Pilot-scale Study Research Articles

Sustainable transformation: Unlocking energy positivity in municipal wastewater treatment through innovative advanced primary treatment configurations for maximum solids separation

Motivated by the growing need for sustainable wastewater management and environmentally friendly solutions for wastewater treatment in the future, the current study explored all possible configurations for advanced primary treatment (APT) on a long-term assessment, encompassing extensive lab and pilot-scale studies for removing particulate organic carbon (POC) in municipal wastewater treatment plants (WWTPs). This study primarily aimed to have a comprehensive insight into various APT configurations for municipal wastewater treatment. The physical-APT method employed a microsieve (MS) with an adjustable drum to 20 and 100 µm mesh. The flocculation process was integrated with one or two consecutive sedimentation tanks to simulate the chemical-APT method. Lastly, the chemical-physical-APT (ChPh-APT) approach was emulated by combining the flocculation process with the MS technique. Considering the best-case scenario to remove utmost POC, the results illuminated a substantial potential for biogas production enhancement by around 85 % (from 1.3 to 2.4 g (cap. d)-1 converted chemical oxygen demand (COD) to biogas) through ChPh-APT configuration. Furthermore, estimations showed that maximum POC removal can significantly reduce energy demand from 42 to 28 kWh (cap. a)-1 while simultaneously increasing green electricity generation from 11 to 33 kWh (cap. a)-1. This transformation will eliminate dependency on external energy sources and significantly increase by-product generation like volatile fatty acids (VFA), Polyhydroxyalkanoate (PHA), and hydrogen (H2) in the concept of a biorefinery. The possible increase in the production of H2 can be from roughly 32 to 58 L (cap. d)-1, PHA recovery from 1.3 to 2.4 g (cap. d)-1, and VFAs from about 12 to 22 g (cap. d)-1. Consequently, this transformation will enhance the efficiency of municipal WWTPs and turn them into energy-positive, sustainable, and resource-recovery entities.

Uncovering the reasons behind high-performing primary sedimentation tanks for municipal wastewater treatment: An in-depth analysis of key factors

The paper presents a long-term and extensive pilot-scale study on the primary settlement of municipal sewage to produce an in-depth understanding relating sedimentation efficiency to surface load, hydraulic retention time (HRT), sludge withdrawal time (SWT), temperature (T), and influent solid mass (TSSmass). Besides, primary sludge (PS) was subject to qualitative and quantitative analysis, intending to explore its potential utilization in various applications. These applications encompass enhanced energy and heat generation through conventional anaerobic digesters and the elevated production of volatile fatty acids (VFAs) in hydrolysis reactors, particularly within the context of biorefineries. TSSmass, T, and SWT were shown to be more important in controlling the removal of solids by primary sedimentation tank (PST) than other factors considered. This study introduces a mathematical model that can predict the PS volume based on factors like TSSmass, T, and SWT as a synthesis of the two disparate facets of the study. This model can immensely help maximize PS production quantitively and qualitatively, which can help elevate energy and VFAs production from PS via anaerobic digesters and hydrolysis reactors in conventional municipal WWTP and biorefineries, respectively. Therefore, this model can confidently be applied for calculating the required hopper volume in PST and ascertaining the optimal volume specifications for anaerobic digesters and hydrolysis reactors. Consequently, it leads to cost savings associated with eliminating under or over-designing. The results showed that by improving PST performance for TSS removal, more chemical oxygen demand (COD) would be available for biogas production in conventional municipal WWTPs (from 42 to 59 g (cap. d)−1). By shifting toward biorefineries, the potential to produce more biogas and VFAs, altering from around 40–50 g (cap. d)−1 and 6–12 gVFAs (cap. d)−1, respectively, will also be indicated.

