The biggest threat to a sustainable water supply in South Africa is not the lack of storage, but rather the contamination of limited available water resources through mining pollution and acid mine drainage (AMD), industrial pollution, wastewater treatment works discharge, raw municipal waste discharge, urban runoff, irrigation return flow and aerial deposition.
Multotec has recently launched a water treatment and metals recovery solutions and services division in partnership with Australian company, Clean TeQ. CJ Liebenberg, environmental process engineer at Multotec, says that the introduction of CIF® locally will have major benefits for industry as a whole.
Liebenberg says that the CIF® technology complements the other products and services in Multotec’s portfolio. “Multotec’s core business revolves around the supply of products and services to the mining and mineral beneficiation industries including solid/liquid separation units such as centrifuges and filter presses. Our aim with CIF® is to assist in the alleviation of water shortage issues and to encourage sustainable development in South Africa. Mining is often regarded as being a non-sustainable enterprise and we intend to be part of the solution.”
CIF® is based on the foundation of IX technology, a technology that has been on the market for more than 50 years. It can be likened with continuous sand filtration, the salient differences being that in CIF® charged resins are used as filtration media instead of sand, and in addition to removing suspended solids, CIF® also “filters” dissolved salts out of the solution.
Clean TeQ has developed three main processes based on CIF®. These are single stage CIF® for resource recovery and dealkalisation applications, dual stage CIF® (DeSALx®) for desalination of water and high recovery reverse osmosis (HiROx®), desalination using CIF® on the front end of RO to remove scaling, improving the overall performance of RO, and re-using RO brine for resin regeneration for a chemical-free membrane system. All three systems can be adapted to produce a zero liquid discharge (ZLD) process.
The main features of CIF® include a resin cleaning step to allow the system to operate in the presence of suspended solids, counter-current flow of aqueous and resin phases for high efficiency ion exchange and that there are minimal moving parts and no complicated internal structures. The plants can be containerised and be fully automated with remote access. These features allow for robustness of the system to treat solutions with high scaling potential.
Water recoveries of more than 95% have been realised using this system and production of either agricultural grade or ultra-pure water with TDS concentration less than 50 mg/l is a reality. The plant has minimal pre-treatment requirements, uses inexpensive chemicals for regeneration and has low power requirements, all of which contribute to lower capital and operating costs when compared with competing technology.
In addition, mobility of the CIF® allows for water treatment in remote locations and the fact that it is automated enables the system to operation independently and to be controlled remotely. Its simplicity facilitates ease of operation and maintenance, eliminating the need for highly skilled labour. Potential by-products in a saleable form such as gypsum can be produced.
Because CIF® is based on IX technology, it is able to treat water originating from numerous sources and can remove a wide range of contaminants at various concentrations. Niche markets identified for CIF® include water treatment in the Acid Mine Drainage (AMD), mine process and effluent water, groundwater and agricultural sectors using containerised systems, although not excluding requests for modular CIF® plants and prospects for CIF® in emerging markets.
The technology has had significant success in the treatment of coal seam gas (CSG) associated water in Australia. With the government having given the green light for exploration of offshore sub-surface exploitation of natural gas in the Karoo, as well as other indications that CSG exploitation might take place in southern Africa this market holds significant potential for CIF® in the future.