液相色谱/质谱联用检测刚果红及其微电解降解的研究

采用液相色谱/质谱联用(LC/MS)检测了模拟印染废水中的刚果红,并用微电解对其进行了降解研究.LC/MS检测刚果红的结果表明,在流动相为甲醇:水(体积比)=70:30、流速为0.6 mL/min、色谱柱为Zorbax XDB0-C18(150 mm× 4.6 mm,5μm)条件下,刚果红的准分子离子的质荷比(m/z)...     

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)...     

利用甘蔗渣制备微生物絮凝剂的预处理方法研究

通过对甘蔗渣进行不同的预处理,确定了提高纤维素酶糖化率和酱油曲霉发酵液絮凝率的方法.利用正交实验对固液比、颗粒粒径、溶剂浓度和预处理时间及其交互作用进行考察,确定较优的工艺方案.结果表明,在相同条件下,碱处理能够有效提高纤维素酶的糖化率,处理后甘蔗渣的酶解液中还原性糖浓度和酱油曲霉发酵液的絮凝率分别为3.46 g/L和...     

pH和元素摩尔比对污泥酸化液沉淀法脱氮除磷的影响

针对剩余污泥水解酸化产生大量多糖、蛋白质和VFAs碳源的同时会有较高浓度的NH+4-N和PO3-4-P溶出的问题,考察了pH值和元素摩尔比对以沉淀法同时去除NH+4-N和PO3-4-P的影响.结果表明,最佳pH为9.0,当pH升高到10.0时NH+4-N去除率略有下降,在特定摩尔比范围内摩尔比对沉淀形成的影响大于pH值...     

Dissipation of carbendazim and chloramphenicol alone and in combination and their effects on soil fungal:bacterial ratios and soil enzyme activities

The dissipation of carbendazim and chloramphenicol alone and in combination and their effects on soil fungal:bacterial ratios and soil enzyme activities were investigated. The results revealed that carbendazim dissipation was little affected by chloramphenicol, whereas chloramphenicol dissipation was found to be retarded significantly by the presence of carbendazim. The inhibitory effect of carbendazim on the fungal:bacterial ratios was increased by the presence of chloramphenicol, and the inhibitory effect of chloramphenicol on neutral phosphatase was increased by the presence of carbendazim. Carbendazim increased soil catalase and urease activities, but this increase was partially diminished by the presence of chloramphenicol. Little interaction was observed between carbendazim and chloramphenicol with regard to their influence on soil invertase. The results obtained in this study suggest that combinations of fungicides and antibiotics may alter the compounds’ individual behaviors in soil and their effects on soil enzymes.     

Atmospheric bulk deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the vicinity of an iron and steel making plant

An IRA-743 resin bulk sampler was validated to monitor long-term bulk deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Six consecutive sampling campaigns (2008-2009) were conducted at four sites around steel complexes in Pohang, South Korea to investigate spatial and seasonal variations of PCDD/F bulk deposition. The bulk deposition within the steel complex showed the highest ∑_4-8PCDD/F (Tetra-Octa) fluxes, ranging from 204 to 608 (mean: 352) pg m⁻² d⁻¹, indicating steel complexes were major sources of PCDD/Fs. The homologue profiles were dominated with lower chlorinated PCDFs. Furthermore, the prevailing winds were confirmed to influence the spatial distribution of PCDD/F deposition. There were apparent seasonal variations of the bulk deposition at each site, and seasonal homologue patterns of PCDD/Fs were clearly observed. According to the passive air sampling, however, no significant seasonal change of ambient air concentrations of PCDD/Fs was observed. Therefore, it was concluded that the seasonal variations of deposition fluxes of PCDD/Fs probably resulted from temperature-dependent gas/particle partitioning.     

