An Introduction to Environmental Chemistry

6.4) by soluble organic compounds such as fulvic acids, derived from the break- down of organic matter in the ‘L’ and ‘Ah’ horiz ...

4.9.3 Soils with gley horizons Gley horizons form when the water table is present within the soil profile. Soils with gley horiz ...

The mollisol (mollic gleysol) in Plate 4.2, for example, has a Bg but no Ag horizon. Gley horizons have a mottled red-brown/grey ...

atmospheric CO 2 into the soil (or CO 2 that has been generated as the result of biological activity) the rather insoluble FeCO ...

2.7). These atoms may form an integral part of the molecule, alternatively they may be present in functional groups (see Section ...

The Chemistry of Continental Solids 121 destroyed or lost to other environments (e.g. the atmosphere or hydrosphere). The volati ...

122 Chapter Four Box 4.14 Physical and chemical properties that dictate the fate of organic contaminants Polarity Polarity is a ...

The Chemistry of Continental Solids 123 pressure of water can be used as a ‘yardstick’ for comparison. At 25°C water has a vapou ...

the particles: (i) a rapidly desorbable fraction; (ii) a slowly desorbable fraction; (iii) a very slowly desorbable fraction; an ...

not substantially changed either the compounds or the matrix. Bound residues usually represent an extreme end-member of ageing. ...

126 Chapter Four Box 4.15 Use of clay catalysts in clean up of environmental contamination The interaction between some organic ...

The Chemistry of Continental Solids 127 – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – Pillared clay Surfactant ...

128 Chapter Four Box 4.16 Mechanisms of microbial degradation and transformation of organic contaminants Mineralization eqn. 1 C ...

The main styles of biodegradation and transformation are described in Box 4.16. Even slight structural molecular transformations ...

130 Chapter Four Organic compounds in soil Changes inmobility Changes in toxicity Enhanced mobility Reduced mobility Decreased t ...

of the contamination. Social and economic considerations will also affect reme- diation options. Cost is always a key issue, and ...

by addition of nutrients, addition of air/oxygen (a process called ‘bioventing’), addition of other terminal electron acceptors ...

on the control plots. Hydrocarbon consumption rate in the control plot was 0.052% d-^1 , but this increased to 0.45% d-^1 when t ...

soil/compost mixture can thus be optimized in terms of aeration, nutrients and temperature, to achieve the most efficient degrad ...

Ex situ on-site bioremediation using a bioreactor— polycyclic aromatic hydrocarbons A bioreactor is a silo containing a slurry o ...