Cake compressibility analysis of BPOME from a hybrid adsorption microfiltration process

This study investigates the utility of a hybrid adsorption-membrane process for cake compressibility evaluation of biotreated palm oil mill effluent. A low-cost empty fruit bunch (EFB) based powdered activated carbon (PAC) was employed for the upstream adsorption process with operation conditions of 60 g/L PAC dose, 68 min mixing time, and 200 rpm mixing speed to reduce the feed-water strength and alleviate probable fouling of the membranes. Two polyethersulfone microfiltration (MF) membranes of 0.1 and 0.2 lm pore sizes were investigated under constant transmembrane pressures (TMP) of 40, 80, and 120 kPa. The compressibility factors (z), which was obtained from the slopes of power plots (function of specific cake resistance (a) and pressure gradient) were evaluated. The z values of 0.32 and 0.52, respectively obtained, for the 0.1 and 0.2 lm MF membranes provided compressible and stable z values as observed from their power plots. Besides, these membranes were found suitable for the measurement of z since the results are in consonance with the established principle of cake compressibility. Moreover, the upstream adsorption mitigated the clogging of the membranes which ultimately led to moderate resistances and cake compressibility. These are indications that with the secondary cake filtration, a sustainable flux can be achieved during BPOME filtration. The membranes exhibited close to 100% restoration after cleaning

A Survey on the Security and the Evolution of Osmotic and Catalytic Computing for 5G Networks

The 5G networks have the capability to provide high compatibility for the new applications, industries, and business models. These networks can tremendously improve the quality of life by enabling various use cases that require high data-rate, low latency, and continuous connectivity for applications pertaining to eHealth, automatic vehicles, smart cities, smart grid, and the Internet of Things (IoT). However, these applications need secure servicing as well as resource policing for effective network formations. There have been a lot of studies, which emphasized the security aspects of 5G networks while focusing only on the adaptability features of these networks. However, there is a gap in the literature which particularly needs to follow recent computing paradigms as alternative mechanisms for the enhancement of security. To cover this, a detailed description of the security for the 5G networks is presented in this article along with the discussions on the evolution of osmotic and catalytic computing-based security modules. The taxonomy on the basis of security requirements is presented, which also includes the comparison of the existing state-of-the-art solutions. This article also provides a security model, "CATMOSIS", which idealizes the incorporation of security features on the basis of catalytic and osmotic computing in the 5G networks. Finally, various security challenges and open issues are discussed to emphasize the works to follow in this direction of research.Comment: 34 pages, 7 tables, 7 figures, Published In 5G Enabled Secure Wireless Networks, pp. 69-102. Springer, Cham, 201

Factors promoting schistosomiasis infection in endemic rural communities of Ifedore and Ile-Oluji/Oke Igbo local government areas in Ondo State, Nigeria

Schistosomiasis, a chronic parasitic disease, is highly endemic in Nigeria and causes severe morbidity among school children in many poor-resource communities in the country. We investigated the factors that promote schistosomiasis infection in rural hyper-endemic communities of two LGAs in Ondo State, South West Nigeria. Data were collected through a household survey, focus group discussions, indepth interviews, key informant interviews among different categories of stakeholders in schistosomiasis control that include community adult members, school pupils, health workers and disease control officers. The quantitative and qualitative data were analysed using the Epi Info (version 6.04a) and Textbase Beta software respectively. A large number (71.1%) of respondents described schistosomiasis as a prevalent infection in their communities and 34.6% reported having a member of their households who was infected with schistosomiasis. The LGA of residence of the respondents significantly influenced the respondents’ perception of the seriousness of the consequences of the disease as more respondents in Ile-Oluji/Oke Igbo LGA perceived it to be a very serious health problem than those in Ifedore LGA [27.8% Ile-Oluji/Oke Igbo LGA vs. 5.9% Ifedore LGA] (p&lt;0.05). The results show that communities in the LGAs are endemic of schistosomiasis mainly because the people have little or no access to safe potable water thereby increasing their rate of contact with natural flowing streams, ponds and or rivers which are or may be infested with susceptible snail intermediate hosts for domestic and occupational activities as about 52% of respondents admitted going to the stream/river. Other factors the study revealed to aid the prevalence of schistosomiasis in the communities is lack of political will and commitment to effective schistosomiasis control and eradication by the government. There was also evidence of community involvement and participation in schistosomiasis control in only one of the four communities studied. To eliminate schistosomiasis in the communities, efforts need to be made and sustained by the government at all levels to ensure increased political will with more community involvement and participation to achieve effective schistosomiasis control.</p

Health care seeking-behaviour of people in Schistosomiasis endemic communities of Ogun and Niger States, Nigeria

A study of the dynamics of health-care seeking-behaviour of people living in communities endemic for schistosomiasis was carried out in Borgu and Shagamu Local Government areas of Niger State and Ewekoro, Odeda and Abeokuta North Local Government Areas of Ogun State, Nigeria. Questionnaires were administered, which was complimented with Focus Group Discussion (FGDs) and in-depth interviews. The study investigated the knowledge, perceptions, beliefs and practices of the people with regards to the signs/symptoms, sources of the infection, actions taken in treating the infection and their preferred health care options. While 64.4% of the 236 respondents identified the river as the source of infection, 67% also mentioned blood in urine, 36.4% mentioned itching and 22.9% mentioned drowsiness as some of the symptoms of the infection: About 59% preferred the orthodox method of treatment and 31.7% preferred both orthodox and traditional methods. It was discovered that the cost of treatment and health education had a significant impact on the respondents' health care seeking-behaviour. Keywords: health, seeking, schistosomiasis, endemic, communities Nigerian Journal of Parasitology Vol. 25, 2005: 121-12

