新型高效污水处理设备--集成一体化生物转筒反应器

介绍了一种新型高效污水处理设备--集成一体化生物转筒反应器(IBDR).IBDR具有微生物浓度高、活性强、生物相分级明显、耐冲击负荷、污泥沉降性能好和不产生污泥膨胀、操作简单灵活、运行成本低等显著特点;并成功地运用于处理餐饮污水和深圳某厂洗涤剂生产废水.在处理餐饮污水时,IBDR比传统的生物转盘处理效果高出20%.     

直接投菌法在城市重污染河流治理中的应用研究

在无截污和清除内源的情况下,对深圳市甘坑河采用梅花式接种法将本源微生物菌剂分两次直接接入河流水体及底泥中。结果表明,第1次接种后的4 d内各项水质指标都不稳定,4 d后,悬浮物、COD、TP和NH3-N等浓度下降,水质明显改善;但从第8天开始,COD、NH3-N和TP的去除率同时下降,本源微生物的处理效率开始降低,需进行第2次接种;第2次接种后,DO浓度提升至2.0 mg/L以上,COD、TP和NH3-N的去除率分别保持在40%、30%和40%以上。结果表明,直接投菌法在城市重污染河道治理中可以初步消除河道的黑臭现象,修复水质。     

含锌多核聚铝絮凝剂的制备及形态特征

以AlCl3·6H2O和ZnCl2为原料,采用一次加碱法制备了一种新型的改性增效聚合铝类多核无机高分子絮凝剂聚合氯化铝锌(PAZC).通过Al-Ferron逐时络合比色法研究了碱化度(B),Al/Zn摩尔比及陈化时间对铝离子形态的影响.采用混凝实验比较PAZC、PAC的混凝效果.结果表明:在相同B值条件下,PAZC的Ala和Alc少于PAC的Ala和Alc,Alb形态多于PAC中Alb形态,并且PAC中Alb形态最高只有60%,而PAZC中Alb最高达到83%.PAZC具有pH适用范围宽,投药量少以及良好的储存性能.     

Influence of environmental temperature and relative humidity on photocatalytic oxidation of toluene on activated carbon fibers coated TiO2

TiO₂ supported on active carbon fiber (TiO₂/ACF), an absorbable photocatalyst, is a new kind of material applied in air purification. In this paper, the influence of environmental temperature (T) and relative humidity (RH) on the gas-solid adsorption of toluene and the photocatalytic oxidation (PCO) efficiency of adsorbed toluene on TiO₂/ACF were studied, and then, the purification capability of TiO₂/ACF was estimated. PCO results showed that although the PCO efficiency increased under high RH and T levels, the amount of adsorption of toluene decreased. Moreover, quantitative analysis results of intermediates indicated that more environmental risk emerged when PCO of toluene was carried out at higher environmental T and RH levels because more toxic intermediates would be accumulated on the TiO₂/ACF. So, it is significant to control the environmental T and RH conditions in the application of the PCO technique. T = 25°C and RH530% is the optimal condition for purifying toluene in our experimental system.     

MoS2 quantum dots based MoS2/HKUST-1 composites for the highly efficient catalytic oxidation of elementary mercury

Due to the ever-tightening regulation on mercury emission in recent decades, there is an urgent need to develop novel materials for the removal of elemental mercury at coal-fired power plants. In this study, a series of MoS₂ quantum dots (QDs)-based MoS₂/HKUST-1 composite materials were prepared. It is found that MoS₂ QDs were encapsulated by HKUST-1 and enhanced the crystallinity and specific surface area of HKUST-1. The MoS₂/HKUST-1 showed excellent performance in catalytic oxidation of Hg⁰ as compared with pristine HKUST-1. It is found that surface layer of lattice oxygens is active and participates in Hg⁰ oxidation, while the consumption of surface oxygens then leads to the formation of oxygen vacancies on the surface. These vacancies are effective in the adsorption and dissociation of O₂, which subsequently participates in the oxidation of Hg⁰. Moreover, the study on the influence of commonly seen gas components, such as SO₂, NO, NH₃ and H₂O, etc., on Hg⁰ oxidation demonstrated that synergistic effects exist among these gas species. It is found that the presence of NO promotes the oxidation of Hg⁰ using oxygen as the oxidant.     

Factors influencing sexual cannibalism and its benefit to fecundity and offspring survival in the wolf spider Pardosa pseudoannulata (Araneae: Lycosidae)

Sexual cannibalism is hypothesized to have evolved as a way to obtain a high-quality meal, as an extreme mate choice or as a consequence of female aggressive spillover. Here, we examined underlying factors likely to influence sexual cannibalism in the wolf spider Pardosa pseudoannulata (Bösenberg & Strand, 1906) from China, including mating status, female egg-laid status, female hunger level, female adult age and mate size dimorphism. The results showed that about 10 % of P. pseudoannulata virgin females cannibalized the approaching males before mating and that 28 % of P. pseudoannulata virgin females immediately cannibalized the males after mating. No incidents of sexual cannibalism during copulation were observed. Before mating, previously mated females and starved females tended to engage in significantly higher rates of attacks compared to virgin and well-fed females. Females that had laid egg sacs tended to engage in a significantly higher rate of attacks and sexual cannibalism than virgin females before mating. Regardless of pre- or post-mating, there was a strong positive relationship between mate size dimorphism and the occurrence of sexual cannibalism. We also tested the effects of sexual cannibalism on the fecundity of cannibalistic females and the survival of their offspring. Our results indicated that sexual cannibalism affected positively the offspring survival of cannibalistic females, but not fecundity. Our findings support the hypothesis that sexual cannibalism has evolved as an adaptive component of female foraging strategy and that it benefits offspring survival as a result of paternal investment.     

