酸性多糖微生物絮凝剂的提取、纯化与分析

对一株链球菌发酵获得的絮凝活性物质进行了分离和提取,并应用DEAE-Sephadex A25,Sephdarose 4B凝胶色谱柱从发酵液中提取活性物质并纯化.通过薄层色谱、气相色谱、紫外光谱、红外光谱、元素分析等表征,初步推测了其主要成分为酸性多糖,其中多糖含量(73%)、糖醛酸含量(20.6%)、多糖分子量为4.3×105,可能还有少量氨基或短肽结构.     

鞘细菌FC9901氧化铁生化机制的研究

本文对分离到的鞘细菌菌株FC990 1氧化铁的生化机制进行了初步研究。结果表明 ,该菌株的营养类型为化能有机营养型 ,其能源主要来自有机碳源的氧化 ,并不能从Fe2 + 氧化过程中获取能量。活性定位研究和 pH、温度、抑制剂试验结果表明 ,该铁氧化活性物质是酶 ,而且是一种胞外酶。铁的生物学氧化属于酶学催化过程 ,并遵守酶的动力学。     

压裂返排液处理系统降污方案设计

泌页HF1井是河南油田承钻的中国石化第一口页岩油气水平井,为避免压裂返排液对环境造成污染同时又不加大联合站正常的污水处理系统负荷,单独对其进行了处理.处理方案设计为:“500 m3接收池+处理撬块一(聚结斜板沉降罐)+处理撬块二(过滤装置)+200 m3玻璃钢储水罐+增压泵提升”处理工艺,处理规模为500 m3/d.设计出水水质为:pH值:6～7,合油≤10 mg/L,悬浮物≤10 mg/L.该方案储水设施密闭,有利于处理后污水水质的稳定.实践表明:污水处理后全部用于回注或集中处理,不再外排;污油全部作为商品油回收;污泥收集后进行集中处理.通过采取上述措施,各类污染物均满足GB 8978-1996《污水综合排放标准》要求.     

投加阳离子聚合物加速UASB反应器中颗粒污泥形成

运行2个UASB反应器,研究常温低浓度进水条件下,投加阳离子季胺盐絮凝剂对厌氧颗粒污泥形成的影响。一个反应器中投加阳离子季胺盐絮凝剂（称A反应器）,另一个反应器作为对照不投加絮凝剂（称B反应器）。经过196 d的运行,2个反应器中均形成了活性较高、沉降性能良好的颗粒污泥。A反应器中的污泥颗粒更多、粒径更大,粒径＞0.5 mm的污泥颗粒的百分比比B反应器的多16%～19.3%。研究结果表明,投加阳离子聚合物加速了颗粒污泥的形成,提高了颗粒污泥的产甲烷活性和沉降性能。     

常温下ABR处理低浓度废水性能及污泥特性

研究了常温(17~25℃)下4隔室厌氧折流板反应器(ABR)处理低浓度废水的运行效果及污泥特性。在水力停留时间(HRT)为24 h,进水COD浓度为1 500、1 000和500 mg/L左右时,平均COD去除率分别为94%、93%和87%。进水COD浓度保持在500 mg/L左右,将HRT降为12 h和8 h,COD的去除率仍达到83%以上。厌氧污泥性质测定结果表明,最后隔室中的污泥浓度、颗粒化程度及产甲烷活性与其他隔室相比明显较低,说明低浓度进水对最后隔室厌氧污泥的性质影响较大。颗粒污泥扫描电镜观察显示,各隔室颗粒污泥内部微生物组成差异较大,第1隔室颗粒污泥以产甲烷球菌为主,第2隔室颗粒污泥中没有明显的优势菌,但杆状菌比第1隔室明显较多,第3、4隔室颗粒污泥中以索氏甲烷丝菌为优势菌。     

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in breast milk from the Pacific Northwest

Breast milk samples from 40 first-time mothers from the Pacific Northwest of the US and Canada were analyzed for polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). Total PBDEs (summation operator PBDEs), calculated by summing values for the 12 PBDEs congeners analyzed, ranged from 6 to 321 ppb (lipid weight) (mean=96 ppb; median=50 ppb). In approximately 40% of the women (15/40), summation operator PBDEs>100 ppb lw in their milk, and four samples had levels >250 ppb lw. PBDE 47 was the dominant congener in most samples, whereas PBDE 153 was predominant in a few (3/40). summation operator PCBs were calculated by summing values for the 82 PCB congeners analyzed, and ranged from 49 to 415 ppb (lipid weight) (mean=147 ppb; median=126 ppb). approximately 30% of the mothers (13/40) have summation operator PBDEs> summation operator PCBs in their milk samples, and approximately 65% (25/40) have BDE 47>PCB 153 in breast milk samples, with BDE 47 averaging 3-fold greater levels than PCB 153. Clearly, the lower brominated PBDEs are surpassing PCBs as a major environmental concern in North America, and are likely affecting significant portions of the populations in these regions. PBDEs have become a major persistent organic pollutant. However, there are no positive correlations between levels of summation operator PBDEs and summation operator PCBs, or between levels of PBDE 47 and PCB 153, suggesting there may be some differences in exposure pathways for PBDEs and PCBs in humans.     

