49 research outputs found
Water management at a base metals refinery
MSc Dissertation
Submitted to
School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, South Africa
12 August 2016Most mineral processing plants have high water requirements for their operational activities. These plants often function in an environment where water is becoming increasingly scarce. An increase in population will result in an increased demand for water, potentially beyond the limits of supply, and hence increased competition for the resource. In South Africa, Gauteng and the North West Province are likely to be first to experience a shortage of potable water.
The key to a sustainable future lies in understanding and utilising resources more efficiently. This holds especially for industries who seek to minimise water usage through better management of resources. The two tools used in this study are the Water Accounting Framework (WAF) and Water Footprinting (WF) method.
This research assisted a refinery in the North West Province understand its water usage and move towards operating in a more sustainable manner. Site water management was improved and the objective of this research fulfilled by:
(i) Surveying the potable water and the storm water systems with a view to assessing the current water accountability and determining methods to improve accountability;
(ii) Determining the water balance for the site and presenting it in the form of a water balance sheet;
(iii) Reporting water usage in accordance with the Minerals Council of Australia’s “Water Accounting Framework for the Minerals Industry”;
(iv) Calculating the water footprints of the refinery; and
(v) Evaluating the water usage at the refinery and identifying ways in which water savings could be achieved.
It was seen that the biggest consumer of water was the boilers and utilities section and the biggest loss of water was through evaporation. The refinery potable water requirement (2 280 m3/y) amounted to 0.16% of the daily water use for the Bojanala Platinum District. Four reports (outputs) were generated using the WAF. The four reports generated provide a
good indication of the movement of water into, out of and during a process. WFs were calculated for the process. The blue WF was calculated to be 832 363 m3 and the green WF was calculated to be 261 970 m3. The product WF was 43.9 m3/t of base metal produced. There was no grey WF as the site does not discharge polluted water.
This research provided an opportunity for the refinery to improve water efficiency onsite as well as improve reporting standards. Water usage was reported using global reporting tools to set a benchmark for the base metals industry.MT201
Application of the water footprinting method and water accounting framework to a base metal refining process
The key to a sustainable future lies in understanding and utilising resources more efficiently. This holds especially for industries that seek to minimise water usage through better management of resources. Most mineral processing plants have high water requirements, yet often function in an environment where water is becoming increasingly scarce. Further, an increase in population will result in an even greater demand for water, potentially beyond the limits of supply. This would lead to even greater competition for the resource. In South Africa, Gauteng and the North West Provinces are likely to be the first to experience a shortage of potable water. A base metals refinery in Rustenburg sought to understand and minimise its potable water usage, as well as report its usage using global tools and frameworks. The two tools used in this study were the Minerals Council of Australia’s ‘Water Accounting Framework for the Minerals Industry’ (WAF) and the Water Footprinting method (WF). The potable water and stormwater systems were surveyed to assess and determine methods to improve water accountability. Using information from the survey, monthly and yearly water balances were presented in the form of a water balance sheet. Using data from the water balance, an input-output and operational model were drawn up in accordance with the WAF. The WAF models assisted in reporting data in a universally consistent manner. Blue, green and grey WFs were calculated for the refinery and recommendations were made to achieve savings in water consumption.Keywords: water, base metals, water footprint, water accounting framewor
Reproductive knowledge and use of contraception among women with diabetes
