Sludge treatment: Current research trends.

The development of porous nanomaterials with high efficiency for environmental remediation has been attracting significant attention and becoming an important topic recently. Metal–organic frameworks (MOF) are hybrid inorganic–organic porous materials containing a metal–oxygen cluster and organic molecules, which are becoming an alternative to traditional inorganic porous materials, such as zeolite and silica, for environmental remediation owing to their fascinating characteristics. Recent studies have demonstrated that MOF are one of the most efficient adsorbents or catalysts in gas separation, solar energy conversion and photocatalytic applications. This review mainly summarizes the recent progress on the adsorptive and degradation treatment of various gaseous pollutants by MOF materials. In this review, the physical and chemical adsorption of gaseous pollutants in air by MOFs will be discussed, and strategies for maximizing the adsorption capacity by tuning the physical and chemical properties of MOFs at the atomic level are systematically summarized. In particular, a promising strategy based on the synergistic effect of adsorption-concentrated photocatalytic oxidation of gaseous pollutants with this newly emerging MOF is also introduced, as it holds great potential in the treatment of gaseous pollutants in consideration of its high efficiency, low cost and being free from secondary pollution. In the end, the challenges faced, the prospects, and our personal perspective on future research directions are also estimated and elucidated.

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Metal–organic framework-based nanomaterials for adsorption and photocatalytic degradation of gaseous pollutants: recent progress and challenges

Chlorinated paraffins are industrial chemicals that can be subdivided into short-chain (SCCP), medium-chain (MCCP), and long-chain (LCCP) chlorinated paraffins. The global production volumes of MCCPs are nowadays suspected to be much higher than those of S- and LCCPs, and the few available studies on the environmental occurrence of chlorinated paraffins report often higher MCCP concentrations than S- or LCCP concentrations in the environment. The present review focuses, therefore, on MCCPs specifically and provides a literature overview and a data analysis of the production volumes, PBT properties (persistence, bioaccumulation potential, and toxicity), and the worldwide measured concentrations of MCCP in environmental samples, biota, and humans. Furthermore, we include our own measurements of technical CP formulations from China, the major global producing country, to estimate the global production amounts of MCCPs. The key findings from this review are that (1) MCCPs are toxic to the aquatic environment,...

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Environmental Risks of Medium-Chain Chlorinated Paraffins (MCCPs): A Review

The industrial chlorinated paraffins (CPs) are comprised of short-chain (SCCPs), medium chain (MCCPs), and long chain (LCCPs) CPs. Although SCCPs and MCCPs are environmentally ubiquitous, little is known about CPs in humans. This study established a method for simultaneous determination of 261 SCCP, MCCP, and LCCP congener groups in one injection by reversed ultrahigh-pressure liquid chromatography coupled with chlorine-enhanced electron spray ionization-quadrupole time-of-flight mass spectrometry. The method yielded good peak shapes, high sensitivities, and low coeluted interferences for all examined CPs. LCCPs with carbon numbers of 21 to 27 were detected in their standard technical mixtures, and MCCPs and LCCPs impurities were detected in the LCCP and MCCP standard technical mixtures, respectively, causing quantification deviations when these mixtures were used for calibration. After considering these impurities’ contribution to the total concentrations, the quantification accuracies for ∑SCCPs, ∑MCCPs...

High-Throughput Determination and Characterization of Short-, Medium-, and Long-Chain Chlorinated Paraffins in Human Blood

Chlorinated paraffins (CPs) are high production volume synthetic chemicals, found ubiquitously in various environmental matrices. However, little information is available on CP contamination in mothers' milk. In this study, 1370 urban mothers' milk samples were collected from 12 Chinese provinces in 2007 and 16 provinces in 2011. CP geographical distribution and congener group profiles were studied to assess the CP levels and figure out the source of exposure in humans. Twenty-eight pooled samples were analyzed for 48 short-chain CP (SCCP) and medium-chain CP (MCCP) congener groups using the GC × GC-ECNI-HRTOFMS method. The median concentrations of SCCPs were 681 and 733 ng/g lipid in 2007 and 2011, respectively; median concentrations of MCCPs were 60.4 and 64.3 ng/g lipid in 2007 and 2011, respectively. Variations of more than 2 orders of magnitude in CP exposure levels were found between different provinces. The levels of CPs increased from 2007 to 2011, which indicates that CP production and use may be an important exposure source. This is the first global comprehensive and large-scale investigation of CPs in mothers' milk, and it lays foundations for improving our understanding of the metabolism of CPs in humans. The high CP concentrations found in Chinese mothers' milk should raise concern about potential toxic effects in both mothers and breastfeeding infants.

Qiu-Xin Huang

Papers

Occurrence, fate and ecological risk of chlorinated paraffins in Asia: A review.

Improvement of zinc substitution in the reactivity of magnetite coupled with aqueous Fe(II) towards nitrobenzene reduction.