A study on the effectiveness factors that influence job performance among employees / Nur Hafizah Ab Hamid and Siti Nabihah Mohamad Jamil

This topic of research is “The Effectiveness Factors That Influence Job Performance among Employees”. This research tries to determine the relationship between factors of personality, teamwork and commitment, and adaptation on workplace effect to job performances among employees. Researchers want to know the performance of employees by specifically in Johor Bahru. This study to identifies and determines factors that have significant influence on job performance. The respondents for this study are 100 employees in Johor Bharu. The researchers had used convenience sampling as a sampling technique. The process of analyzing and interpreting data has presented by figures and tables using method reliability test, frequency, descriptive statistic, correlations and regression analysis. The researchers also have suggestion and recommendation is to helps the companies to increase their employees job performance

The neurobiology of smartphone addiction in emerging adults evaluated using brain morphometry and resting-state functional MRI

The characteristics of smartphone addiction (SPA) can be evaluated by neuroimaging studies. Information on the brain structural alterations, and effects on psychosocial wellbeing, however, have not been concurrently evaluated. The aim of this study was to identify abnormalities in gray matter volume using voxel-based morphometry (VBM) and neuronal functional alterations using resting-state functional MRI (rs-fMRI) in emerging adults with SPA. We correlated the neuroimaging parameters with indices for psychosocial wellbeing such as depression, anxiety, stress, and impulsivity. Forty participants (20 SPA and 20 age-matched healthy controls) were assessed using VBM and rs-fMRI. The smartphone addiction scale –Malay version (SAS-M) questionnaire scores were used to categorize the SPA and healthy control groups. DASS-21 and BIS-11 questionnaires were used to assess for psychosocial wellbeing and impulsivity, respectively. VBM identified the SPA group to have reduced gray matter volume in the insula and precentral gyrus; and increased grey matter volume in the precuneus relative to controls. A moderate correlation was observed between the precuneus volume and the SAS-M scores. Individuals with SPA showed significant rs-fMRI activations in the precuneus, and posterior cingulate cortex (FWE uncorrected, p<0.001). The severity of SPA was correlated with depression. Anxiety score was moderately correlated with reduced GMV at the precentral gyrus. Collectively, these results can be used to postulate that the structural and neuronal functional changes in the insula are linked to the neurobiology of SPA that shares similarities with other behavioural addictions

Forward osmosis (FO) embrane-based technology in urban wastewater treatment

Forward osmosis (FO) membrane-based technology is receiving increased interest from the wastewater treatment industry for\ua0its potential to produce high effluent quality with\ua0a relatively better water flux stability against fouling\ua0than other membrane systems. The application of FO has been widely explored in the wastewater treatment, however, there are a limited number of studies that comprehensively evaluate the FO performance. In addition, the techno-economic feasibility and sustainability of FO application for wastewater treatment have not been fully demonstrated. Therefore, this thesis aims to investigate the performance of FO membrane-based technology in treating urban wastewater under different treatment designs.In this thesis, the experimental studies were executed by setting-up direct filtration and semi-automatic control of forward osmosis membrane bioreactor (FOMBR). These configurations were opted to evaluate the technology integration, membrane performance and nutrients removal. Additionally, the performance of FO was evaluated in terms of techno-economics, energy consumption and carbon footprint from different process design perspectives.A direct filtration study was undertaken in Chapter 4 to concentrate raw wastewater for energy recovery. However, this approach suffers serious biofouling deposition, hence, the performance of different cleaning reagents was evaluated. Under 10 successive cleaning cycles, the physical cleaning only recovered 40 % of the water flux performance, which implied the fouling formed under this configuration was not highly reversible. Due to this limitation, this chapter investigated the potential of free nitrous acid (FNA) as the next generation of ‘green’ cleaning reagent. In this chapter, FNA managed to inactivate 94 % of biomass quantified from the fouling layer, and recovered the water flux performance by 74 %.The severe biofouling deposition in Chapter 4 led to the development of Chapter 5, applying FO in an aerobic membrane bioreactor (FOMBR). As FO relies on the osmotic pressure gradient to drive the water molecules to pass across the membrane, it is inevitable for the reverse salt diffusion to occur. This chapter provides a significant insight into the effect of the reverse salt diffusion in achieving a shortcut pathway for removing nitrogen compounds in a wastewater system, by selectively inhibiting nitrite oxidising bacteria (NOB). Additionally, this FOMBR managed to achieved > 99 % overall nutrient removal over 171 days of operation. However, under such a long-term operation, the weekly physical cleaning only recovered 61 % of water flux performance and structural deterioration of the membrane was observed.In following the previous chapter, Chapter 6 aims to improve the performance of FOMBR by developing a hybrid cleaning strategy to mitigate biofouling deposition in the FOMBR. A weekly physical cleaning was undertaken together with monthly FNA cleaning under 92 days of operation with 90 % water flux recovery recorded. FNA cleaning resulted in a more negatively-charged membrane surface (- 42.34 ± 0.30 mV), hence leading to a stronger electrostatic repulsion between foulants and membrane surface. This contributed to a slower biofouling deposition, with the water flux performance maintained > 5.3 L m-2 h-1 (LMH). A mechanism of FNA cleaning in mitigating the biofouling deposition was proposed for the first time in this chapter.Chapter 7 evaluates the performance of the FOMBR full-scale application in terms of techno-economics, carbon footprint and greenhouse gas (GHG) emissions benchmarked against the traditional membrane-based application (microfiltration (MF)). FO was well reported to have a better rejection performance and ability to concentrate wastewater in comparison to the MF. The wastewater treatment and reclamation costs by using FO were more expensive than MF by $0.16 m-3 and$ 0.75 m-3 respectively. Further improvement of the FO membrane to a certain threshold (water flux = 30 LMH and membrane cost = $ 20 m-2) are required to reduce the treatment cost to be as low as using the MF. This chapter also explores the potential of the FO anaerobic MBR with partial nitrification/ANAMMOX (PN/AMOX) in the mainstream treatment, which suggested minimal net energy consumption and low carbon footprint (0.93 kg CO2 - equivalent m-3) of this integration.Chapter 8 proposes a novel application of FO in concentrating high-rate activated sludge (HRAS) effluent for an efficient PN/AMOX operation in the mainstream treatment. With a low carbon content in the HRAS effluent, the potential of FO in concentrating the NH4+ for an efficient PN/AMOX and the reversibility of the biofouling deposited were further explored. A lower propensity (compared to Chapter 4) of fouling layer was observed, with the overall water flux recovery of 94 % contributed by physical and FNA cleanings. In addition, FO managed to concentrate NH4+ to be within the range of 109 ˗ 220 mg NH4+-N L-1 with the salt concentration of 7.92 ± 3.15 g L-1, which implied the potential of this integration to achieve an efficient PN/AMOX process in the mainstream treatment.In summary, the application of FO in different wastewater treatment designs was comprehensively investigated in this thesis. The direct filtration of raw wastewater was challenging due to severe fouling deposition, however, the similar strategy was applicable to concentrate HRAS effluent that resulted with a relatively lower fouling propensity. Both direct filtration studies reported a satisfactory water flux recovery by FNA cleaning, and same range of performance was recorded by the FOMBR set-up, suggesting the potential of FNA as the next generation of ‘green’ cleaning reagent. The reverse salt diffusion of FO application was utilised in achieving shortcut pathway of nitrogen removal, implying the potential to reduce the carbon footprint of the wastewater treatment plant due to the lower aeration requirement. Overall, the outcomes of this thesis potentially contribute to a new paradigm of membrane-based application in wastewater treatment for an efficient water and energy recoveries

