高浓度豆制品废水预处理实验研究

豆制品是中国的传统食品,在生产过程中产生高浓度废水,如果对高浓度有机废水进行预处理,采用回收蛋白质以及化学混凝处理方法可以大大降低废水浓度,一定程度上可以减轻后续处理的难度、降低处理成本。针对豆制品生产废水问题,对高浓度豆制品废水的预处理方法作了实验研究。采用调节等电点酸沉降的方法回收蛋白质,然后用聚合硫酸铁化学混凝处理上清液以降低COD的含量。实验证明了方法的可行性并得出了最佳实验条件。     

冶金钢铁行业废水中CODcr与TOC相关性研究

CODcr和TOC均是表征水体有机污染程度的指标,对于一般有机废水,理论上两者线性相关。采用线性回归法对冶金钢铁行业废水中TOC和CODcr两项指标的监测数据进行统计分析,建立CODcr对TOC的转换方程,并用相关系数法进行显著性检验。结果表明冶金钢铁行业废水中CODcr值和TOC值的线性关系显著,建立的一元线性回归方程的准确度可以满足水质监测的需要,在一定条件下可以使用TOC监测值间接换算CODcr值。     

测定废水中总铬前处理方法的改进探究

采用COD消解器加热氧化法代替锥形瓶加热氧化法或密塞高压蒸汽法测定总铬,结果表明:此方法缩短了分析时间,操作简便,分析结果准确度高.     

热解吸气相色谱双通道检测空气中TVOC

探讨了通过气相色谱仪双通道检测室内空气中总挥发性有机化合物的可行性.建立了前、后双通道的苯、甲苯、乙酸丁酯、乙苯、苯乙烯、对(间)二甲苯、邻二甲苯、正十一烷等9种典型有机污染物的外标曲线,各组分相关系数R2为0.9995～1,并通过各自的标准曲线来计算其标样考核结果,对比标样真实浓度值,验证前、后双通道的准确性以及相互...     

环境因素对大肠杆菌REP-PCR指纹图谱稳定性影响研究

大肠杆菌作为粪便污染指示生物,其DNA指纹图谱稳定性是制约微生物污染源识别技术发展的瓶颈之一.本研究采用绿色荧光蛋白基因(GFP)标记后的Escherichia coli K12(K12GFP)为受试菌株,利用REP-PCR方法,对大肠杆菌在不同温度、光照、盐度条件下其DNA指纹图谱的稳定性进行了研究.结果表明,绿色荧...     

大连近岸海域经济贝类麻痹性贝毒分析

对2007年1月至2008年10月间大连地区近岸海域经济贝类的麻痹性贝毒采用小鼠生物法检测,结果表明:2007年4月至9月及2008年2月至8月贝类中的麻痹性贝毒超标情况较多,超标率较高的地点是长海财神岛、庄河黑岛.在染毒的贝类种类中,主要以虾夷扇贝为主,在杂色蛤和牡蛎中未检出麻痹性贝毒.通过ELISA的方法研究了虾夷...     

利用绿色荧光蛋白标记革兰氏阴性细菌的研究

构建了具有不同抗性且能够组成型表达绿色荧光蛋白的一系列转座子质粒pTnMod-OCm-G、pTnMod-OTc-G、pTnMod-OKm3-G和pTnMod-OGm-G,并通过三亲本杂交的方法,成功地将荧光蛋白基因分别插入到多环芳烃降解菌株Sphingomonas sp.12A和Pseudomonas sp.12B的基...     

Determination and assessment of total mercury levels in local, frozen and canned fish in Lebanon

Fish is an important constituent of the Lebanese diet. However, very little attention in our area is given to bring awareness regarding the effect of the toxicity of mercury (Hg) mainly through fish consumption. This study aimed to report analytical data on total mercury levels in several fish species for the first time in thirty years and to also made individuals aware of the presence and danger from exposure to mercury through fish consumption. Fish samples were selected from local Lebanese markets and fisheries and included 94 samples of which were fresh, frozen, processed, and canned fish. All values were reported as microgram of mercury per gram of fish based on wet weight. The level of mercury ranged from 0.0190 to 0.5700 μg/g in fresh samples, 0.0059 to 0.0665 μg/g in frozen samples, and 0.0305 to 0.1190 μg/g in canned samples. The data clearly showed that higher levels of mercury were detected in local fresh fish as opposed to other types thus placing consumers at higher risk from mercury exposure. Moreover, the data revealed that Mallifa (yellowstripe barracuda/Sphyraena chrysotaenia), Sargous (white seabream/Diplodus sargus), Ghobbos (bogue/Boops hoops), and shrimp (Penaeus sp.) were among the types containing the highest amounts of mercury. On the other hand, processed fish such as fish fillet, fish burger, small shrimp and crab are found to contain lower levels of mercury and are associated with lower exposure risks to mercury. Lebanese population should therefore, be aware to consume limited amounts of fresh local fish to minimize exposure to mercury.     

宁夏大型扬黄工程运行管理的安全生产现状与对策

1 工程概况 　　宁夏中部干旱地区在工程建成前,自然条件恶劣,荒漠化面积占土地面积的70%以上,干旱、风沙、沙尘暴和冰雹等自然灾害频发.为了改善这些地区自然环境和群众生产生活状况,国家投入大量资金,分别于1975年、1988年、1998年和1999年相继开工建设了固海、盐环定、红寺堡和固海扩灌四大扬黄工程.工程总设计流量77.2m3/s,设计灌溉面积1127km2,干渠总长677km,总装机容量37.9万kW.宁夏大型扬黄工程基本情况详见表1.……