Establishing a successful construction/demolition (C&D) waste recyling operation in the USA is a challenge today, especially because secondary materials markets have not yet matured. Increasingly, municipal solid waste (MSW) landfill operations refuse to accept C&D waste. Skyrocketing tipping fees due to the scarcity of landfill sites, and growing concerns from regulatory agencies and the public, have placed C&D waste recycling operations under intense scrutiny. The experiences of regional C&D recyclers indicate that successful recycling operations require a minimum of 0.8 ha of clear space for processing equipment, incoming waste stockpiles, recycled materials, and manoeuvring room for mobile equipment and operations. Reasonable quality, reliable equipment suitable for these operations generally costs between $300 000 and $750 000 for a 400-500 tonne/day operation. At present, operators of these facilities make a profit almost solely on tipping fees, with the recycling operation functioning mainly to maintain materials throughput. Different categories of C&D recycling machinery and waste processing strategies are presented. Strategies for converting C&D landfills into successful C&D recycling operations are also examined. C&D waste recycling economics are presented to demonstrate the essential ingredients for successful operations.Recycling, Landfill, Machinery, Demolition, Waste, Sustainability, Environmental Impact,

The synthesis of a molecularly imprinted polymer (MIP) composed of tetramethoxysilane (TMOS) and methyltrimethoxysilane (MTMOS) for recognized sulfonamides by sol-gel process has been investigated. The MIP's preparation conditions, the H 2 O/Si molar ratios (R), pH value of competition solution, calcination temperature, and the TMOS and MTMOS molar fractions are discussed. Adsorption and selectivity in different pH solutions were determined by competition experiments between the MIP template (sulfamethazine, SMZ) and the analogue (sulfamethoxazole, SMO) using High-Performance Liquid Chromatography (HPLC). The results show that the selectivity of the MIP in competition solution with pH ¼ 7:4 was higher than that with pH ¼ 4:6. In addition, the second stage temperature of calcination, which was carried out at 375 C, was obtained high selectivity. Moreover, the selectivity of the MIP (10.5) was approximately 3.5 times greater than the nonimprinted polymer (3.72) under the optimum preparation conditions. KEY WORDS: Molecularly Imprinted Polymer / Sulfonamide / Sol-Gel / Sulfamethazine / Sulfamethoxazole / HPLC / Molecular recognition is a phenomenon that can be envisaged as the preferential binding of a molecule to a ''receptor'' with high selectivity over its close structural analogues. This concept has been translated elegantly into the technology of molecular imprinting, which allows specific recognition sites to be formed in synthetic polymers through the use of various templates.1-5 Molecular imprinting of synthetic polymers with a specific target molecule can be done if the target resembles the template or imprint molecule used during polymerization and then removed after polymerization. Polymerization occurs when monomers carrying certain functional groups interact with the template and arrange themselves around the template into a 'frozen' position.6-9 Imprinting has been achieved by three ways; non-covalent, covalent and sacrificial spacer. Non-covalent imprinting relies on the ability of the template molecule to produce one or more strong intermolecular non-covalent interactions with the functional monomers, e.g., H-bonding, electrostatic or -interactions. Removal of the template affords a cavity, which is complementary in size shape and functionality to the template molecule, and which contains the recognition site used for recognizing specific molecules. In covalent imprinting, the template-monomer covalent bond is formed before the polymerization of MIP. Polymerization is conducted in the usual manner but template removal and rebinding is achieved by a chemical rather than physical process. 10 In the sacrificial spacer method, the pre-organized or covalent approach employs reversible covalent bonds, usually involving a prior chemical synthesis step to link the precursors to the template or to a structurally similar molecule.9 In other words, monomers are covalently linked to the template via short spacers. The spacers are eliminated once the imprinting process is completed, giving room and suitable func...