1. Extensive experience in various membrane related pilot and other studies on both fresh water treatment and saline water desalination, especially together with Ikusasa Water membrane supply company (2008 – 2016). (Dr Ian Goldie, Business Manager, Ikusasa Water, 083 270 4506)
    
2. Process selection and design assistance to Moedi Consulting Engineers in designing the 15 Ml/d water treatment plant for Delmas. (Mr Marx Jordaan, 082 783 1378)
    
3. A review of water treatment processes applicable for rural and community water supply in South Africa (2009). Study performed for Overberg Water/Masimbambane. (Mr Danie Theron, Overberg Water, 082 822 3146)
    
4. Treatment of spent waste grain at the Sedgwick whiskey distillery, Wellington (2009). DAF and settlement studies performed for Distell. (Mr Jacques Blignaut, Waste Management, Distell, 083 627 2247)
    
5. Treatment of the effluent at the Parmalat, Bonnievale, production plant. (From 2008, but ongoing). Assistance with Dissolved Air Flotation for Water & Wastes Utilisation Solutions. (Mr Buks Schutte, 082 902 2947)
    
6. Compilation of a Water Safety Plan for Stellenbosch Municipality in conjunction with Chris Swartz Water Utilization Engineering as project managers (2010) (Mr Ronald Brown, 072 561 2257)
    
7. Compilation of Water Safety Plans for Cape Agulhas Municipality’s water treatment systems in conjunction with Chris Swartz Water Utilization Engineering as project managers (2011) (Mr Walter Linnert, 072 047 8248)
    
8. Member of project research team in the following Water Research Commission (WRC) projects:
   
   Development of a prototype nanotechnology-based clay filter pot to purify water for drinking and cooking in rural homes, K8/810 (Project Leader: Prof Maggy Momba, 082 513 7396).
   
   Compilation of guidelines for the selection and use of home water treatment systems and devices, K5/1884 (Project Leader: Prof Maggy Momba, 082 513 7396)
   
   Guidelines on Determining the Vulnerability and Risks of Water Services Infrastructure, K5/1893 (Project Leader: Mr Grant Mackintosh, Emanti Management, 082 327 3357)
   
   Development of a costing model to determine the cost-efficiency and energy effficiency of water treatment technologies and supply options, K5/1992 (Project Leader: Mr Chris Swartz, Chris Swartz Water Utilization Engineers, 082 820 4481)
   
   Decision-support model for the selection, costing and application of drinking water treatment and supply options to address water shortages and improve water services delivery (with focus on upgrading options, water relamation and desalination), K5/2119 (Project Leader: Mr Chris Swartz, Chris Swartz Water Utilization Engineers, 082 820 4481).
    
9. Due Diligence Report on the level of success of the water related activities of a large Water Services provider group in Gauteng for loan application purposes (2011). Study performed for Pine Bridge Investments, New York. (Information regarding the study will only be provided under agreement of confidentiality)
    
10. Investigation into the membrane-based water reclamation plant installed at Alexandria and recommendations for the way forward (2011). Project executed for Ndlambe Municipality (Mr Xolani Masiza, Director Infrastructure, 083 500 0766)
     
11. Investigations into problems experienced with the reverse osmosis membrane system at the Biovac Institute (2011). Project executed on behalf of Project Assignments, Cape Town, to investigate loss in pure water production volumes and provide recommendations to solve the problems. (Mr John Jellicoe, Project Assignments Project Manager, 078 853 1935)
     
12. Training of 230 process controllers in the Western Cape by means of presentation to nine centres in the province, utilising the Telematic Centre at the University of Stellenbosch. Course given and assessed: aspects of SETA Unit Standard 246450: Demonstrate knowledge of the water treatment process, as well as general presentations on water management. (Chris Swartz, Chris Swartz Water Utilization Engineers, 082 820 4481)
     
13. Training on NQF 02 level of process controllers for Drakenstein Municipality with Chris Swartz Water Utilization Engineering. Course given and assessed: SETA Unit Standard 246450: Demonstrate knowledge of the water treatment process. (Mr André Kowalewski, Drakenstein Municipality, 021 807 4705)
     
14. Execution of a project for Ikusasa Water to concentrate tea extract for polyphenols and anti-oxidant recovery using ultrafiltration and reverse osmosis pilot plants (2013). The work was done for the CSIR as client. From the pilot study, specifications were drafted for a demonstration plant. (Dr Ian Goldie, Business Manager, Ikusasa Water, 083 270 4506)
     
15. Assisting with membrane development work with HySA Systems, Dept of Chemistry, University of the Western Cape, regarding improved membranes for gas extraction from flue gas (Prof Ben Bladergroen, 021 959 9309)
     
16. Involved with membrane development work with HySA Systems, University of Cape Town, Chemical Engineering, regarding improved membrane systems for fuel cells (Mr Shiro Tanaka, 021 650 3852)
     
17. Assistance with, and finalisation of, technical reports and publications for various scientists and engineers. (Prof Ben Bladergroen, 021 959 9309; Prof Leslie Petrik, Dept of Chemistry, UWC, 021 959 3878; Dr Willem de Clercq, Soil Science, Stellenbosch University, 021 808 4793; Dr Pia Lipp and Dr Stephan Stauder, Technologiezentrum Wasser, Karlsruhe, Germany, +49 721 967 8127).
     
