Environmental Science & Technology
Environmental Science & Technology
3 years ago

Methylsiloxanes Release from One Landfill through Yearly Cycle and Their Removal Mechanisms (Especially Hydroxylation) In Leachates

Methylsiloxanes Release from One Landfill through Yearly Cycle and Their Removal Mechanisms (Especially Hydroxylation) In Leachates
managing.editor@est.acs.org (American Chemical Society)
In one yearly cycle (2016), D4 and D5 were detected in biogas samples (n = 36, 0.105–2.33 mg/m3) from a Chinese municipal landfill, while D4–D6 were detected in influents/effluents of leachate storage pond (n = 72, < LOQ-30.5 μg/L). Mass loads of cVMS in both biogas (591–6575 mg/d) and leachate influents (659–5760 mg/d) increased from January to July (summer), and then decreased from July to December (winter). Removal experiments indicated that 1) hydrolysis and volatilization were predominant removal mechanism for D4 and D5, respectively, in leachate storage pond, responsible for their more significant removal (94.5–100%) in August; 2) indirect phototransformation (t1/2 = 25.5–87.0 days), such as hydroxylation by OH radical generated in leachates, was the predominant (50.0–75.5%) removal pathway for D6, which led to the largest removal efficiencies (65.2–73.7%) in June, the month with the largest sun light intensity and highest photosensitizer (e.g., Fe2+ and NO3–) concentrations. Monohydroxylated products of D5 and D6, D4TOH and D5TOH, were detected in leachate effluents (39.6–187 ng/L) during May-July. Compared to D5 and D6, volatilization half-lives of D4TOH (86.3 days) and D5TOH (177 days) in leachates were 2.9 and 1.4 times longer, while their hydrolysis half-lives (7.50 days for D4TOH and 21.5 days for D5TOH) were 7.1 and 10 times shorter, respectively.

Publisher URL: http://dx.doi.org/10.1021/acs.est.7b03624

DOI: 10.1021/acs.est.7b03624

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.