天津市大气颗粒物污染特征与来源构成变化

对1985年、2001年和2011年天津市颗粒物的粒径、化学组分以及污染来源的变化趋势进行了对比分析. 结果表明:天津市PM₁₀中细粒子所占比重逐渐增加,由1985年的<0.51升至2011年的0.57. PM₁₀中化学组分发生了明显改变,主要组分由单一的地壳元素发展为二次粒子、碳和地壳元素并重,1985年以地壳元素(Si、Al、Mg、Ca等)为主要组分,2001年以TC、Si、SO₄2-、Al、Ca为主要组分,2011年主要组分除TC、Si、SO₄2-、Ca外,还新增了NO₃-. 各主要组分质量浓度及其占ρ(PM₁₀)比例的变化多样,ρ(Si)所占比例先显著下降后保持平稳,其由1985年的28.7%降至2011年7.6%;碳组分所占比例由2001年的24.9%降至2011年17.9%;二次粒子质量浓度〔即ρ(SO₄2-)、ρ(NO₃-)之和〕所占比例由2001年的10.2%升至2011年的18.3%. 煤烟尘对天津市PM₁₀的分担率由1985年的45%降至2011年的22%,而开放源、二次粒子和机动车尾气尘对PM₁₀的分担率有所增加,三者分别由1985年的29%、6%和3%升至2011年的35%、16%和16%. 环境空气中对颗粒物有重要贡献的源类越来越多,颗粒物的污染特征由煤烟型过渡为混合型再过渡到复合型.      

Municipal wastewater treatment in China: Development history and future perspectives

The history of China’s municipal wastewater management is revisited. The remaining challenges in wastewater sector in China are identified. New concept municipal wastewater treatment plants are highlighted. An integrated plant of energy, water and fertilizer recovery is envisaged. China has the world’s largest and still growing wastewater sector and water market, thus its future development will have profound influence on the world. The high-speed development of China’s wastewater sector over the past 40 years has forged its global leading treatment capacity and innovation ability. However, many problems were left behind, including underdeveloped sewers and sludge disposal facilities, low sustainability of the treatment processes, questionable wastewater treatment plant (WWTP) effluent discharge standards, and lacking global thinking on harmonious development between wastewater management, human society and the nature. Addressing these challenges calls for fundamental changes in target design, policy and technologies. In this mini-review, we revisit the development history of China’s municipal wastewater management and identify the remaining challenges. Also, we highlight the future needs of sustainable development and exploring China’s own wastewater management path, and outlook the future from several aspects including targets of wastewater management, policies and technologies, especially the new concept WWTP. Furthermore, we envisage the establishment of new-generation WWTPs with the vision of turning WWTP from a site of pollutant removal into a plant of energy, water and fertilizer recovery and an integrated part urban ecology in China.     

Fate of proteins of waste activated sludge during thermal alkali pretreatment in terms of sludge protein recovery

Maillard reaction between reducing sugars and amides happened during pretreatment. Over 90 min of TAH at the optimal condition, 67.59% sludge proteins was solubilized. 15.84% soluble proteins broke down to materials with small molecular weight. Proteins are the major organic component s of waste activated sludge (WAS); the recovery of sludge proteins is economically valuable. To efficiently recover sludge proteins, WAS should undergo hydrolysis pretreatment to fully release proteins from sludge flocs and microbial cells into aqueous phase. One of the most widely used chemical methods for that is thermal alkali hydrolysis (TAH). Here, the soluble protein concentration achieved the highest level over 90 min of TAH pretreatment at 80°C; the sludge floc disintegration and microbial cell destruction were maximized according to the content profiles of bound extracellular polymeric substance (EPS) and ribonucleic acid (RNA) of sludge. Both less proteins broken down to materials with small molecular weight and less melanoidin generated were responsible. TAH pretreatment at 80°C for 90 min resulted in the solubilization of 67.59% of sludge proteins. 34.64% of solubilized proteins was present in soluble high molecular; 1.55% and 4.85% broke down to polypeptides and amino acids. The lost proteins via being converted to ammonium and nitrate nitrogen accounted for 9.44% of solubilized proteins. It was important to understand the fate of sludge proteins during TAH pretreatment in terms of protein recovery, which would be helpful for designing the downstream protein separation method and its potential application.     

