Modelling Pesticide and Nutrient Transport in the Cameron Highlands, Malaysia Agro-Ecosystems

Cameron Highlands has a long history of intensive horticulture especially vegetable and flower cultivation. This industry uses large amounts of nutrients and pesticides. Several simulation models were used to assess the movement of pesticides and nutrients in relation to agronomic practices in farm plots cultivated with cabbage and chrysanthemum. It was shown that most of the pesticides are absorbed by the topsoils which are enriched by organic fertiliser, and are not leached beyond the top 10 cm layer. Methamidophos, dazomet, cyromazine, triforine and NO₃N were predicted to cause soil contamination. The application of high amounts of fertilisers can cause nitrate contamination to the groundwater in Cameron Highlands.     

关于美国城市环境管理的启示

城市环境管理是我国环保工作的重点之一,美国城市环境管理中的经验和教训,可以为我们提供一些借鉴。     

Application of aerial photography in combination with GIS for coastal management at small spatial scales: a case study of shellfish aquaculture

Coastal zones are among the planets most threatened ecosystems and effective management of these systems requires spatial tools at appropriate spatial scales. Here we apply aerial photography with Geographic Information Systems (GIS), to map the cumulative anthropogenic footprint of an industry in a spatially defined ecologically important region of the British Columbian coast. Resolution required for such an analysis was made possible through highly detailed aerial photography of the region taken at an elevation of 305 m, at a 1:3000 scale. The approach applied here was successful in accurately detailing the cumulative extent of the anthropogenic activity on the foreshore which could have not been achieved at a coarser resolution. Such information was then effectively applied to visualize and assess the potential impact of an industrial development of the foreshore on bird distribution within the spatially identified region. The degree of overlap between the anthropogenic footprint and small estuaries within the region was also successfully assessed. For ecologically important regions such as Marine Protected Areas, and other such designated sensitive coastal regions, detailed mapping through aerial photography and GIS can aid in first identifying the true extent of an anthropogenic activity and then secondly used to link to possible ecological consequences. This in turn greatly enhances our ability to best manage the region of interest such that conservation priorities can be met.     

Agricultural pesticide residues of farm runoff in the Okanagan Valley,British Columbia,Canada

The objectives of this study were to determine environmental occurrence and concentrations of selected currently-used-pesticides and some transformation products in agricultural farms in the Okanagan Valley (OKV), and to conduct a simple risk assessment of environmental pesticides levels detected in OKV on non-target aquatic organisms. The OKV is the tree fruit country of the Province of British Columbia where considerable amount of pesticides are applied annually. Water, sediment and soil samples were collected at eleven sites in early June and late September following rainfall events and/or extended periods of irrigation from drainage ditches and/or from small streams. Undisturbed reference sites were also sampled. Study results showed that forty of the eighty chemicals analyzed, including organochlorine, nitrogen-containing and organophosphate pesticides commonly used for OKV crops, were detected in runoff and small stream water samples. Among which, endosulfan-sulfate was the most frequently detected chemical. Also, azinophos-methyl (0.699–25.5 ng/L), diazinon (0.088–214 ng/L) exceeded, and α-, β- endosulfan, endosulfan sulphate approached the guidelines for the protection of aquatic life.     

