Environmental pollution induced by heavy metal(loid)s from pig farming

The development of intensive and large-scale livestock farming, such as pig husbandry, is significantly increasing the amount of manure globally. Mineral additives are commonly used in animal feed, and heavy metal(loid)s (HMs) are introduced to the feed via incomplete purification processes of those mineral additives, which leads to inevitable environmental pollution by HMs in conjunction with manure production. When these toxic-metal-containing manures are used as fertilizer, the HMs accumulate in soils and crops, which further causes potential risks to human health and the ecological environment. In this review, the focus is on seven HMs that are related to human activities or frequently contained in animal feed, including copper, zinc, cadmium, chromium, lead, mercury, and arsenic. The toxicities of these HMs and the elimination methods to reduce the HM toxicity of pig manure when it is added to soil, i.e., liquid–solid separation, adsorption, bioleaching, and composting, are summarized. The ultimate aim of this review is to outline the systematic pollution management strategies for HMs from pig farming.     

Carbon dioxide stripping from anaerobic digestate of food waste using two types of aerators

Anaerobic digestate of organic wastes often contains high concentrations of ammonia and carbon dioxide. Ammonia can be removed from digestate by air stripping at elevated pH. However, it is difficult to increase pH of the digestate because dissolved carbon dioxide transforms into bicarbonate and carbonate ions. Thus, carbon dioxide in digestate needs to be removed to reduce alkali consumption in ammonia stripping process. This study aimed to optimize and compare the performances of diffused and packed tower aerators for anaerobic digestate of food waste. The diffused aerator removed 82.1% of dissolved carbon dioxide and 13.7% of total inorganic carbon, and increased pH of digestate from pH 7.87 to pH 8.53, under the following optimized conditions; digestate temperature of 45 °C, air flow rate of three volumes of air added to a unit volume of liquid per minute, aspect ratio of 2, agitation speed of 500 rpm with a turbine impeller, and retention time of 10 min. Operating conditions of the packed tower aerator were also optimized, and it was found that the packed tower aerator removed 15% and 44% less dissolved carbon dioxide and total inorganic carbon, respectively, than the diffused aerator. It was also found that overall coefficients of carbon dioxide mass transfer from liquid to gas phase determined the final pH of digestate and removal efficiencies of carbon species.     

Research achievements and application in anaerobic treatment of organic solid wastes--A review

Anaerobic digestion is a good method, which possesses the optimal combination of volume reduction, probability of success and potential for resource and energy recovery. However, relatively little research has been done on the anaerobic digestion of organic solid wastes ( OSW ), especially in China.However, different substrates, start-up conditions, micro-organisms, processing technologies, pre-treatment methods could influence the result of anaerobic digestion. Anaerobic treatment of municipal OSW is less than that of wastewaters because some problems and obstructions need to be solved. Meanwhile, the application of anaerobic digestion of OSW is also discussed in the present paper.     

Environmental impacts of shrimp farming with special reference to the situation in the continental United States

Shrimp culture technology has resulted in development of a major shrimp farming industry worldwide. Without the shrimp farming industry, increasing demands for shrimp by consumers could not be met, resulting in increased pressure on wild shrimp resources. Unfortunately, there are realized and potential adverse environmental effects on estuarine ecosystems as a result of shrimp farming. The effects can be categorized as wetland destruction for construction of shrimp farms, hypernutrification of estuarine ecosystems by shrim pond effluent, “biological pollution” of native shrimp stocks through escapement of aquaculture stocks, water use and entrainment of estuarine biota, and impacts of shrimp farm chemicals on estuarine systems. While the shrimp farming industry in the United States is small, the United States is effectively addressing all the realized and potential environmental impacts through regulation and research at the federal and state levels. Areas of regulation and research include stringent prohibitions on wetland destruction, regulation of effluents and support of research to eliminate and/or reduce effluents, escapement prevention technology and development of high-health stocks, minimizing entrainment of estuarine biota through water conservation and screening technology, and regulation of chemical use in the shrimp farming industry and support of research on shrimp pathology and environmentally safe disease control. Work is still in progress and not all problems have been resolved to the complete satisfaction of shrimp farmers and estuarine conservationists. However, the situation in the United States should serve as a model of how to encourage sustainable economic development through commercial shrimp farming while abating adverse environmental impacts on estuarine systems. To further improve the situation, the development and adoption of “best management practices” for shrimp aquaculture are recommended.     

