生物早期警报系统在水和废水水质评价中的应用

生物监测是评价环境质量的重要手段，生物早期警报系统根据活生物对污染物的灵敏反应，快速确认污染事件，本文对生物早期警报系统的发展，设计与应用进行探讨。     

Metagenomic insights into responses of microbial population and key functional genes to fulvic acid during partial nitritation

The long-term impact of fulvic acid (FA) on partial nitritation (PN) system was initially examined in this study. The obtained results revealed that the FA lower than 50 mg/L had negligible effect on the nitrite accumulation rate (NAR nearly 100%) and ammonium removal rate (ARR 56.85%), while FA over 50 mg/L decreased ARR from 56.85% to 0.7%. Sludge characteristics analysis found that appropriate FA (<50 mg/L) exposure promoted the settling performance and granulation of PN sludge by removing Bacteroidetes and accumulating Chloroflexi. The analysis of metagenomics suggested that the presence of limited FA (0-50 mg/L) stimulated the generation of NADH, which favors the denitrification and nitrite reduction. The negative impact of FA on the PN system could be divided into two stages. Initially, limited FA (50-120 mg/L) was decomposed by Anaerolineae to stimulate the growth and propagation of heterotrophic bacteria (Thauera). Increasing heterotrophs competed with AOB (Nitrosomonas) for dissolved oxygen, causing AOB to be eliminated and ARR to declined. Subsequently, when FA dosage was over 120 mg/L, Anaerolineae were inhibited and heterotrophic bacteria reduced, resulting in the abundance of AOB recovered. Nevertheless, the ammonium transformation pathway was suppressed because genes amoABC and hao were obviously reduced, leading to the deterioration of reactor performance. Overall, these results provide theoretical guidance for the practical application of PN for the treatment of FA-containing sewage.     

重金属铅在线监测仪器性能对比研究

污染源在线监测仪器的准确性、实时性、连续性与污染源在线监测系统数据可靠性紧密相关。选取4个不同品牌的铅在线监测仪器,综合评价在线测定性能。结果表明,3种铅在线监测仪器的准确度小于10%,4种铅在线监测仪器的零点漂移、量程漂移、重复性误差均小于5%,定量下限小于0.05 mg/L,能较好地应用于铅的在线监测。     

原子荧光光谱法测定环境水体中痕量锡研究

在对环境水进行检测时,一个非常重要的项目就是对锡含量进行检测,所以,运用准确、灵敏的测定方法对环境水体中痕量锡进行检测具有非常重要的意义。文章将结合实验,在对环境水体中的痕量锡进行测定时,运用原子荧光光谱法,对测定环境水体中痕量锡的方法进行了一定的研究。采用原子荧光光谱法测定环境水体中的痕量锡,方法检出限是0.10μg/L,相对标准偏差0.20%~0.90%,实际样品加标回收率为98%~102%,满足环境监测实验室分析测定要求,值得推广。     

分光光度法与离子色谱法测定空气中氯化氢的对比研究

通过对硫氰酸汞分光光度法和离子色谱法测定空气中氯化氢含量的对比发现,两种方法对实验室质控样和实际样品的分析测定均能达到要求,且F检验法分析表明实测结果没有显著性差异。然而,硫氰酸汞分光光度法的测试过程操作繁琐,误差较大,稳定时间较长,且硫氰酸汞具有剧毒,危害操作人员的健康,残液也难以处理。离子色谱法分析操作简单,过程安全可靠,能够有效降低样品受污染的可能性并保证分析质量。     

苯甲酸重副产物的脱色处理

为了有效去除苯甲酸重副产物中含有的交联大分子和碳化物等有色杂质,降低有用组分资源化处理的难度,分别采用吸附和蒸馏两种方法对苯甲酸重副产物进行脱色处理。实验结果表明：大孔树脂、硅藻土、活性炭等作脱色剂不能有效去除苯甲酸重副产物中的有色杂质;在真空度0．093～0．095MPa、蒸馏温度220～240℃条件下进行蒸馏脱色,当温度出现回落时停止蒸馏,平均馏出率为66．99％;蒸馏脱色得到的轻组分颜色呈黄色,可满足中和、酸化、结晶、回收苯甲酸的要求;釜残物可作为燃料通过焚烧利用其热能。     

