Tank Batch Research Articles

Novel calcium-rich biochar synthesis and application for phosphorus and amoxicillin removal from synthetic and urban wastewater: Batch, columns, and continuous stirring tank reactors investigations

This work examines the synthesis of a novel calcium rich biochar (MB-900) and its application for phosphorus (P) and amoxicillin removal from synthetic and treated urban wastewaters under static and dynamic conditions (laboratory column and continuous stirring tank reactors (CSTRs)). Characterization techniques show that MB-900 has an enhanced structural, textural and surface chemical properties. Besides, batch adsorption tests indicate that MB-900 has important P recovery capacity in comparison with various engineered biochars available in the literature. Furthermore, under dynamic conditions, MB-900 efficiently recovers P from both synthetic solutions and real wastewater effluent. Due to a higher residence time, P recovery in CSTR mode are 94.9 and 82.3 mg g−1 for synthetic and urban wastewater, respectively. These values are 1.4, and 6.1 times higher than those obtained in column tests. Mechanism investigations shows that P recovery occurs through electrostatic interactions, complexation, and especially precipitation as hydroxyapatite. Under column and CSTR modes, AMX behaves like a conservative tracer and was not adsorbed by MB-900. Therefore, the resulting P-loaded biochar can be applied in agriculture as a slow release fertilizer without risks related to AMX adsorption/leaching by plants.

Pressure exchanger batch reverse osmosis with zero downtime operation

Batch reverse osmosis is a transient, pressure-driven desalination process that concentrates a given volume of feed over time by continuously recirculating the brine through the membrane module. Since it can closely follow the osmotic pressure of the brine, batch reverse osmosis consumes much less energy than conventional reverse osmosis. However, one of the key challenges with batch and semi-batch reverse osmosis has been to reduce the downtime required for recharging membrane module, pipes and batch tanks with fresh feed at the end of a batch. In this article, we describe a pressure exchanger batch reverse osmosis process that uses a set of two atmospheric pressure tanks which switch at the end of a cycle. Permeation through the membranes is held constant throughout the process, even during flushing, to effectively have zero downtime. The proposed system uses off-the-shelf components, can handle variable recovery, and is easy to scale-up and maintain. We study the system using a reduced order model that can capture external concentration polarization, non-ideal salt rejection, and osmotic backwash. The design is extended to a 100,000 gal per day capacity plant that demonstrates the scalability of the process while operating with a 2nd law efficiency of 48.2 %.

Cement encapsulation processes to mitigate the risks posed by different types of antimony-bearing mine waste

In this study cement encapsulation processes of different types of mine waste generated from the exploitation of Sb ore deposits were evaluated as a way to manage them and avoid further environmental pollution and the negative impact on surrounding ecosystems. For this purpose, Sb-bearing mine waste rocks, mine tailings, and smelting waste were subjected to cementation processes using Portland cement/calcium hydroxide as binder and different binder:mine waste ratios (10:90–80:20 wt%). The encapsulated materials were characterized for their mechanical behavior (compressive strength test), leaching properties (batch shaking and tank leaching tests), and mineralogical and chemical composition by X-ray powder diffraction, scanning electron microscopy, and electron microprobe analysis. A binder:mine waste ratio of 40:60 wt% was found appropriate to decrease the leachable Sb concentrations at levels below the limit for acceptance at non-hazardous waste landfills. Diffusion was the main mechanism controlling Sb leaching. The obtained effective diffusion coefficients and developed compressive strengths indicate that the encapsulated materials were suitable for disposal. Therefore, according to their leaching and strength characteristics, the encapsulated mine wastes derived using the indicated conditions could be deposited at landfills for non-hazardous waste, thus minimizing the environmental hazards caused by their accumulation in the mine surrounding areas. Additionally, according to the Dutch legislation on the use of waste materials in the built sector, some formulations of encapsulated mine tailings already met the Sb leaching requirement for open (un-insulated) construction applications. Therefore, Sb-bearing mine wastes, especially mine tailings, also present a great potential to be recycled as substitutes for natural aggregates in concrete in construction applications. Antimony was mostly preserved in the original Sb-bearing phases [Fe and Sb (oxyhydr)oxides and tripuhyite] after the encapsulation processes. Of compounds resulting from the hydration of Portland cement, C-(A)-S-H phases predominated, having an important role in attenuating the Sb release from the different types of mine waste; average Sb2O5 contents of 0.12–0.31 wt% were found in C-(A)-S-H phases.

