Development of vermicast from sludge and powdered oyster shell

Soil acidification is one of the rising land degradation issues facing world agriculture. The risk of acidification is currently being assessed as part of agriculture productivity and sustainable theme. This study was conducted to produce a new vermicomposting cast as a recycling resource derived from municipal sewage sludge and waste oyster shell. The earthworm, Eisenia Andrei, was fed under different conditions. The most suitable mixture was 77:23 w/w% of sewage sludge and waste oyster shell. Powdered oyster shell (POS) sludge blend provided a stable pH, due to its buffering capacity during vermiculture because of the Ca²⁺ and OH^? release effect. The vermicast products fulfilled the cast standards of Korea Ministry of Environment for all the parameters such as moisture content, pH, salinity, organic carbon, TKN, Phosphate, and heavy metals. Slowly released organic matter when added to soil improves the capacity of the soil to hold nutrients for plants, improve soil aeration for roots, and improves soil drainage. This product will be an addition to already-commercialized sludge vermicast as a higher value product.     

Reducing mercury pollution from artisanal gold mining in Munhena,Mozambique

Artisanal small-scale mining (ASM) is responsible for over 90% of gold production in Mozambique. In 2005, a 15-day pilot training project was held in the village of Munhena, a gold mining community. This intervention aimed at raising awareness related to the environmental and health impacts of mercury amalgamation and introduced alternative practices to reduce mercury release and exposure. In 2007, a 9-day evaluation of the pilot campaign was accomplished and knowledge in regards to mining methods, and the ASM government–community operating relations in Munhena were updated. Miners in Munhena are organized in an association of over 3000 members, work on a 25 year Government granted 143 ha concession and generate a substantial income (producing over 5 kg of gold per month). There remain, however, serious barriers towards sustainable community development. ASM associated environmental and health costs are high, as mercury continues to be used and lost to the environment, and cyanide will be introduced soon. The Government of Mozambique has laid the foundation for supporting this sector; however, resources are limited, and thus restrict ability to fully address these issues. Importantly, malaria and HIV/AIDS are not diagnosed and/or treated effectively within the community, and basic necessities are absent. This paper concludes with recommendations focused on enhancing the ASM sector in Mozambique, and overcoming barriers to sustainability in the community of Munhena.     

Impact of wildflower strips on biological control of cabbage lepidopterans

In a 2-year experiment we investigated whether wildflower strips can be used to enhance the control of cabbage moth, Mamestra brassicae L., and cabbage white butterfly, Pieris rapae L. At two sites, including six organically cultivated fields, M. brassicae egg parasitism and predation rates were determined along with an assessment of larval parasitism rates in M. brassicae and P. rapae using a DNA-based approach. Within each field, plots with and without wildflower strips were sampled and a grid design of 3 m × 3 m was used to analyze the spatial pattern of parasitism. The provision of wildflower strips provided an idiosyncratic effect on the control of lepidopterans: parasitism rates in M. brassicae eggs and larvae were not affected, whereas parasitism rates of larval P. rapae were significantly enhanced by the wildflower strips at one of the two sites. Moreover, at one site predation rates on M. brassicae eggs were significantly enhanced in the wildflower strip plots. Geostatistical analysis showed no distinct spatial patterns in parasitism rates. These results demonstrate that the provision of wildflower strips does not necessarily enhance biological control of lepidopteran cabbage pests and suggest that site-specific environmental factors strongly affect the impact of wildflower strips.     

MAP沉淀法目标产物最优形成条件及分析方法

为了确定鸟粪石(MAP：MgNH₄PO₄·6H₂O)形成的最优条件,引入化学剖析法,利用酸溶液将鸟粪石沉淀法中所得沉淀物溶解后进行相应的元素分析;提出一种根据沉淀物中的NH⁺₄-N含量间接计算确定鸟粪石含量(即纯度)的分析方法.根据这种计算分析方法,分别得出了不同pH条件下以自来水(主要为地下水)和超纯水作为溶剂所合成的鸟粪石纯度,并对pH和Ca²⁺在鸟粪石形成过程中的影响进行了评估.结果表明,该计算分析方法能够有效实现对MAP沉淀法目标产物的定量分析,弥补了国内外目前普遍依靠XRD技术定性判断所得沉淀物中鸟粪石是否存在的缺陷.以超纯水作为溶剂时,使鸟粪石纯度>90%的最佳pH范围在7.5～9.0,而以自来水为溶剂时,获得相同鸟粪石纯度最佳pH范围则是7.0～7.5.实际污水中常常含有相当数量的Ca²⁺,实施碱性条件(pH>8.0)的MAP沉淀势必大幅降低鸟粪石的纯度.因此,对实际污水回收磷而言,MAP沉淀法的最优pH条件应控制在中性范围(<8.0)以内.     

海水中痕量元素测定及其在重金属污染源判别方面的应用

利用电感耦合等离子体质谱(ICP-MS)研究了胶州湾及莱州湾这两个海域中痕量元素污染水平,发展了ICP-MS海水环境中痕量元素的测定方法,同时找出海水环境中具有保守性的数种元素作为污染示踪元素.达到对于海水环境中痕量污染物被动示踪的目的.对18个真实样品进行了识别率试验,识别率可达90%以上,在选取3个海水样品及1个河水样品混合后的模拟分担率实验,也取得了满意的结果,其误差平均值仅有1.17%.