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Adsorption kinetic modeling using pseudo-first order and pseudo-second order rate laws: A review

Year: 2020
Type: article
Abstract: Adsorption for water and wastewater treatment has been the subject of many research in the scientific community, focusing mainly on either equilibrium or kinetic studies. Adsorption kinetics are commonly modeled using pseudo-first and pseudo-second order rate laws. Analyses of published works in the past two decades indicated that the pseudo-second order is considered to be the superior model as it can represent many adsorption systems. However, critical assessment of modeling techniques and practices suggests that its superiority could be a consequence of currently acceptable modeling norms which tend to favor the pseudo-second order model. The partiality was due to several modeling pitfalls that are often neglected. In addition, commonly used model validation tools are often used haphazardly and redundantly. As such, they cannot sufficiently provide any kind of certainty on the validity of a model. To eliminate modeling biasness, a new validation method was proposed and was then employed to re-examine previously published adsorption kinetic data.
DOI: 10.1016/j.clet.2020.100032
Language: English
Open Access status: gold
Estimated APC paid: $2,220
Award: HUMAN EXPLORATION ACTIVITIES ON CELESTIAL BODIES SUCH AS THE MOON AND MARS WILL PRODUCE HUMAN LIFE SUPPORT-DERIVED WASTES AND CONSUME FUEL WATER AND OXYGEN. KEY WASTE STREAMS TO BE EXPECTED INCLUDE (1) BLACK WATER (TOILET-DERIVED); (2) FOOD WASTES (KITCHEN-DERIVED); AND (3) GREY WATER (AKA. HYGIENE WATER). FURTHER WATER AND OXYGEN WILL BOTH NEED TO BE CONSERVED AND RECYCLED. THEREFORE TO SUSTAIN HUMAN LIFE DURING EXTENDED OFF-EARTH EXCURSIONS RECOVERY OF THE CARBON OXYGEN AND HYDROGEN ALONG WITH THE MICROCHEMICALS MAKING UP THE FOOD WATER AND AIR PROVIDED TO THE ASTRONAUTS IS NEEDED TO REDUCE THE FREQUENCY OF EXPENSIVE MAKEUP DELIVERIES OF THESE LIFE SUPPORT PRODUCTS. THE TECHNOLOGY USED TO RECOVER RESOURCES MUST OPERATE USING COMPACT LOW WEIGHT DESIGNS; UTILIZE MINIMAL ENERGY AND OXYGEN FOOTPRINTS; BE SIMPLE TO OPERATE WITH LOW MAINTENANCE; AND RECOVER A HIGH PERCENTAGE OF THE LIFE SUPPORT RESOURCE CHEMICALS THAT CAN PLACED BACK INTO BENEFICIAL USE. THE IDEAL SYSTEM SHOULD ALSO BE FLEXIBLE AND CONTAIN BUILT-IN FAILSAFE MECHANISMS THAT CAN ADJUST AS UNPLANNED EVENTS OCCUR; YET MAINTAIN OPERATIONAL CAPACITY. THE PROPOSED BIOCHEMICAL CONVERSION SYSTEM (BIOSYS) WILL EFFECTIVELY TREAT ALL HUMAN ACTIVITY-DERIVED WASTE (BLACK WATER GREY WATER AND FOOD WASTE STREAMS) WHILE PRODUCING BENEFICIAL BY-PRODUCTS: FUELS RECYCLED