Utilization Of Fly Ash In Heavy Metal Removal From Acid Mine Drainage

Acid mine drainage (AMD) contains very toxic heavy metal with strong acidity. The high concentration of heavy metals in AMD have the potential as a major contamination sources that affect human life, aquatic and other natural resources. In this study, the removal of heavy metals was carried out by using low-cost industrial waste material which is fly ash. The adsorption capacity of fly ash was determined by two methods which are batch adsorption and tank remediation test. The effects of quantity of dosage, pH and heavy metal concentration were investigated. Fly ash consist of carbonate minerals (>50%) with high potential as adsorbent material to treat acid mine. The maximum adsorption rate for fly ash occurred at pH 5 for Pb, pH 7 for Zn and pH 3 for Cu. Adsorption capacity also increased with increasing dose. Fly ash as high alkaline material remediated and neutralized AMD solution from acidic phase (pH 2.11) to neutral phase (pH 7.09). Increasing pH value during treatment process will increase the capacity of the removal of heavy metals.

Experimental investigation on biomass gasification mechanism in supercritical water for poly-generation of hydrogen-rich gas and biochar

Supercritical water gasification (SCWG) technology can realize efficient utilization of biomass. But the gasification mechanism of real biomass is relatively complicated, and complete gasification only can be realized at a relatively high temperature. Identifying reaction mechanism and realize resource utilization of biomass via SCWG technology at a more moderate condition is necessary for industrialization of this technology. In this paper, biomass gasification experiment was conducted, and the gasification mechanism was analyzed. Experiment in quartz tube reactor showed that gasification efficiency and hydrogen yield increased with time and temperature, which reached 90% 14.95 mol/kg at temperature of 700℃, reaction time of 30 min. Carbon distribution study showed that more than 90% carbon was distributed in gas and biochar, proving that SCWG could realize cogeneration of hydrogen and biochar. Thus, experiment was conducted in batch tank reactor to obtain enough liquid and solid products for further study. Reaction mechanism study showed that soybean stem was decomposed to cellulose, hemicellulose, and lignin; then cellulose and hemicellulose were converted to small molecule sugar, which can be further converted to gas; as for lignin, it was decomposed to its monomers first, then it went through de-methoxy reactions and formed gases and phenol; phenol was difficult to be decomposed and could form biochar easily. Study of pore structure evolution of biochar showed that gasification in SCW could produce abundant pore structure, and with gasification proceeding, content of pores increased greatly. Pore size of biochar obtained from gasification of 15 min mainly focused on 6.5 nm and 16 nm. More mesopore were formed at the higher temperature and the diameter of macropore size increased with temperature due to the release of volatiles.

Terrestrial anaerobic digestate composite for fertilization of oligotrophic coastal seas

To promote primary production in oligotrophic seas, we developed a fertilization composite consisting of blast furnace cement and anaerobic digestate with a high nutrient content derived from biogas power plant byproducts. In this study, we investigated the dissolution behavior of nutrients from the fertilization composite and evaluated the effects of the fertilization composite on the growth of marine primary producers. Batch experiments and tank experiments to simulate oligotrophic coastal seas revealed that the nutrients dissolved from the fertilization composite were taken up by marine microalgae and seaweed. The fertilization composite promoted the growth of both planktonic and benthic micro algae. The total amounts of chlorophyll a in the fertilization composite tank increased by 1.4 times compared to control (p < 0.01). The flow of dissolved inorganic nitrogen uptake by marine microalgae increased 3–5 times when the fertilization composite was applied. In Wakame seaweed culture experiments, the nitrogen contents of Wakame from the fertilization composite tank were 1.2 times higher than those cultured in the control tank (p < 0.01). As a result, Wakame leaves cultured in the fertilization composite tank were 1.4 times longer than those cultured in the control tank. Approximately 44% of dissolved inorganic nitrogen from the fertilization composite was taken up by the seaweed. Hence, the fertilization composite was demonstrated to enhance the growth of marine microalgae and seaweed, which are primary producers in marine ecosystems. The fertilization composite proposed in this study can create novel nutrient mass flow by connecting terrigenous anaerobic digestate from biogas power plants to oligotrophic seas and thus stimulate the recovery of fishery production.