Modelling of pore-blocking behaviors of low-pressure membranes during constant-pressure filtration of an agro-industrial wastewater

Despite the widely documented excellent purification capacity of membranes, their main drawback—fouling—is still being extensively researched with a view to finding a sustainable solution. Fouling simply implies the process that results in the performance loss of a membrane due to the deposition of suspended or dissolved matters onto its external surface or the internal pore walls [1]. Fouling eventually leads to a reduction in the active area of the membrane and thereby results in a reduction in flux below the theoretical capacity of the membrane. Fouling or pore-blocking has been identified as the main reason limiting the adoption of membrane purification processes by many industries. Consequently, an apt understanding of the pore-blocking mechanisms of membranes is imperative, as it is a pertinent factor dictating the overall performance of the filtration process. Pore blockage can occur in any of the two commonly known membrane operations: constant-pressure and constant-flux rate. In a constant-pressure operation, pore blockage usually leads to a sharp decline in permeate flux, while a severe pressure rise is usually encountered in a constant-flux rate operation. In principle, governing filtration models can facilitate the design of membrane processes more than any experiment or characterization can, yet data from experiments are usually required for validation purposes [2–5]. To properly control particulate fouling at the design stage, as well as appropriately monitor it during a plant operation, the methods utilized in evaluating the particulate content of feed-water in predicting membrane fouling are crucial. Soluble and colloidal materials are assumed to be responsible for membrane pore blockage, while suspended solids are mainly accountable for the cake layer resistance [4,6,7]. To accurately measure and predict particulate fouling, it is recommended that specific fouling mechanisms/indices be investigated with respect to specific membranes since the Modified Fouling Index (MFI), where a 0.45 μm membrane filter is used and usually represented as MFI0.45, cannot represent all membrane types. This is due to the fact that some principal parameters such as retention of smaller particulates, the nature and concentration of solutes and solvents, proof of cake filtration, pore size distribution, surface morphology, module hydrodynamics and membrane type/material must be considered in such investigations [1,8]. Therefore, in any proposed membrane process with plans for sustainability, pore-blocking modeling is germane for the determination of some key factors necessary for the design of an efficient membrane system. These factors are: (1) the description of the extent of membrane fouling in terms of particle accumulation at the membrane surface or inside the membrane pores; (2) the prediction of the fouling potential of a specific feed with respect to a specific membrane; and (3) the identification of the most appropriate and sustainable cleaning method necessary for the membrane process. In this study, a systemic investigation was carried out on high-strength agro-industrial wastewater to describe the successive steps involved in the flux decline of a membrane filtration process in terms of pore-blocking mechanism. Microfiltration (MF) and ultrafiltration (UF) membranes, which are the popular low-pressure membranes (LPMs), were utilized for the filtration of the high-strength wastewater. The wastewater is specifically a discharge of an end-of-pipe treatment process from the agro-industry palm oil milling process. An upstream adsorption process was applied to lower the feed strength and reduce its fouling effects on the membranes. The investigative experiments were conducted in a constant-pressure and cross-flow filtration mode through polyethersulfone (PES) MF (pore sizes: 0.1 and 0.2 μm) and UF (molecular weight cut-off: 1, 5 and 10 kDa) membranes at the transmembrane pressures of 40, 80 and 120 kPa. The examined results within the frame of the common blocking mechanisms revealed that the blocking index, η, decreased from 2 to 0 in all five membranes. The pore-blocking phenomenon was successively observed from the complete blocking mechanism (i.e., η = 2) down to the cake filtration mechanism (i.e., η = 0). Furthermore, there is an indication that the early blockage of the pores and formation of a cake resulted in a limiting cake height evident from the near-constant trend of the permeate flux. This means that cake filtration could be best used to explain the fouling mechanisms of the feed on the LPMs based 139Modeling of Pore-Blocking Behaviors of Low-Pressure Membranes on the coefficient of determination (R2) values at all applied pressures. This further demonstrates that the fouling is primarily caused by the gradual reversible cake deposition, which could be easily removed by less onerous cleaning methods

Auto-correlation robustness of factorial designs and GAMS in studying the effects of process variables in a dual-objective adsorption system

The performance of factorial designs is still limited due to some uncertainties that usually intensify process complexities, hence, the need for inter-platform auto-correlation analyses. In this study, the auto-correlation capabilities of factorial designs and General Algebraic Modeling System (GAMS) on the effects of some pertinent operating variables in wastewater treatment were compared. Individual and combined models were implemented in GAMS and solved with the trio of BARON, CPLEX and IPOPT solvers. It is revealed that adsorbent dosage had the highest effect on the process. It contributed the most effect toward obtaining the minimum silica and TDS contents of 13 mg/L and 814 mg/L, and 13.6 mg/L and 815 mg/L from factorial design and GAMS platforms, respectively. This indicates a concurrence between the results from the two platforms with percentage errors of 4.4% and 0.2% for silica and TDS, respectively. The effects of the mixing speed and contact time are negligible