序批式生物膜反应器和序批式反应器处理硝酸盐氮污染河水

在序批式反应器(SBR)中添加ZH组合填料构成序批式生物膜反应器(SBBR),并以SBR为对比,研究了2种工艺对污染河水中硝酸盐氮的去除效果。结果表明,(1)进水硝酸盐氮浓度分别为15、20和30 mg/L时,2种工艺对COD的去除率均大于90%,对COD的去除能力均较强,进水硝酸盐氮的增加对COD的去除效果影响不大;第1个缺氧段是COD的主要去除段,此阶段COD的去除率达到80%以上。(2)随进水硝酸盐氮浓度的增加,SBBR中NO-3-N和TN的去除率分别从99.73%和99.24%降至79.75%和65.56%;SBR中NO-3-N和TN的去除率分别从99.91%和99.51%降至55.57%和41.73%。(3)随进水硝酸盐氮浓度的提高,两反应器内亚硝酸盐氮的积累量增大;进水硝酸盐氮浓度为15、20和30 mg/L时,SBBR中的亚硝酸盐氮最大积累浓度分别为2.90、6.82和10.72 mg/L;SBR中亚硝酸盐氮最大积累浓度分别为4.35、9.47和11.89 mg/L。SBBR中亚硝酸盐氮的积累明显低于SBR。     

废水中硝基酚类化合物生物降解的研究进展

硝基酚是一类重要且常用的化工原料,一些硝基酚毒性大且难以生物降解,被美国环保局列入“优先控制污染物名单”。在自然环境条件下,硝基酚的生物降解速率缓慢,导致硝基酚在环境中长期滞留和积累。分析了人工强化条件下废水中硝基酚的生物降解性能,主要从具有降解硝基酚能力的微生物、硝基酚的厌氧生物降解性、硝基酚的好氧生物降解性和硝基酚的共基质代谢降解方面进行了较全面的综述,讨论了该研究当前仍存在的一些问题和研究展望。     

Effect of Florasulam on soil residues and enzyme activity of wheat in drylands北大核心CSCD

Florasulam is a three azole and pyrimidine sulfonamide herbicide, mainly used for weeds prevention and control in winter wheat fields. The main purpose of this experiment was to study the effects of different doses of Florasulam on soil residues and on the enzymatic activity of wheat cultivated in drylands, and to provide the theoretical basis for a scientific use of florasulam. Five doses (0, 15, 30, 45, and 60 mL/667 m2) of Florasulam were applied in order to detect differences in soil residue content and enzymatic activities. Soil residues and enzymatic activities (catalase, phosphatase, urease, dehydrogenase) were measured and analyzed after the 5 different doses of Florasulam were processed. The residual amount of Florasulam in the soils decreased gradually with the growth phase of wheat, and was lower than that of 0.01 mg/kg. The residual amount of Florasulam in different soil layers gradually decreased with the increase of soil thickness. The enzymatic activity of soils treated with Florasulam was basically T3 > T2 > T1 > CK > T4, where T3 was the highest, whereas T4 could inhibit the enzymatic activity. Under these experimental conditions, in order to decrease soil pollution and lower Florasulam residues, it is recommended to apply Florasulam at a concentration range of 30 to 45 mL/667 m2 © 2018 Science Press. All rights reserved.     

粤东花岗岩流域覆盖型风化壳风化特征比较

为了对比在同种基岩与气候背景下,相邻花岗岩流域风化壳的风化程度,借助粒度组成、pH值和磁化率等实验方法,测定了粤东榕江和漯河流域阶地上发育的冲积物覆盖型风化壳.数据结果说明,螺河流域发育的该类型风化壳的风化程度强于榕江流域阶地上发育的该类型风化壳.粒度组成还表明,两流域该类型风化壳具有在<2μm粒级含量上冲积层大于基座风化壳的特征.两个流域风化壳粒度组成差别的原因是两个流域不同的剥蚀速率,榕江流域剥蚀速率较快.pH值在冲积物覆盖型风化壳剖面上呈现三低两高间隔出现的规律.螺河流域风化壳磁化率低于榕江流域是由局部的地貌条件决定,磁化率在粤东地区该类型风化壳的指示意义不准确.