18. Report with recommendations on the Process Design of the Driekoppies and Masibekela (Sibange) Water Treatment Works. 2012. (Study done for Lubisi Consulting, Chalmers Pagiwa, 013 752 6416)
     
19. Performed Blue Drop audits for the Department of Water Affairs at municipalities in the in the Western Cape (2009) and in Eastern Cape, Free State and KwaZulu Natal during the 2012/13 Blue Drop audit year.
     
20. Design and costing of a 100 Ml/d membrane plant for the indirect potable reuse of the Darvill sewage works effluent – a feasibility study for BigenAfrica.. 2013. (Dr Mias van der Walt, 012 843 9085)
     
21. Execution of an investigation into the occurrence of copper tube pit corrosion in the Mossel Bay area and recommendations as to the alleviation of the problem. Confidential report to the Mossel Bay Municipality, 2014. (Mr Eric Louw, 044 606 5270)
     
22. Execution of a pilot study for the removal of iron and manganese from groundwater for use as potable water by the Kouga Municipality. Study performed to obtain design information for a planned new water treatment plant for Jeffreys Bay, 2016. (Report to Kouga Municipality and Water & Pump Solutions, Mr Nell Potgieter, 082 656 5306)
     
23. Design of a 6.5 Ml/d iron and manganese removal plant for the supply of potable water to Jeffrey’s Bay (Kouga Municipality and Water & Pump Solutions, Mr Nell Potgieter, 082 656 5306)
     
24. Upgrade of the 500 m³/d Bathurst Water Treatment Plant. (2016) Design of coagulation/flocculation, lamella settling and filtration systems. (Water & Pump Solutions, Mr Nell Potgieter, 082 656 5306)
     
25. Design of a 840 m³/d biotower stripping system for the removal of hydrogen sulphide from ground water. (Water & Pump Solutions, Mr Nell Potgieter, 082 656 5306)
     
26. Design of a 240 m³/d dissolved air flotation system and assistance in plant design for a laundry effluent water recovery and reuse system. (Dr Ian Goldie, Business Manager, Ikusasa Water, 083 270 4506)
     
27. Design of a 960 m³/d dissolved air flotation system as pre-treatment to membrane filtration for potable water supply to the town of Pearly Beach, Western Cape. 2017 (Dr Ian Goldie, Business Manager, Ikusasa Water, 083 270 4506)
     
28. Presentation of training courses: Membrane technology, Specialist DAF course, Drinking water treatment & application, Industrial effluent treatment & application, compilation of Water Safety Plans
     
29. Process advice to the Western Cape Health Department on process selection for the supply of emergency water to state hospitals in the Western Cape. 2017/18 (Dr Roger Parsons, 083 310 6504)
     
30. Design of a 200 Ml/d DAF system as pre-treatment for membrane seawater desalination. Done for Aveng Water as part of a feasibility study. 2018 (Annamarie Vlok, 010 205 1047)
     
31. Facilitation of one-day courses on Membrane Water Treatment, one-day specialist and design courses on Dissolved Air Flotation for engineers, two-day specialist courses on Process Selection and Application in Drinking and Industrial Water Treatment, Two-day courses on Membrane Technology & Application in Water & Effluent Treatment, Two-day courses on Water Quality & Water Safety Planning, 2016, 2017 & 2018
     
32. Feasibility study and proposal for the treatment of Cookhouse Dairy effluent before disposal by irrigation (Report to Water & Pumping Solutions, Mr Nell Potgieter, 082 656 5306)
     
33. Design of a 13 kl/h DAF system for the Texcare Laundry water recovery plant. 2019. (Mr Cobus Olivier, Kainos Projects Africa, 082 873 2612)
     
34. Design of an 8.3 Ml/d DAFF for drinking water treatment at Drakenstein Municipality. 2019 (Geoff du Toit, Aurecon, 082 296 0712)
     
35. Design of a 280 kl/d DAF plant for the pre-treatment of laundry effluent before further UF and RO clarification. (Mr Leon Croukamp, Coral Clean Laundries, 021 946 2234)
     
