Impact of long‐term pesticide applications on some soil biological parameters

Abstract

The soil oxidative and anaerobic processes, as well as, the microbial biomass were followed during three years in a cotton farm (Tatuí) where the recommended pesticides have been used for several years, and in an experimental field (São Paulo) treated first time with the same pesticides. The oxidative process was monitored by the dehydrogenase (DHA)‐activity using triphenyltetrazolium chloride (TTC) as substrate. The anaerobic process was followed by the iron‐oxide reduction, and the microbial biomass was estimated by the substrate (glucose)‐indiced respiration. Increases in DHA‐activity and in the microbial biomass occurred only in the farm soil, with concomitant decreases in iron‐reduction. In the experimental field soil, the increases in DHA‐activity were followed only by decreases in iron‐reduction. Soil characteristics were the determining factor for different biological parameters after pesticide inputs. All the pesticides produced at least one clear but transient effect.     

Swine wastewater treatment in a two stage sequencing batch reactor using real‐time control

Abstract

A laboratory scale two‐stage sequencing batch reactor (TSSBR) was used to study the effectiveness of pH as a real‐time control parameter in swine wastewater treatment. A Ringlace media was inserted into the A/O (Anoxic/Oxic) reactor for bacteria immobilization. The TSSBR was subjected to three levels of organic loading. The pH and ORP (Oxidation Reduction Potential) patterns obtained were consistent with distinct features, enabling the real‐time control strategy to effectively set a flexible aeration time pending on influent concentration, hence resulting in flexible cycle time and HRT (Hydraulic Retention Time) for the system. The real‐time process ensured a removal efficiency of over 99% and 95%, respectively, for ammonia and TOC (Total Organic Carbon). For NO₃ ^‐‐N and PO₄ ^‐3, the run with influent TOC = 4,000 mg/L yielded the most efficient removal of 61% and 95%, respectively. Test results suggest that pH can be a viable tool for on‐line real‐time control of a biological treatment process.     

Effect of fatty acids and oils on photodegradation of azadirachtin‐A

Abstract

Azadirachtin‐A on exposure to UV‐light (254 nm) as a thin film on glass surface gave a isomerised (Z)‐2‐ methylbut‐2‐enoate product. Half‐life of azadirachtin‐A as thin film under UV light was found to be 48 min. Azadirachtin ‐A was irradiated along with saturated and unsaturated fatty acids, and fatty oils under ultra‐violet light as thin film. Saturated fatty acid increased the rate of photodegradation of azadirachtin‐A, whereas unsaturated fatty acids such as oleic, linoleic and elaidic acid reduced the rate of degradation. Castor, linseed and olive oil accelerated the rate of degradation, whereas neem oil showed no or little change in the rate of degradation of azadirachtin‐A. None of these fatty acids and fatty oils were effective in controlling the rate of degradation of azadirachtin‐A under UV‐light as thin film.     

厌氧序批式反应器中丝状颗粒污泥的形成

以葡萄糖为基质,研究浮动盖式ASBR中颗粒污泥的形成。实验结果表明,污泥在120 d时完全颗粒化,颗粒污泥具有良好的沉降性能(25 m/h)及良好的产甲烷活性,甲酸、乙酸、丙酸及丁酸最大代谢活性分别达到0.216、0.825、0.237和0.796 g COD/(g VSS.d)。电镜扫描(SEM)发现,整个污泥结构均一,均由丝状菌构成。     

基于SCP模型的节能环保市场分析研究

从需求角度出发,区分了节能环保产业中三种不同类型的市场,然后以SCP模型为分析框架,对三种不同类型的市场结构、企业行为和绩效进行了分析和比较,归纳了节能环保产业中不同类型的市场所存在的问题和解决思路。     

城市社会体育志愿者组织建设的实践性研究——以秦皇岛市社会体育志愿者组织为例

应用文献资料法、问卷调查法、实证研究法,探讨了城市社会体育志愿者组织建设的方法策略,即以高校社会体育专业成立志愿者分队为基点,依托当地已有的志愿者组织平台,融合吸纳更多的社会体育志愿者加入社会体育志愿者大队。通过社会体育志愿者分队的组建及服务项目的实施,为政府落实《建立全民健身志愿服务长效化机制工作方案》提供参考意见,同时也为提高社会体育专业学生的专业能力和人文素养搭建平台。     

Reconstructions of Soil Moisture for the Upper Colorado River Basin Using Tree‐Ring Chronologies1