Combination of physicochemical operations and algal culture as a new bioprocess for olive mill wastewater treatment

This work presents a new bioprocess design which allows a substantial reduction of organic and inhibitory compounds and a better quality of the final treated water. The process involves a physicochemical (primary) and a biological (microalgae) treatment, which were tested separately with lab equipment, for olive oil mill wastewater (OMW). Primary treatment of OMW involved flocculation-sedimentation by Flocudex CS-51 and microfiltration using a 0.2 μm membrane. Secondary treatment consisted of Scenedesmus obliquus culture in different OMW dilutions in ultrapure water as culture media: 5, 10, 25, 50, 75 and 100%. Experiments were performed on a laboratory scale in stirred batch tank reactors. The common operating conditions were: pH = 7, temperature = 25 °C, agitation rate = 3.33 Hz, aeration rate = 0.5 min−1 and illumination intensity = 359 μE m−2 s−1. High global removal levels were achieved after primary treatment for chemical oxygen demand (92.6%), total phenolic compounds (98.9%), total organic carbon (75.9%), total nitrogen (63.5%) and inorganic carbon (55.3%). Similar results were obtained for the main OMW constituents after secondary treatment with final harvested biomass rich in energetic compounds, where the highest values of carbohydrates (72.5%) in culture with 5% OMW and lipids (44.9%) in 100% OMW culture were determined.

Advancing the robust manufacture of t-cell therapies through the application of stirred tank bioreactors

Background & Aim With over 90 active trials in the United States with many more in pre-clinical phases T-Cell immunotherapies represent a large share of the expansion we are observing in the regenerative medicine industry. While CAR-T therapies have dominated the headlines, other technologies such as TCR, TIL, Treg, CAR-NK, γδ T-Cells have shown impressive results the oncologic space and elsewhere, however a robust manufacturing process is required to realize these solutions in the clinic. A main hurdle in establishing a robust manufacturing process for these therapies is a lengthy expansion period is typically necessary to reach a relevant dose of therapeutic cells. This only becomes more critical as allogeneic cell therapies become a reality. The issues with current culture methods present with a high cost of goods, increased production timelines, and highly variant expansion rates. Methods, Results & Conclusion At Hitachi Chemical Advanced Therapeutic Solutions, we investigated stirred tank bioreactors as an alternative to standard static and rocking motion culture methods using the ambr15 microbioreactor system and confirming those results in a two liter stirred tank bioreactors. Because of the extensive history stirred tank bioreactors have in cell culture we have demonstrated that a power input of 7.5 W/m3 does not create undo shear stress on T-Cells and were able to directly translate that parameter from the 15mL scale to the 2L. This work focused on defining the specific parameters that would facilitate stirred tank bioreactors as a unique solution for the manufacture of both autologous and allogeneic T-cell therapies with high rates of mass and gas transfer and established process control methods. Given these advantages, a comparison study of T-cells expanded in the stirred tank bioreactor and batch fed static cultures resulted in a three-fold increase in total cell number with the bioreactors. Further development of stirred tank culture methods has demonstrated five population doublings over an eight-day culture period. These outcomes indicate at a T-cell expansion method that could expand the potential of the revolutionary therapies through reduced media requirements, shortened culture periods, and high yields. By further utilizing established techniques in cell culture, T-cell therapies become increasingly viable treatments for a range of indications.

Development of the chemical reactor V-star for continuous flow reactions

This article illustrates the new modeled reactor, that allows to change the process of the flow chemical reaction from batch tank to the continuous mode. The stage efficiency form 1 (ideal plug flow, IPF) to 50 stages in a continuous stirrer tank reactor (CSTR) was plotted and illustrated graphically. Moreover, the descriptions and possibilities of the new reactor (V-star) such as: temperature control, numbers of stages, movement-speed of the reactors platform are also shown in this paper work.

