bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Steps in Preventing, Monitoring and Removing of Fouling Scale on Operation of Evaporator
Authors: Salimin Zainus , Kistriyani Lilis , Ratiko  
Published: May 2020

Abstract
Concentrating of solution by evaporation with tubular heating surface evaporator is the effective method for decontamination of radioactive waste. Radioactive matter was concentrate with decontamination factor 104-105 for Cs-137. The evaporation of liquid waste from Serpong Nuclear Facilities having the permanent hardness of CaSO4 and MgSO4 with ratio of 2:1 generates fouling scale. The presence of scale on the evaporator gives the additional cost i.e. increasing of the capital investment cause of oversize of heat transfer surface area, increasing of energy cost for same evaporator capacity due to the presence of fouling heat transfer resistance, the presence of time loosing for maintenance and descaling, the chemical cost for descaling, and decreasing of the production capacity cause of decreasing of production time comparing the condition without the presence of fouling scale. For the problem solution, it is necessary to perform the sequence action starting the prevention of fouling scale formation, than monitoring of the fouling factor (Rd), and finally removing of fouling scale by chemical descaling. The prevention of fouling scale formation is performed by separation of soluble and suspended solid and utilization of chemical inhibitor before evaporation operation. The monitoring of fouling factor is performed during evaporation operation by reading the operating parameter of evaporation on the control panel i.e. mass flow rate of heating steam, mass flow rate of liquid waste, the input and output of steam temperature, and the input and output of liquid waste temperature. The energy for evaporation can be calculated, than the clean and dirty overall heat transfer coefficient can be calculated, so the fouling factor can be obtain. The removing of fouling scale or descaling process is performed by immersion of evaporator circuits using nitric acid solution of 10% weight concentration, and by mechanical brushing during maintenance activity. The prevention, monitoring, and removing of scale fouling on the operation of evaporator is described on the paper.
Bio-remediation of palm oil mill effluent (POME) using Aspergillus niger immobilized on coconut husk and free cell fermentation
Authors: Thegarathah P , Jewaratnam J , Simarani K 
Published: May 2020

Abstract

Aspergillus niger which is ubiquitous and acts as good biological agent has been chosen to treat POME in this study. Use of, free cell fermentation limits the uptake of substrate as compared to immobilization method which provides larger surface area for cell growth. Therefore, the idea of using coconut husk as immobilization medium has been proposed. Coconut is widely available in Malaysia almost at no cost. Hence, the purpose of this study is to evaluate the bio-degradation of palm oil mill effluent by Aspergillus niger through immobilization on coconut husk and free cell fermentation. Substrates from different types of POME such as. raw, sterile, treated using Aspergillus niger through free cell fermentation and treated with Aspergillus niger cells which are immobilized on coconut husk were prepared at different concentration range from 0 to 100%. Aspergillus niger cells (1 X 105 cells per ml were inoculated into Erlenmeyer flasks and incubated at 30 ± 2 °C and 150 rpm for seven days. Fermentation slurry were used to analyse for turbidity, COD and pH. The results were compared with free cell fermentation method. Raw POME has significantly low turbidity as compared to sterile and treated POME. Autoclaving POME increases the turbidity. 100% sterile POME shows the highest turbidity which is 979.5 FAU and 100% POME which was treated by immobilization on coconut husk shows a reduction in turbidity which gives 900.5 FAU. The presence of coconut husk has significantly increased the COD value as 0% POME (distilled water) with coconut husk shows 3320 mg/l of COD. However, at the end of seven days of treatment, 100% POME which was treated through immobilization shows lower COD as compared to free cell fermentation. pH reading is a concern as treatment method might influence the pH of POME. Range of pH for POME throughout the experiment was between 7.1 and 9.6. Degradation of POME using Aspergillus niger immobilized on coconut husk provides additional incentive that is cheap and sustainable.
A Comparative Study of Conventional Aerator and Microbubble Generator in Aerobic Reactors for Wastewater Treatment
Authors: Marbelia Lisendra , Wan Noor Athina , Paramesti Asa , Damarjati Bimo A. , Widyaparaga Adhika , Deendarlianto  , Bilad Muhammad R. , Budhijanto Wiratni 
Published: May 2020