36. Design of a 120 kl/d DAF plant for the treatment of Pioneer Foods fruit effluent (Mr Cobus Olivier, Kainos Projects Africa, 082 873 2612)
     
37. Renovation and upgrade of a 1 Ml/d DAF system for the treatment of chicken effluent for Bush Valley Chickens, Letsitele. (Mr Dirk Cloete, International Water Technologies, 082 772 1602)
     
38. Investigation with report with recommendations to make the 150 m³/h Rainbow Chicken DAF plant, Hammarsdale, fully operational again (Mr Francois le Roux, Tecroveer, 082 338 4309)
     
39. Investigation with report with recommendations to rectify and upgrade five DAF plants at four fish processing plants in Walvis Bay, Namibia. (Mr Frank Kernstock, +264 81 149 2329)
     
40. Design of a 4 m³/h DAF plant plant for the treatment of algal dam water to drinking water (Mr Luan Schoeman, Utico Water, 082 854 1427)

List of Dissolved Air Flotation Plants Designed

PLANT	YEAR	DESCRIPTION & COMMENTS
Pilot DAFF	1983	24 m3/d fully adjustable DAFF (DAF on top of sand filter) for research and pilot plant purposes (CSIR)
Van Leer Industries	1984	1.9 Ml/d paper effluent treatment (for Explochem Water Treatment))
AEC	1985	7 Ml/d phosphate removal plant (Van Wyk & Louw)
UCOR	1985	20 Ml/d secondary sewage effluent reclamation (Explochem)
Zeekoegat	1987	7 Ml/d secondary sewage effluent reclamation (Babcock)
Daspoort Sewage Works, Pretoria	1989	Thickening of sewage sludge (Biwater)
Centurion Sewage Works, Pretoria	1989	Thickening of sewage sludge (Biwater)
Unilever	1990	500 m3/d plant oil treatment & recovery (Explochem)
Fishwater Flats	1993	7.8 Ml/d secondary sewage effluent reclamation (Explochem)
Sappi, Stanger	1993	3.6 Ml/d paper effluent treatment plant (Explochem)
Taiwan fisheries DAF	1993	700 m3/d oily water treatment (Explochem)
Packo	1994	500 m3/d food processing effluent (Explochem)
Mauritius Laundry	1994	600 m3/d laundry water treatment & reclamation (Explochem)
Belgotex	1994	620 m3/d textile effluent treatment (Explochem)
SADAFCO, Jeddah, Saudi Arabia	1994	600 m3/d dairy effluent treatment plant (Explochem)
SADAFCO, Jeddah, Saudi Arabia	1994	500 m3/d dairy effluent treatment plant (Explochem)
Unilever, Malawi	1994	1 Ml/d plant oil effluent treatment (Explochem)
Unilever, Kenia	1994	2.1 Ml/d plant oil effluent treatment (Explochem)
Zambia Dairies, Zambia	1994	600 m3/d dairy effluent treatment (Explochem)
DV Harris, Umgeni Water	1995	30 Ml/d drinking water treatment from eutrophic source  (plant ran successfully but source since changed to avert the use of activated carbon and plant not in use any more)
Wiggins, Umgeni Water	1995	5 Ml/d water works sludge thickening (Explochem)
Kriel Power Station, ESKOM	1995	6 Ml/d treatment of cooling tower blow-down water (Explochem)
Dyehouse effluent	1996	1.8 Ml/d dye house effluent treatment (Explochem)
Vridi	1996	650 m3/d oily water treatment (Explochem)
Umbilo Sewage Works	1997	900 m3/d sewage sludge thickening plant upgrade (Treffry-Goatley & Assoc)
Oily water, Talbot & Talbot	1997	5.4 Ml/d oily water treatment plant (Talbot & Talbot)
Temba Sewage Works, Pretoria	1998	2.6 Ml/d thickening of sewage sludge (Lektratek Water)
Wastewater reclamation, Foster-Wheeler	2002	650 m3/d wastewater reclamation plant (Foster-Wheeler)
Bench DAF	2003	Design of a bench unit for DAF evaluation studies (Improchem)
Pilot DAF	2004	Design of a 1 m3/h DAFF (DAF on top of a sand filter) pilot plant for general pilot studies (Improchem)
Sappi, Mandini	2004	425 m3/d treatment of paper effluent part-stream (Lektratek)
Rainbow Chicken	2004	200 m3/d chicken processing plant effluent treatment (Total Water Management)
SAPREF	2004	4.5 Ml/d oil removal and recovery plant (Improchem)
Plettenberg Bay, Bitou Mun	2005	15 Ml/d DAF for drinking water treatment
Caltex	2005	2.4 Ml/d petroleum wastewater treatment plant (Improchem)
Roodeplaat,Tshwane	2007	600 m3/d eutrophic water treatment plant (Purion)
Pilot DAF	2014	20 m3/d DAFF (DAF on top of a sand filter) pilot plant for general pilot studies (Explochem)
Oily water DAF, SOIL, Swellendam	2015	72 m3/d effluent treatment plant for oil removal (Alveo).
DAF system for SPP Canning, Hermanus	2015	120 m3/d effluent abalone effluent treatment plant (Sustainable Engineering)