Integrated process for olive oil mill wastewater treatment and its revalorization through the generation of high added value algal biomass

The two-phase continuous centrifugation process for olive oil extraction generates high amounts of olive oil mill wastewater (OMW), characterized by containing large concentrations of numerous contaminant compounds for the environment. An integral process based on physico-chemical (flocculation, photolysis and microfiltration) and microalgal growth stages was proposed for its treatment. Chemical oxygen demand (COD) removal percentages were 57.5%, 88.8% and 20.5% for flocculation, photolysis and microfiltration, respectively. The global removal percentages of organic load in the primary treatment were 96.2% for COD, 80.3% for total organic carbon (TOC) and 96.6% for total phenolic compounds (TPCs). In secondary treatment, different experiments using the microalgae Chlorella pyrenoidosa were performed on a laboratory scale in stirred batch tank reactors. The OMW concentrations in each culture medium were: 5%, 10%, 25%, 50%, 75% and 100% (v/v). The common experimental conditions were: pH = 7, temperature = 25 °C, agitation speed = 200 rpm, aeration rate = 0.5 (v/v) and illumination intensity = 359 μE m−2 s−1. The highest maximum specific growth rate (0.07 h−1) and volumetric biomass production (1.25 mg/(L h)) values were achieved in the culture with 50% of OMW (v/v). The final biomass obtained had a high percentage of carbohydrates, whose content ranged from 30.3% to 89.2% and the highest lipid content (34.2%) was determined in the culture with 25% of OMW (v/v). The final treated water is suitable for its use in irrigation, discharge to receiving waters or for being reused in the same process.

Uranium Resource Recovery from Desalination Plant Feed and Reject Water Using Amidoxime Functionalized Adsorbent

With global demand for nuclear power expected to rise, new nuclear fuel resources must be explored to ensure the viability and sustainability of nuclear power. Uranium recovery from seawater is one potential source, though the low concentration of uranium in seawater is a significant obstacle. As a concentrate of seawater, desalination brine reject would have a significantly higher uranyl concentration. In this work, the adsorption of uranium and competing ions in brine reject is investigated. Adsorption experiments were performed over 84 days in 5-gallon batch tanks with amidoxime adsorbents and samples taken from the feed seawater and reverse osmosis brine reject of the Tampa Bay Desalination Plant. The aqueous concentration and adsorbed mass of uranium, zinc, copper, iron, vanadium, calcium, and magnesium were determined through inductively coupled plasma mass spectroscopy. Aqueous adsorption modeling was used to simulate speciation and adsorption of these ions under the experimental conditions. The ad...

Improvement of MSBR Process for Treatment of Sand-laden Sewage

The influent of a sewage treatment plant was mainly composed of domestic sewage. Modified Sequencing Batch Reactor (MSBR) process was adopted, in order for the design effluent quality to meet the first level B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918 - 2002). High Sand content in the influent caused operational problems such as poor aeration in sequencing batch tank, high sediment content and siphon effect in the effluent of MSBR. The problems were solved by analyzing the reasons and taking improvement measures, thus ensuring the effluent quality to meet the discharge standard.

Comparing Different Schemes of Agricultural Wastewater Lagooning: Depuration Performance and Microbiological Characteristics

Since the number of factors influencing depuration efficiency and energy requirement is high, the choice of the most suitable aeration scheme in aerated lagooning systems treating agricultural wastewater is a difficult task. This study provides technicians and researchers with guidelines on air diffuser position, presence of inoculum and characteristics of microbial mass, focusing organic matter degradation and energy performance of aerated ponds treating citrus processing wastewater. Four experimental batch tanks were set up: three tanks were subject to low air flow rates and times, while a fourth tank was not aerated. The organic matter degradation in the aerated tanks was on average six times higher compared to the non-aerated tank. Positioning the air diffuser at mid-depth and consequent separation of tank contents into two layers determined a decrease in the depuration performance, presumably due to the reduced transfer of oxygen to wastewater. Although the ability of spontaneous microflora to adapt to essential oil concentrations up to 1400 mL L−1 was detected, the effect of inoculum (50% of wastewater with spontaneous microflora already adapted to high essential oil concentration) was not noticeable. Overall, the results of the investigation confirm the suitability of aerated lagoons subject to fine bubble aeration also for agricultural wastewater depuration.