Toxicity,residue, degradation and detection methods of the insecticide triazophos

Environmental Chemistry Letters - Organophosphorus pesticides were widely used in agricultural production and in public health as insecticides and acaricides. Triazophos, an organophosphorus...     

短、中、长链氯化石蜡暴露对细胞代谢影响的比较研究

氯化石蜡(chlorinated paraffins, CPs)在中国大量生产和使用,导致其在环境介质中的含量较高。采用拟靶向代谢组学技术,比较研究了短、中和长链氯化石蜡在人体内暴露水平下(100μg·L~(-1))对HepG2细胞代谢的影响。结果表明,短、中和长链氯化石蜡暴露引起了HepG2细胞增殖活力的降低与代谢活动的显著变化。短链氯化石蜡(SCCPs)暴露对细胞代谢的影响强度略高于中链氯化石蜡(MCCPs)和长链氯化石蜡(LCCPs)。3种氯化石蜡均显著扰乱了脂质代谢,且影响程度相近。显著受影响的代谢通路包括:甘油磷脂代谢、亚油酸代谢、α-亚麻酸代谢、花生四烯酸代谢和鞘磷脂代谢。同时,3种氯化石蜡暴露也显著扰乱了甘氨酸、丝氨酸和苏氨酸代谢,缬氨酸、亮氨酸和异亮氨酸生物合成,牛磺酸和亚牛磺酸代谢;此外,LCCPs还扰乱了苯丙氨酸、酪氨酸和色氨酸生物合成通路。相比于SCCPs和MCCPs,LCCPs对氨基酸代谢表现出更强的干扰效应。     

Trophic mode and organics metabolic characteristic of fungal community in swine manure composting

Fungal trophic modes and substrates utilization ability was observed in composting. Fungi had the higher diversity and more trophic types in thermophilic phase. Fungi had the higher metabolic potential in fresh swine manure and mature production. Redox potential, organics and moisture are main factors impacting fungal community. Composting reduced pathogenic fungi and enrich dung saprotroph fungi in swine manure. The succession of fungal community, trophic mode and metabolic characteristics were evaluated in 60 days composting of swine manure by high-throughput sequencing, FUNGuild and Biolog method, respectively. The result showed that the fungal community diversity reached to the highest level (76 OTUs) in the thermophilic phase of composting, then sustained decline to 15 OTUs after incubation. There were 10 fungal function groups in the raw swine manure. Pathotroph-saprotroph fungi reached to 15.91% on Day-10 but disappeared on Day-60. Dung saprotroph-undefined saprotroph fungi grown from 0.19% to 52.39% during the treatment. The fungal community had more functional groups but the lower substrate degradation rates in the thermophilic phase. The fungal communities on Day-0 and Day-60 had the highest degradation rates of amino acids and polymers, respectively. Redundancy analysis showed that ORP (49.6%), VS/Ash (45.3%) and moisture (39.2%) were the main influence factors on the succession of fungal community in the swine manure composting process.     

北京市工业废水和城市污水中有机氮、有机磷类农药残留分析

建立了基于^18C固相萃取柱和气相色谱／氮磷检测器(GC／NPD)分析水体中环境激素类物质——有机氮、有机磷类农药的分析方法．并对方法的回收率、灵敏度进行了评价。同时分析了北京市七类典型污染点源50个采样点位有机氮、有机磷类农药的浓度。检出的有机氮、有机磷农药包括马拉硫磷、莠去津、对硫磷和乙草胺．检出率都较低。低于8％;检出有机氮、有机磷农药的浓度范围是0．11～4．02mg／L。该方法对有机氮、有机磷农药的回收率除嗪草酮为30％外．其余在83．9％～94．7％之间。     