Abstract
Aeration in aerobic reactor for wastewater treatment has an important role in determining its performance. In this case, sufficient oxygen supply with good mixing is necessary to guarantee a good pollutant biodegradation. However, biodegradation is not the only parameter to consider when designing an aerator, energy consumption and cost also have important roles. In this study, a conventional air diffuser (CAD) and a low-cost microbubble generator (MBG) were compared in a 400-L reactor for two aerobic wastewater treatment process configurations, i.e. suspended culture and attached culture (with pumice stones). Dissolved oxygen (DO) concentration throughout the reactor was initially investigated with tap water. Results indicated that the maximum DO which could be obtained for the two type of aerators were almost similar, in the range of 7.7 to 7.9 mg/L. But the lowest values are different, i.e. 5.6 mg/L for CAD and 6.8 mg/L for MBG, showing that homogeneity was better for MBG. This might be due to smaller bubble sizes produced by MBG which were able to stay inside the liquid for a longer time. Afterward, comparison of the two aerators were performed for aerating activated aerobic sludge. Without pumice stones, DO concentration for MBG and CAD was almost similar, but for MBG, lower values were found in the bottom of the tank indicating the higher activated sludge concentration. When using pumice stones, MBG again shows its superiority indicated by a higher DO values reaching 6.4 mg/L, compared to 5.6 mg/L for the CAD. These results revealed the promising potential of MBG as a low-cost aerator to be used in aerobic reactor for wastewater treatment with attached culture.
Nitrate removal from aqueous solution by adsorption using municipal solid waste-derived activated biochar
Authors: Revilla Patricia Nadine D. , Concepcion Maguyon-Detras Monet , Migo Veronica P. , Alfafara Catalino G. 
Published: May 2020

Abstract
Nitrate is considered as a major groundwater pollutant causing serious health and environmental effects. In this study, the removal of nitrate from aqueous solutions using municipal solid waste-derived activated biochar (MSWAB) via adsorption was explored. Initially, municipal solid waste (MSW), another prominent source of environmental pollution, was used as feedstock to produce biochar, which was chemically activated using potassium hydroxide, producing MSWAB. Activation of MSWAB resulted to an increase in surface area from 2.5 to 6.5 m2/g. The effect of initial nitrate concentration (A), pH (B), and adsorbent dosage (C) on nitrate removal were then evaluated using a 2k factorial experimental design. Results show that initial nitrate concentration, pH, and two-way interactions AB and AC have significant effects on % nitrate removal. Nitrate removal was found to increase as the initial nitrate concentration and pH decreases. Using Response Surface Methodology (RSM), the local optimum conditions for maximum nitrate removal of 66.97 % were determined to be at 30 mg/L initial nitrate concentration and pH 2 at 10 mg/mL adsorbent dosage. The appropriate isotherm for nitrate adsorption onto MSWAB was the Freundlich isotherm. Comparison with commercial activated carbon (CAC) in terms of nitrate removal efficiency at local optimum conditions showed that MSWAB is inferior to CAC. However, it is still notable that MSWAB was able to reduce the nitrate concentration from 30 mg/L to 11.27 mg/L which satisfies the 14 mg/L DENR effluent standard for Class C water bodies, showing its potential as an alternative adsorbent for treatment of nitrate-laden wastewaters.
The Effect of Flow Rate and NaCl Concentration on the Corrosion Behavior of Carbon Steel in NaCl Solutions Containing H2S
Authors: Dwi Rachmawati Indah , Nurdin Isdiriayani , Widiatmoko Pramujo , Devianto Hary , Irmayanti Festi , Saptohadi Samuel 
Published: May 2020

