秦皇岛市重点工业企业VOCs排放及分布特征

工业企业挥发性有机物(VOCs)污染排放对大气环境影响日益突出,工业源VOCs污染防治成为环境保护的重点工作。为进一步提高秦皇岛市工业源挥发性有机物(VOCs)治理的科学性、针对性和有效性,对2019年秦皇岛市重点排污企业VOCs的排污量、区域分布、排放行业等进行了详细调查分析:秦皇岛市重点工业源VOCs排放总量为6875.83t,排放量最大的区域是秦皇岛经济技术开发区,占比51.1%;排放量最大的行业是交通运输设备制造业,占总排放量的33.5%;溶剂使用源的排放量最大,占比52.3%。     

在线固相萃取-超高效液相色谱法检测水中14种有机磷酸酯

与传统固相萃取耗时长、工作量大、有机溶剂使用量多相比,本文建立了一种在线固相萃取-超高效液相色谱串联质谱方法同时测定地表水中14种有机磷酸酯的新方法.地表水样过膜后,直接注入在线固相萃取净化装置,经净化后进入分离柱分离,用乙腈和0.1%的甲酸水溶液梯度洗脱,采用电喷雾离子源正离子多反应监测模式,对14种有机磷酸酯类化合物进行检测,内标法定量.该方法分析时长13.0 min,方法的线性相关系数R~20.98,地表水和自来水样品的加标回收率在64.8%—113%,相对标准偏差RSD在1.2%—9.3%,检出限为0.1—2.7 ng·L~(-1).与常规方法相比,该方法提高了分析通量和灵敏度,准确度好,操作简便,适用于地表水和自来水中有机磷酸酯的检测.     

UV-254 nm活化过硫酸盐降解麻黄碱的影响因素和机理

采用UV-254 nm活化过硫酸盐高级氧化技术去除水中污染物麻黄碱(EPH),并研究了其降解动力学过程和降解机理.考察了过硫酸盐(PS)投加量、EPH的初始浓度、不同pH值及不同离子(HCO~-_3、NO~-_3、Cl~-)对降解效果的影响.结果表明,UV-254 nm活化过硫酸盐工艺能有效去除实验条件下的EPH,其氧化降解反应符合二级动力学方程.EPH去除率随着PS投加量的增加而增大.pH对降解反应有较大的影响,在pH=7的条件下,反应速率最快,表观反应动力学常数(k_(obs))为0.467 min~(-1).进一步研究表明,HCO~-_3、NO~-_3和Cl~-对EPH的降解都存在抑制作用,在相同浓度下,其抑制程度依次为Cl~- NO~-_3 HCO~-_3.通过UPLC-MS/MS鉴定了麻黄碱降解的中间体,并提出了可能的降解机理和转化途径.     

A fractal derivative model to quantify bed-load transport along a heterogeneous sand bed

Environmental Fluid Mechanics - Bed-load transport is a complex process exhibiting anomalous dynamics, which cannot be efficiently described using the traditional advection–diffusion...     

浮游动物DNA宏条形码标志基因比较研究

DNA宏条形码技术作为一种新型生物监测方法,在未来生态环境监测中有巨大的应用潜力。目前,浮游动物DNA宏条形码监测仍在发展阶段,需要首先对其(采样方法、引物选择和数据分析等)进行标准化和调整,然后才能用于常规流域生态监测。其中,如何选择合适的PCR扩增引物是DNA宏条形码生物监测标准化的关键问题之一。本研究比较了COI、18SV9和16S通用引物在浮游动物DNA宏条形码监测中的差异,为初步建立规范化的浮游动物DNA宏条形码监测方法提供技术支撑。结果表明,16S引物对浮游动物具有更好的特异性,其产生的操作分类单元(operational taxonomic unit, OTU)有88.1%属于浮游动物。虽然18SV9引物具有更高的物种覆盖度,不仅能扩增出浮游动物,还能扩增出大量藻类和真菌,但其物种识别敏感性较差,不适合浮游动物物种水平多样性监测。COI引物的浮游动物物种特异性、物种覆盖度和物种识别敏感性都适中,检出的浮游动物物种数量高于18SV9引物和16S引物,更加适合浮游动物DNA宏条形码监测。     

Validation of Bacteroidales-based microbial source tracking markers for pig fecal pollution and their application in two rivers of North China

• Pig feces is the predominant excrement produced by animal husbandry in China. • The PF, Pig-1-Bac^TaqMan, and Pig-2-Bac^TaqMan MST assays showed better performance. • The pig-specific MST assays can contribute to managing the pig fecal pollution. In China, pig feces is the predominant source of excrement produced by animal husbandry. Improper use or direct discharge of pig feces can result in contamination of natural water systems. Microbial source tracking (MST) technology can identify the sources of fecal pollution in environmental water, and contribute to the management of pig fecal pollution by local environmental protection agencies. However, the accuracy of such assays can be context-dependent, and they have not been comprehensively evaluated under Chinese conditions. We aimed to compare the performance of five previously reported pig-specific MST assays (PF, Pig-Bac1^SYBR, Pig-Bac2^SYBR, Pig-1-Bac^TaqMan, and Pig-2-Bac^TaqMan, which are based on Bacteroidales 16S rRNA gene markers) and apply them in two rivers of North China. We collected a total of 173 fecal samples from pigs, cows, goats, chickens, humans, and horses across China. The PF assay optimized in this study showed outstanding qualitative performance and achieved 100% specificity and sensitivity. However, the two SYBR green qPCR assays (Pig-Bac1^SYBR and Pig-Bac2^SYBR) cross-reacted with most non-pig fecal samples. In contrast, both the Pig-1-Bac^TaqMan and Pig-2-Bac^TaqMan assays gave 100% specificity and sensitivity. Of these, the Pig-2-Bac^TaqMan assay showed higher reproducibility. Our results regarding the specificity of these pig-specific MST assays differ from those reported in Thailand, Japan, and America. Using the PF and Pig-2-Bac^TaqMan assays, a field test comparing the levels of pig fecal pollution in rivers near a pig farm before and after comprehensive environmental pollution governance indicated that pig fecal pollution was effectively controlled at this location.     