Oakland Dairy, Cape Town	2015	120 m3/d dairy wastewater treatment (Sustainable Engineering)
Dairy effluent DAF	2016	Renovation and upgrade of a 600 m3/d dairy effluent treatment plant (Dairy Day)
Pearly Beach DAF	2017	960 m3/d high-rate lamella DAF for pre-treatment to membranes for drinking water Ikusasa Water)
Plastics effluent DAF	2018	300 m3/d DAF for the treatment of a plastics recovery effluent (Alveo Water)
Laundry DAF	2019	300 m3/d DAF for the pre-treatment of a laundry effluent before UF & RO (Kainos Africa (Pty) Ltd)
Meulwater DAFF	2019	8.3 Ml/d DAFF plant for drinking water treatment at Drakenstein Municipality (Aurecon)
Laundry DAF	2019	280 m3/d DAF for the pre-treatment of a laundry effluent before UF & RO (Coral Clean, Cape Town)
Pioneer Foods DAF	2019	120 m3/d DAF system for fruit processing effluent treatment. (Kainos Africa (Pty) Ltd)
Bush Valley Chickens DAF	2019	Renovation and upgrade of a 1 Ml/d chicken effluent treatment plant (International Water Technologies)
Distillery effluent DAF	2020	2.5 Ml/d lamella DAF plant for the treatment of effluent from a biological treatment plant for distillery effluent (Tecroveer)
County Fair Chickens	2020	25 m3/h DAF plant for the recovery of by-products from chicken processing effluent (Tesla Water)
Meerlust drinking water DAF	2021	4 m3/h DAF plant plant for the treatment of algal dam water to drinking water (Utico Water)
Algae water DAF	2021	240 m3/d Econo-DAF plant plant for the treatment of algal dam water to drinking water (PCM Consulting)
Pepsico chip effluent DAF	2022	340 m3/d DAF plant for the treatment of chip-making effluent (Talbot)
In2Food, Benoni, effluent	2022	85 m3/d Econo-DAF plant for the treatment of food effluent (BB Water)
Ink effluent DAF	2022	5 m3/d  Econo-DAF plant for ink effluent treatment (Brenton Water)
CBH Chicken abattoir product recovery DAF	2022	1 440 m3/d DAF Econo-DAF system for the recovery of fat and proteins from a chicken abattoir effluent (Superior Systems)
Twinsaver sec sewage purification DAF	2023	1 400 m3/d Econo-DAF system for the pre-treatment of secondary sewage effluent before membranes (AECI Water)
Harmony DAF	2023	1 800 m3/d Econo-DAF system for the treatment of surface water  for mining process water use (AECI Water)
Kelloggs effluent treatment DAF	2023	120 m3/d Econo-DAF system for the treatment of wastewater from the Kelloggs, Extrupet, plan (Chemal Chemical Trading)
Food effluent DAF	2023	50 m3/d Econo-DAF system for the treatment of a food effluent (G-Chem Aquacare)
Gymnasium effluent water DAF	2024	72 m3/d DAF system for the treatment of Gym effluent (WEC Projects)
DAF for surface water treatment for irrigation	2024	680 m3/d Econo-DAF system for the treatment of surface water for vegetable production (Heat Exchange Projects, Namibia)
DAF for surface water treatment for irrigation	2024	860 m3/d Econo-DAF system for the treatment of surface water for vegetable production (Heat Exchange Projects, Namibia)
Avocado processing effluent DAF	2024	220 m3/d Econo-DAF system for the treatment of avocado processing effluent (The Water Boys)
Fish processing effluent DAF	2025	1 400 m3/d Econo-DAF system for the treatment of fish processing effluent and valuable product recovery (Pioneer Fishing)

EMPLOYMENT RECORD

2008- Present: GO Water Management

General consulting work, trading as GO Water Management. Specialising in Dissolved Air Flotation and membrane related projects. Up to a two years ago involved with Ikusasa Water on a part-time basis to promote South African-developed ultrafiltration membranes for rural water supply, as well as in the general application of membranes. Specialising in water reclamation and water, mining water & industrial effluent treatment using DAF and membranes. Performing of general water, water reclamation, mine water and effluent related projects as an independent consultant. Involved with water treatment personnel training, the improvement of drinking water supply and the achievement of Blue Drop status in a number of rural towns in the Western Cape and the Free State. Assisting with, and examining of, post-graduate students and their theses.