Abstract
Most of components in industry are made of carbon steel which has low corrosion resistance. Therefore, the industry’s equipment is highly susceptible to corrosion. This study is focused on the characterization of carbon steel corrosion in flowing NaCl solutions with H2S impurities. The corrosion rate was measured by using potentiostat. H2S gas was generated from the Kipp apparatus to produce a concentration of 600 ppm. The NaCl concentration was varied at 50, 40, 000, and 60, 000 ppm. The flow rate was varied at 0.5, 2.3 and 4.1 ft/s by utilizing a Rotating Disk Electrode (RDE). Corrosion mechanism was predicted by utilizing Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), and confirmed by analysing the composition of the corrosion product using X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). The experimental results indicate that the breakaway velocity for NaCl solutions containing H2S of 600 ppm are around 4, 500 rpm. At low level conductivity, corrosion rate increases as NaCl concentration increases. Then, after reaching 40, 000 ppm, NaCl corrosion rate decreases along with the increase of NaCl concentration. The flow rate, NaCl concentration, and interaction between both variables are influential variable for corrosion rate. There is antagonistic influent to corrosion rate at 1000 rpm flow rate, 50 ppm NaCl, and 60, 000 ppm NaCl.
Phosphorus recovery from septage treatment plant sludge by struvite formation with alkaline hydrolysis as pre-treatment
Authors: Nochefranca C K L , Oyson Z K C , San Pedro A B , Pausta C M , Damalerio R , Promentilla M B , Beltran A B , Saroj D , Orbecido A H 
Published: May 2020

Abstract
Insufficiency of phosphorus due to the limited availability of phosphate rocks is predicted within the next decades. Phosphorus recovery from wastewater sludge was found to be one of the possible alternative sources of phosphorus. Moreover, stringent effluent standards, including that of phosphorus levels, have been newly implemented in the Philippines. Due to these factors, phosphorus recovery from wastewater in Philippine settings was deemed as an important topic to be further studied. In this paper, the feasibility of recovering phosphorus from septage sludge in Metro Manila by the precipitation of struvite crystals was studied. Septage sludge is seen as one of the potential sources and was characterized in terms of the concentration of Mg2+, Ca2+, NH4+ and PO4-3 ions. In the lab-scale experiments conducted, alkaline hydrolysis using sodium hydroxide was performed as a sludge pretreatment before the precipitation proper. Alkaline hydrolysis was done to release the remaining PO4-3 ions from the solids present in the sludge, thereby promoting precipitation after hydrolysis without the need for additional phosphate source. Furthermore, alkaline hydrolysis can effectively release phosphorus without inducing the dissolution of interfering ions such as Ca2+ and other heavy metals. Results show that PO4-3 ions increased by 267.37 mg/L and the total amount of phosphate ions increased from 17.05% to 46.88%, showing the effectivity of the hydrolysis. For the precipitation of struvite, three parameters were controlled: pH, residence time, and Mg:P ratio. After precipitation, the phosphorus recovery efficiency for the runs were each evaluated and analyzed in order to determine the effects of the parameters on phosphorus recovery. The precipitate of the run with the highest phosphorus recovery obtained was then evaluated using XRD analysis. It was found that the sample with the highest phosphorus recovery is 53.12%, which was achieved at pH 9, a residence time of 1 hour, and an Mg:P ratio of 1.5:1. Therefore, it can be concluded that precipitation subjected at pH 9 has the highest potential for higher phosphorus recovery. Further, the residence time has a minimal effect on phosphorus recovery and higher phosphorus recovery can be achieved at a higher Mg:P ratio with increasing potential for struvite recovery.
Simulation of Natural Gas Dispersion and Explosion in Vented Enclosure using 3D CFD FLACS Software
Authors: Juwari  , Handogo Renanto , Cahyono Teguh , Safarudin Mochamad , Panca Anugraha Rendra , Aulia Fadhilatul , Dwi Kurniaty Nuvies , Reza Habibi Muhamad , Nuur Kharisma Muhammad 
Published: May 2020

