New water chemical

Debra Matabvu
Harare City Council could improve water quality and cut purification costs by US$5 million yearly if it starts using a new treatment chemical whose trials ended in mid-April.
Polyaluminum Chlorohydrate can replace up to four chemicals that are presently in use, with studies at Morton Jaffray Water Works showing 100 percent success.
City of Harare officials and Australian-based water purification experts Vista Water Solutions supervised the trials.
Pac is the preferred chemical in countries like New Zealand and the United States.
Harare spends at least US$30 million on nine water treatment chemicals annually, but several researches have condemned the water quality regardless.
Town House previously blamed petroleum companies and food outlets for polluting water sources; however, studies by the Environmental Management Agency in 2014 outed the municipality as the main culprit discharging huge volumes of raw sewage.
In an interview with The Sunday Mail last week, Harare Water Department chief chemist Mr Teddy Mafuko said there will be further studies on latest water treatment techniques.
“The trials were successful and we will be using the chemical soon. This reduces the cost of water treatment by US$400 000 per month. We are now waiting for approval from management to start using that chemical.
“At present, we are using Aluminum Sulphate, which reduces the potential for hydrogen balance, and lime has to be introduced to replace this pH water balance. Therefore, Pac will replace Aluminum Sulphate, lime, Sodium Silicate and Sulphuric Acid.
“In coming months, we will carry out research on Chloride Dioxide to remove smell and colour from the water. This will also reduce the number of treatment chemicals.”