Toxic water can be purified to drinkable water

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 07 July 2011

By Kristin Palitza

South African scientists have developed an environmentally friendly method to clean highly toxic water and convert it into drinkable water. Once available commercially, the method could drastically reduce the negative impact industry has on water pollution worldwide.

Eutectic freeze crystallisation could be used in the mining sector

Called eutectic freeze crystallisation, the technique freezes acidic water – or brine – to produce potable or drinking water as well as useful salts, such as sodium and calcium sulphate.

Alison Lewis, professor for chemical engineering at the University of Cape Town in South Africa, who has led the research since 2007, claims 99.9 percent of the polluted water can be reused after applying the new technique. Unlike other water cleaning methods, it practically doesn’t produce any toxic waste.

“It’s an environmentally friendly and cost-effective technology that can be used pretty much in all industrial sectors that pollute water and thus produce brine,” explains Lewis. This includes sectors like mining, the oil and gas industry, chemical industry, paper processing or sewerage.

The simultaneous separation and purification method is based on bringing the contaminated water temperature down to reach its eutectic point – the lowest possible temperature of solidification. At this point, toxins crystallise to form salts and sink to the ground, while the clean water turns into ice, floating on the surface.

“By its nature, ice is the purest form of water because it repels any impurities. It’s actually very simple,” explains Lewis. “The method is ecologically significant because it can turn toxic waste into a useful product.” Continue reading

Experts to assess extent of acid mine drainage

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 07 September 2010

A team of experts is expected to assess the extent of acid mine drainage in the country and report back to an inter-ministerial committee appointed by Minister of Water Affairs Bulelwa Sonjica.

Johannesburg. Toxic water will eat away at the city's steel foundations.

Cabinet last month mandated the minister to urgently establish a special task team to investigate how government can best deal with reports of acid water drainage in some provinces.

Acid mine water, or water contaminated with heavy metals as a result of mining activities, is affecting the Gauteng, Mpumalanga, North West and the Free State provinces. Reports suggest that this drainage could result in serious health and economic risks for the provinces and the country.

Speaking in Cape Town on Monday, Sonjica said the experts will appraise the risk and look at what has already been done by various institutions and then assess available solutions and technology.

“They will interrogate and assess viability costs of critical short-term interventions, integrate lasting and sustainable medium- and long-term solutions and explore possible partnerships with private sector,” Sonjica said.

The ministerial committee will reconvene in six weeks time to receive a detailed report from the team of experts covering a reappraisal of the risks and assessment of what has been done as well as the viability and costs critical short term intervention.

Responding to media reports that the streets in Johannesburg’s CBD will be flooded with toxic mine water in the coming months, Sonjica assured the public that the situation was under control and there was no need for people to panic.

As a short term measure an amount of R218 million has been budgeted by the department to fit the pumps and avert the situation.

The minister said the country has been faced with the problem of mine water effluent, including acid mine drainage, for over 100 years when mining began. At the time, no legislative measures were in place and environmental considerations were not prioritized.

Over the past 15 years, government has strengthened environmental regulation through the introduction of National Environmental Management Act, Mineral and Petroleum Resources Development Act and the National Water Act.

She said a major challenge for government was to find the perpetrators, naming the gold and coal mines as major culprits.

Source: BuaNews

Water crisis could cripple economic growth

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 23 May 2010

South Africa faces a water crisis that could cripple economic growth and cause a plague of health problems – but critics say the government has yet to act with urgency.

Toxic algae bloom

The most immediate concern is the acid mine drainage (AMD) polluting a vast swathe from the Witwaters-rand to Mpumalanga. Other threats include pesticide run-off, broken infrastructure and failed sewage plants.

As the population grows and economic recovery puts more pressure on limited inland water resources, experts predict a shift of industrial activity to coastal areas where desalination plants will have to meet a growing share of demand.

Environmentalists warn that if the government and industry fail to act, within two years mine water as corrosive as battery acid will gush from Johannesburg’s Wemmer Pan and seep into the city’s streets and gardens.

“It is acutely toxic,” said Mariette Liefferink, who leads a group of non-governmental organisations lobbying for action. “It affects the soil and neural development of the foetus, which leads to mental retardation; it will cause cancer, cognitive problems, skin lesions,” she said. “These are all the foreseeable risks if we do not manage our AMD.”

Acid mine drainage, which occurs when mines close and stop pumping water out of shafts, has contaminated streams and dams on the West and East Rand that feed into the Limpopo and Vaal rivers. Treatment by utilities such as Rand Water renders the water safe, but those who drink straight from rivers are at risk. Continue reading

Most of Africa’s water sources are polluted with toxic matter

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 02 May 2010

Water quality in sub-Saharan Africa is on the decline. Most water resources have unacceptable levels of toxic substances — heavy metals, persistent organic pollutants and biological contaminants, according to a recent report by the Pan Africa Chemistry Network (PACN).

About 50% of Africa’s total water resources are concentrated within the Congo basin

These originate mainly from domestic waste water and local industries.
However, PACN notes that managing water resources in Africa is difficult as many countries do not have quality monitoring programmes.

“There is widespread scarcity of analytical laboratories, substantial under-investment and the absence of a structured framework for water governance,” notes the PACN report. “This makes water pollution statistics hard to come by.”

The report, “Africa’s Water Quality: A chemical Science perspective” of March 2010, however notes that scientists working in Africa have the knowledge, expertise and potential to help formulate and implement sustainable water strategies to maintain quality.

The report is the outcome of a 2009 Sustainable Water Conference hosted by the University of Nairobi, Kenya, and sponsored by the Royal Society of Chemistry (RSC) and world leading agribusiness, Syngenta.

The findings and recommendations represent the views of 180 scientists and practitioners from 14 countries in Africa who attended the conference, as well as the UK, Switzerland, Colombia and Uruguay. Continue reading

Acid mine water threatens Cradle of Humankind

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 18 April 2010

A massive study is under way to investigate the impact of toxic acid mine water and other dangerous sources of pollution to the world-famous Cradle of Humankind World Heritage Site.

Australopithecus sediba was discovered two years ago.

It is here where the nearly two million-year-old hominid skeleton, Australopithecus sediba, was discovered two years ago, and unveiled to global wonder last week.

But in recent years, several scientists have slammed authorities for failing to protect ancient hominid fossils, including the Sterkfontein Caves. These are made of dolomite rock and vulnerable to acidic water from historic mining operations on the West Rand.

Peter Mills, the acting director of research and planning at the Cradle of Humankind World Heritage Site, told the Saturday Star the management authority had commissioned the Council for Scientific and Industrial Research and the Council for Geosciences “to understand the flow of water through the Cradle”.

As gold mines on the West Rand have ceased operating, the water table has returned to pre-mining levels, bringing with it a rising tide of toxic water, characterised by heavy metals and radioactive uranium, as well as high levels of sulphates.

Since 2002, more than 15 million litres of this acidic water has been decanting daily and flowing into the Tweelopie- spruit, through the Krugersdorp Game Reserve, into the Blaauwbankspruit which feeds into the Cradle of Humankind. Continue reading