用微生物对单一碳源利用方法探讨重金属在城市土壤中积累的环境效应

Biolog研究表明，英国阿伯丁市城市土壤的微生物群落结构显著有别于农村土壤，并使微生物对碳源的消耗量增加，消耗速度加快。城市土壤中不仅重金属Cu,Pb,Zn,Ni的含量明显高于农村土壤，而且其化学形态的主成分分析表明，有效态Pb,Zn,Cu及有机态Ni和Cu是导致城市土壤区分于农村土壤的主要因子。相关性分析表明，Biolog的这种变化规律与重金属的上述化学形态密切相关；典型变量分析表明，重金属对城市土壤微生物群落结果的这种损伤具有长期性效应及不可恢复性。     

Environmental and geologic application of solid-state methane sensors

The analysis of methane concentration in natural systems, such as soil, water and atmosphere, is becoming an important and delicate task for environmental research. (1)The characterization of the spatial and temporal variability of these emissions is an important and urgent target for greenhouse-gas and global change studies. In this respect a series of technical specifications are demanded by the scientific community, including sensor portability, low detection limit and the need of analyzing small volumes of gas. Solid-state gas sensors are increasingly used for environmental measurements. A metal oxide semiconductor (e.g., SnO₂, ZnO₂,) is used to fabricate chemical sensors for several gases, in particular methane. The potential of this technique is based on the low conductivity of the material in clean air, which increases with the methane gas concentration in the air. Sensitivity, selectivity, power consumption, long-term stability, and reaction time are all linked together. They all depend on the physico-chemical and geometrical structure of the sensitive layer. This means that improving one parameter has an influence on the others. Therefore, it is necessary to make compromises and select the combination of performances that best meet the application requirements.     

Research achievements and application in anaerobic treatment of organic solid wastes—— A review

1 IntroductionSolid wastes (SW) refer to all the wastes derivedfrom human and animal activities, which are normallysolid and are discarded as useless or unwanted (Juha-Heikki Tanskanen, 2000 ). Generally, the organicfraction accounts for more than 50% -60…     

The evolution of rural areas influenced by large-scale farming: four case studies from Hungary

GeoJournal - In order to study complex transformation of rural areas in the long term, our paper aims to integrate the concepts of rural restructuring and evolutionary economic geography. We argue...     

Study of anaerobic biodegradation of pharmaceuticals and personal care products: application of batch tests

This study evaluated three types of pharmaceuticals and personal care products (methylparaben, ibuprofen and triclosan) at concentration levels of 300, 500, 1000 and 2000 µg/L by implementing batch tests using anaerobic processes and granular biomass. The study aimed to identify the mechanisms of biodegradation and sorption in the degradation of these compounds. The inoculum was granular sludge from a laboratory-scale anaerobic reactor. The characterization results of the inoculum showed an anaerobic biomass with high activity, good sedimentation and a high percentage of organic matter. The results of the removal of the pollutants showed high degradation percentages for methylparaben (close to 99%), with negligible sorption in the sludge. The results also showed insignificant ibuprofen sorption but removal close to 0%. Triclosan showed high biomass sorption and low biodegradation. In addition, at the concentrations tested, none of the compounds had a negative or inhibitory effect on the microbial populations of the system.     