Process intensification of metal solvent extraction studies using a miniaturized solvent extraction plant

This study examines the potential of a miniaturized solvent extraction plant (MSXP) to improve the efficiency and reproducibility of laboratory and pilot-scale metallurgical studies that typically require extended testing periods. The MSXP has been designed to replace conventional solvent extraction (SX) apparatus and aims to reduce start-up time, time to reach equilibrium, and overall test time. Two copper solvent extraction (Cu-SX) research campaigns were conducted to test the functionality, ease of operation, modularity, and reproducibility of the MSXP. The first campaign quantified the extraction efficiency and net copper transfer, while the second campaign operated the MSXP in a semicontinuous countercurrent flow configuration with three extraction and two stripping stages. The main variables studied in the first campaign are the number of stages (1-3), volumetric flow rates (O/A, 1-3), and organic phase residence time in the micro-contactor (0.7-2.4 min). The results demonstrate that the MSXP can work with very low stage efficiencies (48%), while achieving high copper recoveries (> 90%). At the stripping circuit level, we show that the MSXP can operate at superior stage efficiencies (> 100%), with low copper recoveries (30%–55%). The reproducibility evaluation also demonstrates high statistical confidence (< 6% CV) in the obtained process values. The MSXP offers great flexibility in net copper transfer and can be used to benchmark and emulate a wide range of Cu-SX systems. Experimental Cu-SX campaigns can be run in about 60 min while investing roughly US$1.4/h on reagents, which is significantly lower compared to typical campaigns that can last from days to weeks to reach reliable research outcomes and require about US$62/h for reagents. The potential of MSXP extends to more elaborate solvent extraction systems, specifically those designed to purify energy-critical elements like lithium, nickel, cobalt, or rare-earth elements. This study demonstrates the promise of process intensification approaches for improving the efficiency of laboratory and pilot-scale SX studies, which can help in reducing time, reagents, and energy consumption while improving the reproducibility of results.

Pilot Scale Study on the Prevalence and Associated Risk Factors of Canine Distemper and Canine Parvovirus in Ahmadabad and Gandhinagar Cities of Gujarat, India

Pilot Scale Study on the Prevalence and Associated Risk Factors of Canine Distemper and Canine Parvovirus in Ahmadabad and Gandhinagar Cities of Gujarat, India

An integrated physical-chemical system for concurrent carbon, nitrogen, and phosphorus removal in municipal wastewater treatment plants

A substantial quantity of suspended solids (SS) present in municipal wastewater leads to the swift depletion of the ion exchange (IE) capacity of natural zeolites like Clinoptilolite (CIO). This limitation has become the primary factor contributing to the limited adoption of the IE technique within municipal wastewater treatment plants (WWTPs). However, an extensive lab-scale and pilot-scale study conducted over approximately one year has made it possible to efficiently apply the IE system using CIO (main grain size of 0.5–1.0 mm) upstream of the primary sedimentation tank (PST). The primary treated wastewater (PTWW) was introduced to the IE system either by pre-straining or without any pre-treatment. The IE system's capabilities for removing total suspended solids (TSS), chemical oxygen demand (COD), and phosphorus (P) while primarily focusing on ammonium (NH4+) recovery were undergone for a detailed investigation. Frequent backwashing, involving intermittent water and air injection, was used to mitigate clogging as the main problem of the IE system for treating PTWW. The results revealed a mean removal efficiency of 85 %, 60 %, 50 %, and 30 % for NH4+, TSS, TCOD, and total phosphorus (TP), respectively, per cycle exclusively for the IE system. As the system scaled up, a substantial reduction was observed in the adsorption capacity, shifting from approximately 12 to 1 g NH4+ (kgCIO)−1. Despite this drawback, the study's finding showed that prolonged treatment of PTWW for NH4+ removal and recovery in municipal WWTPs, besides substantially reducing carbonaceous pollutants, is applicable. Implementing this application will not only decrease the biological treatment costs for municipal wastewater but also yield valuable by-products, such as NH4Cl, which can serve as a foundational material for the production of ammonium chloride fertilizer. Therefore, transitioning to IE systems in municipal WWTPs will diminish the reliance on resource-intensive methods like the Harber-Bosch procedure for producing nitrogen fertilizer.

Pretreatment of hypersaline and high-organic wastewater with a three-dimensional electrocatalytic system: a pilot-scale study.