Achieving stable operation and shortcut nitrogen removal in a long-term operated aerobic forward osmosis membrane bioreactor (FOMBR) for treating municipal wastewater

Forward osmosis membrane bioreactor (FOMBR) is an integrated physical-biological treatment process that has received increased awareness in treating municipal wastewater for its potential to produce high effluent quality coupled with its low propensity for fouling formation. However, reverse salt diffusion (RSD) is a major issue and so far limited studies have reported long-term FOMBR operation under the elevated salinity conditions induced by RSD. This study investigated the performance of a FOMBR in treating municipal wastewater under a controlled saline environment (6–8 g L NaCl) using two separate sodium chloride draw solution (NaCl DS) concentrations (35 and 70 g L) over 243 days. At 35 g L NaCl DS, the water flux performance dropped from 6.75 L m h (LMH) to 2.07 LMH after 72 days of operation in the first experimental stage, when no cleaning procedure was implemented. In the subsequent stage, the DS concentration was increased to 70 g L and a weekly physical cleaning regime introduced. Under stable operation, the water flux performance recovery was 67% after 21 cycles of physical cleaning. For the first time in FOMBR studies, a shortcut nitrogen removal via the nitrite pathway was also achieved under the elevated salinity conditions. At the end of operation (day 243), the ammonia-oxidising bacteria (Nitrosomonas sp.) was the only nitrifier species in the system and no nitrite oxidising bacteria was detected. The above study proves that a FOMBR system is a feasible process for treating municipal wastewater

Evaluating the membrane fouling formation and chemical cleaning strategy in forward osmosis membrane filtration treating domestic sewage

As a novel filtration process driven by osmotic pressure, forward osmosis (FO) filtration process offers low fouling propensity and is a potential solution to energy generation and resource recovery from wastewater via direct filtration enriching pollutants into small volume of concentrate. In this study, the characteristics of fouling formation on cellulose triacetate (CTA) FO membranes were investigated using direct filtering of raw domestic wastewater in a FO process. The cleaning efficiency of three environmentally friendly reagents (i) reverse osmosis (RO) water, (ii) ethanol (70 w/w%) and (iii) free nitrous acid (FNA) (35 mg HNO-N per L), in fouling control and membrane stability was evaluated through flux and selectivity measurements. From ten successive cleaning cycles, the efficiency of these cleaning reagents in the membrane flux recovery follows the order of ethanol (8.01 ± 0.31 L m h (LMH)) > FNA (5.83 ± 0.36 LMH) > RO water (3.55 ± 0.29 LMH) > control (2.09 ± 0.28 LMH). Although ethanol completely recovered the water flux performance and inactivated the biomass from the fouling layer, it appeared to have compromised the membrane integrity, which was demonstrated by an increased apparent reverse salt flux. After 1 hour of cleaning with ethanol, the apparent reverse salt flux dramatically increased to between 12.58 g m h and 47.21 g m h. The FNA did not show any sign of deteriorating the CTA membrane integrity, however, 94% inactivation of bacteria required 8 hours of exposure time. These results indicate that FNA shows good potential to be used as a cleaning reagent in FO processes for membrane fouling control. Further studies are still needed to improve the efficiency of FNA dosing and required exposure time

