The associations of air pollution exposure during pregnancy with fetal growth and anthropometric measurements at birth: a systematic review and meta-analysis

Environmental Science and Pollution Research - Fetal growth has been demonstrated to be an important predictor of perinatal and postnatal health. Although the effects of maternal exposure to air...     

Effects of soil amendments at a heavy loading rate associated with cover crops as green manures on the leaching of nutrients and heavy metals from a calcareous soil

The potential risk of groundwater contamination by the excessive leaching of N, P and heavy metals from soils amended at heavy loading rates of biosolids, coal ash, N-viro soil (1:1 mixture of coal ash and biosolids), yard waste compost and co-compost (3:7 mixture of biosolids to yard wastes), and by soil incorporation of green manures of sunn hemp (Crotalaria juncea) and sorghum sudangrass (Sorghum bicolor x S. bicolor var. sudanense) was studied by collecting and analyzing leachates from pots of Krome very gravelly loam soil subjected to these treatments. The control consisted of Krome soil without any amendment. The loading rate was 205 g pot(-1) for each amendment (equivalent to 50 t ha(-1) of the dry weight), and the amounts of the cover crops incorporated into the soil in the pot were those that had been grown in it. A subtropical vegetable crop, okra (Abelmoschus esculentus L.), was grown after the soil amendments or cover crops had been incorporated into the soil. The results showed that the concentration of NO3-N in leachate from biosolids was significantly higher than in leachate from other treatments. The levels of heavy metals found in the leachates from all amended soils were so low, as to suggest these amendments may be used without risk of leaching dangerous amounts of these toxic elements. Nevertheless the level of heavy metals in leachate from coal ash amended soil was substantially greater than in leachates from the other treatments. The leguminous cover crop, sunn hemp, returned into the soil, increased the leachate NO3-N and inorganic P concentration significantly compared with the non-legume, sorghum sudangrass. The results suggest that at heavy loading rates of soil amendments, leaching of NO3- could be a significant concern by application of biosolids. Leaching of inorganic P can be increased significantly by both co-compost and biosolids, but decreased by coal ash and N-viro soil by virtue of improved adsorption. The leguminous cover crop, sunn hemp, when incorporated into the soil, can cause the concentration of NO3-N to increase by about 7 fold, and that of inorganic P by about 23% over the non-legume. Regarding the metals, biosolids, N-viro soil and coal ash significantly increased Ca and Mg concentrations in leachates. Copper concentration in leachate was increased by application of biosolids, while Fe concentration in leachates was increased by biosolids, coal ash and co-compost. The concentrations of Zn, Mo and Co in leachate were increased by application of coal ash. The concentrations of heavy metals in leachates were very low and unlikely to be harmful, although they were increased significantly by coal ash application.     

电絮凝处理三次采油废水

采用电絮凝技术对含PAM的三次采油废水进行处理,研究了不同极板、pH、电流密度、极板间距、搅拌速度、反应时间以及极性交换周期对大庆三次采油废水处理效果的影响。通过处理效果和成本分析,铝作为极板时处理效果要优于铁板,最佳实验条件下COD去除率达到了94.6%。同时对三次采油废水的主要性质和电絮凝处理三次采油废水的作用机理进行了分析,发现COD主要通过絮凝沉降作用去除,而电化学氧化作用和气浮作用对COD的去除效果并不显著。与普通化学混凝法相比,电絮凝处理三次采油废水在处理效果和成本方面有着独特的优势。     

堆肥中纤维素和木质素的生物降解研究现状

堆肥是垃圾处理的主要方法之一 ,厨房垃圾、园林垃圾、农村秸秆和日常生活中的废弃纤维产品均可作为堆肥原料 ,这些原料中含有一定量的纤维素和木质素 ,而纤维素和木质素在堆肥过程中较难生物降解。因此 ,国内外学者致力于研究能加速纤维素和木质素降解的高效微生物。研究发现 ,对纤维素和木质素有降解能力的微生物主要是高温放线菌和高温真菌 ,其中有独特降解机制的白腐菌在木质素降解中起着重要作用     

铁炭内电解-厌氧-好氧工艺处理阿维菌素废水的试验研究

血清瓶毒性试验表明 ,AVM对厌氧消化产生强烈的抑制作用。AVM废水经铁炭内电解预处理后 ,COD和AVM的去除率分别达到 19.5 %和 6 8.5 % ,可大大降低废水的毒性。预处理出水再经UASB +生物接触氧化反应器进一步处理 ,当生化系统进水COD为 6 0 0 0— 6 5 0 0mg/L时 ,出水COD为 2 5 0— 2 80mg/L ,总COD去除率达到 95 .6 % ,出水达到生物制药行业排放标准     

环境材料及其评价方法

本文综述了环境材料的实质、特点及其与传统材料在主要内涵、研究重点、评价指标体系和材料选择原则的差异 ,并介绍了环境材料的评价体系与方法和设计原则     

微絮凝-直接过滤工艺在城市污水深度处理中的应用研究

微絮凝 -直接过滤工艺是一种将混凝反应、沉淀截留集中在同一滤柱内同步完成的高效水处理工艺。该工艺应用于城市污水的深度处理中 ,通过絮凝剂的加入 ,具有同步去除PO3 -4 P、SS和部分COD的功能。本文研究了该工艺对二级处理出水中PO3 -4 P、SS和COD的去除效果及其规律。研究表明 :采用聚合氯化铁 (PFC)作为絮凝剂 ,当Fe/P摩尔比为 2∶1时 ,水中PO3 -4 P的去除率达 98.8% ,浓度可降至 0 .1mg/L以下 ,同时SS、COD去除率也有明显提高。与传统的混凝、沉淀除磷工艺相比 ,该工艺具有操作简单、结构紧凑、占地面积小、污泥量少等优点 ,是一种更为经济和简单的处理单元 ,适用于现有城市污水处理厂的除磷和进一步提高水质的深度处理     

三种混凝剂处理煤泥水的对比试验研究

本文介绍了石灰、电石渣及CaCl2 分别与聚丙烯酰胺联用处理煤泥水的对比试验研究结果。结果表明 ,三种方法对煤泥水均有较好的处理效果 ,其中CaCl2 法效果最好 ,但药剂费也最高 ,石灰法和电石渣法处理效果相差不大 ,但电石渣法药剂费较低。     

生物技术在环境保护中的应用及前景

本文从废水、废气、固体废弃物处理及环境监测等几个方面介绍了生物技术在环境保护中的应用和研究进展 ,分析了生物处理工艺的特点及优越性 ,展望了生物技术未来的发展方向和前景     

内蒙古煤矿环境地质问题及其防治对策研究

煤炭是内蒙古最具优势的矿产资源 ,其产值几乎占到该区工业产值的一半。由于历史及政策等因素的影响 ,煤矿开发破坏矿区环境资源、诱发地质灾害和导致环境污染。不同地域矿山开发诱发的环境地质问题不同 ,露天和地下不同的开采方式诱发不同的环境地质问题。国有大中型老矿区地面塌陷问题较为严重 ,成为制约矿山持续发展的主要因素之一。乡镇及个体小煤矿“只开发 ,不治理”加剧了矿山地质环境的恶化。在西部大开发中 ,要吸取“先开发 ,后治理”的历史教训 ,走资源合理开发利用与矿区生态环境保护的绿色矿业之路