Integration of microbial reductive dehalogenation with persulfate activation and oxidation (Bio-RD-PAO) for complete attenuation of organohalides

•Bio-RD-PAO can effectively and extensively remove organohalides. •Bio-RD alone effectively dehalogenate the highly-halogenated organohalides. •PAO alone is efficient in degrading the lowly-halogenated organohalides. •The impacts of PAO on organohalide-respiring microbial communities remain elusive. •Bio-RD-PAO provides a promising solution for remediation of organohalide pollution. Due to the toxicity of bioaccumulative organohalides to human beings and ecosystems, a variety of biotic and abiotic remediation methods have been developed to remove organohalides from contaminated environments. Bioremediation employing organohalide-respiring bacteria (OHRB)-mediated microbial reductive dehalogenation (Bio-RD) represents a cost-effective and environmentally friendly approach to attenuate highly-halogenated organohalides, specifically organohalides in soil, sediment and other anoxic environments. Nonetheless, many factors severely restrict the implications of OHRB-based bioremediation, including incomplete dehalogenation, low abundance of OHRB and consequent low dechlorination activity. Recently, the development of in situ chemical oxidation (ISCO) based on sulfate radicals (SO₄^·−) via the persulfate activation and oxidation (PAO) process has attracted tremendous research interest for the remediation of lowly-halogenated organohalides due to its following advantages, e.g., complete attenuation, high reactivity and no selectivity to organohalides. Therefore, integration of OHRB-mediated Bio-RD and subsequent PAO (Bio-RD-PAO) may provide a promising solution to the remediation of organohalides. In this review, we first provide an overview of current progress in Bio-RD and PAO and compare their limitations and advantages. We then critically discuss the integration of Bio-RD and PAO (Bio-RD-PAO) for complete attenuation of organohalides and its prospects for future remediation applications. Overall, Bio-RD-PAO opens up opportunities for complete attenuation and consequent effective in situ remediation of persistent organohalide pollution.     

多效唑在鱼体内的分布,积累与类脂质含量相关性研究

实验水系统中，植物生长调节剂多效唑在鲤科类金鱼体内分布、积累的研究结果表明，＾３Ｈ－ＭＥＴ主要积累在鱼体消化系统；各器官／组织的积累量依次为：肠＞肝＞鳃＞皮＞肉＞骨；多效唑效生物积累因子（ＢＣＦ）和鱼体类脂质含量之间有较高的正相关性。     

Removal of high concentrations of polycyclic aromatic hydrocarbons from contaminated soil by biodiesel

Solubilizing experiments were carried out to evaluate the ability of biodiesel to remove polycyclic aromatic hydrocarbons (PAHs) from highly contaminated manufactured gas plant (MGP) and PAHs spiked soils with hydroxypropyl-β-cyclodextrin (HPCD) and tween 80 as comparisons. Biodiesel displayed the highest solubilities of phenanthrene (420.7 mg·L^-1), pyrene (541.0 mg·L^-1), and benzo(a)pyrene (436.3 mg·L^-1). These corresponded to several fold increases relative to 10% HPCD and tween 80. Biodiesel showed a good efficiency for PAH removal from the spiked and MGP soils for both low molecular weight and high molecular weight PAHs at high concentrations. Biodiesel was the best agent for PAH removal from the spiked soils as compared with HPCD and tween 80; as over 77.9% of individual PAH were removed by biodiesel. Tween 80 also showed comparable capability with biodiesel for PAH solubilization at a concentration of 10% for the spiked soils. Biodiesel solubilized a wider range of PAHs as compared to HPCD and tween 80 for the MPG soils. At PAH concentrations of 229.6 and 996.9 mg·kg^-1, biodiesel showed obvious advantage over the 10% HPCD and tween 80, because it removed higher than 80% of total PAH. In this study, a significant difference between PAH removals from the spiked and field MGP soils was observed; PAH removals from the MGP soil by HPCD and tween 80 were much lower than those from the spiked soil. These results demonstrate that the potential for utilizing biodiesel for remediation of highly PAH-contaminated soil has been established.     

Spatial–temporal characteristics of haze and vertical distribution of aerosols over the Yangtze River Delta of China

Variation of haze events occurred in the Yangtze River Delta(YRD) of China, the characteristics of meteorological elements and the vertical distribution of aerosols during haze episodes were analyzed by utilizing data of ground observation, radiosonde and CALIPSO. The results illustrate that the frequency of haze events between 1981 and 2010 peaked in winter but bottomed out in summer and decreased from north to south in the YRD region, reaching at the lowest point in "low frequency center" — Shanghai. When haze happened, the most seriously affected area was 2–4 km above the ground and the concentrated range of total backscattering coefficient(TBC) that decreased with altitude was 0.8 × 10~(-3)–2.5 × 10~(-3) km~(-1)·sr~(-1). Particulate depolarization ratio(PDR) was less than 40%in a large part and 93% aerosols over the YRD area were regular particles, while the irregular ones concentrated on 2 km above the surface and the irregularity rose up but the diversity diminished when altitude increased. Color ratio(CR) was lower than 1.2 mostly at all altitudes and distributed asymmetrically above the ground. Nearly 80% aerosols under10 km were fine particles(CR 1.0) and 22.54% coarse particles(CR 1.0) clustered at 2–4 km. Large particles(CR 1.2) aggregated in lower troposphere massively yet relatively smaller ones gathered in middle and upper troposphere. In the YRD region, aerosols with more powerful capabilities were wider and less regular than the ones of Northwestern China.