Carbonate formation by anaerobic oxidation of methane: Evidence from lipid biomarker and fossil 16S rDNA

Carbonate chimneys and other carbonate structures occur widespread in the Gulf of Cadiz and probably reflect the presence of cold seeps and associated release of methane in the geological past, possibly in the Early Pleistocene, but it is unclear under what conditions and by which processes these carbonates were formed. We studied a fossil methane-related carbonate crust collected from the Kidd mud volcano in the gulf. Concentrations of microbial lipids, their stable carbon isotope composition, sequences of fossil 16S rRNA genes of anaerobic methanotrophic archaea in combination with mineralogical and carbon and oxygen isotopic composition of carbonate were obtained for seven different horizons of the crust. This combination of organic and inorganic geochemical techniques with molecular ecological methods gave a consistent view on processes resulting in the formation of the crust and indicated that it took place in two phases and in a downward direction. Archaeal lipid biomarkers and fossil 16S rRNA gene sequence data revealed the dominance of archaeal ANME-2 group and elevated methane partial pressures during the formation of the top part of the crust. The lower part of the carbonate was likely formed in an environment with reduced methane fluxes as revealed by the dominance of fossil remains of ANME-1 archaea. The combination of these methods can be used as an effective tool to reconstruct in unprecedented detail the palaeo-biogeochemical processes resulting in the formation of carbonate fabrics. This interdisciplinary strategy may also be applied for other fossil methane-derived carbonates, generating new concepts and knowledge about past methane-related carbonate systems.     

泥沙运动引起的环境问题及环境泥沙学

从两个方面,即水环境中的泥沙问题和泥沙运动引起的环境问题出发,说明了环境中泥沙问题的普遍性,指出了结合泥沙运动研究环境问题和结合环境科学研究泥沙问题的重要性和必要性,并将这方面的工作概括为“环境泥沙学”.它研究受泥沙运动影响的污染物(包括泥沙颗粒本身)在环境中的迁移转化规律、控制及其应用,其核心是将水利工程科学主要是水力学、泥沙运动力学和环境科学的某些学科,如环境化学、环境地球化学等结合起来,研究与泥沙运动有关的环境问题,并对其研究内容和方法进行了探讨.这方面工作的深入,必然推动环境科学的加快发展,在某种程度上,也将推动泥沙科学的向前发展和丰富泥沙科学的研究内容.     

Trends and characteristics of part-time farming in post-war Japan

Part-time farming is a wide-spread phenomenon in contemporary rural Japan. Characterized by an extremely small-scale rice farming and by a unimodal equitable rural development, most Japanese farm households have combined farming with off-farm employment. In this article, after an examination of the definition of part-time farming (farm household as the unit), the trend of and factors for part-time farming are described and analyzed. Growth and expansion of off-farm employment opportunities, continued small-sized farming, rapid increase in farmland prices and development and diffusion of labor-saving technology are among the major forces which encouraged part-time farming in Japan. Although the overall performance of part-time farms appears less efficient in the use of non-labor resources (e.g., land and machinery), part-time farms still occupy a significant share in the aggregate agricultural production and in the total farmland cropped. Various on-farm and off-farm adjustments are pointed out which have enabled dual employment patterns to be adopted by these people. In essence, due to the limited opportunities for farm-size expansion, part-time farming is considered a necessity, rather than a choise, for most Japanese farm families. But this has also caused some serious agricultural problems, especially with respect to its impact on farmsize structure and inefficient land use. At least for the purpose of maintaining a high income level and for equitable access to opportunities, part-time farming has seemingly contributed beneficially to the farming population of Japan.     

褐铁矿和白云石对垃圾渗滤液厌氧消化增强作用的初步研究

垃圾渗滤液治理一直是城市生活垃圾卫生填埋场的难题。能否利用矿物-微生物交互作用提高垃圾渗滤液有机污染物厌氧转化的效率是值得研究的问题。本文设置4组厌氧生物反应器(分别为只添加褐铁矿或者白云石、同时添加褐铁矿和白云石以及不添加矿物的空白组),考察添加褐铁矿、白云石对垃圾渗滤液厌氧消化的影响。实验结果表明,厌氧生化反应12 d时,添加了褐铁矿和白云石的反应器中COD去除率均达到80%以上,而空白对照组COD去除率仅为50%;4组反应器中溶液pH值变化表明,矿物的存在提高了溶液的pH值0.5左右;4组反应器中氨氮含量变化不大,也没有表现出明显差异。研究认为褐铁矿或白云石矿物在垃圾渗滤液中有机物的厌氧消化过程中起到了重要促进作用。研究结果为提高垃圾渗滤液厌氧处理效率提供了一个可供参考的方法。     