The three-dimensional electrocatalytic oxidation (3DEO) is a promising electrochemical system in the treatment of refractory wastewater, but still far from large-scale applications. In this work, we prepared 146.5 Kg Ti-Sn-Sb@γ-Al2O3 particle electrodes to construct a 3DEO system for the pretreatment of hypersaline and high-organic wastewater in an industrial park sewage plant, with activated carbon particle electrodes as a comparison. The average COD removal rates of Ti-Sn-Sb@γ-Al2O3 and activated carbon-based 3DEO systems were 24.43 and 48.73%, respectively, and the energy consumption of the two 3DEO systems were 102.8 and 31.4 kWh/Kg COD, respectively. However, compared to the negligible enhancement of wastewater biodegradability in the activated carbon 3DEO system, the Ti-Sn-Sb@γ-Al2O3 3DEO system greatly improved the biochemical index (B/C) from 0.021 to 0.166 (by 690.5%). Due to its superior catalytic capacity, Ti-Sn-Sb@γ-Al2O3 outperforms activated carbon in improving biodegradability as the latter relies mainly on adsorption. The results of this work provide a 3DEO engineering practice experience on the pretreatment of hypersaline and high-organic wastewater.

Management of secondary effluent using novel membrane technology to recover water and magnesium ions for phosphate precipitation: An integrated pilot-scale study

Phosphorus and magnesium are comprised as essential resources in the European Union's list of critical raw materials. Access to those nutrients together with growing potable water demand is becoming a serious problem. Many efforts have been made to develop effective technologies for recycling water and essential nutrients from wastewater over the past few decades. Here, we present a new approach for the recovery of water simultaneously with the reclamation of Mg2+ and phosphates from secondary effluent (SE) and anaerobic digestion liquor (ADL) at WWTPs. Following the circular economy principles, our technology manages SE and produces two important products, (1) pure water (permeates) and (2) Mg-rich concentrates (by-streams/retentates), for further phosphate recovery from ADL in the form of struvite (MAP). The present study proposes an approach of combining energy-saving membrane processes (ultrafiltration (UF) and nanofiltration (NF)) with ionic exchange (IE) with the UF-NF-IE-NF-concentrates serving as a source of Mg2+ in struvite (MAP) precipitation from ADL. Different reaction conditions led to the development of typical MAP crystal forms, such as pyramids, needles, and x-shapes. The study also demonstrated that due to the low heavy metal content and narrow size distribution, the MAP generated could also be employed as a fertilizer.

The Impact of Non-Concentrated Storage on the Centrifugation Yield of Microchloropsis gaditana: A Pilot-Scale Study.

Non-concentrated algae storage can bridge the period between algae harvesting and processing while avoiding the stress conditions associated with the concentration step required for concentrate storage. This study aimed to examine organic matter losses during the non-concentrated storage of Microchloropsis gaditana at pilot-scale. Algae cultures (400-500 L) were stored for up to 12 days either at an 8 °C target temperature or at 19 °C as the average temperature. The centrifugation yield of stored algal cultures decreased from day 5 or day 8 onwards for all storage conditions. After 12 days, the centrifugation yields were between 57% and 93% of the initial yields. Large differences in centrifugation yields were noted between the algae batches. The batch-to-batch difference outweighed the effect of storage temperature, and the highest yield loss was observed for the 8 °C cooled algae batch. The analysis of stored algae before and after centrifugation suggested that the decreasing yields were not related to respiration losses, but rather, the decreasing efficiency with which organic matter is collected during the centrifugation step.

Beyond Microplastics: Implementation of a Two-Stage Removal Process for Microplastics and Chemical Oxygen Demand in Industrial Wastewater Streams

Wastewater from plastic manufacturing or processing industries is often highly polluted with microplastics (MPs) and high levels of oxidizable organic matter, which results in a high chemical oxygen demand (COD). When industrial wastewater enters wastewater streams, the high microplastic load is a high burden for municipal wastewater treatment plants (WWTPs), as they are not sufficiently removed. To prevent MP from entering the WWTPs, an upstream prevention method is essential. This paper presents a pilot-scale plant study for the removal of MP and COD from industrial wastewater that was tested on-site at a plastic manufacturer in Germany. Eight test phases were performed over 3 months, with each test phase processing 1 m3 wastewater and four treatments. Per test phase, 12 samples were analyzed for 5 parameters: COD, total suspended solids (TSSs), particle count, pH, and turbidity. The results showed an average decrease in MP by 98.26 ± 2.15% measured by TSSs and 97.92 ± 2.31% measured by particle count. This prevents the emission of 1.1 kg MP/m3 water and an estimated 2.7 t MP/year. The COD was reduced efficiently by 94.3 ± 8.9%. Besides MP and COD, this treatment allows reuse of water and agglomerates, resulting in a reduction in the CO2 footprint.

