陶粒复合垂直流人工湿地对污水季节性处理效果的试验研究

研究了四种陶粒组合、一种石灰石碎石5套复合垂直流人工湿地在不同季节处理生活污水的运行效果。结果表明:陶粒组合人工湿地系统对COD、TP、NH3-N的去除效果均优于石灰石碎石湿地;复合垂直流人工湿地对COD的去除效果在冬季有所下降,但仍保持在50%以上;湿地系统对TP去除率受季节性变化影响不显著,但随着复合垂直流人工湿地系统的运行,基质层对TP的吸附逐渐饱和,去除效率缓慢下降;1号~5号人工湿地对氨氮的去除率分别从秋季42.0%、55.1%、61.1%、49.9%、50.2%下降至冬季21.9%、31.0%、36.5%、28.5%、29.2%,春、夏季处理效率开始回升,并保持稳定的状态。     

我国应急预案体系现状及展望——以上海为例

应急预案在自然灾害等突发事件发生时可以起到迅速反应的作用,因此成为突发事件应急管理中重要的一环。我国的应急预案体系已经基本建成,但还存在着预案格式雷同、脱离部门实际、分级体系科学性和可操作性不强、不同预案间接洽性不够、预案建设数量质量不够、缺乏后续管理等种种问题。分析了国内应急预案体系的现状,并探讨了对应急预案体系的改进方法。     

Estimates of carbon dioxide emissions based on incomplete condition information: a case study of liquefied natural gas in China

Recent calculations of carbon dioxide (CO₂) emissions have faced challenges because data consist of only partial information, which is called “incomplete information.” According to the emission factor method, energy consumption and CO₂ emission factors with incomplete information may lead to unmatched multiplication between themselves, which affects accuracy and increases uncertainties in emission results. To address a specific case of incomplete information that has not been fully explored, we studied the effects of incomplete condition information on the estimates of CO₂ emissions from liquefied natural gas (LNG) in China. Based on Chinese LNG sampling data, we obtained the specific-country CO₂ emission factor for LNG in China and calculated the corresponding CO₂ emissions. By applying hypothesis testing, regression analysis, variance analysis, or Monte Carlo (MC) simulations, the effects of incomplete information on the uncertainty of CO₂ emission calculations in three cases were analyzed. The results indicate that calorific values have more than a 9.8% impact on CO₂ emission factors and CO₂ emissions with incomplete sample information. Regarding incomplete statistical information, the impact of statistical temperature on CO₂ emissions exceeds 5.5%. Regarding incomplete sample and statistical information, sample and statistical temperatures can individually increase estimate biases by more than 5.2%. Significantly, the impacts of sample temperature and statistical temperature may offset each other. Therefore, the incomplete condition information is quite important and cannot be ignored in the estimation of CO₂ emissions from LNG and international fair comparison.

     

Comparison of biochar- and activated carbon-supported zerovalent iron for the removal of Se(IV) and Se(VI): influence of pH,ionic strength,and natural organic matter

Biochar (BC) and activated carbon (AC) were both produced from corn straw. Biochar-supported zerovalent iron (BC-ZVI) and activated carbon-supported zerovalent iron (AC-ZVI) were synthesized and applied for Se(IV)/Se(VI) removal. The sorption capacity of BC-ZVI for Se(IV) and Se(VI) was reported at 62.52 and 35.39 mg g^?1, higher than that of AC-ZVI (56.02 and 33.24 mg g^?1), respectively, due to its higher iron content and more positive charges. The spectroscopic analyses showed that Se(IV)/Se(VI) were reduced to Se(0)/Se(-II) of less toxicity and solubility. The effects of various factors such as pH, ionic strength, co-existing cations and anions, and natural organic matter (NOM) were also investigated. Ionic strength showed no significant effect on Se(IV)/Se(VI) removal, but pH was critical. The presence of NO₃^? and SO₄^2? did not cause obvious inhibition to the removal, while PO₄^3? inhibited the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI) significantly. Common cations (K⁺, Ca²⁺, and Mg²⁺) were found to slightly enhance the removal, while NOM significantly decreased the sorption capacity of BC-ZVI and AC-ZVI for Se(IV)/Se(VI). Besides, NOM showed stronger inhibition effect on AC-ZVI than that on BC-ZVI. These results indicated that BC-ZVI, compared with AC-ZVI, could be a promising sorbent to remove Se(IV)/Se(VI) due to its low cost and high efficiency.

     

Potential metal-binding ability of proteins in the extracellular slime of Laccaria bicolor exposed to excessive Cu and Cd

Environmental Science and Pollution Research - Ectomycorrhizal fungi can enhance the tolerance of plants to heavy metal stress by reducing the accumulation of heavy metals in the aerial parts of...     

Nonionic surfactant enhanced biodegradation of m-xylene by mixed bacteria and its application in biotrickling filter

In this study, m-xylene biodegradation was examined in bacteria-water mixed solution and biotrickling filter (BTF) systems amended with the nonionic surfactant Tween 80. The mixed bacteria were obtained from the activated sludge of a coking plant through a multisubstrate acclimatization process. High-throughput sequencing analysis revealed that Rhodanobacter sp. was the dominant species among the mixed bacteria. In the bacteria-water mixed solution, the bacterial density increased with increasing Tween 80 concentration. Hence, Tween 80 could be utilized as substrate by the mixed bacteria. Tween 80, with concentrations of 50–100 mg L^?1, could enhance the bioavailability of m-xylene and consequently improve the degradation efficiency of m-xylene. However, further increasing the initial concentration of Tween 80 would decrease the degradation efficiency of m-xylene. At concentrations exceeding 100 mg L^?1, Tween 80 was preferentially degraded by the mixed bacteria over m-xylene. In BTF systems, when the m-xylene inlet concentration was 1200 mg m^?3 and the empty bed residence time was 20 sec, the removal efficiency and elimination capacity of BTF1 with Tween 80 addition were at most 20% and 24% higher than those of BTF2 without Tween 80 addition. Overall, the integrated application of the mixed bacteria and surfactant was demonstrated to be a highly effective strategy for m-xylene waste gas treatment.

