From the Proceedings of the 1974 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 19-20, 1974, Flagstaff, Arizona / An examination of potential water sources for power plant cooling in Arizona is presented along with information pertinent to Arizona's future water needs relative to electrical usage growth. It has been projected that Arizona's peak electrical power demands in 1980 and 1990 will exceed that of 1970 by some 5000 megawatts and 16000 megawatts of electricity respectively. At present, the bulk of the electrical energy generated in the western states originates at hydroelectric installations. Utilization of nuclear reactors for power generation requires a larger amount of cooling water than is required for a comparable fossil-fueled plant. It is suggested that the utilization of reclaimed wastewater for cooling purposes is a viable and attractive alternative to groundwater pumpage from both economic and ecological standpoints. Savings arise from conservation of fuel normally required for well pumps, costs of well construction are not required, quantities of fresh water should be released for consumption by alternate users, and a previously unused resource would be effectively recycled.

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / Intensive strip and leach mining activity within a confined region usually causes environmental impacts both on the land and on water quality. Adverse water quality effects could be realized long after any mining activity has ceased due to the continuous leaching by precipitation of contaminants from spoils piles and leach dumps. The Miami, Arizona region is unique in its surface and subsurface hydrology. Two unconnected aquifers underlay the region with both serving as domestic (private and municipal) and industrial (mining) supply sources. The shallow floodplain alluvial aquifer is hydraulically connected to surface drainage from mine tailings and leach dumps. Several wells drawing from this aquifer have been abandoned as a municipal supply source due to severe water quality degradation. Water quality in these wells varies directly with precipitation indicating a correlation between surface drainage over and through tailings and leach piles. Expansion of spoils dumps into natural recharge pathways of the deeper Gila Conglomerate aquifer has raised concern that this aquifer may also be subjected to a long term influx of mine pollutants. Questions have also been raised concerning the potential effects of a proposed in situ leaching operation on the water quality of the conglomerate aquifer.

Thesis submitted in the requirements for the degree Doctor Technologiae: Chemical Engineering in the Faculty of Engineering at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY, 2013 / To date, limited information has been published on textile wastewater treatment, for re-use, in South Africa (SA), with treatment processes focusing on conventional wastewater treatment methods. A large contributor to the contamination of water within textile industries is from dyehouse processes. A major concern in textile wastewater treatment is the release of azo dyes and their metabolites, some of which are carcinogenic and mutanogenic, into the environment since they are xenobiotic and aerobically recalcitrant to biodegradation. A necessity therefore exists to find an effective treatment method capable of removing both the strong colour and the toxic organic compounds from textile wastewater. Membrane bioreactors (MBRs) are favoured when treating high-strength wastewater, since the membrane area is determined by the hydraulic throughput and not the biological load; no sludge is wasted and all bacteria are retained within the reactor, including specific bacteria capable of degrading the toxic, non-biodegradable constituents present in textile wastewater. MBR systems, using various configurations have been utilised extensively in the rest of the world to treat textile wastewater at both lab and pilot-scale. This DTech project formed part of a collaborative Water Research Commission (WRC) funded project K5/1900 - Pilot application of a dual-stage membrane bioreactor (dsMBR) for industrial wastewater treatment. The main purpose of this study was the on-site evaluation of a pilot-scale dsMBR incorporating two ultrafiltration (UF) sidestream membrane modules for the treatment, recovery and re-use of textile wastewater. The objectives of this project were to determine the treatment efficiency of the system; to evaluate the degree of colour removal from the textile wastewater; to improve residual colour removal within the system using treatment processes, such as NF and RO, as well as to propose a design and cost for a full-scale plant. A textile industry located in Bellville, Western Cape, was chosen as the industrial partner for the on-site evaluation of a semi-automated pilot wastewater treatment MBR plant using two 5.1 m2 Norit X-flow AirliftTM membrane modules. Since the wastewater treatment system was located on the premises, real continuously changing industrial wastewater was being treated. The industrial textile wastewater was treated in a series of tanks: 1) an anaerobic tank, which cleaved the azo bonds of the reactive dyes; 2) an anoxic tank containing reduced amounts of dissolved oxygen, in which denitrification occurred; and 3) an aerobic tank, in which i) nitrification, as well as ii) mineralisation of the aromatic amines occurred. The UF-membrane modules would account for the removal of any organic material. The wastewater stream was characterised by a chemical oxygen demand (COD) range of between 45 to 2,820 mg/L and an average biological oxygen demand (BOD) of 192.5 mg/L. The dsMBR achieved an average COD reduction of 75% with a maximum of 97% over the 220 day test period. The COD concentration obtained after dsMBR treatment averaged at 191 mg/L, which was well within the City of Cape Town industrial wastewater discharge standard. The average reduction in turbidity and TSS was 94% and 19.6%, respectively, during the UF-MBR stage of the system. Subsequent treatment of the UF permeate with nanofiltration (NF) for 4 days, alternated with reverse osmosis (RO) for 14 days removed both the residual colour and salt present in the UF permeate. A consistent reduction in the colour of the incoming wastewater was evident. The colour in the wastewater was reduced from an average of 659 ADMI units to ~12 ADMI units in the NF permeate, a lower American dye manufacturing index (ADMI) (i.e. method of colour representation) compared to the potable water (~17 ADMI units) utilised by the industrial partner in their dyeing processes. The colour was reduced from an average of 659 to ~20 ADMI units in the RO permeate, a lower ADMI and therefore colour when compared to the potable water. An average conductivity rejection of 91% was achieved with conductivity being reduced from an average of 7,700 to 693 μS/cm and the TDS reduced from an average of 5,700 to 473 mg/L, which facilitated an average TDS rejection of 92%. Based on the composition of the UF permeate fed to the RO membrane a maximum removal of 98.7% was achieved for both conductivity and total dissolved solids (TDS). The proposed full-scale plant would incorporate a UF-MBR system, followed by NF, RO, flocculation and a filter press. Therefore, the two waste products produced during operation of the proposed full-scale plant, would be the solid filter cakes and the liquid filtrate from the filter press. Implementing the proposed full-scale plant it would cost the industrial partner an operating cost of ZAR 113.85 and ZAR 3,415.49 to treat 97.1 m3 and 2,913 m3 of textile wastewater, respectively, per day and per month. This results in an annual saving of ZAR 845,848 on potable water expenses. This research, would provide SA textile industries, with an option to: 1) reduce their water consumption, thereby utilising less of a valuable decreasing commodity; 2) meet the SA government discharge standards and reduce their discharge costs; 3) reduce their carbon footprint (i.e. reduce their impact on the environment) by re-using their treated wastewater and therefore using less water from the municipality; and 4) decrease their annual expenditure on water, since the treated wastewater would be available for re-use.