Treatment of effluents from Food Services Establishment (FSEs) by physico-chemical processes: a case study for Trinidad & Tobago

BackgroundEffluents from Food Services Establishments (FSEs) contain primarily Fats, Oil and Grease (FOG) which severely impact on sewers and the environment when released in high concentrations. In Trinidad & Tobago, it is estimated that approximately 231,304 kg/day of unaccounted for FOG bearing wastewaters from FSEs, are released into the environment with no viable treatment in the country. This research explored the optimization of physico-chemical processes for the treatment of FOGs for subsequent release into sewers.ResultsBench-scale studies analysed the characteristics of FSE’s effluents from three popular sources, conducted the treatment of these effluents using Jar Tests, and subsequently confirm results via a pilot plant study. Characterization showed the mean concentration of the parameters examined to be; FOG (511 mg/l ± 116 mg/l), Suspended Solids (446 mg/l ± 146 mg/l), Chemical Oxygen Demand (2229 mg/l ± 963 mg/l) and pH (6 ± 0.3). Jar Tests were conducted using Poly-aluminium Chloride (PACl) as coagulant, anionic and cationic polyelectrolytes as flocculant aids with suitable pH adjustments of samples to determine the isoelectric point for the coagulant. Effluent results showed FOG removal levels of 99.9% and final effluent concentration of 0.17 mg/l. This was attained using PACl concentration of 250 mg/l, a 0.1% low cationic polyelectrolyte (CP 1154) at 4 mg/l with the pH of sample adjusted to 8. The pilot plant achieved a 97.4% removal of FOG (residual of 16.8 mg/l) using the same coagulant dosing, and pH value, but increasing the strength of the flocculant aid to 0.1% medium cationic (CP1156) at 5 mg/l.ConclusionExperimentation showed high concentrations of emulsified FOG can be efficiently removed to levels below the permissible requirements (20 mg/l) for entry into sewer systems in Trinidad and Tobago using coagulation, flocculation and sedimentation techniques. Pilot scale study also revealed that a higher strength and/or dose of the cationic polyelectrolyte and increased times in primary and final tanks were required to attain the desired results as in the bench level study, where equipment limitations in the flocculation tank were faced. This is in alignment with theory where factors critical for agglomeration is equipment type and density charge. It is, concluded that the optimum combination of chemicals and the respective dosages attained at the bench level study should prove effective should the right equipment be made available.

Pilot-scale removal of PFAS from chromium-plating wastewater by anion exchange resin and activated carbon: Adsorption difference between PFOS and 6:2 fluorotelomer sulfonate

Chromium-plating wastewater is an important source of per- and polyfluoroalkyl substances (PFAS) contamination. Currently, adsorption is considered to be one of the main technologies for the removal of PFAS from wastewater. However, no pilot-scale studies have been conducted to investigate its application in chromium-plating wastewater and the adsorption characteristics of 6:2 fluorotelomer sulfonate (6:2 FTS), the alternative to perfluorooctane sulfonate (PFOS). In this study, we evaluated the removal of PFAS from chromium-plating wastewater by granular activated carbon (GAC) and anion exchange resin (AER) at a pilot-scale. The breakthrough curves of PFOS and 6:2 FTS were similar in GAC columns, but significantly different in AER columns, with PFOS and 6:2 FTS reaching 10% breakthrough at about 45,000 BV and 4,000 BV, respectively. The replacement of 6:2 FTS by PFOS and other coexisting organic substances resulted in the concentrations of 6:2 FTS in the AER effluent reaching up to 3.8 times the influent concentrations. Density functional theory (DFT) calculations showed that the adsorption energy of PFOS on the quaternary amine group of AER was more negative than that of 6:2 FTS, and the weak affinity of AER for 6:2 FTS was closely related to the solvent effect. According to the cost analysis, if 6:2 FTS becomes the target PFAS, AER adsorption will no longer have a cost advantage over GAC adsorption. This study can provide technical support for the adsorptive removal of PFAS from electroplating wastewater and guide the development of efficient adsorbents for PFAS alternatives.