Mixing of Newtonian and viscoelastic fluids using “butterfly” impellers

The mixing of high viscosity and viscoelastic fluids may be performed in industry using a “butterfly” impeller, which has received scant attention. This paper describes the characterisation of these impellers using both Newtonian and viscoelastic (Boger) fluids with an identical base viscosity under laminar flow conditions in batch tanks without baffles. Measurements are made using two rotational speeds (N=30 or 60rpm) over a wide range of impeller to tank diameter ratios from 0.53 to 0.98. Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) have been used to determine local velocity fields, shear rates, flow numbers and mixing times, with impeller power number Po obtained from torque measurements. A down-pumping flow pattern is observed, with maximum normalised velocities of 25% of the impeller tip speed observed in the axial plane, increasing to 60% in the rotational plane due to solid body rotation. Angle resolved measurements found these to be slightly increased as the impeller passes the image plane, with viscoelastic fluids displaying a greater uniformity of velocity across the image planes due to elastic energy storage. Maximum shear rates are greatest between the impeller and the wall, yet remain low i.e. O(10)s−1. Mixing times obtained from PLIF show that mixing times in viscoelastic fluids show a slight reduction compared to the Newtonian equivalent. The impeller power number was determined as Po=0.6 in the turbulent regime, while the laminar constant Kp and the Metzner–Otto constant ks were equal to 122 and 16.0 respectively.

Use of leaching tests to quantify trace element release from waste to energy bottom ash amended pavements

A series of roadway tests strips were paved on-site at a landfill in Florida, U.S. Waste to energy (WTE) bottom ash was used as a partial course aggregate replacement in a hot mix asphalt (HMA) and a Portland cement concrete (PCC) pavement, along with control HMA and PCC sections. This allowed for a comparison of the relative degree of leaching between both materials (HMA and PCC) as well as between the ash-amended and control pavements. Batch and monolithic tank leaching tests were conducted on the pavements. Testing of the PCC samples demonstrated that Mo and Al were elevated above regulatory thresholds for both the control and ash amended samples. Further leach testing demonstrated that the release of Mo was likely from the PCC and not a result of the inclusion of the BA into pavement. Batch leach testing of ash-amended HMA samples revealed Sb as a constituent of potential concern. The results of the monolith leaching test displayed leaching of Sb within the same order of magnitude as the regulatory threshold. Calculation of the leachability index (LI) for Sb found that it would have limited mobility when incorporated in the HMA matrix.

Systematic Regeneration of Waste Sulfuric Acid in Semiconductor Manufacturing Using Batch Vacuum Distillation

We describe herein a systematic regeneration of waste sulfuric acid produced in semiconductor manufacturing, using batch vacuum distillation (BVD). During the recycling process, dilute sulfuric acid feed was continuously concentrated and fed back to the original wafer washing step. It consisted of a batch tank to charge the feed solution, condenser to capture generated vapor, receiving tank to receive condensed distillate liquid, and vacuum pump to reduce the system pressure. The improper control of the vacuum operation led to incomplete condensation; consequently, the vacuum pump became dysfunctional. The goal of this study was to prevent such mishap. After the feed condition was defined, a basic design was conceived, and the main characteristics of the BVD were determined. The results of sensitivity analyses on the feed and operating conditions have been discussed. The strategies for designing the vacuum pump’s capacity should be changed depending on phase equilibria at the target pressure.

