人工补水条件下的缺水河流生态修复综合评价方法

构建了人工补水条件下的缺水河流生态修复多目标综合评价指标体系,对生态修复中影响评价指标量化结果的因素进行了综合考虑,提出了包含主、客观因子并反映层次关系的综合权重确定方法,进而建立了一种人工补水条件下的缺水河流生态修复综合评价方法,以更好地解决多目标决策中的总目标量化问题.最后,以正在建设的永定河生态修复工程为例,通过构建典型的生态修复情景方案,对建立的评价指标体系进行应用,确定各评价指标的综合权重系数,并对构建的情景决策方案进行了综合评估,验证本文提出的评价指标权重综合调整的必要性,说明构建的人工补水条件下的缺水河流生态修复综合评价方法的合理性与可行性.结果表明,所提出的评价方法不仅对人工补水条件下的河流生态修复决策具有一定的实用价值,而且对其它类型生态修复多目标综合决策评价也具有借鉴意义.     

两相法筛选高效除磷菌的研究

利用模拟除磷菌生存环境的两相法,设计厌氧-好氧两相交替条件,配合厌氧相含底物无磷培养基和好氧相含磷无底物培养基,进行高效除磷菌的筛选和菌株除磷能力检测.两相法包括前期富集、筛选、检测前驯化和检测共四个阶段.采用两相法从运行良好的SBR反应器中筛得15株菌,所有菌株均具有除磷能力,菌株除磷能力强.两相法筛选除磷菌具有针对性强,工作量小,筛选获得的菌株多样性好和高效除磷菌比例高等优点.     

某单井站场管道积液及腐蚀特性研究*

为应对湿天然气管道存在的明显积液,导致管材腐蚀,目前经验性的检测点选择方式导致检测成本和工作量过大问题。基于某单井站场工况条件和现场壁厚检测数据,针对站场主管线,采用Fluent软件建模分析管线内液相分布规律。结果表明:含液率大小随原料气含水量、流量、压力的变化而呈正相关变化,运用Correl函数对现场壁厚检测数据和模拟结果进行对比验证,发现两者的相关度达到0.61以上,这为现场合理选择腐蚀检测点提供依据,降低了现场检测工作量和检测成本。     

Algal growth inhibition by river water pollutants in the agricultural area around Lake Biwa, Japan

An ecotoxicological study of river water discharged from the agricultural area around Lake Biwa was performed by using algal bioassays to guide chemical analysis. Water samples were collected once a week, at least, for 1 year starting in April 1997 and continuing until April 1998. The toxicities of the dissolved and particulate-adsorbed extracts of water samples were evaluated by the algal growth inhibition test and concentrations of individual pesticides were determined. Most of the river water that was collected during the periods when pesticides were applied to the paddy fields caused algal growth inhibition. Some extracts were found to contain herbicides (molinate, mefenacet, simetryn, or esprocarb) as major compounds. According to chemical assay and bioassay, simetryn was identified as the most toxic compound that caused algal growth inhibition.     

轻型汽油车蒸发排放特征及温度对蒸发排放的影响

车辆蒸发排放是城市地区大气环境中VOCs（挥发性有机物）的重要人为源.选取满足国五排放标准的轻型汽油车,采用满足国Ⅵ（A）汽油标准的汽油,在密闭舱内设定两种不同温度,研究蒸发排放特征及温度对蒸发排放的影响.结果表明:①6辆车热浸VOCs蒸发排放因子范围为0.01~0.10 g/h,昼间损失VOCs蒸发排放因子范围为0.09~1.49 g/d,低于已有研究中国四或国三车辆的蒸发排放水平.②昼间损失VOCs蒸发排放水平远超过热浸VOCs蒸发排放水平.③热浸蒸发排放过程中密闭舱内VOCs质量呈近似线性增长,昼间损失蒸发排放过程中密闭舱内VOCs质量呈先快后缓的增长特征.④温度升高后,热浸和昼间损失VOCs蒸发排放因子均明显增加.温度由25℃升至38℃后,热浸VOCs蒸发排放因子增加36.0%~533.9%;温度从18~33℃升至23~38℃后,昼间损失VOCs蒸发排放因子增加16.7%~106.2%.研究显示,温度变化对热浸和昼间损失VOCs蒸发排放因子均影响明显.      

Qualitatively and quantitatively assessing the aggregation ability of sludge during aerobic granulation process combined XDLVO theory with physicochemical properties

Inexact mechanism of aerobic granulation still impedes optimization and application of aerobic granules. In this study, the extended Derjaguin, Landau, Verwey, and Overbeek(XDLVO) theory and physicochemical properties were combined to assess the aggregation ability of sludge during aerobic granulation process qualitatively and quantitatively. Results show that relative hydrophobicity of sludge and polysaccharide content of extracellular polymeric substances(EPS) increased, while electronegativity of sludge decreased during acclimation phase. After 20 days' acclimation, small granules began to form due to high aggregation ability of sludge. Since then, coexisted flocs and granules possessed distinct physicochemical properties during granulation and maturation phase. The relative hydrophobicity decreased while electronegativity increased for flocs, whereas that for granules presented reverse trend. Through analyzing the interaction energy using the XDLVO theory, small granules tended to self-grow rather than self-aggregate or attach of flocs due to poor aggregation ability between flocs and granules during the granulation phase. Besides, remaining flocs were unlikely to self-aggregate owing to poor aggregation ability, low hydrophobicity and high electronegativity.     