A pilot-scale study of a novel system for simultaneous nitrogen and carbon removal: technological advancement of a structured bed reactor with intermittent aeration (SBRIA) in real domestic sewage treatment.

This study outlines the development of an effective pilot-scale simultaneous denitrification and nitrification (SDN) system using intermittent aeration for the removal of carbon and nitrogen from real domestic sewage. Given the limited research in this area, the main objective was to evaluate the overall performance of the SBRIA system on a pilot scale and show its benefits in domestic wastewater treatment. The structured bed reactor with intermittent aeration (SBRIA) notably achieved 57% efficiency in removing total nitrogen without requiring external carbon sources. It also demonstrated impressive removal rates of 56% for total chemical oxygen demand (CODT) and 82% for biochemical oxygen demand (BOD5), indicating its effectiveness in degrading organic matter. In addition, the SBRIA showed high pH control and managed the consumption of alkalinity without the need for an alkalizer, maintaining consistent mean values of 7.7 ± 0.8 for pH and 166.8 ± 79.8 mg·L-1 for alkalinity. The system also proved resilient against toxic shocks caused by significant variations in influent characteristics. This study offers valuable insights and compelling results into a cost-effective and efficient treatment approach using an innovative technology not previously applied at the pilot scale. Its potential to remediate polluted water is substantial.

Exploring the Potential of Peracetic Acid for Wastewater Disinfection: Insights from a Pilot-Scale Study

Exploring the Potential of Peracetic Acid for Wastewater Disinfection: Insights from a Pilot-Scale Study

Biological Iron Removal and Recovery from Water and Wastewater.

Iron is a common contaminant in source water and wastewater. The mining and metallurgical industries in particular can produce and discharge large quantities of wastewater with high iron concentrations. Due to the harmful effects of iron on organisms and infrastructure, efficient technologies for iron removal from water and wastewater are needed. On the other hand, iron is a valuable commodity for a wide range of applications. Microorganisms can facilitate iron removal and recovery through aerobic and anaerobic processes. The most commonly utilized microbes include iron oxidizers that facilitate iron precipitation as jarosites, schwertmannite, ferrihydrite, goethite, and scorodite, and sulfate reducers which produce hydrogen sulfide that precipitates iron as sulfides. Biological iron removal has been explored in various suspended cell and biofilm-based bioreactors that can be configured in parallel or series and integrated with precipitation and settling units for an effective flow sheet. This chapter reviews principles for biological iron removal and recovery, the microorganisms involved, reactor types, patents and examples of laboratory- and pilot-scale studies, and full-scale implementations of the technology.

Кетчуп из томатного жмыха: физико-химические, микробиологические и органолептические показатели

Tomato (Solanum lycopersicum L.) is one of the most important crops that is extensively used in the food processing industry. During tomato processing, abundant by-products such as skins, pulps, seeds, and waste are generated and cause environmental burdens. To solve this problem, tomato pomace was subsequently used as a material for making tomato sauce. However, it is essential that the production of tomato ketchup meets the required standards. Therefore, it is important to analyze the physicochemical and sensory characteristics of the product. We aimed to study the effect of corn starch addition on the physicochemical and sensory properties of tomato ketchup made from tomato waste and to assess the acceptability of tomato sauce formulated with different concentrations of corn starch. &#x0D; Tomato ketchup was cooked at 90°C for 15 min and then hot-filled into a sterile glass bottle. It was then analyzed for physical properties (color, viscosity, and total dissolved solids), chemical properties (pH, titratable acidity, moisture content), microbiological quality (total bacteria, mold, and yeast), and sensory acceptance.&#x0D; The results showed that corn starch influenced the color characteristics of the tomato sauce. Adding more than 4% of corn starch increased the viscosity and total solids content significantly (p &lt; 0.05). Also, corn starch addition decreased the water content and acidity, as well as increased the pH of the tomato sauce. Microbiological analysis showed no growth of bacteria, mold, or yeast in any of the test samples. According to sensory analysis, the tomato sauce with 1% of corn starch had the highest acceptance, while higher concentrations of corn starch decreased the texture acceptance. &#x0D; Our findings may indicate that, with proper formulation, tomato by-products can be used as raw materials to develop sustainable alternative value-added products that consumers accept organoleptically. Further investigations can be conducted in the pilot-scale studies to enhance the feasibility of tomato pomace ketchup as a commercial product.