Mn/TiO2和Mn-Ce/TiO2低温脱硝催化剂的抗硫性研究

在低温选择性催化还原(SCR)反应条件下考察了烟气残余SO2对Mn/TiO2和Mn-Ce/TiO2催化剂选择性催化还原活性的影响,同时对SO2的影响机理进行了探讨.结果发现,Mn/TiO2催化剂在SO2反应气氛中失活很快,硫铵盐的沉积和活性组分的硫酸化是催化剂失活的重要原因;Ce的加入可以有效地抑制催化剂活性组分的硫酸化,同时还能降低硫酸盐在催化剂表面的稳定性,从而可以提高催化剂的抗硫性.     

Insight into the distribution of metallic elements in membrane bioreactor: Influence of operational temperature and role of extracellular polymeric substances

The distribution of metallic elements in a submerged membrane bioreactor(MBR) was revealed at different temperatures using inductively coupled plasma-optical emission spectrometry(ICP-OES), and the role of extracellular polymeric substances(EPS) was probed by integrating scanning electron microscopy(SEM) with confocal laser scanning microscopy(CLSM) over long-term operation. More metallic elements in the influent were captured by suspended sludge and built up in the fouling layer at lower temperature. The concentration of metallic elements in the effluent was 5.60 mg/L at 10°C operational temperature, far lower than that in the influent(51.35 mg/L). The total contents of metallic elements in suspended sludge and the membrane fouling layer increased to 40.20 and 52.19 mg/g at 10°C compared to 35.14 and 32.45 mg/g at 30°C, and were dominated by the organically bound fraction. The EPS contents in suspended sludge and membrane fouling layer sharply increased to 37.88 and 101.51 mg/g at 10°C, compared to 16.87 and 30.03 mg/g at 30°C. The increase in EPS content at lower temperature was responsible for the deposition of more metallic ions. The strong bridging between EPS and metallic elements at lower temperature enhanced the compactness of the fouling layer and further decreased membrane flux. This was helpful for understanding the mechanism of membrane fouling at different operational temperatures and the role of EPS, and also of significance for the design of cleaning strategies for fouled membranes after long-term operation.     

天津滨海新区地面沉降趋势预测

在分析天津市滨海新区地面沉降概况及灾害的基础上,利用天津地面沉降监测网26年的水准测量资料,采用数据拟合和多核函数方法,研究了天津滨海地区地面沉降随时间的变化规律,对滨海地区地面沉降的趋势进行预测。结果表明地面沉降这一"缓发型"的地质灾害一旦致灾,会给经济建设带来无法挽回的巨大损失。     

用粉末活性炭作前助凝剂提高PAC除藻效果的研究

采用烧杯搅拌实验研究了用粉末活性炭作前助凝剂提高聚合氯化铝(PAC)去除铜绿微囊藻的有效性。结果表明,单独使用粉末活性炭作前助凝剂的除藻效果并不好,而先投加20 mg/L高岭土,再将15 mg/L PAC与粉末活性炭同时投加,除浊除藻效果明显提高。考虑首先充分发挥粉末活性炭对有机物的去除能力,在除浊除藻率仍然较高的情况下,采用粉末活性炭先于高岭土2 min投加的方式,粉末活性炭的最佳助凝剂量为10mg/L。采用粉末活性炭、高岭土和FeCl3依次投加的完整助凝技术路线,除浊除藻效率最高。碱性水体比酸性水体有利于联用三种助凝剂除藻。扫描电镜(SEM)观察结果表明,采用助凝技术,藻细胞主要与高岭土无机颗粒发生凝聚,投加粉末活性炭有助于絮凝体体积增长,而在絮凝阶段投加FeCl3可使絮凝体的分维数达到1.947的最高值。联用粉末活性炭、高岭土和FeCl3是非常有效的助凝除藻新技术。