1989- 2008: Water Research Commission:

Funding and management of research projects in the fields of drinking water, municipal waste water and industrial effluents. More than 100 projects were finalised in this period.

Development and use of decision support systems. Performing of strategic planning.

Process design of dissolved air flotation plants and solving of water treatment problems.

Liaison with international organisations through the Global Water Research Coalition and “Emerging Technologies” with the AWWA Research Foundation. The focus areas were water purification and water reclamation. Involved in compiling the latest WateReuse Foundation Report Direct Potable Reuse – the way forward, Tchobanoglous et al. Involved with WHO in establishing Water Safety Plans as tool for improved drinking water supply.


1982-1988-Division of Water Technology, CSIR:

Development of water-related products for and in conjunction with outside clients. Most of these activities revolved around the CSIR processes for Acid Mine Drainage treatment.

Execution of water and effluent treatment projects and general water treatment development work, with specialization in Dissolved Air Flotation development and process design.

Execution of mining and industrial water management projects for industry. More than 60 projects were undertaken during this period.

1978-1982: Chemical Engineering Research Group, CSIR:

Computer-aided design of heat exchangers for industry.

Purchase, adaptation and maintenance of overseas heat exchanger and process design programmes. General chemical engineering projects for outside clients.

1973-1978: Uranium Enrichment Corporation:

Commissioning and operation of pilot uranium enrichment plants.

Writing of the commissioning handbook for the uranium enrichment demonstration plant.

Commissioning, and later operation, of the feed, waste and hydrogen plants as well as half of the enrichment capacity of the uranium enrichment plant.

1971-1973: SASOL oil-from-coal plant:

Material balances; plant optimisation studies; design of heat exchangers and pumping systems on the Phenosolvan, Nitrogen and Water and Effluent plants at SASOL I.

Member of the design team with Lurgi, responsible for process design of the El Paso and Panhandle oil-from-coal plants, Texas.


PUBLICATIONS AND REPORTS

Below is a list of reports and publications concerning a variety of water and effluent treatment, strategic planning and decision making papers since becoming involved with water and wastewater management:

1. Offringa G and Prinsloo J (1982) Removal of suspended solids in final effluent at Sappi Kraft Paper Mill, Mandini. NIWR Con¬tract Report, Pretoria, November

2. Offringa G (1983) Treatment of Rustenburg Platinum Mine Process Water. NIWR Interim Report, Pretoria, January

3. Offringa G, van Vuuren LRJ and Carstens P-A du T (1983) The water supply and effluent situation at Da Gama Textile Company (Pty) Ltd, East London, during 1982/83 and proposals to reduce water intake and effluent pollution load. NIWR Progress Report No. 4, Pretoria, April

4. Offringa G (1983) Reuse of Dekama treated municipal wastewater by Scaw Metals Limited. NIWR Contract Report, Pretoria, April

5. Offringa G (1983) Preliminary investigations into biological growth in tailing dams underdrains at Bafokeng, Impala Platinum Limited, NIWR Contract Report, Pretoria, April

6. Offringa G and Turner J (1983) Treatment of seawater at Alusaf. NIWR Contract Report, June

7. Offringa G (1983) Corrosion inhibition of PM4 and PM5 vacuum pump sealing water system at Mondi Paper Company Limited, Merebank. NIWR Contract Report, Pretoria, July

8. Offringa G and de Fanti R (1983) The water supply and effluent situation at Mondi Paper Company Ltd, Merebank, Durban. NIWR Progress Report No. 14, Pretoria, August

9. Van Vuuren LRJ and Offringa G (1983) Effluent treatment and water reuse in die pulp and paper industry. Paper presented at Seminar: Water Conservation. Northern Transvaal Chamber of In¬dustries, Pretoria, 18 August

10. Offringa G (1983) The water supply and effluent situation at Mondi Board Mills, Springs, and recommended approach to alleviate some problems experienced. NIWR Progress Report No. 5. Pretoria, October

11. Offringa G, Scheepers J and van Vuuren LRJ (1983) Dissolved air flotation pilot test runs on Rotofloc overflow at Mondi Board Mills, Felixton. NIWR Contract Report, Pretoria, October

12. Offringa G, van Vuuren LRJ, Ross WR, Airey DD and Connell AD (1983) Abatement of environmental pollution of final effluent from Mondi Board Mills, Felixton. NIWR Draft Contract Report, Pretoria, October