SO_4~(2-)和Se(Ⅵ)对紫花苜蓿和大麦吸收Se的影响

在温室中用砂培和水培方法种植紫花苜蓿和大麦,以此来研究SO_4~(2-)和SE(Ⅵ)对作物吸收Se的影响以及SO_4~(2-)和Se(Ⅵ)之间的相互作用。试验结果证明,紫花苜蓿和大麦体内都能累积Se(Ⅵ)并达到危害人类和动物健康的水平。Se(Ⅵ)对紫花苜蓿和大麦的干物质量都有不利的影响。当溶液含Se(Ⅵ)量超过0.1mg L~(-1)时,两者的干物质量减少25％—35％,含Se(Ⅵ)量超过lmg L~(-1)时,作物减产50％以上。SO_4~(2-)对植物吸收Se(Ⅵ)有明显的拮抗作用,能减少植物对Se(Ⅵ)的吸收,溶液中含SO_4~(2-)量超过2dS m~(-1),植物吸收Se(Ⅵ)减少99％,这是因为Se(Ⅵ)和SO_4~(2-)有相似的化学和物理性质,植物吸收Se(Ⅵ)和SO_4~(2-)的机理是极相似的。因此,当SO_4~(2-)在根的吸收基上成为主要离子时,植物组织中含Se(Ⅵ)量就会大大减少。含Se(Ⅵ)量较高的井水或农业排水是否可以用于灌溉,主要取决于水中的SO_4~(2-)含量。     

凉山州邛海宾馆污水深度处理工艺与效果

利用原有的化粪池作厌氧池,并以射流曝气生物接触氧化处理工艺为主体,串联消毒杀菌装置,即采用厌氧—好氧—化学杀菌三级串联深度处理邛海宾馆污水取得良好效果。处理后的水质清澈透明,无异采,COD31mg/l,BOD_52.1mg/l,去除率均在95％以上。     

Incorporation of sewage sludge in clay brick and its characterization.

This study reports the use of sewage sludge generated from sewage treatment plant (STP) as raw material in a clay brick-making process. The physico-chemical and mineralogical characterization of the sewage sludge and clay were carried out in order to identify the major technological constraints and to define the sludge pretreatment requirements if necessary. Moreover, the effects on processing conditions and/or on changes of typical final characteristics are also evaluated. Bricks were produced with sewage sludge additions ranging from 10 to 40% by dry weight. The texture and finishing of the surface of sludge-amended clay bricks were rather poor. As for the physical and chemical properties, bricks with a sludge content of up to 40 wt.% were capable of meeting the relevant technical standards. However, bricks with more than 30 wt.% sludge addition are not recommended for use since they are brittle and easily broken even when handled gently. A tendency for a general degradation of brick properties with sludge additions was observed due to its refractory nature. Therefore, sludge bricks of this nature are only suitable for use as common bricks, which are normally not exposed to view, because of poor surface finishing.     

香根草和黑麦草对重金属铅的生理响应及累积性研究

以香根草(Vetiveria zizanioides)和黑麦草(Lolium perenne)为材料,通过水培研究了0,5,10,50,200,500 mg/L铅处理对两种植物生长、生物量的影响及铅在植物根、茎叶中的累积特征,结果表明,(1)铅浓度10 mg/L以下,香根草和黑麦草能够正常生长;铅浓度为5 mg/L条件...     

Cause analysis of the fire and explosion during crude oil desulfurization in China

A serious fire and explosion accident that resulted in massive crude oil leakage and severe environmental pollution occurred on 16 July, 2010, in Dalian Port, China. To investigate the root cause of accident and conduct a wide-range investigation, desulfurizing agent JH02, which has a similar ingredient to the desulfurizing agent HD used in Dalian Port, and TS02 were employed in this study to determine the role of desulfurizing agents in the accident. The thermal behavior of crude oil, desulfurizing agents, and their mixtures was measured by using a C80 calorimeter. By using the calorimetric data, the kinetic parameters of the chemical reaction, such as activation energy, pre-exponential factor, and self-accelerating decomposition temperature of crude oil, as well as JH02, TS02, and their mixtures, were calculated and compared. The results indicated that the direct cause of the accident was the thermal runaway initiated by the increasing instability of the crude oil–desulfurizing agent mixture. Excess pressure in the oil pipeline triggered the physical explosion, but it alone was not enough to cause a serious damage. Furthermore, a stable desulfurizing agent such as TS02 could not ensure a safe desulfurizing process. The results of this study would benefit the safety management of desulfurizing processes during production and storage.