岗位安全与职业健康标准化生产研究

中国加入WTO后，国有企业面临如何应对企业的安全生产问题，东风汽车载重车公司作为国有大型企业在新形式下审时度势积极应对挑战，在推行岗位安全与职业健康标准化生产方面作了一些有益的探讨。     

垂直流-水平潜流复合人工湿地深度处理电镀废水的效果

采用垂直流-水平潜流复合人工湿地对金华清湖电镀厂排放的电镀废水尾水进行深度处理,研究复合人工湿地对电镀废水的深度净化效果,并对复合人工湿地在低(30 cm·d-1)、高(55 cm·d-1)水力负荷条件下的去除效果进行对比试验,探讨水力负荷对复合人工湿地处理能力的影响.复合人工湿地主要由调节池、垂直流人工湿地、水平潜流人工湿地和集水池四部分组成,电镀厂化学沉淀处理后的尾水先经一级垂直流人工湿地的基质和植物根系的过滤、吸附作用,刺激微生物活性,再流入水平潜流人工湿地完成二级处理,依靠植物、微生物、基质三者的联合作用从而使电镀废水得到深度净化.其中,垂直流人工湿地种植凤眼莲(Eichhornia crassipes)、稗草(Echinochloa crusgalli)和空心莲子草(Herba Alternantherae)3种水生植物,潜流人工湿地种植藨草(Scirpus triqueter)、黄菖蒲(Iris pseudacorus)、芦苇(Phragmites communis)、千屈菜(Lythrum salicaria)和美人蕉(Canna indica)5种水生植物.结果表明,复合人工湿地对电镀废水的净化效果非常显著,对Zn、Cu、Cr、Mn四种重金属和COD具有很高的去除率,处理后Zn、Cu、Cr、Mn和COD的质量分数分别为15.9%、12.4%、15.2%、28.5%和32.9%.其中,Cu、Mn和COD出水符合<污水综合排放标准>(GB8978-1996)一级标准,而Zn、Cr虽有很高的去除率,但并未达到标准.研究同样表明,复合人工湿地对电镀废水的去除效率存在一个最适宜的处理时间,过短和过长的处理时间都不利于污染物的去除.低、高水力负荷对比试验研究表明,水力负荷对COD的去除效果影响较大,对Zn、Cu、Cr、Mn的影响较小;在高水力负荷条件下,复合人工湿地对Zn、Cu、Cr、Mn四种重金属仍然具有很高的去除率,其质量分数分别降到32.3%、27.7%、30.8%、43.2%.     

Effects of La3+, Ce3+ on nitrogen removal in sequencing batch reactor

Batch experiments were conducted to study the short-term biological effects of rare earth ions (La³⁺, Ce³⁺) and their mixture on the nitrogen removal in a sequencing batch reactor (SBR). The data showed that higher NH₄ ⁺-N removal rate, total inorganic nitrogen removal efficiency, and denitrification efficiency were achieved at lower concentrations of rare earth elements (REEs) (<1 mg/L). In the first hour of the aeration stage of SBR, the presence of REEs increased the total inorganic nitrogen removal efficiency and NH₄ ⁺-N removal efficiency by 15.7% and 10%–15%, respectively. When the concentrations of REEs were higher than 1 mg/L, the total inorganic nitrogen removal efficiency decreased, and nitrate was found to accumulate in the effluent. When the concentrations of REEs was up to 50.0 mg/L, the total inorganic nitrogen removal efficiency was less than 30% of the control efficiency with a high level of nitrate. Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.     

SBR/混凝协同工艺处理城市污水的效果

将无机混凝剂直接投加到SBR反应器中,组成SBR/混凝协同工艺对城市污水进行处理研究.考察了混凝剂的投加量、混凝剂的种类、投药时间等因素对污水处理效果的影响,探讨了新型复合混凝剂(PISC)对污泥膨胀的抑制作用.实验结果表明,与普通的序列间歇式活性污泥法(SBR)相比,当采用新型复合混凝剂与SBR组成的协同工艺处理城市污水时,在适宜的条件下,不仅污水中的CODCr、TP和sS的去除率可分别提高13.5%、47.6%和11.5%,水力停留时间缩短1/3左右,而且该协同工艺可明显抑制污泥膨胀,并改善高膨胀活性污泥的沉降浓缩性能.