Electrocoagulation/Flotation Treatment of Synthetic Surface Water

Rainfall generated surface runoff water could contaminate groundwater through transportation of suspended solids and organic matter in to the aquifer. Surface runoff water composition mainly depends on soil amendment. Surface runoff mainly contains clay, minerals, organic and inorganic matter, total dissolved lead, zinc. ECF technology presents an alternative for the removal of total suspended solids, turbidity, and organic matter from generated surface runoff water. This research presents development of bench scale ECF unit for the treatment of synthetic surface water. Experiments were conducted in a 10 liter Plexiglas unit provided with two aluminum electrodes, one serving as cathode, and other as anode. Direct current was applied to the electrodes by an external power supply. Optimal operational parameters were varied depends up on strength of the surface water. For low strength synthetic surface water the optimal operational variables were determined as an applied current of I = 2 ampere and a treatment time of 30 minutes. The overall turbidity removal efficiency was found to be 80 and transmittance was found 94.1 under such conditions. For medium strength synthetic water the optimal operational variables were determined as an applied current of I = 3 ampere and a treatment time of 30 minutes. The overall turbidity removal efficiency was found 70 and transmittance was found 93 under such conditions. Further experimentation was carried out on the determination combined maximum organic matter and turbidity removal efficiencies. Effect of chemical coagulants lime, aluminum sulfate octa decahydrate and ferric sulfate in ECF treatment was investigate

Electrocoagulation/Flotation Treatment of Synthetic Surface Water

Rainfall generated surface runoff water could contaminate groundwater through transportation of suspended solids and organic matter in to the aquifer. Surface runoff water composition mainly depends on soil amendment. Surface runoff mainly contains clay, minerals, organic and inorganic matter, total dissolved lead, zinc. ECF technology presents an alternative for the removal of total suspended solids, turbidity, and organic matter from generated surface runoff water. This research presents development of bench scale ECF unit for the treatment of synthetic surface water. Experiments were conducted in a 10 liter Plexiglas unit provided with two aluminum electrodes, one serving as cathode, and other as anode. Direct current was applied to the electrodes by an external power supply. Optimal operational parameters were varied depends up on strength of the surface water. For low strength synthetic surface water the optimal operational variables were determined as an applied current of I = 2 ampere and a treatment time of 30 minutes. The overall turbidity removal efficiency was found to be 80 and transmittance was found 94.1 under such conditions. For medium strength synthetic water the optimal operational variables were determined as an applied current of I = 3 ampere and a treatment time of 30 minutes. The overall turbidity removal efficiency was found 70 and transmittance was found 93 under such conditions. Further experimentation was carried out on the determination combined maximum organic matter and turbidity removal efficiencies. Effect of chemical coagulants lime, aluminum sulfate octa decahydrate and ferric sulfate in ECF treatment was investigate

Electrocoagulation/Flotation Treatment of Synthetic Surface Water

Rainfall generated surface runoff water could contaminate groundwater through transportation of suspended solids and organic matter in to the aquifer. Surface runoff water composition mainly depends on soil amendment. Surface runoff mainly contains clay, minerals, organic and inorganic matter, total dissolved lead, zinc. ECF technology presents an alternative for the removal of total suspended solids, turbidity, and organic matter from generated surface runoff water. This research presents development of bench scale ECF unit for the treatment of synthetic surface water. Experiments were conducted in a 10 liter Plexiglas unit provided with two aluminum electrodes, one serving as cathode, and other as anode. Direct current was applied to the electrodes by an external power supply. Optimal operational parameters were varied depends up on strength of the surface water. For low strength synthetic surface water the optimal operational variables were determined as an applied current of I = 2 ampere and a treatment time of 30 minutes. The overall turbidity removal efficiency was found to be 80 and transmittance was found 94.1 under such conditions. For medium strength synthetic water the optimal operational variables were determined as an applied current of I = 3 ampere and a treatment time of 30 minutes. The overall turbidity removal efficiency was found 70 and transmittance was found 93 under such conditions. Further experimentation was carried out on the determination combined maximum organic matter and turbidity removal efficiencies. Effect of chemical coagulants lime, aluminum sulfate octa decahydrate and ferric sulfate in ECF treatment was investigate

