Involvement of the auxin-cytokinin homeostasis in adventitious root formation of rose cuttings as affected by their nodal position in the stock plant.

Enhanced levels of indole-3-acetic and raised auxin to cytokinin ratios in the stem base contribute to the positive acropetal gradient in rooting capacity of leafy single-node stem cuttings of rose. Cuttings excised from different nodal positions in stock plants can differ in subsequent adventitious root formation. We investigated the involvement of the auxin-cytokinin balance in position-affected rooting of Rosa hybrida.

Landfill Mining - Wet mechanical treatment of fine MSW with a wet jigger.

The motives for landfill mining are various. In the last couple of years Enhanced Landfill Mining (ELFM) has become increasingly important in academic discourse and practical implementation. The main goal of ELFM is to recover as much material as possible from deposited municipal solid waste (MSW).

Removal of nitrogen from MBT residues by leachate recirculation in combination with intermittent aeration.

Mechanical-biological treatment (MBT) techniques have been used to reduce the emission potential of waste before placement in landfills for a couple of years, especially in Europe. The main focus of MBT is on the reduction of native organic substances and not on nitrogen compounds. As a result, the concentrations of organic substances in leachate from MBT landfills are considerably reduced in comparison to leachates from municipal solid waste landfills, while the ammonia nitrogen concentrations remain at a high level.

Spatial variability of nitrous oxide and methane emissions from an MBT landfill in operation: strong N2O hotspots at the working face.

Mechanical biological treatment (MBT) is an effective technique, which removes organic carbon from municipal solid waste (MSW) prior to deposition. Thereby, methane (CH4) production in the landfill is strongly mitigated. However, direct measurements of greenhouse gas emissions from full-scale MBT landfills have not been conducted so far.

Energy efficiency of substance and energy recovery of selected waste fractions.

In order to reduce the ecological impact of resource exploitation, the EU calls for sustainable options to increase the efficiency and productivity of the utilization of natural resources. This target can only be achieved by considering resource recovery from waste comprehensively. However, waste management measures have to be investigated critically and all aspects of substance-related recycling and energy recovery have to be carefully balanced.

Long term monitoring of leachate flux into drainage pipes of MSW landfills.

The measurement of leachate quality and quantity is an essential part of the monitoring of landfills in the different phases during their lifespan. These measurements allow the evaluation of the decomposition processes in the landfill and the efficiency of technical installations for the reduction of the leachate generation. Normally the measurements are made at the outlet of larger sections of the landfill or at the overall landfill.

Operating problems in anaerobic digestion plants resulting from nitrogen in MSW.

Organic waste and municipal solid waste usually contain considerable amounts of different nitrogen compounds, which may inhibit anaerobic degradation processes and cause problems in the downstream and peripheral devices. This refers particularly to the different process stages of anaerobic digestion, to wastewater treatment, and to exhaust air treatment. Neither the knowledge about nitrogen problems nor the technologies for elimination of nitrogen compounds from the wastewater or the exhaust air of anaerobic digestion can be regarded as state-of-the-art.

Comparison of selected aerobic and anaerobic procedures for MSW treatment.

This paper considers selected efficiency rates and process data of aerobic and anaerobic procedures for the treatment of municipal solid waste and residual waste. Data are exclusively related to mechanical-biological treatment (MBT) procedures for generating waste appropriate for landfilling. The following aspects are regarded: general framework conditions for the application of MBT, efficiency of decomposition and of stabilisation, air and water emissions and energy balances.