预处理对造纸污泥厌氧消化产甲烷性能的影响研究

采用碱(NaOH)和生物(蘑菇渣、绿色木霉)2种方法分别预处理造纸污泥,并将预处理后的造纸污泥与味精废液进行联合厌氧消化,研究不同预处理方式对造纸污泥的影响以及对后续联合厌氧消化甲烷产率的影响.结果表明,造纸污泥经过碱(NaOH)预处理和生物预处理(蘑菇渣、绿色木霉)后,污泥颗粒的结构变得紧实、平滑,颗粒间的孔隙度减少,污泥絮体中的纤维长度明显变短、污泥中的SCOD增加了35.5%~1130%、VSS降低了6%~19%、SVsludge增加了32%~192%,NH3-N浓度提高了36%~62.4%,表明预处理后污泥中的大分子物质被降解成小分子物质,且碱预处理对污泥产生的变化较生物处理大;经预处理后的造纸污泥与味精废液联合厌氧消化,甲烷得率分别为:NaOH预处理0.32m3 CH4/kg VS、蘑菇渣预处理0.23 m3 CH4/kg VS,较CK分别提高了54%~88%和12%~34%,可见碱预处理提高甲烷产率效果更明显,由于蘑菇渣预处理具有成本低、解决二次污染、实现废物再利用等优点,因此两者在预处理提高造纸污泥厌氧消化甲烷产率方面都具有重要意义.     

The effect of environmental regulation on plant-level product mix: A study of EPA's Cluster Rule

This paper examines the effect of the U.S. Environmental Protection Agency's Cluster Rule on the product-mix decisions of plants in the pulp, paper, and paperboard industries. The Cluster Rule combines regulatory requirements from the Clean Air Act and Clean Water Act that are based on plants altering their production processes away from chlorine-based bleaching agents. In addition to, or instead of, altering production processes, plants may plausibly comply with the regulation by reducing output of bleached products or dropping some of these products entirely. Using a difference-in-difference-in-differences approach, we find evidence that plants facing both air and water Cluster Rule regulation (treatment group) are more likely to drop bleached products relative to unbleached products compared to plants facing only air Cluster Rule regulation (control group). Furthermore, we find evidence that plants in the control group alter their product mixes toward bleached products.     

Morpho-histological and enzymatic alterations in earthworms Drawida willsi and Lampito mauritii exposed to urea,phosphogypsum and paper mill sludge

The effects of varying concentrations of urea, phosphogypsum and paper mill sludge (PMS) on the morphology, histology, tissue protein content, lipid peroxidation (LPX), activities of lactate dehydrogenase (LDH), acetylcholinesterase (AChE) and catalase in earthworms Drawida willsi and Lampito mauritii have been studied over an exposure period of 24?hr. Integumentary lesions, clitellar swelling and loss of pigmentations were found to be major morpho-pathological changes in the worms. Histology indicated cuticular damage, ruptured epithelium and muscle fibres with accumulation of cellular debris. Lowest tissue protein content (57.02?±?4.02?mg/g tissue) and highest LPX (0.113?±?0.04, 0.137?±?0.08?nmol/mg protein) were noticed in D. willsi at a high concentration of PMS, whereas highest tissue protein content was observed in L. mauritii (115.32?±?7.18?mg/g tissue) with the same treatment. In both the species, LDH activity was minimum at a high concentration of urea (0.172?±?0.02; 0.247?±?0.08?U/mg protein). AChE activity was highest (0.099?±?0.002?U/mg protein) at a high concentration of PMS in D. willsi, whereas catalase activity was the maximum (0.338?±?0.02?U/mg protein) at high concentrations of PMS in L. mauritii. The study indicated that morpho-histological and enzymatic alterations in these earthworms exposed to agrochemicals could be useful biomarkers to evaluate soil toxicity.     

造纸污泥硫化氢释放量及控制研究

研究TCuSO_4、NaClO、KMnO_4、H_2O_2处理液及其浓度对造纸污泥硫化氢释放量的影响.结果表明.随各处理液浓度增大,硫化氢释放量有不同程度的减少;各种处理液均能明显降低造纸污泥硫化氢释放量,效果从好到差依次为CuSO_4、NaClO、KMnO_4、H_2O_2;CuSO_4的除臭机制是铜离子抑制细菌生长,同时与硫化氢反应生成不溶的CuS;而NaClO、KMnO_4、H_2O_2除臭机制是抑制细菌生长和氧化硫化氢产生单质硫;干污泥硫化氢释放量比湿污泥大.     

Efficient water use in industries: cases from the Indian agro-based pulp and paper mills

Agro-based pulp and paper mills in India are one of the most polluting industries; in addition, they are high consumers of raw water. Growing scarcity of high quality freshwater as well as stringent regulatory standards is compelling these units to explore appropriate water management options. Based on data obtained through a questionnaire survey and plant visits, this work provides an overview of the water use and effluent treatment status in Indian agro-residue and recycled pulp and paper mills. The challenges faced by this sector are reviewed and practices adopted by progressive units to minimize freshwater use are illustrated through case studies.     

辽西褐土施肥及养分循环再利用中长期试验Ⅰ. 作物产量

在辽宁西部褐土上历时10 a的田间试验结果表明：氮肥对提高作物产量效果最好,平均增产率50%,平均每千克 N增产粮食21 kg。供试褐土富磷,试验前3 a施磷肥不显增产作用,之后增产明显,10 a平均增产率10.9%,平均每千克 P增产粮食47 kg。供试褐土富钾,连续10 a施钾肥不显增产作用。 在施用化肥基础上每年以60%收获产品直接堆腐回田,可比对应的化肥处理分别增产（10 a平均）40.6%（无肥对照）、19.5%（N肥基础）、12.1%（NP肥）和8.1%（NPK肥）,平均年增产粮食（混合、烘干）分别为1.54、1.08、0.79、0.52 t/hm2。养分循环再利用的作物增产效益在试验的10 a中有着逐年增长的趋势,表明以堆肥形式循环回田养分的作物增产作用有着明显的残效叠加效应。     

日本关于制浆造纸厂排水的生物影响研究现状

日本自１９９４年以来的近６年中,对全国近２０个制浆造纸厂排水进行了生物影响实验研究,研究内容主要是排水对生物急性毒性实验、亚急性毒性实验、慢性毒性实验与二恶英分析、采用食物链上不同等级的三类水生生物与发光菌等为实验生物、毒性指标主要有ＬＣ５０、ＩＣ２０、ＩＣ５０、ＥＣ１０、ＥＣ３０、ＬＯＥＣ、ＮＯＥＣ等,排水的ＣＯＤ／ＢＯＤ比值也与生物毒性具相关性。     

科技英语文摘的文体与表达

科技论文的文摘是关系到论文能否被录用、发表及检索的重要因素。文章从文体的角度论述科技文摘的写作与翻译方法及注意问题,指出科技论文摘要应与国际惯例接轨,注意文体的严谨、准确、明了和科学性等问题;并为科技论文文摘撰写提供了重要依据。     

基于MICP技术的再生骨料改性研究综述

分析总结了微生物矿化技术对再生骨料堆积密度、吸水率、压碎指标3个方面性能的影响,结果显示,微生物矿化技术处理后的再生骨料物理力学性能有明显改善,且改善效果与微生物活性和处理时间有重要关联.     

我国建筑垃圾再生资源化分析

首先根据我国目前能源和环境两大难题,说明建筑垃圾再生资源化的重要性和迫切性.进而分析了建筑垃圾特性和分类,对国内外建筑垃圾的资源化再生利用现状进行了研究,对建筑垃圾再生资源化提出新的建议.