Application Potential of Cavex® Double Effect Hydrocyclone for the Classification of Mine Tailings – A Pilot Scale Study

ABSTRACT The Cavex® Double Effect (DE) hydrocyclone is a double-efficiency classification unit, working as a single stage without the need for additional intermediate equipment such as pumping. The aim of this work is to evaluate the physical response of design and operating variables of the Cavex® DE hydrocyclone on the classification performance of mine tailings. We conducted tests at a pilot level and the subsequent industrial scale, to know the real application potential of the DE hydrocyclones and scopes for future implementation. The result from the study reveals that double classification helps to significantly lower the fine bypass in the underflow to produce the desired quality of sand for tailing dam construction. It is also concluded that the DE hydrocyclones increase the recovery of sand (sand/slime ratio) and also improve the global water recovery in the process when compared with conventional single-stage hydrocyclones.

Cathode Active Material Synthesis and Battery Performance Tests for Li-Ion Batteries Obtained from Domestic Raw Materials: A Special Case Study from Ore to Battery

The energy requirement brought by technological developments from the past to the present evolves depending on the society's desire to be mobile, which is increasing day by day. Many technological devices such as electrical vehicles, smart phones, computers, drones, cameras meet the required energy from rechargeable lithium-ion batteries. However, the increasing world population and the increasing specifications of the technological devices developed in parallel with the per capita energy consumption by making the raw material resources needed for the production of these technological devices even more important. Nickel, cobalt and manganese compounds, which are the main raw materials used in the cathode production of NMC type lithium-ion batteries, are among these elements of strategic and critical importance, and the production of these chemicals in appropriate quality is of great importance for the industrial development of lithium-ion-based domestic battery technologies in each country. Meta Nikel Kobalt A.Ş., is the first and the only industrially scaled nickel-cobalt plant using HPAL technology in northern hemisphere at . In Gördes plant, nickel-cobalt-manganese hydroxide intermediate product concentrate (MHP) is produced from low grade Gördes lateritic ore following the unit operations of ore preparation, mineral processing, high pressure acid leaching, neutralization and precipitation and is currently completely exported to overseas. However, due to the responsibility of transforming domestic resources to high value-added technological products and obtaining value-added products, research in this field has been regarded and the necessary technological infrastructure and specific knowledge have been created. Within the scope of this project, precious metals in the MHP intermediate product obtained from Gördes lateritic ore were leached and valuable elements are taken to the liquid phase and crystallized after further purification processes such as solvent extraction and ion exchange. As a result, metal salts with purity up to 99.99% were obtained. The obtained nickel, cobalt and manganese sulphate salts were precipitated together with the developed co-precipitation process to obtain precursor in the form of NMC 622. After that, the precursor is treated with lithium and the cathode active material (CAM) is obtained by going through various heat treatments by systematically designed test campaign. The coin cell made with the CAM obtained from domestic raw materials showed a capacity of 184.55 mAh/g at 0.1C. It showed a capacity of 170.58 mAh/g in the first cycle and 157.45 mAh/g in the 50th cycle at 0.5 C, and the capacity conservation was calculated as 92.3% after 50 cycles at 0.5 C. The CAM obtained in the pilot-scale studies carried out according to the lab-scale developed process and sent to for making pouch type battery. In the 10 Ah capacity cells of the produced pouch type, 82% capacity conversation has been achieved as a result of 1000 cycles at a charge/discharge rate of 0.5 C at 100% CoC(Dept of Discharge) in the voltage range of 3-4.15V. Figure 1

(Invited) Development and Scale-up of Membrane Capacitive Deionization (MCDI) for Desalination and Water Reuse