The access of water globally is becoming more strained, why the focus on industrial water use is increasing. The present study examined how industries should approach water efficiency projects, what organizational constraints that should be addressed, and what effects water saving measures have on economic costs, environmental impact and influence from water related risks. The study has been conducted at Saab Group. Primary data for water supply amount and cost has been obtained from twelve sites for the year of 2018. Data from these sites has been used to estimate the water use for the other 43 sites included in this study. Interviews with employees across Saab´s organization and with external stakeholders have functioned as important sources of information, combined with investigations of internal company documents. To facilitate for companies to structurally address water efficiency projects, the concept of the Deming Cycle is developed in this study. The steps included are necessary to address major identified organizational constraints which are lack of communication, lack of incentives for employees, and lack of economic incentives. Furthermore, with water often having energy embedded into it, a new Water Management Hierarchy is developed to include the interrelated aspects of energy supply and energy recovery. The potential for pipe leakages and the challenge to detect these are also identified. If the time from leak occurrence to repair in 2018 was eliminated, the total water supply in Arboga could have been reduced with 10100 m3 which corresponds to 35% of total supply to the site, respectively 35900 m3 and 42% in Björkborn. In Tannefors, water saving measures are identified for a surface treatment process, a facility with testing equipment, and by utilization of groundwater. Not all water saving measures result in reduced annual operating costs, due to an increased energy demand. Furthermore, if neglecting the possibility of energy recovery when aiming for water use reduction, the results show that replacing a once-through cooling system using potable municipal water as a medium with a dry-cooling unit, can increase greenhouse gas emissions. In 2018, the simultaneously implementable water saving measures in Tannefors would have reduced the water supply with 40600 m3, which corresponds to 22% of the total supply to the site. The greenhouse gas emissions would simultaneously have been reduced with 0.4 tonnes CO2eq. If also addressing energy supply reduction and energy recovery, some measures achieves a reduction of over 35 tonnes CO2eq, which results in enhanced economic viability from reduced operating costs. This study suggest that organizational constraints have to be addressed to successfully implement identified water saving measures. To allow economic motivation for all water saving measures in Tannefors, a payback period of over 7 years has to be applied, which can be lowered if the measure also reduces energy demand or increases energy recovery. In order to avoid sub-optimization of water saving measures, the current Water Management Hierarchy has to include the aspects of energy supply and energy recovery. If the aim is to reduce a corporation’s water use, the largest sites with heavy industrial processes should be addressed first. However, the potential impact from water related risks at smaller sites should not be neglected, in order to ensure safe operations and avoid increased costs in the company´s supply chain. / Tillgången av vatten blir alltmer ansträngd globalt, varför fokus på industriell vattenanvändning ökar. Den här studien undersökte hur industrier bör förhålla sig till vatteneffektivitetsprojekt, vilka organisatoriska begränsningar som bör hanteras, och vilka effekter vattenbesparande åtgärder har på ekonomiska kostnader, miljöpåverkan och påverkan från vattenrelaterade risker. Studien har genomförts på Saab Group. Primärdata för vattentillförselmängd och kostnad har erhållits från tolv platser för år 2018. Data från dessa siter har används för att uppskatta vattenanvändningen för de övriga 43 siterna som ingår i denna studie. Intervjuer med anställda inom Saabs organisation och med externa intressenter har fungerat som viktiga informationskällor, i kombination med undersökningar av interna företagsdokument. För att underlätta för företag att strukturellt ta itu med vatteneffektivitetsprojekt, så utvecklas Demingcykel-konceptet i den här studien. De inkluderade stegen är nödvändiga för att hantera viktiga identifierade organisatoriska begränsningar som är brits på kommunikation, brist på incitament för anställda och brist på ekonomiska incitament. Vidare, då vatten ofta är en energibärare, utvecklas en ny vattenminskningshierarki för att inkludera de sammanhängande aspekterna av energitillförsel och energiåtervinning. Potentialen för rörläckage och utmaningen att upptäcka dessa identifieras också. Om tiden från läckage till reparation under 2018 eliminerades, kunde den totala vattentillförseln i Arboga ha minskat med 10100 m3 vilket motsvarar 35% av total vattentillförsel till siten, respektive 35900 m3 och 42% i Björkborn. I Tannefors identifieras vattenbesparingsåtgärder för en ytbehandlingsprocess, en anläggning med testutrustning, och genom utnyttjande av grundvatten. Alla vattenbesparande åtgärder resulterar inte i minskade årliga driftkostnader, på grund av ett ökat energibehov. Vidare, om möjligheten för energiåtervinning förbises när reducering av vattenanvändning är målet, visar resultaten att ersättningen av ett kylsystem som använder kommunalt dricksvatten utan recirkulering med en luftkyld enhet, att utsläppen av växthusgaser kan öka. Under 2018, så skulle de simultant implementerbara vattenbesparande åtgärderna i Tannefors ha minskat vattentillförseln med 40600 m3, vilket motsvarar 22% av den totala tillförseln till siten. Utsläppen av växthusgaser hade samtidigt minskats med 0.4 ton CO2eq. Om även energitillförsel och energiåtervinning tas i beaktande, uppnår vissa åtgärder en minskning på över 35 ton CO2eq, vilket resulterar i förbättrad ekonomisk lönsamhet från minskade driftkostnader. Denna studie föreslår att organisatoriska begränsningar måste hanteras för att framgångsrikt genomföra identifierade vattenbesparande åtgärder. För att möjliggöra ekonomisk motivering för alla vattenbesparande åtgärder i Tannefors, måste en återbetalningstid på över sju år tillämpas, vilken kan sänkas om åtgärden också minskar energibehovet eller ökar energiåtervinningen. För att undvika suboptimering av vattenbesparande åtgärder, måste den nuvarande vattenhierarkin inkludera aspekterna av energitillförsel och energiåtervinning. Om målet är att minska ett företags vattenanvändning, bör de största anläggningarna med tunga industriprocesser först adresseras. Dock bör den potentiella påverkan från vattenrelaterade risker på mindre siter inte försummas, för att säkerställa säker drift och undvika ökade kostnader i företagets värdekedja.

