Enhancement of anaerobic biodegradability of flower stem wastes with vegetable wastes by co-hydrolysis

The vegetable wastes and flower stems were co-digested to evaluate the anaerobic hydrolysis performance of difficultly biodegradable organic wastes by introducing readily biodegradable organic wastes. The experiments were carried out in batches. When the vegetable wastes were mixed with the flower stems at the dry weight ratio of 1 to 13, the overall hydrolysis rate increased by 8%, 12%, and 2% according to the carbon, nitrogen, and total solid （TS） conversion rate, respectively. While the dry weight ratio was designed as 1 to 3, there was a respective rise of 5%, 15%, and 4% in the conversion rate of carbon, nitrogen, and TS. The enhancement of anaerobic hydrolysis from the mixed vegetable wastes and flower stems can be attributed to the formation of volatile fatty acids （VFA） and nutrient supplement like nitrogen content. The maximum VFA concentration can achieve 1.7 g/L owing to the rapid acidification of vegetable wastes, loosing the structure of lignocellulose materials. The statistic bivariate analysis revealed that the hydrolysis performance was significantly related to the physical and biochemical compositions of the feeding substrate. Especially, the soluble carbon concentration in the liquid was significantly positively correlated to the concentration of nitrogen and hemicellulose, and negatively correlated to the concentration of carbon and lignocellulose in the feeding substrate, suggesting that the regulation and control of feedstock can have an important influence on the anaerobic hydrolysis of organic wastes.     

UF膜与混凝粉末活性炭联用处理微污染原水

采用混凝、粉末活性炭和UF膜分离的联用技术对黄浦江原水进行试验 ,结果表明 ,混凝、粉末活性炭可有效地去除溶解性有机物 .混凝处理主要去除大分子量的有机物 ,粉末活性炭主要去除低分子量的有机物 .混凝、粉末活性炭还能有效地去除三氯甲烷生成潜能 (THMFP) ,对于低分子量的THMFP ,混凝去除效果很差 ,而粉末活性炭去除很好 .试验还表明 ,混凝、粉末活性炭还可大大降低膜的滤饼层阻力 ,当混凝剂投加量为 4mg/L时 ,膜的滤饼层阻力最小 .     

介质阻挡放电等离子体分解CO2

温室效应导致全球变暖已成为全球性的环境问题之一.采用放电等离子体法转化CO2,不仅可消纳温室气体,缓解全球变暖的巨大影响,还可制备化工原料CO和O2.充分利用了C1(含1个碳原子的化合物分子)资源,对高频同轴式介质阻挡放电等离子体分解纯CO2进行了研究.结果发现:在采用不锈钢光滑内电极,放电间隙为2.0mm,注入功率为180W,气体流量为170mL/min的条件下,CO2转化率可达18.2%,CO和O2产率分别为10.1%和4.7%;增大注入功率,减小气体流量、选择合适的放电间隙和内电极形式,均有利于提高CO2转化率,获得更多的CO和O2.     

氢气还原海绵铁去除水体中硝酸盐的研究

利用小球烧结和氢气还原工艺制备了粒径1mm～5mm的多孔性球形海绵铁,对球形海绵铁去除水体中硝酸盐的效率及去除动力学进行了研究。结果表明:溶液初始pH值对硝酸盐去除效率的影响显著,初始pH值小于3时,硝酸盐的去除率随溶液初始pH的增加而逐渐降低;初始pH值大于3时,硝酸盐的去除率又随之升高。硝酸盐浓度低于10mgN/L时,硝酸盐去除率随着硝酸盐初始浓度的增加而增加,硝酸盐的残余量保持在0.4mgN/L左右;硝酸盐浓度高于20mgN/L时,硝酸盐的去除率随初始硝酸盐浓度的增加而略有降低。球形海绵铁去除硝酸盐为一级动力学反应,反应级数为0.970～1.378,表观反应速率常数为0.314h-1～0.536h-1。海绵铁还原硝酸盐的主要产物为氨氮,随着还原反应的进行,溶液pH值快速增加,氨氮以分子态氨的形式从水中逸出。进行归纳总结和对比,并以多环芳烃的提取为例列举了各方法的应用步骤,从而为其他环境样品其他有机物分析预处理提供参考。     

玉溪市城市绿地系统规划研究

本文系统地分析了玉溪市绿地系统现状及城市绿地建设存在的问题，结合国际城市绿化发展的趋势，为玉溪市今后的绿地建设提出思路和对策。     

Dissipation and residue behavior of mepiquat on wheat and potato field application

