Manure sampling for nutrient analysis: variability and sampling efficacy

Reliable estimation of nutrient concentrations is required to manage animal manure for protecting waters while sustaining crop production. This study was conducted to investigate sample variability and reliable nutrient analysis for several manure types and handling systems. Serial samples were collected from dairy, swine, and broiler poultry operations while manure was being loaded onto hauler tanks or spreaders for field application. Samples were analyzed for total solids (TS), total nitrogen (N), ammoniacal nitrogen (NH4-N), total phosphorus (P), and potassium (K). The least number of samples needed for reliable testing of total N and P, defined as +/- 10% of the experimental means with 99% probability, was obtained for each farm using a computer-intensive random resampling technique. Sample variability within farms, expressed as the coefficient of variation (CV), was mostly 6 to 8% for farms that used agitation of manure storages but several times higher (20-30%) on farms where no agitation was applied during the sampling period. Results from the random resampling procedure indicated that for farms that used agitation, three to five samples were adequate for a representative composite for reliable testing of total N and P; whereas for farms without agitation, at least 40 samples would be required. Data also suggest that using book values for manure nutrient estimations could be problematic because the discrepancies between book standards and measured farm data varied widely from a small amount to several fold.     

三峡工程对洞庭湖水位影响研究

利用河流动力学Ｓａｉｎｔ Ｖｅｎａｎｔ方程组，通过建立描述长江水情的数值模式，进行三峡工程对长江城陵矶站水位影响预测。在预测结果的基础上，根据城陵矶站与洞庭湖各湖区水位代表站的水位相关关系，研究三峡工程对洞庭湖水位的影响。     

燃煤电厂袋式除尘专家系统开发研究

开发了一种袋式除尘系统故障专家诊断方法,用于诊断整个袋式除尘系统的故障现象,通过现场数据采集、操作人员与专家系统的人机对话对故障现象进行分析、推理,并做出相应的解决方案指导操作人员排查故障.燃煤电厂袋式除尘专家系统以知识库、推理机为核心,实现整个袋式除尘系统的设备故障诊断功能和维修故障指导功能,辅以解释机构,人机界面来指导用户如何准确无误地操作运行本系统和袋式除尘控制系统.系统被划分为4个模块:专家系统简介模块,在线故障诊断模块,离线故障诊断模块和专家指导模块.     

Anaerobic benzene biodegradation by a pure bacterial culture of Bacillus cereus under nitrate reducing conditions

A pure culture using benzene as sole carbon and energy sources was isolated by screening procedure from gasoline contaminated soil. The analysis of the 16S rDNA gene sequence, morphological and physiological characteristics showed that the isolated strain was a member of genus Bacillus cereus. The biodegradation performance of benzene by B. cereus was evaluated, and the results showed that benzene could be e ciently biodegraded when the initial benzene concentration was below 150 mg/L. The metabolites of anaerobic nitrate-dependent benzene oxidation by strain B. cereus were identified as phenol and benzoate. The results of substrate interaction between binary combinations for benzene, phenol and benzoate showed that the simultaneous presence of benzene stimulated the degradation of benzoate, whereas the addition of benzene inhibited the degradation of phenol. Benzene degradation by B. cereus was enhanced by the addition of phenol and benzoate, the enhanced e ects were more pronounced at higher concentration. To our knowledge, this is the first report that the isolated bacterial culture of B. cereus can e ciently degraded benzene under nitrate reducing conditions.     

南京市近十年降尘趋势分析

基于南京市积累的近十年降尘监测数据,按年度、季度和月度分析降尘的时间趋势变化,结果为全市降尘总体呈显著下降趋势,城区降尘污染明显高于郊区县;全市降尘量季度分布是春季〉夏季〉秋季〉冬季,且存在显著性差异;在春季的4月降尘量达到最高。按行政区、功能区分析降尘的空间分布变化,结果为各降尘功能区以交通区污染最重,道路尘、建筑尘和机动车尾气尘是城市环境管理的重点。     

景观型人工湿地污水处理系统构建及植物脱氮效应研究

将15种景观植物,其中包括4种陆生木本植物引入人工湿地,用于构建景观型人工湿地污水处理系统.该实验系统由12个独立处理单元组成,其中包括由4个平行处理单元构成的一级处理系统及由8个处理单元构成的二级跌流系统.对植物在各处理单元中的氮积累特征及植物氮吸收对系统脱氮贡献率进行研究,结果表明,在进水TN浓度为37.5~55.6 mg/L时,植物吸收脱氮贡献率仅为1%~3%,其不能准确反映植物在系统中的重要作用.因此,本研究采用植物脱氮效应(有植物与无植物系统脱氮的差异)来衡量植物在处理系统中的综合作用,其包括植物吸收贡献及植物与根际微生物、填料基质的协同效应之和,分析表明,植物协同效应占系统脱氮效应的80%以上.     

农村污水处理技术综述

当前,农村污水污染是农村环境污染的主要表现,农村污水污染已对农村地区的水体、土地等自然环境产生严重影响,为确保农村水源安全和农民身体健康,农村污水治理刻不容缓。本文通过归纳和分析国内外农村污水处理技术及其特点,提出了适合中国国情的农村污水实用处理技术。从可持续发展、清洁生产和节能减排的角度来考虑,针对中国农村地区资金短缺、能源不足的情况,采取一次性投资低、能耗低、运行稳定、运行费用低、维护管理方便的实用技术是解决中国农村污水污染问题的主要途径。     

建设全国性碳排放交易中心发展CDM项目

清洁发展机制（CDM）是《京都议定书》提出的在全球范围内实施温室气体减排的重要机制,是发达国家与发展中国家基于项目的合作形式,是一种“双赢”政策。文章首先简述了清洁发展机制及与碳交易市场的情况,接着论述了清洁发展机制在中国的发展,提出建设全国的碳排放交易中心及意义,从而促进CDM在中国的发展。     

浅谈高酸原油适应性改造项目的HSE管理

青岛石油化工有限责任公司加工高酸原油适应性改造项目是中国石化2009年22个重点工程建设项目之一,投资共约15亿元。该项目分Ⅰ、Ⅱ两个标段,包括新建160×10^4t／a延迟焦化、100×10^4t／a汽柴油加氢等4套装置,改造常减压、催化重整、柴油加氢等3套装置,以及公用工程及配套工程。2008年9月26日奠基开工,2009年9月28日中交,2009年11月11日陆续开工投产。     

响应面法优化TiO2光催化预处理树脂废水

为探讨不同环境因素对TiO₂光催化对树脂废水预处理效果的影响,采用响应面法对影响树脂废水Ti0₂光催化处理过程中的3个主要因素pH、TiO₂量及废水初始COD进行优化,并以COD去除率为响应值。经统计学分析和响应面模型建立,确定了悬浮态TiO₂光催化处理树脂废水的最佳控制条件为:pH值4.06、TiO₂投加量2.45 g/L、初始COD 2 007mg/L。在因素最优组合的条件下,废水COD去除率可达39.8%,与响应面模型最大预测值41%非常接近。与其他物化预处理方式相比,Ti0₂光催化对废水COD和挥发酚的去除率最高,且对废水生化性有很大提高,具有良好的应用前景。