual DEF and BIO treatments. Therefore, the combined process of DEF–BIO process may be an efficient and promising method for the remediation.     

户用沼气池建设对改善农村生态环境效果分析

通过对河南省9个县(市)中9个乡(镇)的非沼气户和沼气户土壤、地表径流和室内空气进行监测,定量对比分析了户用沼气池建设对农村生态环境改善效果。结果显示,沼气户土壤中的速效磷、速效钾、有机质和全氮含量要高于非沼气户,且"四位一体"生态模式沼气户土壤中4种养分含量明显高于"三位一体"生态模式;沼气户地表径流中的COD、NH₃-N、 TP浓度均低于非沼气户;沼气户室内空气中的CO、SO₂、NH₃、PM₁₀浓度均低于非沼气户,且室内空气中的4项污染物浓度随季节变化而不同。这说明户用沼气池建设对于增加土壤养分、减轻农村面源污染、改善农户居住环境、实现节能减排效果显著。     

沼液贮存及田间施用后大肠菌群的消长动态

以猪场粪污水厌氧发酵产生的沼液为材料,分别在冬春季和夏秋季对其采用加盖和无盖2种方式贮存,定期检测沼液中大肠菌群数量;通过田间生菜种植试验,定期施用大肠菌群数量(以下均以CFU计)分别为104(WF)、105(LF)、106(MF)和107g-1(HF)的沼液,在沼液施用完毕后第3、10、17和24天检测土壤、生菜表面和生菜体内大肠菌群数量。结果表明:夏秋季大肠菌群存活时间较长,沼液无盖贮存可使大肠菌群数量减少。沼液贮存50 d后,除冬春季无盖贮存的沼液中大肠菌群数量达到GB 8978—2002《污水综合排放标准》中三级排放要求,可以排放以外,其他处理均未达到排放要求。沼液中大肠菌群数量越高,经农田施用后土壤中大肠菌群数量越多,生菜表面和体内大肠菌群数量也越高,但随时间延长大肠菌群数量变化略有不同。检测期内,WF处理农田土壤中大肠菌群数量显著低于其他处理;沼液施毕后第3天,WF处理生菜表面及体内大肠菌群数量均显著小于HF和MF处理;24 d时各处理生菜体内大肠菌群数量均检测不到,达到GB 4789.3—2010《食品安全国家标准食品微生物学检验大肠菌群计数》要求,生菜表面大肠菌群数量对数值小于3.51,但未达GB 4789.3—2010要求。     

灰浆层对钢筋混凝土楼板耐火极限的影响

为保护钢筋混凝土结构不因受到高温影响使结构急剧丧失承载能力而倒塌,常采用增加灰浆层的办法。钢筋在混凝土与灰浆层保护层的包裹之内,可以缓解温度急剧上升。但典型灰浆层对钢筋混凝土的耐火极限的报道还不多。本文针对灰浆层对钢筋混凝土的耐火极限影响进行了试验研究。比较了增加灰浆层与不加抹灰层在耐火极限、烧损面、残余强度等方面的变化,讨论了灰浆层对结构防火的贡献。结果证明：钢筋在混凝土在灰浆层保护层的包裹之内,可以缓解温度急剧上升,保护层使建筑物有一定的耐火作用;增加钢筋混凝土结构构件的保护层厚度能够有效提高构件的耐火极限;混凝土砂浆保护层直接关系到混凝土结构的承载力,直接关系到混凝土结构的耐久性与耐火性。     

新型阳离子絮凝剂在煤泥水处理中的应用研究

介绍了新型阳离子絮凝剂在选煤厂煤泥水治理环境保护中的应用。证明了该絮凝剂是一种质量优良性能稳定的高效阳离子絮凝剂,并取得了明显的经济效益和环境效益。      

悬浮液-流动注射-氢化发生原子荧光法测定沉积物中的Pb

研究了一种把悬浮液进样与氢化发生相结合原子荧光光谱法测定沉积物中Pb的方法。控制悬浮液的粒径在0.088mm以下,用磁力搅拌器搅拌以保证悬浮液分散均匀稳定,方法中以盐酸作介质,K3Fe(CN)6为氧化剂,采用水溶液标准作标准曲线测定了沉积物中的Pb,该法的线性范围为0～200μg/L,检出限为0.26μg/L,回收率为92%～107%,精密度小于6.5%。将此法用于标准物质的分析,测定值均在标准值范围之内,结果令人满意,具有实际应用价值。     

