Woodlands

Sustainability is at the core of all operations in the Woodlands Dairy milk  processing plant in Humansdorp, South Africa. Determined to minimize the use of resources and eliminate waste, Woodlands Dairy also aims for a smaller carbon footprint by lowering its energy consumption.

Woodlands Dairy employs over 1,400 people and prides itself on an innovative spirit, agility and speed in new product development, and excellent customer service. The product range includes various cheeses, butter, cream, custard, flavoured milks, and amasi, a fermented milk similar to cottage cheese that is very popular in Southern Africa. The company also produces extended shelf life (ESL) fresh milk and is one of the largest manufacturers of UHT milk in South Africa, marketed under the brand First Choice.

The Woodlands Dairy factory comprises a milk sterilisation and packaging plant, as well as a cheese factory. In 2012, the company adopted an environmental management system (EMS) to improve its energy efficiency and waste management, and to decrease both its emissions and use of natural resources. The EMS complies with the international ISO 14001 standard and aims to minimize operational impacts on the environment, ensure legal compliance, and continuously improve the company’s environmental performance.

Memthane® is an anaerobic membrane bioreactor (AnMBR) process which contains the micro biological anaerobic process (excludes oxygen), this technology turns medium to high-strength wastewater into energy and clean water that can be directly reused or discharged. The system was developed in a cooperation between Veolia subsidiary Biothane and Pentair. The Biothane reactor processes the wastewater and generates biogas. Pentair’s X-Flow membranes separate the sludge and produce clean water. The sludge from the reactor remains rich in nutrients and can be used by local farmers as fertiliser. Woodlands Dairy calls its new Memthane installation a Resource Recovery Plant, or RRP. Whereas all effluent from the various production processes used to end up in a combined effluent sump, the new wastewater plant is capable of processing 1.5 MLD. At a later stage, this is set to be upgraded to 2 MLD. The incoming feed stream with about 10,000 ppm of COD is turned into a high quality effluent with less than 100 ppm. As dairy processing is an energy-intensive operation, the biogas is a welcome bonus used to heat the on-site biogas boiler.

Process wastewater from the factory is sent over a vibration screen into the Acidification tank, where variations in feed water is equalized. This tank is operated at a minimum retention time to promote pre-acidification. From here, the pre-acidified wastewater is sent to the anaerobic digester (Memthane) where most of the organic material and suspended solids are converted into biogas. To retain the anaerobic biomass in theanaerobic digester and produce a clean effluent, which is purified by RO later, four ultrafiltration (UF) skids are utilised. The anaerobic digester content is continuously recirculated through these UF skids, where the pressure forces clean liquid (UF permeate) through the membranes. This permeate goes in the RO feed tank and is then fed to RO units for further treatment.The UF skids are operated at a low crossflow velocity in order to reduce energy consumption, but in order to maintain the flux rate at an acceptable level, thecake layer formation on the membrane  surface area needs to be controlled.

Biothane is Veolia Water Technologies  techno center for industrial effluent treatment and anaerobic technologies in specific. Memthane is one of the latest developments done with Pentair X-flow as exclusive partner.