13. Offringa G and Vennekens MJA (1983) Treatment of effluent at Mondi Timber Mills, Sabie. NIWR Status Report, December

14. Offringa G and Botha GR (1984) Proposed new system for water savings on the cucumber washing line for Irvin and Johnson Ltd, Benrose. NIWR Project Report, January

15. Offringa G (1984) Water and effluent management by Mondi Board Mills, Bellville. NIWR progress Report, January

16. Offringa G (1984) Water and effluent management by Mondi Board Mills, Umgeni. NIWR progress Report, January

17. Offringa G (1984) Treatment of Rustenburg Platinum mine water. Paper delivered at the Water Symposium, Rustenburg Platinum Mine, 8 February

18. Offringa G (1984) Dissolved air flotation trials at Sappi Cape Kraft (Pty) Ltd, Milnerton. NIWR contract Report, February

19. De Vries PM van Wyk, Vennekens M, Carstens P-A du T, Offringa G (1984). Investigation into the reclamation of sewage and mine water at Kloof Mine, Gold Fields of South Africa Ltd. NIWR contract Report, February

20. Offringa G, van Vuuren LRJ and Render D (1984) Survey of effluent systems at Da Gama Textile Company (Ltd), East London. NIWR contract Report, March

21. Offringa G, van Vuuren LRJ, Ross WR, Airey DD and Connell AD (1984) Abatement of environmental pollution of final effluent from Mondi Board Mills, Felixton, NIWR Final Contract Report, Pretoria, March

22. Offringa G (1984) Comments on the Karper Engineering Ltd. Report: Jan Tshatshu and Makalaka study. NIWR project Report, September

23. Offringa G (1984) Dissolved air flotation in water treatment. Paper delivered at the NIWR/IWPC/WRC Symposium on Purification and Distribution of Water, Pretoria, 18 October

24. Offringa G and De Fanti R (1984) The water supply and effluent situation at Mondi Paper Company Limited, Merebank, Durban. NIWR Progress Report No. 15, Pretoria, July

25. Offringa G, Van Vuuren LRJ, Carstens PA du T and Iles T (1984) The water supply and effluent situation at Da Gama Tex¬tile Company (Pty) Ltd., East London, during 1983/1984 and proposals to reduce water intake and effluent pollution load. NIWR Progress Report No. 15, Pretoria, July

26. Vennekens MJA and Offringa G (1985) Treatment of effluent at Mondi Saw Mills, Northern Mill, Graskop. NIWR Progress Report No. 2. January

27. Offringa G, Vennekens MJA and Carstens P-A du T (1985) Reuse of Diepsloot secondary effluent as make-up water in the UCOR cooling water system. NIWR Contract Report. March

28. Offringa G (1985) Survey of the effluent system at Da Gama Textile Company (Ltd), East London. NIWR Status Report. March

29. Offringa G, Vennekens MJA, Scheepers JA and Carstens P-A du T (1985) UCOR: Treatment of final effluent. NIWR Contract Report. June

30. Offringa G, Vennekens MJA, Carstens P-A du T and Iles T (1985) The water supply and effluent situation at Da Gama Textile Company (Pty) Ltd, East London, during 1984/85 and Proposals to reduce water intake and effluent pollution load. NIWR Progress Report No. 6. May

31. Offringa G (1985) Dissolved air flotation treatment of final effluent from three South African Board Mills. Paper presented at the Symposium Forest Products Research International - Achieve¬ments and the Future, Pretoria, 22-26 April

32. Van Vuuren LRJ, Offringa G and Williams PG (1985) Development and application of DAF technology in South Africa. The Institute of Water Pollution Control Year Book 1985

33. Offringa G, Vennekens MJA and de Fanti (1985) The water supply and effluent situation at Mondi Paper Company Limited, Merebank, Durban. NIWR Progress Report No.17. July

34. Offringa G and Van Vuuren LRJ (1985) Conversion of the existing Mondi Board Mills, Felixton effluent treatment plant into a 2 Ml/d water treatment plant. NIWR Project Report. October

35. Brabyn NR, Smith EJ, Davies CJ, Bindoff AL, GrovesGR and Offringa G (1985) Technical performance evaluation of treatment processes for the recycling of paper machine wastewater. Paper presented at Symposium Forest Products Research Interna¬tional Achievements and the Future, Pretoria, 22-26 April.