Economic, energy and carbon footprint assessment of integrated forward osmosis membrane bioreactor (FOMBR) process in urban wastewater treatment

The application of forward osmosis (FO) membrane-based technology in urban wastewater treatment has received increased attention, however, its techno-economic feasibility and sustainability have not been fully demonstrated. In this study, the feasibility of FO application in urban wastewater treatment was assessed in terms of economic performance, energy consumption and greenhouse gas (GHG) emissions benchmarked against microfiltration (MF). Three different scenarios of wastewater treatment and water reclamation were proposed: (A) forward osmosis aerobic membrane bioreactor (FOAeMBR); (B) FOAeMBR integrated with reverse osmosis (RO); (C) forward osmosis anaerobic membrane bioreactor (FOAnMBR) integrated with partial nitrification/anammox (PN/AMOX) process. In this study, the wastewater treatment and reclamation costs by using FO in scenarios A and B were more expensive than MF by $0.16 per m and$0.75 per m respectively due to the larger surface area of FO membrane required. In scenario C, the wastewater treatment cost of using FO ($1.11 per m) was equivalent to MF. This was due to the good rejection performance of FO and its ability to concentrate wastewater, hence, resulting in a higher efficiency of (PN/AMOX) in comparison to MF. In addition, the application of FO in scenario C generated total GHG emissions to be as low as 0.93 kg CO equivalent m, which was 1.5 and 4.1 times lower than scenarios A and B respectively. The minimal net energy consumption and low carbon footprint of FO application in scenario C suggests this integration will likely be a feasible membrane-based technology for the next generation of wastewater treatment

Improving wastewater management using free nitrous acid (FNA)

Free nitrous acid (FNA), the protonated form of nitrite, has historically been an unwanted substance in wastewater systems due to its inhibition on a wide range of microorganisms. However, in recent years, advanced understanding of FNA inhibitory and biocidal effects on microorganisms has led to the development of a series of FNA-based applications that improve wastewater management practices. FNA has been used in sewer systems to control sewer corrosion and odor; in wastewater treatment to achieve carbon and energy efficient nitrogen removal; in sludge management to improve the sludge reduction and energy recovery; in membrane systems to address membrane fouling; and in wastewater algae systems to facilitate algae harvesting. This paper aims to comprehensively and critically review the current status of FNA-based applications in improving wastewater management. The underlying mechanisms of FNA inhibitory and biocidal effects are also reviewed and discussed. Knowledge gaps and current limitations of the FNA-based applications are identified; and perspectives on the development of FNA-based applications are discussed. We conclude that the FNA-based technologies have great potential for enhancing the performance of wastewater systems; however, further development and demonstration at larger scales are still required for their wider applications

The Current State-Of-Art of Copper Removal from Wastewater: A Review

Copper is one of the chemical elements that is widely used in various sectors nowadays together with the development of civilization especially in agricultural and industrial sectors. Copper is also considered as one of the heavy metals that is commonly present in wastewater. This preliminary study conducted is mainly focused on the techniques of removal of copper in wastewater. There are a variety of approaches for treating industrial effluent contaminated with heavy metals such as copper. Copper separation can be accomplished using a variety of technologies, each of which has advantages that vary depending on the application. Chemical removal techniques that are commonly used for copper removal are adsorption, cementation, membrane filtration, electrochemical method, and photocatalysis. This study compares the fundamentals and performances of the treatment techniques in addition to the future perspective of copper removal in detail. The study highlights the present research in terms of its strengths and shortcomings, pointing out deficiencies that need to be addressed in future studies, pointing to future research prospects

The Current State-Of-Art of Copper Removal from Wastewater: A Review

Copper is one of the chemical elements that is widely used in various sectors nowadays together with the development of civilization especially in agricultural and industrial sectors. Copper is also considered as one of the heavy metals that is commonly present in wastewater. This preliminary study conducted is mainly focused on the techniques of removal of copper in wastewater. There are a variety of approaches for treating industrial effluent contaminated with heavy metals such as copper. Copper separation can be accomplished using a variety of technologies, each of which has advantages that vary depending on the application. Chemical removal techniques that are commonly used for copper removal are adsorption, cementation, membrane filtration, electrochemical method, and photocatalysis. This study compares the fundamentals and performances of the treatment techniques in addition to the future perspective of copper removal in detail. The study highlights the present research in terms of its strengths and shortcomings, pointing out deficiencies that need to be addressed in future studies, pointing to future research prospects