Abstract
Natural gas is used as fuel in industries, power plants, commercial installations, and households. In its application, natural gas leaks can be considered as a major hazard because of its flammable and explosive nature. In addition to fuel, heat and oxygen sources, fires and explosions can occur if the concentration of natural gas in the air is between Low Flammable Limit (LFL) and Upper Flammable Limit (UFL). If the release of natural gas is not ignited, it will immediately form a Vapor Cloud Explosion (VCE) that can cause an explosion if it meets ignition point. Therefore, a research on dispersion patterns in a particular area or space is needed to minimize hazards and to develop safety procedures and regulations. This research aims to determine the external parameters that affect the dispersion and explosion caused by natural gas by using FLACS software from PT. Gexcon Indonesia. This software can display overpressure graphs of time and 3D visuals of simulations. The external parameters consist of vent size (5.4 m2 and 2.7 m2), wind direction, lighter position (center and back), day and night condition, and the presence of a obstacle (with and without obstacle). From the research results by the simulations, it is obtained that the highest overpressure value when there is an obstacle with a vent size of 2.7 m2; wind direction from the north; night condition, and back ignition point is 0.503 bars at 40, 835 s which can cause most buildings to collapse and the death rate to increase.
Integrated life cycle assessment-analytic hierarchy process (LCA-AHP) with sensitivity analysis of phosphorus recovery from wastewater in Metro Manila
Authors: Pausta Carla Mae J. , Razon Luis F. , Orbecido Aileen H. , Saroj Devendra P. , Promentilla Michael Angelo B. 
Published: May 2020

Abstract
The adverse environmental impact caused by eutrophication has recently prompted the Philippine government to issue stringent regulatory standards for wastewater effluent quality. The involved stakeholders and industries are assessing the integration of biological nutrient removal (BNR) technologies in the current sewage treatment plant (STP) scenario. Moreover, efforts are being done to utilize wastewater as a resource such us recovery of nutrients as struvite fertilizer from the wastewater sludge. Since BNR and nutrient recovery systems are not yet integrated in STPs, the magnitude of the environmental impacts are yet to be evaluated in the Philippine setting. This study covers the holistic evaluation of the overall environmental performance scores of the following scenarios using a consequential Life Cycle Assessment (LCA) framework integrated with Analytic Hierarchy Process (AHP) in the context of Water-Energy-Food Nexus: 1) current STP scenario; 2) BNR technology; and 3) nutrient recovery system. The environmental impact assessment was done using IMPACT 2002+ methodology in terms of the following impact indicators: human health, ecosystem quality, climate change, resources, aquatic acidification, and aquatic eutrophication. Value judgments from relevant stakeholders were elicited to rank the relative importance of the impact indicators in the evaluation of the overall environmental performance score. The LCA-AHP results show that the integration of a nutrient recovery system is the most preferred scenario. Sensitivity analysis was also done to evaluate the effects of changes in diet and utilization of alternative energy.
Dynamic simulation of insulin-glucose interaction in type 1 diabetes with MATLAB Simulink®
Authors: Mufti Azis Muhammad , Kristanto Jonas , Sarto  
Published: May 2020

Abstract
Diabetes is a complex multifactorial disease where a person endures hyperglycemia in a long period. There have been large interest to perform dynamic simulation of insulin-glucose interaction to obtain a new insight of glucose homeostasis in a diabetic patient. Type 1 diabetes is characterized by the inability of β-cell in the pancreas to produce insulin and hence type 1 diabetes patient needs continuous insulin injection throughout their lives. Here, an educational module for process control in chemical engineering education has been developed to describe the insulin-glucose interaction. The model used an extended version of the minimal model (Bergman model) to simulate the interaction of insulin-glucose using state-space and SIMULINK. The state-space model development through classic linearization method followed by open-loop as well as a closed-loop simulation in SIMULINK was presented. The model was then used to simulate the meal disturbance over 24 h of simulation time. Various PI parameters were compared based on ITAE tuning methods in order to evaluate the dynamics of insulin-glucose interaction.
Adsorption of Ammonium Ions Using Activated Carbon Derived from Artocarpus odoratissimus Skin
Authors: Anisuzzaman S M , Zahrim A Y , Rajin M , Saalah S , Ismail N M , Duraim R , Krishnaiah D 
Published: May 2020

