Mineralization of Catechol by Fenton and Photo‐Fenton Processes

Catechol is one of the most abundant phenolic components of olive mill wastewaters. In this article, the mineralization of this compound in synthetic aqueous solutions by the Fenton and photo‐Fenton processes is studied. It has been found that for 1.44 mM catechol, the total organic carbon of solutions is reduced about 94.4% at best after 60 min of Fenton treatment at optimized conditions of pH 3.0, 0.2 mM Fe²⁺, 7.09 mM H₂O₂, and 25°C. A faster and overall mineralization is attained by applying photo‐Fenton with UVA irradiation. o‐Benzoquinone, 1,2,3‐trihydroxybenzene and 1,2,4‐trihydroxybenzene were identified by GC–MS as primary quinonic and polyhydroxylated derivatives. Small amounts of generated carboxylic acids like muconic, maleic, malonic, acetic, oxalic, and formic acids were detected by ion‐exclusion chromatography. The Fe(III) complexes of these acids persist in the medium under Fenton conditions, while their photolysis by UVA light and that of other by‐products account for by the faster degradation and total mineralization achieved in the photo‐Fenton process. A reaction sequence for catechol mineralization by Fenton and photo‐Fenton involving all intermediates detected is proposed.     

The effect of cultivation method on erosion in agricultural catchments: integrating AHP in GIS environments

The cultivation method used in agricultural catchments can have a great effect on erosion processes; as such, determining the effects on form and degree is crucial. One commonly held hypothesis is that a shift to minimum tillage methods should reduce the rate of erosion. Here, we examine the effect of cultivation methods and environmental conditions on soil erosion risks in field crops and orchards in an agricultural catchment in northern Israel. The examination was conducted using AHP (analytic hierarchy process) and GIS (geographic information system)‐based computer simulations. Field validation of the simulations was conducted during the 2009–2010 winter season. The spatially explicit data on cultivation method, combined with environmental and climatic data, yielded an explanation of most of the variation in erosion risks in the catchment (kappa =0·93). Of the 10 criteria examined, the cultivation method and slope were the two variables with the greatest effect on increased soil erosion. Furthermore, soil loss risks were reduced substantially as a result of substituting conventional tillage with reduced tillage; substituting reduced tillage with conservation tillage; and changing the tillage direction to perpendicular to the direction of the slope. These results are reasonable in light of the modifications that mechanical tools cause in the soil structure, as observed in the penetration depth and the aggregate stability measurements used in this study. Despite the difficulty in collecting spatially explicit data on cultivation methods, we believe that it is of utmost importance to use such data to study erosion risks in agricultural catchments. Copyright © 2014 John Wiley & Sons, Ltd.     

阳信黄冠梨种植气候条件分析

利用阳信县历史气象资料,对比阳信县气候条件与黄冠梨生长所需条件,统计分析种植黄冠梨有利和不利的气候条件,结果证明：阳信县气候条件适宜种植黄冠梨,对引进培育名优品种具有一定的指导意义。     

法紫菜生物多样性及其栽培生物学基础

综述了重要经济红藻法紫菜属物种多样性及其地理分布,修订了法紫菜属中文名称,回顾了紫菜生活史研究的历程,基本概括了法紫菜栽培生物学基础研究成果。根据文献报道及最新研究成果,认为紫菜属和法紫菜属共有138个物种,集中分布在北半球的温带、亚热带海域,其中我国是物种多样性较高的国家之一,其物种及变种数达到25个。法紫菜生活史的阐明对紫菜栽培产业的发展具有奠基性的作用,其中我国藻类学家曾呈奎和张德瑞在法紫菜生活史研究中作出了重要的贡献,提出了壳孢子的概念,被广泛接受并沿用至今。壳孢子采苗和丝状体培养技术是发展紫菜栽培业的重要基础,丝状体生长发育及壳孢子形成的分子机制将是未来法紫菜生物学研究的重点和难点。尽管根据已发表的相关文献大致梳理了法紫菜相关生物学基础研究的成果,但限于篇幅对栽培生产中相关技术的优化、完善与推广以及新品种培育等均未作介绍。     

我国海洋渔业经济组织的演进与培育研究

我国海洋渔业从业主体类型多样,数量众多。对个体经济组织、合作经济组织、公司组织和企业战略联盟这4种海洋渔业主要经济组织进行了概述,分析了每种海洋渔业经济组织的演进,进而提出了顺应演进趋势对其进行培育的对策建议。     

Assesing the effect of an olive mill wastewater evaporation pond in Sousse, Tunisia

Olive oil is a typical and valuable agro-industrial product in Mediterranean countries. In Tunisia, olive mill wastewaters (OMW) reach an amount of about 1,000,000 t year⁻¹ and constitute a serious organic pollution risk because of the high chemical oxygen demand values and the presence of phytotoxic and antibacterial polyphenols. OMW have been generally stored in pond sites to be eliminated by natural evaporation or valorised by spreading on cultivated soils or by composting. Many researches on the interactions of OMW with soils at laboratory scale (columns) have been reported, but less attention have been paid to the effect of OMW on soils at field scale. The aim of this work is to investigate an area used for >15 years as an uncontrolled OMW pond site. The transformations of soil properties and groundwater occurring during OMW storage were characterised by the pH, phenolic contents, electrical conductivity (EC), moisture content and organic contents. The soil samples were taken from two borings and compared to those of a control one located near the pond site. Groundwater samples were taken on the accessible and nearest water wells to the evaporation ponds. The permeable silty and sandy layers in the site support the infiltration of OMW near the evaporation ponds. This infiltration has reached a depth of 6 m at a distance of almost 50 m laterally. The results show that the OMW infiltration in the subsoil has affected the pH, EC, organic content, phenolic compounds and the moisture.     

云南省怒江傈僳族自治州的人口问题

1964年以来,怒江傈僳族自治州人口增长与经济发展失调,由此而造成诸多社会-经济矛盾,严重妨碍着当地的发展。为改变现状,兹建议:完善和认真执行少数民族地区的计划生育政策,并由政府给予少量资助,在州内或向州外进行适量的人口迁移,以缓和人口压力,促进经济发展。     

湖北省1991年度柑桔冻害与避冻栽培区划

文章研究了湖北省各地1992年柑桔单产的减产率与1991年12月最低气温的关系，发现两者之间是一种指数相关关系，它能较好地解释冻害程度与最低气温的关系。用Gumbel分布计算了59个台站5、10、20、25和50年一遇的最低气温。并根据各地不同的10年一遇最低气温，将湖北省分成适宜、次适宜和不适宜柑桔种植区。为柑桔避冻栽培提供了科学依据。     

清初中期黑龙江耕作业的发展及影响因素

该文阐述清初中期黑龙江省耕作业发展较快并形成了一定规模。从以渔牧猎业为主体向农牧渔猎并重方向演变 ,它是特定的自然、政治、军事、社会等因素综合作用的结果。其中 ,温带森林与森林草原环境、严酷的气候和清朝统治者的“封禁”政策延缓了在此之前耕作业的开发与发展 ;边防军事需要与汉族人口的大规模迁入是耕作业开发与发展的根本动力。     

Stress on tropical karst cultivated with wet rice: Bohol, Philippines

Wet rice cultivation represents one of the most intensive uses of tropical karst. Under wet field conditions karstlands can be highly resilient, but nevertheless vulnerable to change. The karst environment in this study has been cultivated for at least five centuries. However, the post-World War II era has fostered a host of pressures that have altered the local ecology. Resulting stress in the irrigation systems and society threaten the maintenance of this viable karst-based agricultural economy.