模拟酸雨对砂浆影响的研究

建立了周期浸泡法和喷淋试验法等两种加速腐蚀试验方法,并分别研究Ph为5.6、3.5和Ph为1.0、S²₄-为0、0.06、0.1、0.2mol/L六种模拟酸雨对砂浆的影响。研究结果表明：砂浆受蚀后强度降低,其下降的程度与材料中CaO和SO₃/CaO的比值成二元线性关系;酸雨中＋的侵蚀将使材料中CaO、MgO、Al₂O₃和Fe₂O₃组分流失,H⁺.和SO的协同作用,使材料中的SO₃/CaO的比值增大;受蚀后的砂浆其物相发生较大的变化,变化趋势是原［CaNa］［SiAI］₄0₈、KAISi₃0₈、0.62NaAISi_{208·0.38CaAl2等矿物晶体逐渐消失,而转化成CaSO4·2H2O、CaAl2i2O8、Ca－Fe－Al－S－Si－O,甚至体积更大的Ca3Al6O12·CaSO4。因此,酸雨对砂浆的影响,主要是H⁺侵蚀引起的溶解腐蚀和SO²4-侵蚀引起的膨胀腐蚀。}     

泥浆含砂量对泥水盾构泥浆成膜性能影响的试验研究

为在高渗透砂卵石地层泥水盾构施工中确保开挖面稳定、保证施工安全,泥浆顺利成膜至关重要.依托京张高铁清华园隧道工程,采用自行设计的泥浆渗透试验装置,配制6种不同含砂量的泥浆,在与实际地层渗透系数相似的试验地层中进行渗透试验.对泥浆在渗透过程中的成膜类型、成膜质量、渗透深度、滤失量、闭气性能等相关指标进行分析,得到适用于高...     

电渗析法脱除氨法烟气脱硫浆液中的氟离子

利用异相膜电渗析装置去除氨法烟气脱硫浆液中的F~-。考察了脱硫浆液p H、F~-初始质量浓度、Cl~-初始质量浓度、膜堆两端电压、浓缩室和淡化室循环流量等操作参数对F~-去除效果的影响。实验结果表明:在酸性条件下,F~-去除率更高;脱硫浆液中F~-初始质量浓度越高,F~-去除率越高;Cl~-初始质量浓度较低时会增加F~-去除率,过高时又会降低F~-去除率。优化的操作条件为:膜堆两端电压25 V,浓缩室和淡化室循环流量300 L/h。一级电渗析进行100 min后,Cl~-去除率接近100%,F~-去除率只有47.3%。二级电渗析进行100 min时,F~-去除率达92.2%。一、二级电渗析F~-累积去除率达96.1%。     

Synthesis of a novel humic acid-based polycarboxylic dispersant for coal water slurry

A novel humic acid-based polycarboxylic-type (HAP) dispersant for coal–water slurry (CWS) was successfully synthesized in aqueous solution from the copolymerization of HA, acrylic acid and maleic acid. The structure of HAP was characterized by Fourier transform infrared (FTIR), thermogravimetry (TG) and ¹H NMR. With HAP as a dispersant for Linfen coal slurry, the effects of the mass ratio of HA and monomer, initiator concentration, reaction temperature and reaction time on the HAP dispersant performance were discussed by examining the apparent viscosity of CWS. The results showed that CWS prepared withHAP dispersant performed excellent dispersity and stability. When the dosage of HAP was up to 0.5 wt.%, the apparent viscosity of CWS was 505 mPa·s. Experiments on the stability of CWS containing 0.5 wt.% HAP demonstrated that the penetration ratio reached 85.45 % after 96 h, which was higher by 12.87 % than that of CWS prepared with HA. And the CWS produced with HAP had lower dewatering rate within the storage time, which was less 1.85 % than that of CWS with HA when the storage time was 72 h. Furthermore, the maximum coal content of CWS with 0.5 wt.% HAP may reached 70 wt.%. This work found a new route for utilizing humic acid and enlarged the selecting range of the dispersant for CWS. It has a positive significance for protection of environment.