Anderson, SallyRose, Glenn Tootle, and Henri Grissino‐Mayer, 2012. Reconstructions of Soil Moisture for the Upper Colorado River Basin Using Tree‐Ring Chronologies. Journal of the American Water Resources Association (JAWRA) 48(4): 849‐858. DOI: 10.1111/j.1752‐1688.2012.00651.x Abstract: Soil moisture is an important factor in the global hydrologic cycle, but existing reconstructions of historic soil moisture are limited. We used tree‐ring chronologies to reconstruct annual soil moisture in the Upper Colorado River Basin (UCRB). Gridded soil moisture data were spatially regionalized using principal components analysis and k‐nearest neighbor techniques. We correlated moisture sensitive tree‐ring chronologies in and adjacent to the UCRB with regional soil moisture and tested the relationships for temporal stability. Chronologies that were positively correlated and stable for the calibration period were retained. We used stepwise linear regression to identify the best predictor combinations for each soil moisture region. The regressions explained 42‐78% of the variability in soil moisture data. We performed reconstructions for individual soil moisture grid cells to enhance understanding of the disparity in reconstructive skill across the regions. Reconstructions that used chronologies based on ponderosa pines (Pinus ponderosa) and pinyon pines (Pinus edulis) explained more variance in the datasets. Reconstructed soil moisture data was standardized and compared with standardized reconstructed streamflow and snow water equivalent data from the same region. Soil moisture and other hydrologic variables were highly correlated, indicating reconstructions of soil moisture in the UCRB using tree‐ring chronologies successfully represent hydrologic trends.     

A Question of Boundaries: The Importance of “Revenuesheds” for Watershed Protection1

Patterson, Lauren A., Jeffrey Hughes, Glenn Barnes, and Stacey I. Berahzer, 2012. A Question of Boundaries: The Importance of “Revenuesheds” for Watershed Protection. Journal of the American Water Resources Association (JAWRA) 48(4): 838‐848. DOI: 10.1111/j.1752‐1688.2012.00655.x Abstract: Watersheds transcend jurisdictional boundaries; raising important questions of who should pay for watershed protection, and how can watershed governance be funded? The responsibility and cost for watershed protection has progressively devolved to local governments, resulting in additional negative externalities and financing challenges. Watershed governance structures have formed at the scale of the watershed, but they often lack the financing mechanisms needed to achieve policy goals. Financing mechanisms via local governments provide a reliable source of revenue and the flexibility to address watershed specific issues. We develop a “revenueshed” approach to access the initial challenges local governments face when seeking to finance trans‐jurisdictional watershed governance. The revenueshed approach engages local governments into discussion and implementation of financial strategies for collaborative watershed governance. Legislation places water quality regulations primarily on local governments inside the watershed. The revenueshed approach extends the financial and stewardship discussion to include local governments outside the watershed that benefit from the watershed. We applied the revenueshed approach to the Mills River and Upper Neuse watersheds in North Carolina. Mills River had a partnership governance seeking revenue for specific projects, whereas the Upper Neuse sought long‐term financial stability to meet new water quality legislation.     

System Dynamics to Sustainable Water Resources Management in the Eastern Snake Plain Aquifer Under Water Supply Uncertainty1

Abstract: Water supply uncertainty continues to threaten the reliability of regional water resources in the western United States. Climate variability and water dispute potentials induce water managers to develop proactive adaptive management strategies to mitigate future hydroclimate impacts. The Eastern Snake Plain Aquifer in the state of Idaho is also facing these challenges in the sense that population growth and economic development strongly depend on reliable water resources from underground storage. Drought and subsequent water conflict often drive scientific research and political agendas because water resources availability and aquifer management for a sustainable rural economy are of great interest. In this study, a system dynamics approach is applied to address dynamically complex problems with management of the aquifer and associated surface‐water and groundwater interactions. Recharge and discharge dynamics within the aquifer system are coded in an environmental modeling framework to identify long‐term behavior of aquifer responses to uncertain future hydrological variability. The research shows that the system dynamics approach is a promising modeling tool to develop sustainable water resources planning and management in a collaborative decision‐making framework and also to provide useful insights and alternative opportunities for operational management, policy support, and participatory strategic planning to mitigate future hydroclimate impacts in human dimensions.     

散堆填料对海水脱硫吸收系统性能影响的实验研究

在海水烟气脱硫中试实验台上进行了填料形式、填料高度变化对脱硫效率和系统压降影响规律的实验研究;研究中将喷淋空塔和分别填装A型、B型、C型3种填料的吸收塔进行了综合性能对比,并进行了填料高度分别为0.6、1.2和1.8 m的对比实验。结果表明,填料塔的脱硫效率高于喷淋空塔;当空塔气速为3 m/s时,填装C型填料的吸收塔的综合性能最优;当空塔气速小于2.5 m/s时,填装A型填料的吸收塔的综合性能最优;在满足相同脱硫效率的指标下,虽然增加填料高度降低了海水喷淋量,并且系统压降出现一定比例下降,但是在工程设计中必须综合考虑塔高、填料支架载荷等因素选择合适的填料堆积高度。