Cape Town, South Africa, falls within a winter rainfall region, making it difficult to assess the feasibility of rain- and stormwater harvesting. The reason for this is because the region’s high water demand period coincides with the low rainfall summer season, thereby limiting the availability of this alternative water resource when most needed. During this study, rainwater harvesting for toilet flushing purposes, collected from roof surfaces, was practically assessed by means of inserted flow meters at a pilot study site in Kommetjie, Cape Town. The combined and single system roof- and land surface runoff yields and savings of commercial buildings within the Kommetjie business area, were also theoretically assessed by making use of a mathematical roof- and land surface runoff model specifically developed during this study. The statistical testing of the hypotheses statements relating to the pre- and post-harvesting savings at the pilot study building, compared against the average actual municipal water usage, were performed. Hypotheses testing were also performed in order to compare the theoretical rain- and stormwater runoff yields for the commercial business area against the average actual municipal water consumption. The conclusions drawn from this study indicated that valuable potable water, as well as related financial savings, can be achieved within a winter rainfall region, thereby making rain- and stormwater harvesting a feasible option for commercial businesses in Cape Town. / Environmental Sciences / M.Sc. (Environmental Management)

Cape Town, South Africa, falls within a winter rainfall region, making it difficult to assess the feasibility of rain- and stormwater harvesting. The reason for this is because the region’s high water demand period coincides with the low rainfall summer season, thereby limiting the availability of this alternative water resource when most needed. During this study, rainwater harvesting for toilet flushing purposes, collected from roof surfaces, was practically assessed by means of inserted flow meters at a pilot study site in Kommetjie, Cape Town. The combined and single system roof- and land surface runoff yields and savings of commercial buildings within the Kommetjie business area, were also theoretically assessed by making use of a mathematical roof- and land surface runoff model specifically developed during this study. The statistical testing of the hypotheses statements relating to the pre- and post-harvesting savings at the pilot study building, compared against the average actual municipal water usage, were performed. Hypotheses testing were also performed in order to compare the theoretical rain- and stormwater runoff yields for the commercial business area against the average actual municipal water consumption. The conclusions drawn from this study indicated that valuable potable water, as well as related financial savings, can be achieved within a winter rainfall region, thereby making rain- and stormwater harvesting a feasible option for commercial businesses in Cape Town. / Environmental Sciences / M.Sc. (Environmental Management)