POTABLE WATER OXYGEN PROTEIN CAKE AND MACHINERY LUBE OILS. THE BIOSYS CONCEPT IS BASED ON A SERIES OF SUCCESSFUL PROJECTS PERFORMED BY THE PROJECT TEAM OVER THE PAST 15 YEARS THAT FOCUSED ON CONVERTING WASTEWATER INTO VALUE-ADDED PRODUCTS. THE KEY DEVELOPMENT GOALS FOR THE BIOSYS PROJECT ARE (A) BE ENERGY AND OXYGEN USE NEUTRAL; (B) HAVE A COMPACT PROCESS FOOTPRINT AND LOW PAYLOAD WEIGHT; (C) BE CAPABLE OF TREATING WATER AND AIR TO REUSABLE QUALITIES; AND (D) BE CAPABLE OF PRODUCING CO-PRODUCTS THAT CAN ALSO BE USED FOR LIFE SUPPORT. THE PRIMARY BIOSYS CONCEPT DESIGN UTILIZES A SERIES OF TREATMENT STEPS TO CONVERT WASTEWATER CONSTITUENTS AND CABIN CO2 INTO RECOVERED BENEFICIAL LIFE SUPPORT PRODUCTS. THE DESIGN IS COMPOSED OF BOTH ANAEROBIC AND AEROBIC BIOREACTOR UNITS; LIPIDS EXTRACTION; A MICROALGAE REACTOR; AND AN ADSORPTION POLISHING STEP. THIS DESIGN RESULTS IN THE TREATMENT OF THE CONTAMINANTS IN THE WATER TO ESSENTIALLY ZERO CONCENTRATIONS. SEVERAL PRODUCTS WILL BE PRODUCED AS SYSTEM OUTPUTS: (1) HYDROGEN - FUEL FOR FUEL CELLS; (2) METHANE - ALSO AS FUEL FOR FUEL CELLS OR POTENTIALLY FED INTO THE AEROBIC BIOREACTOR FOR PRODUCING MORE PROTEIN AND/OR LIPIDS; (3) RECOVERED O2 - RECYCLED BACK INTO THE CABIN ENVIRONMENT; (4) LIPIDS - PRODUCTION OF GREEN LUBE OILS OR USED AS A NUTRACEUTICAL; (5) PROTEIN CAKE (WITH OR WITHOUT LIPIDS) - A FOOD SOURCE; (6) SOIL AMENDMENTS - FERTILIZER; AND (7) RECOVERED WATER - RECYCLED AS POTABLE WATER. ONE CHALLENGE COULD BE OXYGENATING THE AEROBIC UNIT WHICH CAUSES AN OXYGEN SINK THAT MAY BE TOO COSTLY. HENCE TO REDUCE ENERGY/OXYGEN USE A DESIGN OPTION WHICH ELIMINATES THE AEROBIC STAGE AND REPLACES IT WITH A PASSIVE SOLIDS SEPARATOR WILL BE CONSIDERED. THE RESEARCH PLAN INVOLVES EVALUATION OF EACH UNIT OPERATION PERFORMANCE VIA SMALL REACTOR SYSTEMS OPERATED USING A WIDE VARIATION OF FEED RATES AND COMPOSITION TO TEST NORMAL AND STRESSED PERFORMANCE. OPTIMIZED INDIVIDUAL UNITS WILL BE INTEGRATED INTO A BENCH SYSTEM THAT WILL IN TURN BE EVALUATED FOR ITS OPERATIONAL PERFORMANCE UNDER STRESS. MASS AND ENERGY BALANCES ACROSS THE ENTIRE SYSTEM AND IN BETWEEN EACH UNIT OPERATION WILL BE USED TO OPTIMIZE THE PERFORMANCE OF THE BENCH SYSTEM. A PILOT SYSTEM WILL BE CONSTRUCTED BASED ON THE WORK DONE IN THE BENCH PHASE AND ITS PERFORMANCE WILL BE EVALUATED. PAYLOADS AND SYSTEMS OPERATION PROTOCOLS WILL BE EVALUATED AND INCLUDED AS PART OF A COMPREHENSIVE DESIGN EVALUATION. PUBLICATIONS INCLUDING REPORTS PEER-REVIEWED PAPERS AND PRESENTATIONS WILL BE KEY PRODUCTS ALONG WITH OUTREACH TO RECRUIT FUTURE STEM MAJORS INTERESTED IN SPACE EXPLORATION.
OpenAlex ID: W3112726656
FWCI: 26.75
Cites: 46
Cited by: 1,487
Related to: 10