NATURE - GEOLOGY

Nature - Geology

Nature - Geology

Answer 1A

The development of water reuse schemes in Australia has been generally slow in comparison to some other countries. It is only in the past few years that the Australian water agencies have begun to shift their focus of water management to a total water cycle approach. This has led to the development of strategies to reduce the overall amount of wastewater discharged to the ocean and rivers. With increasing pressures on water resources, the concept of beneficial use of treated wastewater has rapidly become an imperative for water agencies around the world. Water reclamation, recycling and reuse are now recognised as key components of water and wastewater management. Along with the technology advances in wastewater treatment, the opportunity for water reuse has never been more viable. The benefits of using recycled water include protection of water resources, prevention of coastal pollution, recovery of nutrients for agriculture, augmentation of river flow, savings in wastewater treatment, groundwater recharge, and sustainability of water resource management (Angelakis & Bontoux, 2001). However, given these benefits, water reuse should not be treated simply as a means to an end but should be implemented in conjunction with other water conservation measures. Australia is one of the driest inhabited continents on earth. The national water consumption rates are now generally considered to be unsustainable, with about a quarter of Australia's surface water management areas either approaching or exceeding sustainable extraction limits (Australian Bureau of Statistics, 2002). The factors that have been cited as driving forces behind the introduction of water reuse in Australia are summarised as follows (Higgins et al., 2002; Stenekes, Schafer & Ashbolt, 2001; National Water Quality Management Strategy, 2000).

• Drought and prediction of possible further droughts from climate change.

• Meeting the needs of a growing population.

• Demand from the general community to have greener water strategies and water

conservation.

• Increased urbanisation of Australia's towns and cities.

• Increased industrial and agricultural needs.

• To allow conservation of higher quality water for suitable uses.

• Heightened awareness of the potential benefits of using recycled water in the agricultural industry.

2. The concentration of five soil heavy metals (Pb, Co, Cr, Cu, Hg) was measured in forty sampling sites in central Transylvania, Romania, regions known as centres of pollution due to the chemical and metallurgical activities. The soil samples were collected from locations where the ground is not sliding and the probability of alluvial deposits is small. The concentration of heavy metals was measured by using the Inductively Coupled Plasma Spectrometry method. Data were verified by using the Neutron Activation Analysis method. In some locations, the concentration for the investigated heavy metals exceeds the concentration admitted by the Romanian guideline. The highest concentration of lead (1521.8 ppm) and copper (1197.6 ppm) was found in Zlatna. The highest concentration of chromium was found in Târnaveni (1080 ppm). The maximum admitted concentrations in the sensitive areas revealed to be exceed from five to forty times.

List of abbreviations: NAA = Neutron Activation Analysis, ICP = Inductively ...