Sulphur uptake by salt grasses,mangroves, and seagrasses in anaerobic sediments

Stable sulfur isotope analyses show that rooted estuarine plants growing in anoxic sediments incorporate substantial amounts of ³⁴S-depleted sulfides, or oxidation products thereof. In roots, this incorporation predominates over sulfate uptake from interstitial porewater. Either the plants incorporate normally toxic sulfides, or they are creating and using a specialized nutrient pool of oxidized sulfides at the root-sediment interface.     

A behavioural analysis of hop farming in Hereford and Worcestershire

Behavioural studies in agricultural geography are comparatively rare, and this paper demonstrates the importance of the satisficer concept of economic behaviour when examining patterns of hop production in the West Midlands. The main farm and farmer characteristics of the hop growers are outlined before attention is focused on the relative importance of physical, economic and socio-personal factors in the decision-making process. Whilst economic factors dominate the ranking, socio-personal factors have a significant effect on the hop growers' decision-behaviour. Opportunity cost and social inertia are forwarded as important concepts in accounting for patterns of hop farming and a multivariate analysis emphasized the complexity and individuality surrounding farmers' decision-making behaviour. Differences in attitudes and behaviour are shown to be related to variations in the hop farmers' personality and rationality and to differences in their age, education, experience and traditions.     

模拟厌氧水稻土中氮、砷变化及迁移研究

矿渣和酸性矿山废水的排放会使矿区周围的农田受到污染。为研究厌氧条件下矿区农田中氮和砷之间的联系,本文通过摇瓶实验探究了含砷水铁矿在厌氧含氮农田中释放的砷形态的变化,通过柱实验探究了水稻生长对氮、砷形态和浓度的影响。研究结果发现,在厌氧条件下,外源氮的加入促进了砷污染水稻土中As(Ⅴ)的还原,使生成的As(Ⅲ)浓度最高达396μg/L;在柱实验模拟的厌氧农田不同层位中,水稻的生长过程促进了氮和砷的还原以及砷向下层位的迁移,使装置中的As(Ⅲ)浓度最高达517μg/L;摇瓶实验和柱实验在相近的厌氧条件下,NO^-₃的存在能够直接参与As(Ⅴ)还原。研究结果为农田砷污染的治理提供了一定的参考价值。     

南京地下水开采引起的环境地质问题及防治对策

近些年来,南京市的地下水开采量呈上升趋势,引发了泉水干涸、地面沉降、塌陷、水质恶化等一系列环境地质问题。对此进行了全面细致的分析,并提出了防治这些环境地质问题的措施,对我国城市地下水资源的合理规划和管理具有一定的借鉴意义。     

沉积物中细菌叶绿素的环境指示意义

沉积物中的光合细菌与细菌叶绿素（BChl）包含着丰富的古湖泊和古海洋信息。对光合细菌的生存环境,BChl的分布、保存、演化规律等方面进行了阐述,并探讨了湖泊和海洋沉积物中BChl的环境指示意义。BChl作为厌氧光合细菌的主要色素,不但可以指示水体中厌氧光合细菌的演变,而且能够反映化变层深度变化和水体环境特征,揭示季节性和年际尺度的气候变化。同时,根据沉积物中BChl含量可以估算古气候环境下湖泊和海洋的厌氧初级生产力。     

秦皇岛地区奥陶纪硅质岩地球化学特征及沉积环境意义

秦皇岛地区位于华北地台东北缘,该区奥陶系亮甲山组和马家沟组主要由细晶白云质灰岩、细晶白云岩、豹皮状灰岩、砾屑灰岩组成,灰岩中普遍含有结核状、条带状和团块状硅质岩。XRD分析显示硅质岩主要矿物成分为石英、方解石和少量白云石,硅质岩显微镜下为蠕虫状、球状、针状玉髓集合体,个别样品可见交代结构。硅质岩贫Mn、Fe,Mn/Ti...