Background. Poorly controlled diabetes is associated with poor maternal and fetal outcomes, yet many women become pregnant before establishing control. Reducing unintended pregnancies is a vital step towards improving perinatal and maternal morbidity and mortality.Objectives. To assess the reproductive knowledge and use of contraception in women of reproductive age attending diabetes outpatient clinics.Methods. A prospective descriptive study was conducted of women known to have diabetes, aged 18 - 45 years, attending the diabetic clinics at Groote Schuur Hospital or the local community health centres in Cape Town, South Africa. A questionnaire consisting of social, demographic and family details as well as contraceptive use and knowledge was administered.Results. Some common themes emerged, namely that 44.2% of the women with previous pregnancies had had unintended pregnancies, and that this was more common among single (58.8%) and younger women. Women with type 1 diabetes had better knowledge than those with type 2 diabetes of how pregnancy affects diabetes, but better knowledge did not translate to better contraception use. Despite the fact that 102 participants (88.7%) attended diabetes clinics two or more times a year, knowledge ofpregnancy- and reproductive health-related complications was limited, and only 30 participants (26.1%) had received advice on contraception at these clinics.Conclusion. Knowledge about the impact of diabetes on pregnancy and that of pregnancy on diabetes was suboptimal. We recommend that reproductive health services be included at the routine diabetes clinic visit
Regional trade in south Asia-impediments and the way forward
The paper sets out to suggest that regional trade between South Asia is quite low when compared to other regional blocks like NAFTA, EU 15, ASEAN, and MERCOUSER. The paper identifies non cooperation between India and Pakistan to be the main reason behind low trade in South Asia. The paper focuses on the pending trade issues between both countries that are preventing India and Pakistan to increase bilateral trade and economic cooperation. The first issue discussed in the paper is granting of MFN status to India by Pakistan. The paper finds that it is in the benefit of both countries if Pakistan gives MFN status to India. But before such a step is taken, it is essential that Pakistan moves from a positive list approach to a negative list approach. Pakistan can include industries like textiles in the negative list to prevent the flood of cheap Indian textiles. Once MFN status is granted to India, Pakistan would be able to raise more substantive issues, notably Indian NTBs, subsidies, and protective tariffs. Currently India practices various forms of NTBs against Pakistan. The visa restrictions and absence of financial services are the major NTBs. Such NTBs have prevented Pakistan to export more to India. Another trade issue highlighted in the paper is that of transit facility. India does not provide Pakistan a transit route to Nepal and Bhuttan. In contrast Pakistan has provided Afghanistan transit route to India, though Pakistan does not allow India a transit route to Afghanistan or beyond. The paper finds that there is a high risk of informal trade in case Pakistan provides India with the land route to Afghanistan through its territory. It is anticipated that most Indian exports to Afghanistan would be smuggled back into Pakistan affecting Pakistan’s local industry. The transit facility is by far the most complicated trade issue of the three. Though the paper concludes in favor of granting India MFN and against the imposition of NTBs, It only gives a conditional recommendation in favor of granting India transit route to Afghanistan in case India provides Pakistan transit route to Nepal and Bhuttan.Regional Trade Agreements, Barriers to Trade, WTO
Reproductive knowledge and use of contraception among women with diabetes
Background. Poorly controlled diabetes is associated with poor maternal and fetal outcomes, yet many women become pregnant before establishing control. Reducing unintended pregnancies is a vital step towards improving perinatal and maternal morbidity and mortality. Objectives. To assess the reproductive knowledge and use of contraception in women of reproductive age attending diabetes outpatient clinics. Methods. A prospective descriptive study was conducted of women known to have diabetes, aged 18 - 45 years, attending the diabetic clinics at Groote Schuur Hospital or the local community health centres in Cape Town, South Africa. A questionnaire consisting of social, demographic and family details as well as contraceptive use and knowledge was administered.Results. Some common themes emerged, namely that 44.2% of the women with previous pregnancies had had unintended pregnancies, and that this was more common among single (58.8%) and younger women. Women with type 1 diabetes had better knowledge than those with type 2 diabetes of how pregnancy affects diabetes, but better knowledge did not translate to better contraception use. Despite the fact that 102 participants (88.7%) attended diabetes clinics two or more times a year, knowledge of pregnancy- and reproductive health-related complications was limited, and only 30 participants (26.1%) had received advice on contraception at these clinics.Conclusion. Knowledge about the impact of diabetes on pregnancy and that of pregnancy on diabetes was suboptimal. We recommend that reproductive health services be included at the routine diabetes clinic visit.