水生和陆生生物体中卤系阻燃剂的差异性富集研究:以鲶鱼和家鸽为例

分析了水生(鲶鱼)和陆生(家鸽)生物体中卤系阻燃剂(HFRs)的组成和浓度。鲶鱼中短链氯化石蜡(SCCPs)浓度均值为30 800 ng·g~(-1)lw(脂肪归一化浓度),是最主要的HFRs,然后依次是多溴联苯醚(PBDEs)(2 300 ng·g~(-1)lw)、四溴双酚A(TBBPA)(37 ng·g~(-1)lw)、六溴环十二烷(HBCD)(21 ng·g~(-1)lw)、德克隆(DP)(14 ng·g~(-1)lw)、十溴二苯乙烷(DBDPE)(7.1 ng·g~(-1)lw)和六溴苯(HBB)(6.2 ng·g~(-1)lw);而家鸽中PBDEs含量最高(17 000 ng·g~(-1)lw),其次是SCCPs(7 600 ng·g~(-1)lw)DP(1 600 ng·g~(-1)lw)DBDPE(14 ng·g~(-1)lw)HBB、TBBPA和HBCDs(未检出)。鲶鱼和家鸽HFRs组成比较发现,鲶鱼中具有较高百分含量的低溴代PBDE单体和较低的fanti值,而家鸽中具有较高百分含量的高溴代PBDE单体和较高的fanti值。实验结果初步表明,水生生物较多地富集水溶性较大的化合物,陆生生物则较多地富集疏水性较强的化合物。研究认为以上水生和陆生生物体中污染物的差异性富集现象可能与化合物因不同物理化学性质导致的不同环境迁移行为有关。     

Phosphate-induced differences in stabilization efficiency for soils contaminated with lead,zinc, and cadmium

Phosphates can cost-effectively decrease the mobility of Pb in contaminated soils. However, Pb always coexists with other metals in soil, their competitive reactions with phosphates have not been tested. In this study, the abilities of KH₂PO₄, K₂HPO₄, and K₃PO₄ to stabilize Pb, Zn, and Cd in soils contaminated with a single metal or a ternary metal for different phosphorus/metal molar ratios were investigated. Results indicated that the stabilization efficiency of KH₂PO₄, K₂HPO₄, and K₃PO₄ for Pb, Zn, and Cd in single metal contaminated soil (P/M ratio 0.6) was 96.00%–98.74%, 33.76%–47.81%, and 9.50%–55.79%, respectively. Competitive stabilization occurred in the ternary system, Pb exhibited a strong competition, the stabilization efficiency of Zn and Cd reduced by 23.50%–31.64%, and 7.10%–39.26%, respectively. Pyromorphite and amorphous lead phosphate formed with excess KH₂PO₄ or K₂HPO₄ addition, while K₃PO₄ resulted in the formation of a hydroxypyromorphite precipitate. Amorphous Zn and Cd phosphates and hydroxides were the primary products. The immobilization rate of Zn and Cd depends on pH, and increased significantly in response to the excess phosphate application. This approach provides insight into phosphate-induced differences in stabilization efficiency in soils contaminated with multiple metals, which is of theoretical and engineering significance.

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The CPCAT as a novel tool to overcome the shortcomings of NOEC/LOEC statistics in ecotoxicology: a simulation study to evaluate the statistical power

Species reproduction is an important determinant of population dynamics. As such, this is an important parameter in environmental risk assessment. The closure principle computational approach test (CPCAT) was recently proposed as a method to derive a NOEC/LOEC for reproduction count data such as the number of juvenile Daphnia. The Poisson distribution used by CPCAT can be too restrictive as a model of the data-generating process. In practice, the generalized Poisson distribution could be more appropriate, as it allows for inequality of the population mean \(\mu\) and the population variance \(\sigma ^2\). It is of fundamental interest to explore the statistical power of CPCAT and the probability of determining a regulatory relevant effect correctly. Using a simulation, we varied between Poisson distribution (\(\mu =\sigma ^2\)) and generalized Poisson distribution allowing for over-dispersion (\(\mu <\sigma ^2\)) and under-dispersion (\(\mu >\sigma ^2\)). The results indicated that the probability of detecting the LOEC/NOEC correctly was \(\ge 0.8\) provided the effect was at least 20% above or below the mean level of the control group and mean reproduction of the control was at least 50 individuals while over-dispersion was missing. Specifically, under-dispersion increased, whereas over-dispersion reduced the statistical power of the CPCAT. Using the well-known Hampel identifier, we propose a simple and straight forward method to assess whether the data-generating process of real data could be over- or under-dispersed.