Marine and farmed fish on the Polish market: comparison of the nutritive value and human exposure to PCDD/Fs and other contaminants

Chemical analyses were performed in nine fish species that are popular on the Polish market. These included Baltic fish (cod, herring, salmon), fish farmed in Poland (carp, trout), marine fish imported from China (Alaska pollock, sole), and farmed fish imported from Vietnam and China (sutchi catfish, tilapia). The nutritional composition (amino acid, micro- and macronutrients, fat-soluble vitamins - A₁, D₃, E) and certain contaminants (organochlorine pesticides, OCPs; indicator polychlorinated biphenyl, PCB₆; polychlorinated dibenzo-paradioxins and polychlorinated dibenzofurans, PCDD/Fs; dioxin-like polychlorinated biphenyls, dl-PCBs; organotin compounds, OCTs; dyes, malachite green and crystal violet; veterinary drug residues, nitrofurans and chloramphenicol; toxic metals, Cd, Pb, Hg) in the muscle tissues of fish were determined. It was confirmed that the fish species analyzed were excellent sources of amino acids, and were rich in phosphorous and selenium. Baltic Sea fish (salmon, herring), fish farmed in Poland (carp and trout), and tilapia were also rich in vitamin D₃.Traces of OCP, PCB₆, OCT, dyes, veterinary drug residues, and heavy metals were detected in concentrations which do not pose a threat to consumers at the current rate of fish consumption in Poland. However, the problem might arise from the content of PCDD/Fs and dl-PCBs in fatty Baltic fish. The fish species analyzed, differed in their nutritional values and degrees of contamination. We suggest that for optimum health and safety, it is advisable that consumers include a variety of different fish species in their diets.     

Effects of pH and ionic strength on sulfamethoxazole and ciprofloxacin transport in saturated porous media

Many antibiotics regarded as emerging contaminants have been frequently detected in soils and groundwater; however, their transport behaviors in soils remain largely unknown. This study examined the transport of two antibiotics, sulfamethoxazole (SMZ) and ciprofloxacin (CIP), in saturated porous media. Laboratory columns packed with quartz sand was used to test the effects of solution pH and ionic strength (IS) on their retention and transport. The results showed that these two antibiotics behaved differently in the saturated sand columns. In general, SMZ manifested a much higher mobility than CIP for all experimental conditions tested. Almost all SMZ transported through the columns within one pore volume in deionized water (i.e., pH=5.6, IS=0), but no CIP was detected in the effluents under the same condition after extended column flushing. Perturbations in solution pH (5.6 and 9.5) and IS (0 and 0.1M) showed no effect on SMZ transport in the saturated columns. When pH increased to 9.5, however, ~93% of CIP was eluted from the sand columns. Increase of IS from 0 to 0.1M also slightly changed the distribution of adsorbed CIP within the sand column at pH 5.6, but still no CIP was detected in the effluents. A mathematical model based on advection-dispersion equation coupled with equilibrium and kinetic reactions successfully simulated the transport of the antibiotics in water-saturated porous media with R(2)=0.99.     

基于活性污泥的厨余垃圾厌氧发酵产酸研究

以厨余垃圾和活性污泥为原料,考察了不同接种比例对厌氧发酵产物的挥发性脂肪酸产量、pH值和COD去除率的影响.结果表明,当厨余垃圾和活性污泥接种比例为4∶1时,挥发性脂肪酸产量在第3天达到最大值为42.7 g/L,产率提高了40%,COD去除率达到了35.6%,pH值没有发生较大的差异,其变化幅度在4～6之间.     

新型结构ABR的设计与水力特性研究

针对ABR自身的缺点,设计出一种新型结构的ABR.该反应器为双层结构,共有5部分组成,各部分容积各不相同.该反应器的设计思想是将ABR与生物滤池以及活性炭吸附等工艺相联合.这种设计能够最大程度地发挥各工艺的优势,进而达到更好的处理效果.通过脉冲响应实验对该反应器的水力特性进行研究,得出不同水力停留时间(HRT)下的停留...     

Fenton-双泥SBR工艺深度处理难降解反渗透浓缩液

采用Fenton试剂处理反渗透浓缩渗滤液(简称浓缩液),并探讨了双泥SBR工艺对Fenton处理后浓缩液与人工配水混合处理的可行性.结果表明,Fenton氧化对COD、TN和NH3-N的平均去除率分别为43.5%、22.5%和19.5%.对溶解性有机物(DOMs)的去除率为52.5%,其中胡敏酸(HA)、富里酸(FA)...     

含泥钾矿浮选分离技术研究

从钾矿性质和浮选技术2个方面对盐湖含泥钾矿进行资源化利用研究,首先运用X射线荧光光谱、X射线衍射和扫描电镜对含泥钾矿的矿泥化学组成及其结构特征进行了分析,其次选用盐酸十八胺和煤油为浮选药剂,对浮选法脱除钾矿中泥进行了研究.结果表明,盐湖矿泥中70%以上为以长石、粘土和粉砂等为主的硅铝酸盐;矿泥多充填包裹于盐类矿物粒晶间...     

人工湿地基质的筛选及其对猪场废水厌氧消化液中氨氮吸附性能研究

采用静态吸附实验,对比了岷江砂、沱江砂、青衣江砂、沸石、活性炭对猪场废水厌氧消化液中氨氮的吸附去除效率,基于氨氮去除能力、购买成本与运费的比较,筛选出性价比较高的基质--岷江砂作为四川地区人工湿地的基质处理猪场废水厌氧消化液.吸附实验表明,砂对氨氮的去除率随振荡时间和投加量的增加而增加.通过吸附等温曲线Langmuir...     

改性硅藻土用于巢湖水脱磷研究

采用改性硅藻土强化混凝处理巢湖水,以达到除磷的目的.研究了改性硅藻土除磷最适操作条件,并将改性硅藻土同几种常规混凝剂的处理效果和其经济性进行了对比.结果表明:改性硅藻土和水的混合搅拌速度梯度为260 s-1左右,絮凝反应速度梯度为20 s-1左右,絮凝时间15 min,沉淀时间1 h,改性硅藻土投加量50～100 mg...     

不同营养水平下悬浮细菌数量对生物粘泥性质的影响

循环水系统中的微生物有悬浮态和附着态,悬浮细菌的存在对附着态生物粘泥的生长及特性有明显影响。通过向模拟循环冷却水系统中投加不同数量初始悬浮细菌,考察在营养水平不同的情况下,悬浮细菌数量对生物粘泥化学组成和脱氢酶活性的影响。结果表明,营养水平不同,初始悬浮细菌数量对生物粘泥的化学组成和脱氢酶活性的影响程度不同;在不同营养水平下,应分别控制初始悬浮细菌数量。贫营养下,初始悬浮细菌数量应控制在6×105个/mL左右;中营养下,初始悬浮细菌数量应控制在1×105～2.6×105个/mL之间;富营养下,初始悬浮细菌数量应控制在0.11×105～2.6×105个/mL之间最不利于生物粘泥的生长。     

气氛对垃圾焚烧中重金属迁移特性的影响

对城市生活垃圾焚烧过程中Ni、Cd、Cu、Pb、Cr和Zn 6种重金属在不同气氛中的挥发率进行了研究,同时比较了氧化性气氛和还原性气氛、中性气氛和酸性气氛以及在混合气氛中各重金属的挥发率。结果表明,氧化性和还原性气氛对Ni、Cu和Cr挥发影响较大,Cr、Cd、Pb和Zn在还原气氛下挥发率比在氧化气氛下高,而Ni和Cu则...