Bacterial contamination of Saudi Arabian paper currency: A report from Al-Kharj
Background: Currency is a public support tool for exchange of commodity and services. It’s prevalent practice for acquiring bread to broast and bath to bed has connected all human being together irrespective of race and occupation. Currency notes along with their denomination values also carry pathogens if contaminated and will act as an agent for infection transference. Therefore the objective of this cross-sectional study was to assess the load microbial pathogens of paper currency collected in selected public places of Al-Kharj, Saudi Arabia.Methods: Currency notes under study were assessed through microbiological culture, microscopic and biochemical visualization techniques.Results: The results from this cross-sectional study suggested that lower the currency denominations higher was the microbial contaminations, frequency percentage was lower with higher isolations. Small eateries were the biggest source of contaminated currency from the ten selected centres. Percentage microorganism occurrence for Bacillus sp., Staphylococcus sp., Klebsiella sp. and E. coli was 56.84%, 25.03%, 13.40% and 04.71% respectively in all currency notes under study.Conclusions: The outcomes of this study revealed that currency notes can be a source for microbe transmission causing infectious diseases represent public health hazards to the community and individuals
Investigation of the viable role of oil sludge-derived activated carbon for oily wastewater remediation
A wide range of studies has been carried out to describe the equilibrium data of adsorption for the surface adsorption process. However, no extensive investigation has been carried out to evaluate the oil sludge based activated carbon surface adsorption. Therefore, the possibility of carbon active production using different oil sludges and consequently the adsorption mechanism of these kind of adsorbents is still unknown. In this study, a novel low-cost approach was introduced to synthesize the activated carbon using oil sludge applying a two-step process including carbonization and chemical activation. In this way, four different types of oil sludges were characterized and then applied to synthesize different carbon actives and their performance were investigated as an adsorbent. The results showed that all synthesized activated carbons, with about 6% ash and pH = 7 and the specific surface area of 110 m2/gr, have the ability to treatment of oily wastewater; which can be referred to the high carbon content (>80%). The iodine number and the efficiency of prepared activated carbon were obtained as 406.8 mg/g and 94%, respectively. The adsorption process was also studied at different process conditions such as temperature (308–338 K), pH value (3–9) and adsorbent amount (50–200 mg/L) to find the optimum condition for wastewater treatment. The results show that the pH value has an optimum in the adsorption rate (the maximum adsorption was measured at pH = 5) and the adsorption capacity can be reduced by increasing the temperature or decreasing the adsorbent amount. Moreover, three different adsorption isotherm models were applied, i.e., Langmuir, Temkin, and Freundlich isotherms; which the Langmuir equation was more suitable than others investigated isotherm models with R2 ≈ 0.999
Regional trade in south Asia-impediments and the way forward
The paper sets out to suggest that regional trade between South Asia is quite low when compared to other regional blocks like NAFTA, EU 15, ASEAN, and MERCOUSER. The paper identifies non cooperation between India and Pakistan to be the main reason behind low trade in South Asia. The paper focuses on the pending trade issues between both countries that are preventing India and Pakistan to increase bilateral trade and economic cooperation. The first issue discussed in the paper is granting of MFN status to India by Pakistan. The paper finds that it is in the benefit of both countries if Pakistan gives MFN status to India. But before such a step is taken, it is essential that Pakistan moves from a positive list approach to a negative list approach. Pakistan can include industries like textiles in the negative list to prevent the flood of cheap Indian textiles. Once MFN status is granted to India, Pakistan would be able to raise more substantive issues, notably Indian NTBs, subsidies, and protective tariffs. Currently India practices various forms of NTBs against Pakistan. The visa restrictions and absence of financial services are the major NTBs. Such NTBs have prevented Pakistan to export more to India. Another trade issue highlighted in the paper is that of transit facility. India does not provide Pakistan a transit route to Nepal and Bhuttan. In contrast Pakistan has provided Afghanistan transit route to India, though Pakistan does not allow India a transit route to Afghanistan or beyond. The paper finds that there is a high risk of informal trade in case Pakistan provides India with the land route to Afghanistan through its territory. It is anticipated that most Indian exports to Afghanistan would be smuggled back into Pakistan affecting Pakistan’s local industry. The transit facility is by far the most complicated trade issue of the three. Though the paper concludes in favor of granting India MFN and against the imposition of NTBs, It only gives a conditional recommendation in favor of granting India transit route to Afghanistan in case India provides Pakistan transit route to Nepal and Bhuttan