A modified LC-MS method for the analysis of mepiquat residue in wheat, potato, and soil was developed and validated. A hydrophilic interaction liquid chromatographic column has been successfully used to retain and separate the mepiquat. Mepiquat residue dynamics and final residues in supervised field trials at Good Agricultural Practice (GAP) conditions in wheat, potato, and soil were studied. The limits of quantification for mepiquat in all samples were all 0.007 mg kg^?1, which were lower than their maximum residue limits. At fortification levels of 0.04, 0.2, and 2 mg kg^?1 in all samples, recoveries ranged from 77.5 to 116.4 % with relative standard deviations of 0.4–7.9 % (n?=?5). The dissipation half-lives (T _1/2) of mepiquat in soil (wheat), wheat plants, soil (potato), and potato plants were 4.5–6.3, 3.0–5.6, 2.2–4.6, and 2.4–3.2 days, respectively. The final residues of mepiquat were below 0.153 mg kg^?1 in soil (wheat), 0.052–1.900 mg kg^?1 in wheat, below 0.072 mg kg^?1 in soil (potato), and below 1.173 mg kg^?1 in potato at harvest time. Moreover, pesticide risk assessment for all the detected residues was conducted. A maximum 0.0012 % of acceptable daily intake (150 mg kg^?1) for national estimated daily intake indicated low dietary risk of these products.     

Toxicity of propargylic alcohols on green alga--Pseudokirchneriella subcapitata

The present study evaluates the toxicity of 34 propargylic alcohols, including primary, primary homo-, secondary, and tertiary alcohols, based on their effects on phytoplankton. A closed-system algal toxicity test was applied because the closed-system technique presents more realistic concentration-response relationships for the above compounds than the conventional batch tests. The green alga, Pseudokirchneriella subcapitata, was the test organism and final yield and growth rate were chosen as the test endpoints. Among all the propargylic alcohols tested, 1-pentyn-3-ol is the most toxic compound with its EC50 equal to 0.50 mg L(-1), which can be classified as a "R50" compound (very toxic to aquatic organisms, EC50/LC50 < 1 mg L(-1)), following the current practice for classification of chemicals in the European Union (EU). There are several other compounds including 2-decyn-1-ol, 3-decyn-1-ol, 1-hexyn-3-ol, 3-butyn-2-ol, and 3-hexyne-2,5-diol, which deserve more attention for their possible adverse impact on the aquatic environment, because these alcohols can be classified as "R51" compounds (toxic to aquatic organisms, EC50/LC50 between 1 and 10 mg L(-1)). Compared to the base-line toxicity relationship (narcosis QSAR) derived previously, tertiary propargylic alcohols can be identified as nonpolar narcotic chemicals, while secondary alcohols and primary alcohols with low molecular weight generally exhibit obvious excess toxicity in relation to the base-line toxicity. Finally, quantitative structure-activity relationships were established for deriving a preliminary estimation of the toxicity of other propargylic alcohols.     

宝钢焦化废水处理脱氮研究与实践

针对上海提高新排放标准中总氮(TN)≤35 mg/L的要求,对焦化废水进行了脱氮研究。选取现场缺氧-好氧-好氧(A-O-O)工艺中前两段的A-O生化沉淀池1出水,在SBR内进行反硝化脱氮实验,考察葡萄糖、葡萄糖+乙酸钠、甲醇和甲醇+乙酸钠单一或复合碳源及投加反硝化菌种对脱氮的影响,确定最佳碳源为甲醇+乙酸钠,最佳反硝化水力停留时间为16 h。当反硝化菌液投加浓度为1 mg/L时,SBR出水TN满足达标排放要求。结合实验结果对宝钢焦化废水原有AO-O工艺改造升级为A-O-A-O二段脱氮工艺,并对生化出水实施进一步的物化混凝处理。改造后,工艺长期运行稳定,最终出水完全达到上海市污水综合排放标准(DB 31/199-2009)TN≤35 mg/L的要求,并满足氰化物、氟化物以及COD的排放要求。     

假单胞菌好氧降解四溴双酚A的特性

为了解四溴双酚A(TBBPA)的好氧降解特性,采用选择富集法从活性污泥中分离出一株能够高效降解四溴双酚A的菌株。根据其形态、生理生化特性及16S rDNA核苷酸序列分析,该菌株被鉴定为假单胞菌属(Pseudomonas sp.)。研究结果表明,该菌株可通过好氧共代谢方式实现四溴双酚A的降解,葡萄糖是四溴双酚A降解的最佳碳源,其最优降解条件为葡萄糖8 g/L,牛肉膏0.5 g/L,pH值为7.0,培养温度为35℃,摇床转速为150 r/min。在该条件下其生物降解过程符合一级动力学模型,6 d后的降解率高达95.6%。LC-MS结果表明,四溴双酚A在好氧降解过程中会生成异丙苯酚类物质。