Desalination and water reuse are the key solutions to address global water scarcity. It is important to recognize the water-energy interactions and develop energy-efficient technologies to separate ions from brackish water, seawater and reclaimed wastewater. Most recently, membrane capacitive deionization (MCDI), inspired by energy storage devices (e.g., supercapacitors), is a promising desalination technology with several advantages of energy efficiency (TDS < 4000 ppm), high water recovery, less chemical additive, and environmental friendliness. In MCDI, ions are electrostatically captured within highly porous carbon electrodes through the formation of electrical double layer during the charging step, and then released into the solution by discharging the electrodes. By incorporating ion-exchange membranes (IEMs) in front of each electrode, the desalination performance can be significantly improved, achieving high salt adsorption capacity and charge efficiency. Over the past few years, we have made efforts to scale up the MCDI stacks for commercialization purposes, which are composed of 32 pairs of 400 mm × 200 mm activated carbon electrodes. Note that a stop-flow operation is applied in the discharge process to increase the water recovery (> 75%). A pilot-scale study of an MCDI system was performed to reclaim the secondary effluents from a municipal wastewater treatment plant. In addition, MCDI prototypes offer promising engineering opportunities for water recycling in high-tech industries, including reverse osmosis reject and wet scrubbing. Furthermore, we will discuss the challenges and perspectives for the future of MCDI as a cost-efficient, low-energy approach for desalination and resource recovery.

Effect of dissolved ozone flotation thickening process on coliform bacteria and antibiotics simultaneous abatement: A pilot-scale study

This study focused on the removal of the total coliforms, fecal coliforms and four target antibiotics in the dissolved ozone flotation (DOF) thickening sludge process. Additionally, the thickened effluent chromaticity and its effect on thickened sludge hydrolysis process were investigated. Ozonation in the DOF process could inactivate coliforms by oxidizing cellular components and destroying genetic material, as well as altering the chemical structure of antibiotics, leading to the degradation of antibiotics. At an O3 dosage of 16 mg/g TS, the concentration of total coliforms and fecal coliforms decreased by 2.2 log and 2.4 log, corresponding to an overall removal rate of 99.4 % and 99.7 %, respectively. The total degradation rate of four target antibiotics (tetracycline (TC), oxytetracycline (OTC), norfloxacin (NOR), ofloxacin (OFL)) were 66.5 %, 68.8 %, 53.3 % and 57.5 %, respectively. The chromaticity removal rate of the thickened effluent reached 95 %. Analysis of fluorescence spectra indicated alterations in the fluorescence properties of dissolved organic matter, resulting in a decrease in fluorescence intensity by ozonation. The thickened sludge had higher hydrolysis rates, resulting in a greater production of volatile fatty acids (VFAs). This was mainly attributed to the increased amount of soluble protein and carbohydrate in the substrate after DOF treatment, which was more conducive for the rapid conversion of hydrolysis into VFAs during the initial stage. These results provided new ideas for upgrading and transforming the thickening process of wastewater treatment plants (WWTPs).

Pilot-scale study of sorption-enhanced gasification of sewage sludge

Sustainable management and disposal alternatives for sewage sludge (SS) should be pursued due to the substantial increment in its global production, as well as due to the raising interest in the renewable energy and synthetic fuels deployment. Since SS present high moisture (>95 % wt.), drying would play an essential role in SS management. In this work, SS pre-treated in a solar-drying facility has been successfully used as feedstock in a 30 kWth bubbling fluidised-bed (BFB) gasification pilot plant operating under Sorption Enhanced Gasification (SEG) conditions, i.e. using CaO as bed material and steam as gasifying agent. The influence of key operating SEG parameters (such as temperature, steam-to-carbon ratio and sorbent-to biomass proportion) in the syngas yield and composition (H2, CO, CO2, CH4, CxHy, H2S, COS, NH3 and tars) has been carefully assessed. As a matter of comparison, steam-oxygen gasification conditions have been also tested in the facility using solar-dried SS as feedstock. The results obtained demonstrate the possibility of producing a syngas with high H2 contents of 70–73 vol% and relatively low CO and CO2 contents (i.e. 2–3 vol% and 8 vol% respectively).