Magnetotactic bacteria: Characteristics and environmental applications

• Magnetotactic bacteria (MTB) synthesize magnetic nanoparticle within magnetosomes. • The morphologic and phylogenetic diversity of MTB were summarized. • Isolation and mass cultivation of MTB deserve extensive research for applications. • MTB can remove heavy metals, radionuclides, and organic pollutants from wastewater. Magnetotactic bacteria (MTB) are a group of Gram-negative prokaryotes that respond to the geomagnetic field. This unique property is attributed to the intracellular magnetosomes, which contains membrane-bound nanocrystals of magnetic iron minerals. This review summarizes the most recent advances in MTB, magnetosomes, and their potential applications especially the environmental pollutant control or remediation. The morphologic and phylogenetic diversity of MTB were first introduced, followed by a critical review of isolation and cultivation methods. Past research has devoted to optimize the factors, such as oxygen, carbon source, nitrogen source, nutrient broth, iron source, and mineral elements for the growth of MTB. Besides the applications of MTB in modern biological and medical fields, little attention was made on the environmental applications of MTB for wastewater treatment, which has been summarized in this review. For example, applications of MTB as adsorbents have resulted in a novel magnetic separation technology for removal of heavy metals or organic pollutants in wastewater. In addition, we summarized the current advance on pathogen removal and detection of endocrine disruptor which can inspire new insights toward sustainable engineering and practices. Finally, the new perspectives and possible directions for future studies are recommended, such as isolation of MTB, genetic modification of MTB for mass production and new environmental applications. The ultimate objective of this review is to promote the applications of MTB and magnetosomes in the environmental fields.     

Biofiltration and disinfection codetermine the bacterial antibiotic resistome in drinking water: A review and meta-analysis

• Published data was used to analyze the fate of ARGs in water treatment. • Biomass removal leads to the reduction in absolute abundance of ARGs. • Mechanism that filter biofilm maintain ARB/ARGs was summarized. • Potential BAR risks caused by biofiltration and chlorination were proposed. The bacterial antibiotic resistome (BAR) is one of the most serious contemporary medical challenges. The BAR problem in drinking water is receiving growing attention. In this study, we focused on the distribution, changes, and health risks of the BAR throughout the drinking water treatment system. We extracted the antibiotic resistance gene (ARG) data from recent publications and analyzed ARG profiles based on diversity, absolute abundance, and relative abundance. The absolute abundance of ARG was found to decrease with water treatment processes and was positively correlated with the abundance of 16S rRNA (r² = 0.963, p<0.001), indicating that the reduction of ARG concentration was accompanied by decreasing biomass. Among treatment processes, biofiltration and chlorination were discovered to play important roles in shaping the bacterial antibiotic resistome. Chlorination exhibited positive effects in controlling the diversity of ARG, while biofiltration, especially granular activated carbon filtration, increased the diversity of ARG. Both biofiltration and chlorination altered the structure of the resistome by affecting relative ARG abundance. In addition, we analyzed the mechanism behind the impact of biofiltration and chlorination on the bacterial antibiotic resistome. By intercepting influent ARG-carrying bacteria, biofilters can enrich various ARGs and maintain ARGs in biofilm. Chlorination further selects bacteria co-resistant to chlorine and antibiotics. Finally, we proposed the BAR health risks caused by biofiltration and chlorination in water treatment. To reduce potential BAR risk in drinking water, membrane filtration technology and water boiling are recommended at the point of use.     

Utilization of MSWI fly ash as partial cement or sand substitute with focus on cementing efficiency and health risk assessment

• Washed MSWI fly ash was used as partial cement or sand substitute. • Sand replacing is beneficial for strength, while cement replacement reduces strength. • Cementing efficiency factor and mortar pore structure explain the strength results. • Health risk assessment was conducted for MSWI fly ash blended cement mortar. • CR and HI contributed by different exposures and heavy metals were analyzed. The strength of cement substituted mortar decreases with the increase in fly ash amount, whereas the strength increases when the fly ash is blended as sand substitute. A mortar with highest strength (compressive strength= 30.2 Mpa; flexural strength= 7.0 Mpa) was obtained when the sand replacement ratio was 0.75%. The k value (cementing efficiency) of fly ash varied between 0.36 and 0.15 for the fly ash fraction in binder between 5% and 25%. The k values of fly ash used for sand replacement were all significantly above that used for cement substitution. The macropores assigned to the gaps between particles decreased when the fly ash was used as sand replacement, providing an explanation for the strength enhancement. The waste-extraction procedure (toxicity-sulphuric acid and nitric acid method (HJ/T 299-2007)) was used to evaluate metal leaching, indicating the reuse possibility of fly ash blended mortar. For the mortar with the mass ratio of fly ash to binder of 0.5%, the carcinogenic risks (CR) and non-carcinogenic hazard quotient (HQ) in sensitive scenario for blended mortar utilization were 9.66 × 10^-7 and 0.06, respectively; these results were both lower than the threshold values, showing an acceptable health risk. The CR (9.89 × 10^-5) and HQ (3.89) of the non-sensitive scenario for fly ash treatment exceeded the acceptable threshold values, indicating health risks to onsite workers. The main contributor to the carcinogenic and non-carcinogenic risk is Cr and Cd, respectively. The CR and HQ from inhalation was the main route of heavy metal exposure.