Wet Oxidation of Dairy Sewage: The Kinetic Study of Decomposition of the Milk Components

Abstract The article presents the results of kinetic studies of the wet oxidation process of dairy sewage. The dairy sewage, obtained straight from the production line, was subjected to oxidation at pH close to the natural value of 7. Experiments were carried out in a stirred batch tank reactor at the oxygen partial pressure equal to 1 MPa and at temperature ranging from 473 to 593 K. The effectiveness of organic compounds decomposition was estimated based on the measurement of TOC. The kinetics of decomposition of milk components, ie lactose, protein and fat, as well as the kinetics of oxidation of intermediate products was the aim of the study. Measurement of the concentration of protein, fat and lactose was done with a milk composition analyzer, calibrated in relation to the dairy sewage. The obtained results were used to develop a mathematical model of wet oxidation of dairy sewage, including the group of analyzed compounds.

Adsorption of Cr(III) and Mg(II) from Hydrogen Peroxide Aqueous Solution by Amberlite IR-120 Synthetic Resin

In concentration of hydrogen peroxide, first, the solution should be quite pure, and then, it concentrate with methods such as vacuum distillation and cooling crystallization, because impurities in the hydrogen peroxide solution in high concentrations are causing decomposition of this substance; that is very dangerous. The purpose of this article is separation of chromium and magnesium cations from 35wt% commercial hydrogen peroxide solution by ion exchange method with strong acid cation resin Amberlite IR-120 H + with styrene divinylbenzene copolymer network and sulfunic acid functional group. In separation of chromium and magnesium, we used batch system and tank equipped with mixer. Effect of the amount of resin and contact time on the separation of cation is investigated. The metal ion concentration in the original solution and the metal ions left unsorbed were determined by Inductively coupled plasma spectrometry (Varian Vista ICP-AES) technique. In determining the effect of the amount of resin and contact time on separation of cation, amount of chromium and magnesium in hydrogen peroxide solution was 0.1 mg/mL, 0.3 mg/mL and 0.5 mg/mL. Experimental results obtained from the separation of chromium and magnesium compared with Freundlich, Langmuir and Jovanovic adsorption isothermal models. Results show that these models only in a certain range of concentration, are consistent with experimental results.

Inhibitory effects of industrial olive-oil mill wastewater on biomass production of Scenedesmus obliquus

The three-phase extraction process of olive oil yields highly contaminated wastewater (OMW). This waste is frequently dumped untreated either onto soil or into water sources. The biodegradation of this wastewater by the biomass production of microalgae was studied. The experiments were performed in stirred batch tank reactors on a laboratory scale using Scenedesmus obliquus, microalga tolerant to phenolic compounds. The culture medium was prepared with 2.5%, 5%, 10% and 20% OMW (v/v) in water. The experimental conditions were pH=7.0, T=298K, 350rpm and aeration 1(v/v)/min with continuous illumination at an intensity of 298μEm−2s−1. Four additional comparative cultures were carried out: (1) 5% OMW without fat matter (WF); (2) 5% OMW pretreated with active carbon (WC); (3) synthetic mineral medium (RL); and (4) urban wastewater from the secondary treatment (UW). The maximum specific growth rates for the different cultures were μm=0.037±0.003h−1 (10% OMW), μm=0.04±0.002h−1 (WC), μm=0.049±0.001h−1 (WF), μm=0.048±0.0h−1 (RL) and μm=0.052±0.012h−1 (UW). These results indicate that the fat content in the OMW and its dark colour are the main inhibitors factors of the growth of S. obliquus.

Biodiesel Production in Batch Tank Reactor Equipped to Helical Ribbon-like Agitator

Biodiesel as an alternative and renewable fuel could be applied in diesel engines in order to reduce air contamination and dependence to fossil fuels. So far, various processes were prepared for biodiesel production, but using transesterification method via base catalyst in batch reactors could result in a reasonable yield of biodiesel. At the present study, a batch tank reactor equipped to a helical ribbon-like agitator was designed and manufactured. Using this reactor, the production efficiency was considerably promoted and the required residence time was reduced. Experiments were conducted at 6:1 molar ratio of alcohol to refined soybean oil, operational temperature of 64?C, KOH concentration of 1%wt oil, and three levels of agitation speed; 600, 750, and 900 rpm. The agitator design and its helicon movement led to a uniform phase formation of insoluble alcohol and oil. Therefore, at 900 rpm stirring speed and after 20 min residence time, 97.3% conversion of triglycerides to methyl esters (biodiesel) could be achieved.