Search

With the ever increasing population growth in urban areas, stakeholders have adopted numerous water sensitive urban design (WSUD) measures to enable the recycling and reuse of stormwater for a range of non-potable fit-for-purpose uses. This chapter highlights the most common measures adopted across Australia in the recent past, their benefits and limitations. Findings suggest that the adoption of WSUD measures have provided multiple tangible and intangible benefits from a social, environmental and economic context. For further expansion and adoption of WSUD measures, the multiple benefits need to be communicated and shared with the scientific and the broader community further to create sustainable and water resilient urban areas.

Despite the many positive impacts of petroleum hydrocarbons to human industrialization and activity, environmental contamination by petroleum hydrocarbons represents a major cause of marine and terrestrial pollution. Petroleum hydrocarbons contain various compounds such as alkanes, light aromatics (MAHs), cycloalkanes, heavy aromatics (PAHs) and asphaltenes, among others. A number of these compounds are potentially carcinogenic and mutagenic. Among the various remediation technologies, bioremediation or the use of microorganisms to degrade the hydrocarbons is considered a clean, cost-effective and environmentally friendly approach. Unlike other physical and chemical methods, it does not lead to secondary contamination, generally resulting in the complete mineralization of hydrocarbons. Several reports have now confirmed bioremediation as a promising technology to clean up the environments. This chapter presents an overview of current bioremediation approaches for the treatment of petroleum hydrocarbons.

Because of their ubiquity, abundance and metabolic activities, microorganisms play a crucial role in the biogeochemical cycling of elements in the environment. Any perturbations in the activity and diversity of the microbial community are likely to lead to significant impacts in terms not only of biogeochemical cycling but also ecosystem resilience. Human activities and industrialization have resulted in the release of millions of tonnes of chemicals and pollutants into the environments; some of these are toxic to living organisms. However there is a lack of information about the toxicity effects at the ecosystem level; where toxicity tests have been included in studies the basis has been the use of target species including plants (e.g. radish germination), worms (e.g. earthworm survival) and microbes (e.g. the Microtox bioassay test) to evaluate the effect of the pollutant on the target organisms. Microbial ecotoxicology represents an emerging discipline that encompasses microbial ecology, microbial toxicology, chemistry and physics and that offers great potential in the assessment of the fate and impact of environmental pollutants at the ecosystem level. In this introduction we discuss the importance of microbial ecology together with some of the advantages of the application of the recently established microbial ecotoxicology discipline in order to reliably assess the impact of contamination on the resilience and the functionality of the microbial community.

The dinitrotoluene (DNT) isomers 2,4- and 2,6-DNT are highly toxic compounds, and their occurrence in groundwater and soils is a widespread problem mainly due to the explosive manufacturing industry and from the commercial production of polyurethane foam. Moreover, these compounds have mutagenic and carcinogenic properties making them a great hazard to the public health. Thus, their removal from the environment is paramount, and bioremediation strategies can be applied for the environmental cleanup. Pure cultures of microorganisms able to degrade at least 2,4-DNT have been recently isolated as well as a consortium and different plant species. The pure cultures are an Arthrobacter strain isolated from crude oil-contaminated soil, a Rhodococcus pyridinovorans NT2, and Shewanella marisflavi EP1, while the consortium named UHasselt Sofie 3 (UHS3) was formed by Burkholderia HC114, Variovorax paradoxus VM685, Bacillus, Pseudomonas mandelii HC88, and Ralstonia HC90. These microorganisms perform the degradation of the dinitrotoluenes in aerobic conditions except the marine strain Shewanella marisflavi. The plant species able to grow in the presence of 2,4-DNT and proposed for phytoremediation are hemp, flax, sunflower, and mustard. The intermediates reported in the majority of successful biodegradation studies are 4-methyl-5-nitrocatechol (4M5NC) and 2-hydroxy-5-methylquinone (2H5MQ) under aerobic conditions, while 2,4-diaminotoluene is obtained as an end product via the formation of 2-amino-4-nitrotoluene (2A4NT) and 4-amino-2-nitrotoluene (4A2NT) under anaerobic conditions. These microorganisms add to the growing number of isolates with the ability to degrade these types of compounds since strain DNT was isolated. This mini-review focuses on the microorganisms involved in the degradation of the dinitrotoluene isomers 2,4- and 2,6-DNT in recent years. Information related to the degradation of these contaminants is critical to understanding and predicting their fate in the environment.

Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are two major environmental contaminants which threaten our health and environment. The removal of these key environmental pollutants from the environment is therefore paramount. Among the cleanup methods currently being used, traditional methods such as chemical and physical treatments tend to be expensive, laborious and may cause secondary contamination. Phytoremediation, the use of plants and associated microorganisms, represents a promising, nondestructive and cost-effective in situ technology for the degradation or removal of contaminants. Grasses belonging to the Poaceae family have drawn significant attention in this regard due to their fast growth, dense, fibrous root systems, and the demonstrated fast removal of PAH and PCB compounds from soils in which these plants have been grown. In this review, we review research on the use of grasses for the degradation of PAHs and PCBs and highlight the benefits of this phytoremediation approach.