Transport of copper as affected by titania nanoparticles in soil columns

The effects of TiO₂ nanoparticles on the transport of Cu through four different soil columns were studied. For two soils (HB and DX), TiO₂ nanoparticles acted as a Cu carrier and facilitated the transport of Cu. For a third soil (BJ) TiO₂ nanoparticles also facilitated Cu transport but to a much lesser degree, but for a fourth soil (HLJ) TiO₂ nanoparticles retarded the transport of Cu. Linear correlation analysis indicated that soil properties rather than sorption capacities for Cu primary governed whether TiO₂ nanoparticles-facilitated Cu transport. The TiO₂-associated Cu of outflow in the Cu-contaminated soil columns was significantly positively correlated with soil pH and negatively correlated with CEC and DOC. During passage through the soil columns 46.6-99.9% of Cu initially adsorbed onto TiO₂ could be “stripped” from nanoparticles depending on soil, where Cu desorption from TiO₂ nanoparticles increased with decreasing flow velocity and soil pH.     

Zinc accumulation and synthesis of ZnO nanoparticles using Physalis alkekengi L

A field survey and greenhouse experiments were conducted using Physalis alkekengi L. to investigate strategies of phytoremediation. In addition, ZnO nanoparticles were synthesized using P. alkekengi. P. alkekengi plants grew healthily at Zn levels from 50 to 5000 mg kg⁻¹ in soils. The plants incorporated Zn into their aerial parts (with mean dry weight values of 235-10,980 mg kg⁻¹) and accumulated biomass (with a mean dry weight of 25.7 g plant⁻¹) during 12 weeks. The synthesized ZnO nanoparticles showed a polydisperse behavior and had a mean size of 72.5 nm. The results indicate that P. alkekengi could be used for the remediation of zinc-contaminated soils. Moreover, the synthetic method of synthesizing ZnO nanoparticles from Zn hyperaccumulator plants constitutes a new insight into the recycling of metals in plant sources.     

Predicting the bioavailability of sediment-associated polybrominated diphenyl ethers using a 45-d sequential Tenax extraction

A 45-d Tenax extraction was used to evaluate the bioavailability of polybrominated diphenyl ethers (PBDEs) in three spiked sediments. The effect of aging on desorption kinetics of PBDEs was investigated by incubating one of the sediments for 7, 14, 30 and 60 d at room temperature. Desorption kinetics were well described by a three-compartment model. The fraction of very slow desorption (Fvs) contributed the most of the desorbed PBDEs from sediments. The total desorption amount of PBDEs decreased with the increase of total organic carbon in the sediments, suggesting that organic matter is an important factor controlling the partition of PBDEs in sediments. The total desorption amount of PBDEs decreased while log [(Fslow+Fvs)/Frap] increased with logKow of PBDE congeners, indicating that the bioavailability of PBDEs in sediment decreases with logKow of the congeners. As the residential time of PBDEs in the sediment increased from 7 to 60 d, Frap of individual PBDE congeners decreased gradually with simultaneous increase of Fvs. There was a good positive correlation between Frap and F6/F24, indicating that either 6 h or 24 h Tenax extraction could be a proxy for Frap and bioavailability. In general, the results in present study suggest that the bioavailability of nona- and deca-BDEs in sediment is very low due to their strong hydrophobicity and large molecular size.     

煤矿区大气降尘饱和烃分布特征

煤矿区域粉尘较多,大气环境状况较差。应用GC-MS技术鉴定平顶山市石龙区降尘样品中饱和烃组分,分析其样品中正构烷烃的分布特征,并结合生物标志物参数解析其来源。结果表明,降尘样品中共鉴定出nC11～nC35正构烷烃、34种萜类化合物和18种甾烷化合物,还有二环倍半萜烷、烷基环己烷系列和丰富的姥鲛烷和植烷。正构烷烃碳数主要呈三峰态和双峰态分布,其碳优势指数CPI值分布在1.45～3.78之间。生物标志物参数C29甾烷20S/(20S 20R)值范围是0.34～0.40,C31霍烷22S/(22S 22R)值范围是0.54～0.59。由正构烷烃碳数分布特征和植物蜡碳数Cn(wax)分布特征、以及CPI值、甾烷和萜烷标志物参数值等分析认为,石龙区降尘饱和烃具有自然源与人为源双重来源。煤的普遍存在与其开采、加工活动密集是其最大的人为来源,而较明显的生物来源则可能为生物质碎屑或磨脱颗粒,或者是由于粗大的大气颗粒物易富集生物源正构烷烃所致。