Water, Sewage & Effluent September-October 2017 | Page 42

networking contributor industry debate environment infrastructure municipalities
“ While the original interest was for desalination , our recommendation was to rather use the Pall filter system . Presently , in Switzerland , there are four fully equipped container systems waiting for deployment to Cape Town .”
Steve Herbst – Prei Instrumentation A Pall mobile container system ready for delivery .
“ They have done nothing in the interim ,” he adds .
This scenario is being played out against a backdrop of denial and doublespeak , Herbst points out , referencing the Q & A column in the Sunday Times newspaper of 13 August 2017 , in which De Lille danced around answering the question why the City was so illprepared for the water crisis . The mayor cited that the City requires about 500Ml per day to meet the needs of the population . She said that of this , 250Ml can be satisfied , while 250Ml will come from “ a desalination boat parked in the sea ”. This ‘ flotilla ’ ( as reported in later articles ) has not materialised , so the province is once again looking for other solutions .
Why the Pall system
Prei and Hach have been very active in the acid mine draining ( AMD ) arena , with plants located in the eMalahleni coal mining area . “ We have put equipment on all of those plants , because it ’ s a very harsh environment ,” Herbst points out . He explains that in treating the acid mine water , a material akin to cement is produced , as large quantities of lime are required to neutralise the acid . The pH probes are thus not operating in water , but this thick cement-like substance requires daily cleaning and recalibrating . This in turn , becomes a serious maintenance issue and the standard combination pH electrode probes need replacing on a weekly basis . With the Prei / Hach system , however , the pH probes can last anything up to two years , if used in the described manner , Herbst assures .
These AMD plants supply the eMalahleni Local Municipality with clean water , better than the municipality ’ s water treatment plant can , which extracts water from the highly polluted Witbank dam , awash with sewage flowing directly into it .
In the gold mining sector , Prei / Hach has three areas covered by their equipment , namely , the Eastern , Western , and Central Basins . “ This water , however , is going back into the rivers directly , at present ,” he says . Nevertheless , by 2020 , the Trans Caledon Tunnel Authority ( TCTA ) wants this outflow to be drinking water , Herbst adds and says that with the Pall filtration system , this is possible .
How it works
The system is a complete , automated Pall membrane filtration system in a 12.2m-high cube container . With appropriate site preparation and minimal labour , the system can be operational within hours .
Using the same state-of-the-art hollow fibre membranes as hundreds of installed Aria FAST systems worldwide , the Aria FAST mobile system transforms groundwater , surface water , and secondary effluent into water that is free from harmful bacteria , cysts , and particles . The 60C is a compact system designed for up to 280m 3 / hr ( 1 200gpm ) for both drinking water and industrial-use water . Iron , manganese , and arsenic components can be effectively removed when oxidised to their particulate form .
The system is designed to operate in tandem with other water treatment technologies , such as reverse osmosis .
The modular units are available for purchase or long-term lease to deliver high-quality membrane filtration without the expense of costly civil works .
Herbst is of the strong belief that this is the answer to some of the water crises crippling the country . u
Pall Corporation is a global leader in high-tech filtration , separation , and purification , and forms part of the Danaher Water Quality Group . Included in this portfolio is Hach , scientific laboratory and field instrumentation company .
Prei Instrumentation is the recognised distributor for both Pall and Hach in South Africa .
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R10,100 ( Excl . VAT ) for 12 months
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40 Water Sewage & Effluent September / October 2017