Iron and Magnesium Impregnation of Avocado Seed Biochar for Aqueous Phosphate Removal

There has been increasing interest in using biochar for nutrient removal from water, and its application for anionic nutrient removal such as in phosphate (PO43−) necessitates surface modifications of raw biochar. This study produced avocado seed biochar (AB), impregnated Fe- or Mg-(hydr)oxide onto biochar (post-pyrolysis), and tested their performance for aqueous phosphate removal. The Fe- or Mg-loaded biochar was prepared in either high (1:8 of biochar to metal salt in terms of mass ratio) or low (1:2) loading rates via the co-precipitation method. A total of 5 biochar materials (unmodified AB, AB + High Fe, AB + Low Fe, AB + High Mg, and AB + Low Mg) were characterized according to their selected physicochemical properties, and their phosphate adsorption performance was tested through pH effect and adsorption isotherm experiments. Fe-loaded AB contained Fe3O4, while Mg-loaded AB contained Mg(OH)2. The metal (hydr)oxide inclusion was higher in Fe-loaded AB. Mg-loaded AB showed a unique free O–H functional group, while Fe-loaded AB showed an increase in its specific surface area more than 10-times compared to unmodified AB (1.8 m2 g−1). The effect of the initial pH on phosphate adsorption was not consistent between Fe-(anion adsorption envelope) vs. Mg-loaded AB. The phosphate adsorption capacity was higher with Fe-loaded AB in low concentration ranges (≤50 mg L−1), while Mg-loaded AB outperformed Fe-loaded AB in high concentration ranges (75–500 mg L−1). The phosphate adsorption isotherm by Fe-loaded AB fit well with the Langmuir model (R2 = 0.91–0.96), indicating the adsorptive surfaces were relatively homogeneous. Mg-loaded biochar, however, fit much better with Freundlich model (R2 = 0.94–0.96), indicating the presence of heterogenous adsorptive surfaces. No substantial benefit of high loading rates in metal impregnation was found for phosphate adsorption. The enhanced phosphate removal by Mg-loaded biochar in high concentration ranges highlights the important role of the chemical precipitation of phosphate associated with dissolved Mg2+

Iron and Magnesium Impregnation of Avocado Seed Biochar for Aqueous Phosphate Removal

There has been increasing interest in using biochar for nutrient removal from water, and its application for anionic nutrient removal such as in phosphate (PO43−) necessitates surface modifications of raw biochar. This study produced avocado seed biochar (AB), impregnated Fe- or Mg-(hydr)oxide onto biochar (post-pyrolysis), and tested their performance for aqueous phosphate removal. The Fe- or Mg-loaded biochar was prepared in either high (1:8 of biochar to metal salt in terms of mass ratio) or low (1:2) loading rates via the co-precipitation method. A total of 5 biochar materials (unmodified AB, AB + High Fe, AB + Low Fe, AB + High Mg, and AB + Low Mg) were characterized according to their selected physicochemical properties, and their phosphate adsorption performance was tested through pH effect and adsorption isotherm experiments. Fe-loaded AB contained Fe3O4, while Mg-loaded AB contained Mg(OH)2. The metal (hydr)oxide inclusion was higher in Fe-loaded AB. Mg-loaded AB showed a unique free O–H functional group, while Fe-loaded AB showed an increase in its specific surface area more than 10-times compared to unmodified AB (1.8 m2 g−1). The effect of the initial pH on phosphate adsorption was not consistent between Fe-(anion adsorption envelope) vs. Mg-loaded AB. The phosphate adsorption capacity was higher with Fe-loaded AB in low concentration ranges (≤50 mg L−1), while Mg-loaded AB outperformed Fe-loaded AB in high concentration ranges (75–500 mg L−1). The phosphate adsorption isotherm by Fe-loaded AB fit well with the Langmuir model (R2 = 0.91–0.96), indicating the adsorptive surfaces were relatively homogeneous. Mg-loaded biochar, however, fit much better with Freundlich model (R2 = 0.94–0.96), indicating the presence of heterogenous adsorptive surfaces. No substantial benefit of high loading rates in metal impregnation was found for phosphate adsorption. The enhanced phosphate removal by Mg-loaded biochar in high concentration ranges highlights the important role of the chemical precipitation of phosphate associated with dissolved Mg2+