Abstract
Wastewater consists of various contaminants including ammonium ions, which are toxic to aquatic life if the concentration exceeds the standard limit. The need for finding an effective treatment to remove the pollutant is crucial, as it is difficult to remove it due to its resistance and tenacity to the environment. In this study, Artocarpus odoratissimus or commonly known as “Tarap” skin (TS) was used as a precursor for the preparation of activated carbon (AC) by two-step KOH activation. The TS was pyrolysed first at 350°C prior to KOH activation at 1:1 of impregnation ratio and 800oC of activation temperature under nitrogen gas flow in a tubular furnace. Percentage of yield, surface area, and porosity, morphology structure, surface functionalities and as well as the ability of TS based AC to adsorb ammonium ions were investigated and analysed. The properties of carbon showed that the carbon yield produced was 18.5% with a 1372.51 m2/g of surface area, 0.6756 cm3/g of pore volume and 2.1453 nm of average pore radius. The adsorption capacity of carbon at equilibrium was 1.858 mg/g. The isotherm model and kinetic study for adsorption of ammonium ions were studied using Langmuir and Freundlich, Pseudo-first order and Pseudo-second order, respectively. The equilibrium data obey the Langmuir isotherm model with the highest correlation (R
2 = 0.9373). As for the kinetic study, the adsorption process follows Pseudo-second order, which has R
2 value of 0.9964 and adsorption capacity, qe
of 1.737 mg/g.
Attitude and Perception on The Disposal of Pharmaceuticals and Personal Care Products In Malaysia: A Pilot Study
Authors: Binti Muhamad Marina , Binti Mohamed Zuki Fathiah 
Published: May 2020

Abstract
Pharmaceutical and personal care products (PPCPs) are common products being used widely and easily accessible to everyone. While it is beneficial for human use, the adverse effects once introduced to the ecosystem are alarming. Studies also show that PPCPs penetrated the surface water bodies. Numerous studies have proven that the occurrences of PPCPs especially in the water bodies have given substantial effects towards animals especially those associated with water. This trace has changed the physical features of the animals and has significantly reduced the amount of the species at the area. Even though the amount of PPCPs being introduced to the environment increasing based on the usage by consumers, a lot of studies have been carried out to remove the PPCPs from the environment using advanced technologies. Considering the feasibility of the technologies to be implemented, most of these novelties are yet to be installed in the water treatment plant due to its installation cost, maintenance fees and shortage of skilled operators to operate the machinery. Although the advanced technologies are highly reliable to remove the PPCPs, it is golden to tackle the issue from the grassroots level which will be the preventive measures rather than treatment actions. Hence, the main objective of this study is to evaluate the level of attitude and practice among the general public towards the PPCPs handling and disposal. This will later be translated into a baseline study so to have a guided database for future outreach programs and policy-making purposes. The method used in this study was a self-administered survey questionnaire which was distributed randomly among 44 respondents. University Malaya students were selected as the sample of this study for its feasibility and diversified characteristics demographically and socio-demographically. The data were then analysed by classifying it and studying the trends of each class to identify the gap of current practices. The study findings demonstrated that although most of the respondents do not have knowledge (77.3%; n=34) on PPCPs, their attitude toward the disposal of PPCPs is highly positive. However, even though the attitude perceived is positive toward the PPCPs waste handling techniques, the actual practice is showing otherwise. The lack of knowledge, proper facilities for disposal and guidelines found to be the main contributing factors to such practices. Finally, this study found that knowledge and attitude per se will not be enough to achieve good practices in handling the disposal of PPCPs to control the penetration of the traces into the environment. Unless there are enough designated facilities for the disposal and proper guidelines on the disposal manners to facilitate for the general public is being introduced, only then the good attitude that was shown can be delivered to prevent more PPCPs being introduced to the environment.
Development of recovery technology of valuable metals from sea water
Authors: San J. , Onoe K. 
Published: May 2020

Abstract
From the viewpoint of resource recovery, the characteristics of seawater can be expressed as “a multicomponent aqueous solution with a wide range of concentration distribution”. In salt production and desalination processes, production rates of recovery target components are calculated according to needs, and separation engineering of components based on membrane separation and crystallization operations are developed cleverly. The purpose of this study is to apply for changes in needs of valuable metals expected in the future. In order to recover valuable resources from brines, applied technologies considering for environmental conservation should be required. In this paper, we set up bivalent metal ions of Mg2+, Ca2+, Ba2+ and Sr2+ as the components to be recovered from seawater, and the systematic recovery method of bivalent metal ions using isothermal reactive crystallization of carbonate is proposed.