36. Van Steenderen RA and Offringa G (1985) Chemical survey of the Ngagane catchment area and the Iscor Newcastle water purifica¬tion works. NIWR Project Report. October

37. Offringa G and Scheepers JA (1985) Removal of algae by dissolved air flotation at Swartwater Dam, Qwaqwa. NIWR Contract Report. November

38. Offringa G (1985) Dissolved air flotation treatment of final effluent from three South African board mills. Paper Southern Africa, 6(1)

39. Offringa G and Vennekens MJA (1985) Evaluation of the effluent treatment plant at Mooi River Textiles. NIWR Contract Report. February

40. Offringa G, Vennekens MJA, Carstens P-A du T, de Fanti R and Orbin AE (1986) The water supply and effluent situation at Mondi Paper Company Limited, Merebank, Durban. NIWR Progress Report No. 18, Pretoria, February

41. Offringa G and Coopmans EJA (1986) Phosphate removal from Johannesburg northern sewage works` secondary effluent by dis¬solved air flotation. Municipal Engineer, 17(5), 19-25

42. Offringa G, Vennekens MJA, Botha A, Carstens P-A du T and Schoonbee A (1986) Upgrading of the SAPPI, Enstra dissolved air flotation plant from 20 Ml/d to 30 Ml/d. NIWR Contract Report. August

43. Offringa G, Botha A, Schutte IB and Schoonbee A (1986) Pretreatment of Iscor, Pretoria, effluent by dissolved air flota¬tion. NIWR Contract Report. October

44. Offringa G, Le Roux JD, Botha A and Van Steenderen RA (1987) NIWN-ondersoeke : Vaalkopskema, WNNR Statusverslag, Pretoria, NIWN, Januarie

45. Offringa G and Carstens P-A du T (1987) The potential use of coal ash in structured reed beds for effluent treatment. Paper presented at International Symposium Ash - a valuable resource, Pretoria, 2-6 February


46. Offringa G, Vennekens MJA, De Villiers HA and Botha A (1987) Dissolved air flotation studies in the pulp and paper in¬dustry. Presented at the Biennial IWPC Conference, Port Elizabeth, 12 to 15 May

47. Heymann JB, Offringa G, Van Steenderen RA and Botha A. (1987) Treatment of effluent from the Karbochem, Newcastle, syn¬thetic rubber plant. CSIR Contract Report, Pretoria, NIWR. March

48. Offringa G, Vennekens MJA, Schoonbee A, De Fanti R and Orbin A (1987) The water supply and effluent situation at Mondi Paper Company Limited. Merebank, Durban, NIWR progress Report No. 21. March

49. Van Vuuren LRJ, Offringa G, Le Roux JD and Van Steenderen RA (1987) NIWN-ondersoek : Vaalkop- waterskema, WNNR Statusverslag No. 2, Pretoria, NIWN, April

50. Offringa G and Van Vuuren LRJ (1987) Treatment of eutrophic water. Paper presented at Simposium Hartbeespoort Dam Quo vadis?, Pretoria, September 1

51. Offringa G (1988) The control of microbiological growth in heat exchange systems. CHEMSA, 14(5), 145-147

52. Offringa G (1988) Die ingenieur in diens van die waternywerheid. Archimedes 30(4), 16-18

53. Botha A, Offringa G and Whyte D (1989) Development of an integrated flocculation system specifically aimed at batch water treatment systems for small users. CHEMSA, 15(3), 91-95

54. Offringa G (1990) Treatment of eutrophic waters in South Africa. SA J. of Science, 86(1), pp.6-8

55. Offringa G (1992) Strategic Plan for Research on Potable Water in South Africa. Water Research Commission, Pretoria, South Africa

56. Gehr R, Swartz C and Offringa G (1993) Removal of trihalomethane precursors from eutrophic water by dissolved air flotation. Wat. Res., 27(1), pp 41-49

57. Offringa G (1994) Dissolved Air Flotation in Southern Africa. Paper presented at IAWQ - IWSA - AWWA - Joint Specialized Conference on Flotation Processes in Water and Sludge Treatment, Orlando, Florida, USA, 26-28 April

58. Offringa G (1996) A Decision Support Model for the Determination of Water Research Priorities. PhD Thesis, University of Pretoria, Pretoria, South Africa

59. Offringa G and De Wet G. (1996) A Quality of Life-based Decision Support Model for the Determination of Water Research Priorities. Water SA, 22 (4), pp359 - 372

60. Offringa G (2000) Membrane Development in South Africa. Membrane Technology, 119, pp 4-7

61. Offringa G (2004) Water Supply in South Africa – formidable challenges and innovative solutions. Presented at The 2nd International Implementation Conference on Safe Water for Improving Health, Gallagher Estate, 4-7 November

62. Offringa G, Mjoli N, Venter SN, Kfir R and Moolman A (2007) A New Strategic Framework for Water-related Health Research. Water SA, 33 (5), pp589 - 592

63. Offringa G and Swartz CD (2009) A Review of Water Treatment Processes Applicable for Rural and Community Water Supply in South Africa. Internal Report for Overberg Water/Masimbambane, March