Assessment of Biocatalytic Production Parameters to Determine Economic and Environmental Viability

The minimum selling price (MSP), specific energy consumption, and greenhouse (GHG) emissions resulting from biobased production of adipic acid, succinic acid, 1,3-propanediol, 3-hydroxy propionic acid, and isobutanol were estimated for various combinations of titer, yield, and volumetric productivity. The MSP, energy consumption, and GHG emissions of anaerobic biobased commodity chemical processes were found to be nearly the same for a given titer, yield, and productivity. The estimated MSP of biobased commodity chemicals produced via aerobic respiration was found to be nearly 30% higher than those of produced through anaerobic fermentation. It was determined that biocatalyst yields of ≥0.32 g/g and titers of ≥45 g/L result in lower production cost, energy consumption, and GHG emissions, when compared to conventional petrochemical production processes. The economic and environmental benefits of improving titer beyond 125 g/L and volumetric productivity beyond 2 g/L·h were found to be low when producing biobased commodity chemicals using a biocatalyst. Comparative economic analysis indicated that provision of feedstock is the dominant cost in commercially viable biobased commodity chemical production systems

Fast Pyrolysis of Lignin Pretreated with Magnesium Formate and Magnesium Hydroxide

Kraft lignin (Indulin AT) pretreated with magnesium formate and magnesium hydroxide was fast-pyrolyzed in a continuously fed, bench-scale system. To avoid fouling issues typically associated with lignin pyrolysis, a simple laboratory test was used to determine suitable ranges of magnesium hydroxide and formic acid to lignin for feeding without plugging problems. Various feedstock formulations of lignin pretreated with magnesium hydroxide and formic acid were pyrolyzed. For comparison, calcium formate pretreated lignin was also tested. The organic oil yield ranged from 9% to 17% wt % on a lignin basis. Carbon yields in the oil ranged from 10% to 18% wt % on a lignin basis. Magnesium formate pretreatment increased oil yield and carbon yield in the oil up to 35% relative to the higher 1:1 g magnesium hydroxide/g lignin pretreatment. However, a lower magnesium hydroxide pretreatment (0.5:1 g magnesium hydroxide/g lignin) resulted in oil yields and carbon yields in the oils similar to the magnesium formate pretreatments. Magnesium formate pretreatment produced more oil but with a higher oxygen content than calcium formate under the same conditions. The GC-MS analysis of product oils indicated that phenols and aromatics were more prevalent in pyrolyzed magnesium-formate-pretreated lignin

Heuristics To Guide the Development of Sustainable, Biomass-Derived, Platform Chemical Derivatives

Hundreds of catalytic routes to upgrade biomass-derived platform chemicals have been proposed. In this study, we developed process selection and development heuristics for these catalytic transformations from techno-economic analysis of catalytically upgrading furfural (a potential platform chemical) to eight derivatives that vary in chemical functionality and process complexity. These heuristics included simple cost equations based on catalyst performance as well as process complexity to predict the minimum selling price of platform chemical derivatives. Additionally, design rules were developed to guide the development of catalytic technologies for upgrading platform chemicals. The conversion of platform chemicals to hydrocarbons must be avoided. For commercial relevance, attaining catalyst yield of 60% and weight hourly space velocity of at least on the order of 0.1 h^–1 are necessary. Precious metal catalysts, such as Pt, cannot be used if the desired platform chemical derivative is priced below 1.00 (US$/kg). Finally, it has been learned that the feasible plant size of platform chemical production is comparable to that of a lignocellulosic-based biofuel production