Implications: The integrated application of mixed bacteria and surfactant was demonstrated to be a promising approach for the highly efficient removal of m-xylene. Surfactant can activate mixed bacteria to degrade m-xylene by increasing its bioavailability. Besides, surfactant can be utilized as carbon source by the mixed bacteria so that the growth of mixed bacteria can be promoted. It is expected that the integrated application of both technologies will become more common in future chemical industry.     

长江流域鄂西四河流大型底栖动物群落结构特征及水质生物学评价

鄂西水系是国家级水源保护区,也是湖北省重要的生态旅游区。为了解鄂西水生态健康状况,于2014年10月~2017年1月不同时段在宜昌国家可持续发展实验示范区卷桥河（J）、清江利川段（Q）、宜昌市水源地黄柏河（H）和丹江口入库河流天河郧西段（T）开展了底栖动物群落特征研究。研究表明：4个河段共采集到大型底栖动物5门8纲18目61科。基于底栖动物指示种耐污性及其丰度占比分析,表明J、Q和T三河流污染程度沿水流方向呈加重趋势,而H水体健康状况整体较好。运用FBI和SIGNAL底栖生物评价指数,显示四条河流健康程度沿水流方向均呈下降趋势,但H变化趋势平缓,结果表明H水体上下游均处于较健康状态,其他3条河流上游或源头水体健康状况良好,下游受到较重污染。对主要环境因子（TP、NH₃-N、COD_Mn和TN）做主成分分析表明,轴1的解释率达到65.1%,表明轴1可以有效表征主要环境压力梯度。FBI和SIGNAL指数与轴1线性拟合度均较高,表明二者在鄂西河流水生态健康评估中可作为快速生物评价指数。     

某石化废水的综合毒性评价及其处理工艺对毒性的削减规律研究

利用生物毒性测试对环境中的污染物进行生态风险评价,是目前风险评价中的研究热点。本研究以明亮发光杆菌(Photobacterium phosphoreum)、斜生栅藻(Scenedesmus obliquus)和大型溞(Daphina magna)为受试生物,对某石化厂废水的处理流程中5个主要单元出水的急性毒性进行了测试,分析了其急性毒性与理化指标间的相关性;同时,为了解不同处理单元毒性去除效果及主要毒性来源,结合毒性鉴别评价(toxicity identification evaluation,TIE)技术对各阶段出水的毒性削减及其主要致毒物质类别进行了分析。毒性测试结果表明,该废水处理厂对石化废水的毒性去除效果比较显著,其中进水对明亮发光杆菌、斜生栅藻和大型溞分别表现为中毒、高毒和剧毒,最终处理后出水的毒性分别为无急性毒、中毒和微毒,对毒性的去除效率分别为96.4%、74.3%和99.5%。TIE结果表明,石化废水中的主要致毒物质是非极性有机物和可滤型物质。本研究结果为石化废水的综合生物毒性评价提供了研究基础,为探讨废水生物毒性的去除提供了实例参考。     

Physiological and biochemical responses of <Emphasis Type="Italic">Machilus ichangensis</Emphasis> Rehd. et Wils and <Emphasis Type="Italic">Taxus chinensis</Emphasis> (Pilger) Rehd. to elevated O<Subscript>3</Subscript> in subtropical China

Considerable researches have documented the negative effects of ozone on woody species in North America and Europe; however, little is known about how woody tree species respond to elevated O₃ in subtropical China, and most of the previous studies were conducted using pot experiment. In the present study, Machilus ichangensis Rehd. et Wils (M. ichangensis) and Taxus chinensis (Pilger) Rehd. (T. chinensis), evergreen tree species in subtropical China, were exposed to non-filtered air (NF), 100 nmol mol^?1 O₃ (E1) and 150 nmol mol^?1 O₃ (E2), in open-top chambers under field conditions from 21st March to 2nd November 2015. In this study, O₃ fumigation significantly reduced net photosynthesis rate (Pn) in M. ichangensis in the three measurements and in T. chinensis in the last measurement. Also, non-stomatal factors should be primarily responsible for the decreased Pn. O₃ fumigation-induced increase in malondialdehyde, superoxide dismutase, and reduced ascorbic acid levels indicated that antioxidant defense mechanism had been stimulated to prevent O₃ stress and repair the oxidative damage. Yet, the increase of antioxidant ability was not enough to counteract the harm of O₃ fumigation. Because of the decrease in CO₂ assimilation, the growth of the two tree species was restrained ultimately. The sensitivity of the two tree species to O₃ can be determined: M. ichangensis > T. chinensis. It suggests a close link between the rising O₃ concentrations and the health risk of some tree species in subtropics in the near future.     

强化我国引进环境保护技术宏观调控的探讨

１０年来,我国引进环境保护技术近万项,总金额近千亿元。如何充分发挥引进环境保护技术的作用,推动我国环境科学技术的进步,必须对我国引进环境保护技术进行宏观调控,本文对建立和完善我国引进环境保护技术运行机制等进行了探讨。