64. Offringa G (2009) Report on the treatment of spent grain centrate at Sedgwick Distillery. Internal Report to Distell, June

65. Offringa G (2009) UF Solution to Rural Water Supplies? Desalination & Water Reuse, 1914, pp 26 – 29

66. Offringa G and Schmollgruber E (2011) Close-out report for the Alexandria wastewater reclamation works. Report to the Ndlambe Local Municipality

67. Offringa G, Theron D and Linnert W (2011) Ensuring Blue Drop water quality with the use of membrane ultra-filtration technology. Presented at the 3rd Municipal Water Quality Conference, Cape Town International Convention Centre, 27 June – 1 July

68. Momba MNB, Offringa G, Nameni G, Brouckaert B (2010) Nanotechnology-based clay filter pot to purify water in rural homes. Research Report No KV 244/10, Water Research Commission, Pretoria

69. Mwabi JK, Adeyemo FE, Mahlango TO, Mamba BB, Brouckaert BM, Swartz, CD, Offringa G, Mpenyana-Monyatsi L and Momba MNB (2011) Household water treatment systems: A solution to the production of safe drinking water by the low-income communities of Southern Africa. Physics and Chemistry of the Earth 36 pp1120–1128

70. Offringa G (2012) Concluding Report on Water Quality and Membrane Fouling Problems Experienced at The Biovac Institute. Internal report. The Biovac Institute, Cape Town

71. Offringa G, Victor N, Victor S, September C and Goldie I (2013) Report on Membrane Concentration of Tea Extract. Internal Report. Ikusasa Water and CSIR, Cape Town

72. Momba MNB, Mwabi JK, Brouckaert BM, Swartz C, Offringa G and Rugimbana RO (2013) South African Guidelines for the Selection and Use of Appropriate Home Water Treatment Systems by Rural Households. Research Report No TT 580/13, Water Research Commission, Pretoria

73. Momba MNB, Mwabi JK, Mamba, BB, Brouckaert BM, Swartz C, Offringa G and Rugimbana RO (2013) Selection and Use of Home Water Treatment Systems and Devices. Research Report No 1884/1/13, Water Research Commission, Pretoria

74. Offringa G (2014) Final Report on Copper Tube Pit Corrosion in the Mossel Bay Area. Internal report to the Mossel Bay Municipality.

75. Offringa G (2015) Process design of a DAF system for canola oil effluent treatment. Design and report to Sustainable Engineering, Somerset West

76. Offringa G and Van Schoor P (2016) Pilot plant trials to assess the feasibility of biological iron and manganese removal for the provision of potable water to the Kouga Municipality. Report to Kouga Municipality.

77. Offringa G (2016) Design of a Dissolved Air Flotation/Filtration system for the modification of the Meulwater drinking water treatment works. Report to Aurecon, Cape Town.

78. Offringa G (2016) Recommendations to make the 150 m3/d Rainbow Chicken DAF Plant, Hammersdale, fully operational again. Report to Improchem.

79. Offringa G (2017) Reuse of seepage water for toilets in the building at 9, Dorp Street, Cape Town. Report to B.N. Buziba & Associates, Cape Town.

80. Offringa G (2017) Process design of a 180 m3/h Dissolved Air Flotation system for drinking water treatment. Report to Waterskills SA, Pretoria.

81. Offringa G (2017) Design of a 840 m3/d biotower stripping system for the removal of hydrogen sulphide from ground water. Report to Water & Pump Solutions, Port Elizabeth.

81. Offringa G (2018) Process design of of a 200 Ml/d DAF system as pre-treatment for membrane seawater desalination. Report to Aveng Water, Johannesburg

82. Offringa G (2018) Process design of a 380 m3/d Dissolved Air Flotation system as pretreatment for the membrane treatment and reuse of laundry effluent. Report to Ikusasa Water, Somerset West

83. Offringa G (2020) Report with recommendations to make the 150 m³/h Rainbow Chicken DAF plant, Hammarsdale, fully operational again. Report to Tecroceer, Johannesburg
 

84. Offringa G (2020) Report with recommendations to rectify and upgrade five DAF plants at four fish processing plants in Walvis Bay, Namibia. Report to Heat Exchange Products, Water treatment, Windhoek.

85. Offringa G (2021) Report with recommendations to rectify and upgrade the 22 m³/h chicken abattoir effluent treatment system at Swazi Poultry Processing, Matsapha, Swaziland. Report to International Water Technologies, Pretoria

86. Offringa G (2023) Report on the assessment and recommendations for the renovation and improvement of the 5 Ml/d Amawandle Pelagic Fisheries Dissolved Air Flotation (DAF) effluent treatment plant

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