Water regime-nitrogen fertilizer incorporation interaction: Field study on methane and nitrous oxide emissions from a rice agroecosystem in Harbin, China

Water regime and nitrogen (N) fertilizer are two important factors impacting greenhouse gases (GHG) emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we conducted a two-year field experiment to study the impacts of water regime and N fertilizer on rice yields and GHG emissions in Harbin, China, a cold region located in high latitudes. Our results showed that intermittent irrigation significantly decreased methane (CH₄) emission compared with continuous flooding, however, the decrement was far lower than the global average level. The N₂O emissions were very small when flooded but peaked at the beginning of the disappearance of floodwater. The N fertilizer treatments increased CH₄ emissions at low level (75kgN/ha). But both CH₄ and N₂O emissions were uninfluenced at the levels of 150kgN/ha and 225kgN/ha. Rice yields increased under intermittent irrigation and were highest at the level of 150kgN/ha. From our results, we recommended that the intermittent irrigation and 150kgN/ha as the ideal water regime-nitrogen fertilizer incorporation for this area to achieve low GHG emissions without impacting rice yields.     

油田生产设施环境安全距离理论与案例分析

为保护油田生产设施周围环境及居民人身财产安全,在油田设施和周围不同环境功能区之间设置科学的环境安全距离,是一种经济、有效的环境保护与安全管理措施。文章提出油田生产设施环境安全距离的概念,以及有毒气体井喷泄漏、噪声污染、管线泄漏和火灾爆炸的环境安全距离估算模式,将油田生产设施分为井场、站库和管线三类,提出环境安全距离估算方法。最后以重庆开县"12.23"特大井喷事故为例,对硫化氢毒气井喷泄漏的环境安全距离进行估算,与实际情况相对比后证明估算结果可靠。     

膜蒸馏处理糖精钠生产废水

采用直接接触式膜蒸馏(DCMD)工艺处理糖精钠生产废水。分析了经过活性炭吸附预处理前后,膜蒸馏连续循环运行的效果。实验结果表明,未经预处理的废水在膜蒸馏过程中,废水中所含有机物不仅导致膜材料的润湿,引起产水电导率升高及膜孔润湿,促进盐晶体在膜表面附着,使产水通量下降。经吸附预处理后,膜蒸馏过程中产水通量介于10.40～11.24 kg/(m2.h)。吸附预处理能有效减缓产水通量的衰减,提高产水水质。废水经过活性炭预处理后进行膜蒸馏浓缩处理,当浓缩倍数达到5倍时,通量保持在10.55 kg/(m2.h)左右;产水水质稳定,截留率在99.5%以上。研究结果表明,吸附-膜蒸馏工艺可以应用于糖精钠生产废水的回用处理,有明显的应用前景。     

Degradation of Acid Orange 7 in aqueous solution by dioxygen activation in a pyrite/H2O/O2 system

Increasing attention has been paid to pyrite due to its ability to generate hydroxyl radicals in air-saturated solutions. In this study, the mineral pyrite was studied as a catalyst to activate molecular oxygen to degrade Acid Orange 7 (AO7) in aqueous solution. A complete set of control experiments were conducted to optimize the reaction conditions, including the dosage of pyrite, the AO7 concentration, as well as the initial pH value. The role of reactive oxygen species (ROS) generated by pyrite in the process was elucidated by free radical quenching reactions. Furthermore, the concentrations of Fe(II) and total Fe formed were also measured. The mechanism for the production of ROS in the pyrite/H₂O/O₂ system was that H₂O₂ was formed by hydrogen ion and superoxide anion (O₂ ^·?) which was produced by the reaction of pyrite activating O₂ and then reacted with Fe(II) dissolved from pyrite to produce ^·OH through Fenton reaction. The findings suggest that pyrite/H₂O/O₂ system is potentially practical in pollution treatment. Moreover, the results provide a new insight into the understanding of the mechanism for degradation of organic pollutants by pyrite.     

