Diffusive gradients in thin films using molecularly imprinted polymer binding gels for in situ measurements of antibiotics in urban wastewaters

• Selective molecularly imprinted polymer (MIP) binding gel was prepared. • MIP-DGT showed excellent uptake performance for antibiotics. • In situ measurement of antibiotics in wastewaters via MIP-DGT was developed. • The MIP-DGT method was robust, reliable, and highly sensitive. Urban wastewater is one of main sources for the introduction of antibiotics into the environment. Monitoring the concentrations of antibiotics in wastewater is necessary for estimating the amount of antibiotics discharged into the environment through urban wastewater treatment systems. In this study, we report a novel diffusive gradient in thin films (DGT) method based on molecularly imprinted polymers (MIPs) for in situ measurement of two typical antibiotics, fluoroquinolones (FQs) and sulfonamides (SAs) in urban wastewater. MIPs show specific adsorption toward their templates and their structural analogs, resulting in the selective uptake of the two target antibiotics during MIP-DGT deployment. The uptake performance of the MIP-DGTs was evaluated in the laboratory and was relatively independent of solution pH (4.0–9.0), ionic strength (1–750 mmol/L), and dissolved organic matter (DOM, 0–20 mg/L). MIP-DGT samplers were tested in the effluent of an urban wastewater treatment plant for field trials, where three SA (sulfamethoxazole, sulfapyridine, and trimethoprim) and one FQ (ofloxacin) antibiotics were detected, with concentrations ranging from 25.50 to 117.58 ng/L, which are consistent with the results measured by grab sampling. The total removal efficiency of the antibiotics was 80.1% by the treatment plant. This study demonstrates that MIP-DGT is an effective tool for in situ monitoring of trace antibiotics in complex urban wastewaters.     

The influence on carbon,nitrogen recycling,and greenhouse gas emissions under different C/N ratios by black soldier fly

Environmental Science and Pollution Research - Currently, sustainable utilization, including recycling and valorization, is becoming increasingly popular in waste management. Black soldier fly...     

Manganese-modified biochar for highly efficient sorption of cadmium

Environmental Science and Pollution Research - In this study, corn stalk was modified by manganese (Mn) before (MBC1) and after (MBC2) pyrolysis at different temperatures (400~600 °C)...     

Magnetic nanoparticles incorporation into different substrates for dyes and heavy metals removal—A Review

Environmental Science and Pollution Research - Substantial discharge of hazardous substances, especially dyes and heavy metal ions to the environment, has become a global concern due to...     

面向实时人群动力学分析的深度基本图网络

当前行人疏散实验中基本图计算方法通常是通过对每个行人进行跟踪实现的.但这种跟踪方法难以实现实时人群动力学分析.针对这一问题,提出了深度基本图网络.实验提出的网络框架由两个模块组成,即多尺度递归卷积神经网络(MSR-Net)和光流模块,分别对行人密度和行人速度进行估计.具体来讲,MSR-Net学习了输入图像与行人密度图之...     

Using Si depletion in aerosol to identify the sources of crustal dust in two Chinese megacities

Depletion of Si in transported dust has been recognized for many years. It can be used to distinguish between transported and local dust in cities, although it rarely has been. Here we use the variations of the Si/Al ratio in 15 months of continuous PM_2.5 samples at Beijing (northern China) and Chongqing (southwestern China) to reveal the seasonal patterns of their dust sources. For both cities, peaks of concentration for Si and Al in PM_2.5 corresponded with minima of Si/Al, and could often be linked to pulsed air flow from deserts to the northwest. With significant depletion (up to 80%) and homogeneous distribution at urban and rural sites, Si/Al showed a clear seasonal evolution, which decreased from spring to summer, increased from fall to winter, and collapsed during Chinese Spring Festival, indicating the dominance of transported dust, local fugitive dust and firework influence, respectively. The low ratios implied that desert dust is a common source during spring at Chongqing, whereas its presence during cold season at Beijing was also more frequent than expected. Failing to recognize the depletion of Si may lead to an overestimate of desert dust by 15%–65% when using the average abundance of Al in crust (6%–8%), as in previous studies. The difference in Si/Al ratio between local and transported dust implies that >60% of the dust at Beijing came from outside the city during the springs of 2004–2006. This result can help resolve the contradictory findings on this topic that have been presented earlier.     

3种浮床植物系统对富营养化水体净化效果研究

研究了风车草(Cyperus alternifolius)、菖蒲(Acorus calamus)和富贵竹(Dracaena sanderiana)3种浮床植物系统对富营养化水体净化效果,试验共持续35 d。结果表明,在水温24～30℃条件下,风车草和菖蒲生长良好,生物量大,而富贵竹生长较差,生物量增加少;3种植物对NH_4~+-N的去除率分别为76.8%、85.5%和53.6%,对TN的去除率分别为69.1%、66.2%和54.4%,对TP的去除率分别为76.9%、84.6%和61.5%,对PO_4~(3-)-的去除率分别为91.7%、91.7%和75%,对真实色度有明显的去除效果;3种植物对氮磷和真实色度去除效果与对照之间均达到显著差异(P0.05),自然沉淀是浊度去除的主要原因,植物吸收同化作用是NH_4~+-N去除的主要途径,植物吸收是溶解性磷去除的主要途径。试验表明,风车草和菖蒲对富营养化水体中氮磷和真实色度有较好的去除效果,可作为富营养化水体治理的优良物种而推广使用。     

超临界水氧化法处理造纸黑液

采用自制的超临界水氧化反应装置,对造纸工业排放的黑液进行处理。考察了反应温度、反应压力、反应时间、过氧量(初始反应时所加氧气的量与废水完全氧化所需氧气的理论量的比,%)等对黑液中COD去除率的影响。实验结果表明,处理黑液的最佳反应条件为:反应温度500℃,压力26M Pa,过氧量500%,反应时间120s。在此最佳条件下处理COD为85 000m g/L的造纸黑液,COD去除率可达99.9%。     

Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-Rotate_N simulation model

Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-Rotate_N simulation model. EU-Rotate_N was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter.