Evaluating greywater reuse potential for sustainable water resources management in Oman

This study aims to evaluate the potential of greywater availability in Muscat Governorate in the Sultanate of Oman, to establish a methodology for greywater quantity estimation, to test greywater quality in order to assess reuse potential, and to examine public acceptance for reuse.Total fresh water consumption and greywater generation from different household sources were measured by water meters in five selected households during summer and winter. Additionally, a survey was designed and conducted in five administrative areas of Muscat Governorate, with the objective of testing a methodology for estimating greywater generation potential in these areas. Collected data were compared with that used by the Ministry of Housing, Electricity and Water, Sultanate of Oman. The survey covered a total of 169 houses and 1,365 people. Greywater samples were collected and analyzed from showers, laundries, kitchens and sinks in some of these households to determine their water quality parameters. Statistical analysis results indicated that there is no significant variance in the total fresh water consumption between data used by the ministry and those measured and estimated during this study, highlighting the applicability of the tested method. The study concluded that the average per capita greywater generation rate is 151 Lpcd. Greywater production ranged from 80 to 83% of the total fresh water consumption and most of the greywater is generated from showers. Further, 55 to 57% of the greywater generated in a typical Omani household originated from the shower, 28 to 33% originated from the kitchen, 6 to 9% originated from laundry, and 5 to 7% originated from sink, which constitutes approximately 81% of the total fresh water consumption. The physical, chemical, and biological analyses of the grab samples revealed that greywater contains significant levels of suspended solids, inorganic constituents, total organic carbon, chemical and biochemical oxygen demands, total Coliforms and Escherichia Coliform bacteria. The public acceptance survey illustrated that approximately 76% of the respondents accepted the reuse of greywater for gardening, 53% for car washing and 66% for toilet flushing.     

Perception,knowledge and attitude towards environmental issues and management among residents of Al-Suwaiq Wilayat,Sultanate of Oman

The purpose of this study was to determine residents’ perception, knowledge and attitude towards environmental issues and management in the Al-Suwaiq Wilayat (administrative zone) of Al-Batinah North, Sultanate of Oman. For this purpose, a questionnaire was used with questions on issues related to environment and surveyed across 109 households in the Wilayat following a random sampling method in early 2015. The results show that education, health-related infrastructure and unemployment are ranked as most important issues for government attention today and in coming 10 years besides their concern for the environment. Resident’s perceptions on most important environmental issues were concerned about solid-waste pollution, degradation of coastal areas, saltwater intrusion and land degradation. The sources for environmental information, government agencies, local media and schools were regarded as most reliable. Top environmental priorities were suggested to deal with enforcement of regulations, provide effective environmental awareness and education programs. Further, it is suggested that additional studies should be conducted such as ‘State of Environment Reporting’, thereby such reporting, for instance would provide some form of verification of reported behaviour and improved knowledge.     

Risk assessment of safety and health (RASH) for building construction

In this research Risk Assessment of Safety and Health RASH method for building construction has been developed with risks classified into Safety Risks and Health Risks. 11 factors representing safety risks and 8 factors representing health risks were identified based on field survey in Oman. 40 Safety and Health specialists were involved in carrying out risk assessment using the existing method of risk analysis RA and the proposed RASH method. It was found that RASH method resulted in superior accuracy for assessment of risk zones than the existing RA method. The accuracy by RASH was almost twice the accuracy by RA. The overall percentages of the correct answers for the four scenarios using the RASH method and the RA method were 72.5 percent and 40 percent respectively. The proposed RASH method gave fewer errors than the existing RA method for all scenarios. Two scenarios were found to be the most problematic ones with largest overestimation of risks occur when using the existing RA method. Wilcoxon Ranked Test showed that the two methods are significantly different (z = −3.357, p > 0.01). The new method RASH is statistically acceptable and it resulted in better response in terms of estimating the risk than the RA method.     

Key actor perspectives on stakeholder engagement in Omani Environmental Impact Assessment: an application of Q-Methodology

Stakeholder engagement (SE), particularly with representatives of locally affected communities, is integral to Environmental Impact Assessment (EIA) processes, so critical evaluation of SE is necessary across a range of different socio-political contexts. EIA SE practice in the Sultanate of Oman is examined using Q-Methodology, a qualitative-quantitative discourse analysis technique, in order to evaluate key-actor perspectives and policy directions. Four discourses emerge, pertaining to (1) the institutionalisation of SE; (2) business as usual; (3) rights-centred engagement; and (4) decentralisation of EIA institutions. Consensus emerges that shows support for transparency and formalisation of SE; greater citizen-centred decision-making power; transparency in government guidelines; and the elimination of developer-led consultation processes. Policy options for reforming EIA policy are discussed, including a code of participation practice and a toolkit of suitable engagement methods.     

Controlling groundwater pumping online

Groundwater over-pumping is a major problem in several countries around the globe. Since controlling groundwater pumping through water flow meters is hardly feasible, the surrogate is to control electricity usage. This paper presents a framework to restrict groundwater pumping by implementing an annual individual electricity quota without interfering with the electricity pricing policy. The system could be monitored online through prepaid electricity meters. This provides low transaction costs of individual monitoring of users compared to the prohibitive costs of water flow metering and monitoring. The public groundwater managers' intervention is thus required to determine the water and electricity quota and watch the electricity use online. The proposed framework opens the door to the establishment of formal groundwater markets among users at very low transaction costs. A cost–benefit analysis over a 25-year period is used to evaluate the cost of non-action and compare it to the prepaid electricity quota framework in the Batinah coastal area of Oman. Results show that the damage cost to the community, if no active policy is implemented, amounts to (−$288) million. On the other hand, the implementation of a prepaid electricity quota with an online management system would result in a net present benefit of $199 million.     

Performance assessment of 20.4 kW eco-house grid-connected PV plant in Oman

ABSTRACT

The aim of this article is to analyse the performance of the Photovoltaic (PV) and to study the effect of soiling on the energy generation under Muscat environmental conditions. The generated energy is consumed in the eco-house, and the access energy is fed back to the electric grid. Two-ways metre was used to record the energy taken from the grid or fed back to the grid. The system was monitored from December 2014 until today. Various performance parameters of the plant were evaluated which include system efficiency, performance ratio (PR), capacity factor (CF) and different types of PV system losses and yields. The annual average values of recorded ambient temperature and solar radiation were 32°C and 482 W/m², respectively.

The total annual energy produced was 23,595 kWh, whereas the annual average daily reference yield, array yield and final yield were 5.59, 3.78 and 3.64 kWh/kW_P/day, respectively. The annual average daily PR and CF were 0.67 and 0.15, respectively, while the annual average system efficiency was 10.3%. Furthermore, the annual average daily capture, system and cell temperature losses were 1.82, 0.14 and 2.95 h/day,respectively, with a small reduction in energy production when modules left uncleaned.     

An overview of waste materials recycling in the Sultanate of Oman

Various wastes and by-product materials are generated in the Sultanate of Oman including reclaimed asphalt pavement (RAP) aggregate, demolition concrete, cement by-pass dust (CBPD), copper slag, petroleum-contaminated soils (PCS), discarded tires, incinerator ash, and others. Recycling of such materials in construction is not practiced. Research data are also minimal into the potential use of selected materials in construction applications. This paper will present the results of several laboratory studies conducted into the use of PCS in asphalt concrete mixtures; on the use of CBPD in soil stabilization and flowable fill mixtures; on the utilization of copper slag and CBPD as cementitious materials; on the use of incinerator ash in cement mortars; and on the use of RAP aggregate in road bases and sub-bases. Laboratory data generally indicate that it is feasible to partially reuse some of these materials in construction provided that economic incentives and environmental concerns are taken into consideration.     

