Improving ozonation to remove carbamazepine through ozone-assisted catalysis using different NiO concentrations

The carbamazepine (CBZ) abatement is herein evaluated using catalytic ozonation at different NiO concentrations as catalyst: 100, 300, and 500 mg      

Growth of Dehalococcoides spp. and increased abundance of reductive dehalogenase genes in anaerobic PCB-contaminated sediment microcosms

Polychlorinated biphenyls (PCBs) contaminate 19% of US Superfund sites and represent a serious risk to human and environmental health. One promising strategy to remediate PCB-contaminated sediments utilizes organohalide-respiring bacteria (OHRB) that dechlorinate PCBs.

However, functional genes that act as biomarkers for PCB dechlorination processes (i.e., reductive dehalogenase genes) are poorly understood. Here, we developed anaerobic sediment microcosms that harbor an OHRB community dominated by the genus Dehalococcoides. During the 430-day microcosm incubation, Dehalococcoides 16S rRNA sequences increased two orders of magnitude to 10⁷ copies/g of sediment, and at the same time, PCB118 decreased by as much as 70%. In addition, the OHRB community dechlorinated a range of penta- and tetra-chlorinated PCB congeners including PCBs 66, 70?+?74?+?76, 95, 90?+?101, and PCB110 without exogenous electron donor. We quantified candidate reductive dehalogenase (RDase) genes over a 430-day incubation period and found rd14, a reductive dehalogenase that belongs to Dehalococcoides mccartyi strain CG5, was enriched to 10⁷ copies/g of sediment. At the same time, pcbA5 was enriched to only 10⁵ copies/g of sediment. A survey for additional RDase genes revealed sequences similar to strain CG5’s rd4 and rd8. In addition to demonstrating the PCB dechlorination potential of native microbial communities in contaminated freshwater sediments, our results suggest candidate functional genes with previously unexplored potential could serve as biomarkers of PCB dechlorination processes.

     

Incorporating stakeholder decision support needs into an integrated regional Earth system model

A new modeling effort exploring the opportunities, constraints, and interactions between mitigation and adaptation at regional scale is utilizing stakeholder engagement in an innovative approach to guide model development and demonstration, including uncertainty characterization, to effectively inform regional decision making. This project, the integrated Regional Earth System Model (iRESM), employs structured stakeholder interactions and literature reviews to identify the most relevant adaptation and mitigation alternatives and decision criteria for each regional application of the framework. The information is used to identify important model capabilities and to provide a focus for numerical experiments. This paper presents the stakeholder research results from the first iRESM pilot region. The pilot region includes the Great Lakes Basin in the Midwest portion of the United States as well as other contiguous states. This geographic area (14 states in total) permits cohesive modeling of hydrologic systems while also providing strong gradients in climate, demography, land cover/land use, and energy supply and demand. The results from the stakeholder research indicate that, for this region, iRESM should prioritize addressing adaptation alternatives in the water resources, urban infrastructure, and agriculture sectors, including water conservation, expanded water quality monitoring, altered reservoir releases, lowered water intakes, urban infrastructure upgrades, increased electric power reserves in urban areas, and land use management/crop selection changes. For mitigation in this region, the stakeholder research implies that iRESM should focus on policies affecting the penetration of renewable energy technologies, and the costs and effectiveness of energy efficiency, bioenergy production, wind energy, and carbon capture and sequestration.     

基于农村信用体系建设的涉农经济组织和农户信用提升研究

我国涉农经济组织和农户的信用存在一些难以规避的缺陷,导致农业贷款难的困境。本文从涉农经济组织和农户信用道德建设,信用制度与法律建设,产权制度,信用环境,信用标准及信用等级评定,信用组织创新,征信和信用担保中介服务市场,农村信用管理等八个方面阐述了农村信用体系建设的基本思路,并讨论了涉农经济组织和农户的信用提升问题。     

城市再生水景观利用水华识别和预警方法探讨

城市再生水景观回用的主要问题是水体富营养化导致水华的暴发。为了抑制藻类的大规模生长,需要提前采取预防措施,以便将有可能爆发水华的藻类及时杀死或除去。目前,人们已经对景观水体中常见藻类的生长规律做了深入的研究,发现水体中藻数量(藻密度)的多少与水体的pH值和DO值的变化有密切而相对稳定的关系。通过在线实时监控pH值和DO值,找到△pH、△DO与藻类生长之间的关系,并结合pH、DO、温度、正磷酸盐和总氮等指标,实现实时识别和预测水华爆发的目的。     

Ammonium-dependent regulation of aerobic methane-consuming bacteria in landfill cover soil by leachate irrigation

The impacts of landfill leachate irrigation on methane oxidation activities and methane-consuming bacteria populations were studied by incubation of landfill cover soils with leachate and (NH₄)₂SO₄ solution at different ammonium concentrations. The community structures and abundances of methane-oxidizing bacteria (MOB) and ammonia-oxidizing bacteria (AOB) were examined by PCRDGGE and real-time PCR. Compared with the pure (NH₄)₂SO₄ solution, leachate addition was found to have a positive effect on methane oxidation activity. In terms of the irrigation amount, ammonium in leachate was responsible for the actual inhibition of leachate. The extent of inhibitory effect mainly depended on its ammonium concentration. The suppression of the predominant methaneconsuming bacteria, type I MOB, was responsible for the decreased methane oxidation activity by ammonium inhibition. Methaneconsuming bacteria responded diversely in abundance to ammonium. The abundance of type I MOB decreased by fivefold; type II MOB showed stimulation response of fivefold magnification upon the first addition but lessened to be lower than the original level after the second addition; the amount of AOB was stimulated to increase for 20-30 times gradually. Accumulated nitrate from nitrification strengthened the ammonium inhibition on type I and type II MOB, as a result, repetitive irrigation was unfavorable for methane oxidation.     

催化臭氧氧化过程中溴酸盐的生成机制研究

以黄河下游某水厂滤后水为目标物,选择了9种催化剂,在间歇反应装置中研究了单独臭氧和催化臭氧氧化过程中溴酸盐（BrO 3-）的生成情况,结果表明,在催化臭氧氧化过程中,NiO、CuO、Fe3O4、Al2O3加入使BrO 3-质量分数分别降低34.0%、32.8%、29.2%、20.8%.选取Fe3 O4作为催化剂研究催化...     

The role of body size versus growth on the decision to migrate: a case study with Salmo trutta

In a population exhibiting partial migration (i.e. migration and residency tactics occur in the same population), the mechanisms underlying the tactical choice are still unclear. Empirical studies have highlighted a variety of factors that could influence the coexistence of resident and migratory individuals, with growth and body size considered to be key factors in the decision to migrate. Most studies suffer from at least one of the two following caveats: (1) survival and capture probabilities are not taken into account in the data analysis, and (2) body size is often used as a proxy for individual growth. We performed a capture–mark–recapture experiment to study partial migration among juvenile brown trout Salmo trutta at the end of their first year, when a portion of the population emigrate from the natal stream while others choose residency tactic. Bayesian multistate capture–recapture models accounting for survival and recaptures probabilities were used to investigate the relative role of body size and individual growth on survival and migration probabilities. Our results show that, despite an apparent effect of both size and growth on migration, growth is the better integrative parameter and acts directly on migration probability whereas body size acts more strongly on survival. Consequently, we recommend caution if size is used as a proxy for growth when studying the factors that drive partial migration in juvenile salmonid species.