New filtration system solves water quality challenges for Limpopo packing house 

The importance of water quality cannot be understated in food and agricultural applications, which is why businesses in these sectors must comply with SANS 241-1:2015 potable water standard. When a fruit packing business in Hoedspruit, Limpopo, began experiencing challenges meeting this standard with their existing sand filtration system to treat incoming water from the Blyde River pipeline, they contacted Allmech, leading South African manufacturer of boilers and supplier of water treatment components, to assist.

“The customer was experiencing problems with turbidity, colour, Faecal Coliform and Escherichia coli (E.coli) in the water, and requested our assistance in supplying a new river water filtration plant,” explains Anelia Hough, water treatment consultant at Allmech. “Their packing house operations during peak production time are running 24/7 with a water flow demand of 8500l per hour. Our site analysis indicated that the sand filtration system was insufficient to supply the peak demand on site. Manual chlorine dosing was implemented in the feed line to the factory and office and the Allmech team designed a new water treatment plan to treat the key parameters to ensure compliance with SANS 241-1:2015.”

The maintenance coordinator at the agricultural client, says that the Allmech team was patient and helpful in steering the company through its options and getting the new system approved by the directors. “Once we had approvals in place, the installation was very quick and although with any new system there are some teething issues, since installing the new system we’ve had no issues meeting the standards we need to adhere to when washing and preparing fruit,” he says. “The aftersales service and support from Allmech has also been good.”

Improved filtration with a cost-effective system

“We proposed a water treatment plant using filtration media that offers capabilities to remove 90% to 95% of the solids and chemicals, as well as reducing biological oxygen demand (BOD),” says Hough. “This media provides a practical, low-cost solution and double the performance of a sand filter. In fact, it’s up to 100 times better at removing sub-5 micron particles.”

The new system is verified to achieve log 3 reduction (1000 times) down to 4 microns, with no coagulation or flocculation, and no biofouling means greatly reduced Legionella risk from the filter.

“Product water will have at least 50% lower chlorine oxidation demand than an equivalent sand filter, so there’s lower concentration of disinfection by products including trihalomethanes (THMs),” says Hough.

The filtration media is also expected to last the life of the filtration system, so there is little maintenance required from that point of view.”

Allmech further proposed automated disinfection via inline dosing to ensure no bacterial growth in reservoir tanks or in the feed line to the factory and offices. Allmech conducted the turn-key construction and installation of the water treatment plant in December 2020 and the plant has been fully operational since January 2021.

The Latest SANAS testing laboratory report was completed in July 2021 indicating no Faecal Coliform and E.coli present after water treatment. The turbidity in N.T.U raw water sample is 125 after water treatment plant <1 (SANS 241:15 Class 1 Standard <5). The colour in PtCo units prior to the installation of the treatment plant was 43 (the required limit is <15) and since installation as achieved a rating of 4.

“We are grateful for the opportunity to assist our client and always enjoy designing site-specific solutions to help address our customers’ water quality challenges. The best reward is when the client implements the solutions and operates the plant within specifications,” Hough concludes.

Allmech is also the only authorised South African agent for Runxin valves, produced by the global Wenzhou Runxin Manufacturing Machine Co., headquartered in China.For more information, visit www.allmech.co.za.