Toxic metals in commercial marine fish in Oman with reference to national and international standards

Commercially important fresh (581) and frozen (292) marine fish samples of 10 species were collected from seafood factories and evaluated using AAS and ICP-OES. Metal levels significantly (p < 0.05) varied within and between species. However, there were no significant correlations among metals. There were significant interspecific differences for all metals, and yellowfin tuna had the highest level of cadmium and mercury however, red seabream had maximum numbers above the standards. The metal accumulation significantly varied between bottom feeders of intermediately size locally caught fish. The mean cadmium level ranged from 0.0049 to 0.036 mg kg⁻¹ and 1.37% of the total samples exceeded the EU and FAO standards. Mean lead content varied between 0.029 and 0.196 mg kg⁻¹, few samples crossed the EU (2.63%) and FAO (1.6%) limits. Mean mercury level ranged from 0.015 to 0.101 mg kg⁻¹ and none of the samples exceeded the EU limit. Of the total samples analyzed red seabream (2.06%), yellowfin tuna (1.14%), emperor (0.34%), santer bream (0.22%), king fish (0.11%) and skipjack tuna (0.11%) samples crossed the EU limits. In general, fish from these regions are within the safety levels recommended by various organizations and do not pose a health risk in terms of human diet.     

Impact of NOx Emissions Released from a Gas Turbine-Based Power Plant on the Ambient Air Quality

The number of gas turbine- (GT-) based power plants is rapidly increasing to meet the world’s power demands. Until a few years ago, fossil fuel, and specifically fuel oil, was considered the major energy source for gas turbine operation. Due to the high amount of pollution that fuel oil generates, natural gas has become a popular source of energy due to its lower emissions compared to fuel oil. As a result, many GTs have switched to natural gas as an alternative to fuel oil. However, pollutants expelled from GT-based power plants operating on natural gas impact surrounding air quality. The objective of this study was to examine the dispersion of nitrogen oxides (NO_x) emitted from a GT-based power plant located in the Sultanate of Oman. Supported by CALPUFF dispersion modeling software, six scenarios were investigated in this study. The first four scenarios considered a case where the GT-based power plant was operating on natural gas during winter and summer and for open and combined cycle modes. The remaining two scenarios considered, for both open and combined cycle modes, the case where the GT-based power plant was operating on fuel oil. Whether run by natural gas or fuel oil, CALPUFF simulation results for both seasons showed that NO_x concentrations were higher when GTs were used in the combined cycle mode. The concentrations were still lower than the allowable concentrations set by the United States Environmental Protection Agency (U.S. EPA) standards. In contrast, for the case where the power plant operated on fuel oil, the NO_x one-hour average simulated results exceeded the allowable limits only when the combined cycle mode was activated.     

Comparative chemical analysis of some traditional Omani-made kohl

Fourteen different types of Omani-made kohl were collected from different locations in Oman. The kohl samples were analyzed using different analytical techniques including X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray microanalysis, and inductively coupled plasma mass spectroscopy after sample digestion. The results show that six kohls (kohls 1–6) are mineral-based, four of which, namely lasif, cold ethmid, hot ethmid, and original ethmid, contain very high levels of Pb (basically galena). The other two kohls (red ethmid and black ethmid) contain mostly iron (hematite, magnetite, and goethite). The other kohl samples (kohls 7–14) are basically amorphous carbons, one of which is made by charring date stones while the rest are basically soot collected from burning different materials. Compared to the results obtained by inductively coupled plasma mass spectroscopy, energy-dispersive X-ray microanalysis yielded higher concentrations of major elements while some minor elements were not detected; this is probably related to some limitations in the latter technique. Based on this study, carbon-based kohls possess much lower levels of toxic elements than mineral-based kohls; consequently, the former can be considered as the less hazardous kohls. However, concerns about the use of soot in cosmetics are rising because of the presence of some carcinogenic compounds such as polyaromatic hydrocarbons in soot.