中-韩自贸区建立对辽宁环保产业的影响及对策研究

建立中-韩自由贸易试验区是党中央、国务院做出的重大决策,是深入贯彻党的十八大精神,在新形势下全面深化改革、扩大开放战略的重大举措。辽宁省环保产业发展起步较早,尽管近年来在全国的位次有所下滑,但在产品门类、技术、人才、关联产业以及园区化、集群化的发展模式上仍具有一定优势。面对中-韩自由贸易试验区对环境服务业战略转型的机遇和挑战,辽宁省应明确提出环保产业发展战略和目标定位,要强化政府的主导作用,加强不同环境服务分类影响研究,实施国内环境服务企业的"走出去"战略,加快环境服务业发展和战略转型的法规和政策体系建设,制定针对国内环境服务企业的扶持战略,解决战略转型的保障问题。本文以自贸区贸易效应为理论依据,根据辽宁省环保产业发展现状,探索在新时期如何利用辽宁省的区位优势不断创造市场空间,加快政府职能转变,积极推进环保产业贸易和投资便利化,强化资本、技术、人才等要素构建,加强园区建设,培育领军企业。     

A review on the formation of titania nanotube photocatalysts by hydrothermal treatment

Titania nanotubes are gaining prominence in photocatalysis, owing to their excellent physical and chemical properties such as high surface area, excellent photocatalytic activity, and widespread availability. They are easily produced by a simple and effective hydrothermal method under mild temperature and pressure conditions. This paper reviews and analyzes the mechanism of titania nanotube formation by hydrothermal treatment. It further examines the parameters that affect the formation of titania nanotubes, such as starting material, sonication pretreatment, hydrothermal temperature, washing process, and calcination process. Finally, the effects of the presence of dopants on the formation of titania nanotubes are analyzed.     

A Study on the Treatment of CO2, SO2, Nox,and Fly Ash by Pulse Activation

ABSTRACT

This paper presents a technique for the complete, simultaneous decomposition of CO₂, SO₂, and NO_x, as well as the simultaneous removal of fly ash by ultra-high voltage pulse activation. Ultra-high voltage narrow pulse is used to make the gases in the reactor become active molecules, which are then dissociated into nonpoisonous gas molecules and solid particles under the control of a directional reaction model. By using a sufficient charge and a strong electric field, the fly ash can be removed. It becomes the carrier of C and S, and its efficiency is 99.5%. Owing to the action of catalyst B (using Ni as the mother's body), the activation energy of CO₂, SO₂, and NO_x gases is reduced in great magnitude, and their removal efficiency can reach 75~90% at normal pressure and 180 °C.     

1999年我国主要气象灾害及异常气候事件

１９９９年，我国先后出现了干旱、暴雨洪涝、台风、风雹、沙尘暴、雪灾和冻害等多种气象灾害，特别是干旱持续时间长、范围广，旱情重。除上述气象灾害外，本年度还出现了冬暖，夏凉、春寒、倒春寒、夏季高温和秋老虎等异常气候事件，本文主要是几种主要气旬灾害和异常气候事件的发生特点和影响进行了分析和评述。     

胶州市东部滞洪区水污染情况调查及相应对策与建议

通过对胶州市东部滞洪区水质现状的调查,发现水环境污染情况较为严重.水污染的主要原因是污水直接入渠,水体自净能力差.可通过实施截污与污水收集系统建设相结合、防止污水入湖及实施东部滞洪区湖水自净建设工程等措施改善东部滞洪区的污染现状.     

微波消解-氢化物发生原子荧光光度法测定土壤中的汞

建立了微波消解-氢化物发生原子荧光光度法测定土壤中汞的方法。对微波消解条件、样品粒度等进行了优化,用3 mL硝酸和2 mL盐酸的混合酸作消解溶剂,在设定的微波条件下汞提取完全。用3%的盐酸作为反应载流,0.01%硼氢化钾与0.5%氢氧化钠的混合液为还原剂,直接定容后应用HG-AFS测定,通过测定国家标准参考物质和加标回...