Assessing construction and demolition waste on masonry works to avoid future generation

The difficulty of dealing with construction and demolition waste (CDW) on construction sites is not new and continues to be a significant environmental problem. Currently the CDW collection system in Spain is done in a decentralized manner by each sub-contracted company, being necessary to implement effective waste management measures ensuring a correct management and minimization. During the last years several measures have been launched in order to improve and encourage the reuse and recycling of CDW. A widespread solution for CDW recovery is using them as a landscaping aggregate or for road bases and sub-bases. However, measures encouraging onsite prevention still need to be enhanced. This paper studies the major work stage generating CDW and analyses the categories of CDW produced during its execution. For this, several real building sites have been analysed in order to quantify the estimation of CDW generated. Results of this study show that a significant contributor to the CDW generation on building construction sites in Spain are the masonry works. Finally, a Best Practices Manual (BPM) is proposed containing several strategies on masonry works aimed not only at CDW prevention, but also at improving their management and minimization. The use of this BPM together with the Study and Plan of CDW management --required by law--, promotes the environmental management of the company, favouring the cohesion of the construction process organization at all stages giving rise to establishing responsibilities in the field of waste and providing a greater control over the process. Keywords: construction and demolition waste, management, masonry works, good practice measures, prevention.

Mimics of the binding sites of opioid receptors obtained by molecular imprinting of enkephalin and morphine.

Molecular imprinting of morphine and the endogenous neuropeptide [Leu5]enkephalin (Leu-enkephalin) in methacrylic acid-ethylene glycol dimethacrylate copolymers is described. Such molecular imprints possess the capacity to mimic the binding activity of opioid receptors. The recognition properties of the resultant imprints were analyzed by radioactive ligand binding analysis. We demonstrate that imprinted polymers also show high binding affinity and selectivity in aqueous buffers. This is a major breakthrough for molecular imprinting technology, since the binding reaction occurs under conditions relevant to biological systems. The antimorphine imprints showed high binding affinity for morphine, with Kd values as low as 10(-7) M, and levels of selectivity similar to those of antibodies. Preparation of imprints against Leu-enkephalin was greatly facilitated by the use of the anilide derivative rather than the free peptide as the print molecule, due to improved solubility in the polymerization mixture. Free Leu-enkephalin was efficiently recognized by this polymer (Kd values as low as 10(-7) M were observed). Four tetra- and pentapeptides, with unrelated amino acid sequences, were not bound. The imprints showed only weak affinity for two D-amino acid-containing analogues of Leu-enkephalin. Enantioselective recognition of the L-enantiomer of phenylalanylglycine anilide, a truncated analogue of the N-terminal end of enkephalin, was observed.

Chemical characterization of emissions from a municipal solid waste treatment plant

Gaseous emissions are an important problem in municipal solid waste (MSW) treatment plants. The sources points of emissions considered in the present work are: fresh compost, mature compost, landfill leaks and leachate ponds. Hydrogen sulphide, ammonia and volatile organic compounds (VOCs) were analysed in the emissions from these sources. Hydrogen sulphide and ammonia were important contributors to the total emission volume. Landfill leaks are significant source points of emissions of H2S; the average concentration of H2S in biogas from the landfill leaks is around 1700 ppmv. The fresh composting site was also an important contributor of H2S to the total emission volume; its concentration varied between 3.2 and 1.7 ppmv and a decrease with time was observed. The mature composting site showed a reduction of H2S concentration (<0.1 ppmv). Leachate pond showed a low concentration of H2S (in order of ppbv). Regarding NH3, composting sites and landfill leaks are notable source points of emissions (composting sites varied around 30–600 ppmv; biogas from landfill leaks varied from 160 to 640 ppmv). Regarding VOCs, the main compounds were: limonene, p-cymene, pinene, cyclohexane, reaching concentrations around 0.2–4.3 ppmv. H2S/NH3, limonene/p-cymene, limonene/cyclohexane ratios can be useful for analysing and identifying the emission sources.

National priorities list : 786 current and proposed sites in order of ranking and by state, October 1984.

Mode of access: Internet.

Formerly utilized MED/AEC sites remedial action program : final report.

Issued April 1978.

Formerly utilized MED/AEC sites remedial action program : radiological survey of the E.I. DuPont DeNemours and Co., Deepwater, New Jersey : final report /

Contract no. W-7405-ENG-26.

Formerly utilized MED/AEC sites remedial action program : radiological survey of the former GSA 39th street warehouse, 1716 Pershing Road, Chicago, Illinois : final report /

Jan. 1979.

Formerly utilized MED/AEC sites, remedial action program : radiological survey of the former Horizons Inc., Metal Handling Facility, Cleveland, Ohio : final report /

Feb. 1979.

Formerly utilized MED/AEC sites remedial action program : radiological survey of the Seneca Army Depot, Romulus, New York : final report /

Feb. 1979.

Formerly utilized MED/AEC sites, remedial action program : radiological survey of the Pennsylvania Railroad Landfill site, Burrell Township, Pennsylvania : final report /

Feb. 1979.

Formerly utilized MED/AEC sites remedial action program : radiological survey of the Museum of Science and Industry, 57th Street and Lake Shore Drive, Chicago, Illinois /

Final report, Feb. 1979.

Formerly utilized MED/AEC sites remedial action program : radiological survey of the St. Louis Airport storage site, St. Louis, Missouri /

September 1979.

Formerly utilized MED/AEC sites remedial action program : radiological survey of the former Simonds Saw and Steel Co., Lockport, New York /

"Work performed by Oak Ridge National Laboratory, Oak Ridge, Tennessee."

Formerly utilized MED/AEC sites remedial action program : radiological survey of the former Virginia-Carolina Chemical Corporation Uranium Recovery Pilot Plant, Nichols, Florida /

January 1980.

Formerly utilized MED/AEC sites remedial action program : radiological survey of the Building Site 421, United States Watertown Arsenel, Watertown, MA /

Feb. 1980.