Proposed Treatment System Research Articles

Photo-thermal activation of persulfate for the efficient degradation of synthetic and real industrial wastewaters: System optimization and cost estimation

The photo-thermal activation of persulfate (PS) was carried out to degrade various pollutants such as reactive blue-222 (RB-222) dye, sulfamethazine, and atrazine. Optimizing the operating parameters showed that using 0.90 g/L of PS at pH 7, temperature of 90 °C, initial dye concentration of 21.60 mg/L, and reaction time of 120 min could attain a removal efficiency of 99.30%. The degradation mechanism was explored indicating that hydroxyl and sulfate radicals were the prevailing reactive species. The degradation percentages of 10 mg/L of sulfamethazine and atrazine were 83.30% and 70.60%, respectively, whereas the mineralization ratio was 63.50% in the case of real textile wastewater under the optimal conditions at a reaction time of 120 min. The treatment cost per 1 m3 of real wastewater was appraised to be 1.13 $/m3 which assured the inexpensiveness of the proposed treatment system. This study presents an effective and low-cost treatment system that can be implemented on an industrial scale.

Hemodialysis Wastewater Treatment via Electrocoagulation and Electro-Oxidation: Modular Pilot-Level Modeling and Simulation.

Hemodialysis treatment in specialized clinics within the same hospital significantly impacts environmental water health due to contaminated wastewater. The issues observed included changes in electrical conductivity, the presence of dangerous bacterial loads, toxicity from heavy metals, total cyanide content, and helminth parasite eggs. The level of damage is dependent on the patient's health under treatment. This research will use a modular system that employs electrocoagulation and electro-oxidation processes at the laboratory and pilot levels to treat hemodialysis wastewater using synthetically prepared and real samples extracted from local clinics. The results showed that these hybrid systems improved various physicochemical parameters. Specifically, decreases in electrical conductivity of 49 %, total suspended solids of 27-100 %, chemical oxygen demand of 49 %, biochemical oxygen demand of 49 %, and cation and anion loading were observed at 96-100 % and pH 8.13 UpH in accordance with the established standards. With these results and the experimental conditions used, the proposed treatment system was modeled using the GPS-X program, and it was concluded that the modular system used and the electrocoagulation/electro-oxidation/activated carbon configuration is suitable for treating wastewater from hemodialysis and that scaling up this process to facilities that have dialysate machines more advanced than those considered in this work is possible.

Assessment of Phytotoxicity in Untreated and Electrochemically Treated Leachates through the Analysis of Early Seed Growth and Inductively Coupled Plasma-Optical Emission Spectroscopy Characterization

The treatment of stabilized leachates with high refractory organic matter content, which are over 10 years old, presents a challenge. This study explored the potential of electro-coagulation (EC) and electro-oxidation (EO) treatment systems to address this issue. The objective of this study was to investigate the phytotoxicity of the proposed treatment system on seed growth and examine possible relationships between phytotoxicity results and the characterization of leachates, effluents, soil, and radicles. Phytotoxicity tests were conducted on seeds of Lactuca sativa, Cucumis sativus, and Phaseolus vulgaris, using Inductively Coupled Plasma-Optical analysis. The evolution of organic matter was monitored by fractionating the chemical oxygen demand (COD) and humic substances. The biodegradability index increased from 0.094 in raw leachate to 0.26 and 0.48 with EC and EO, respectively. Removal rates of 82%, 86%, 99%, and 81% were achieved for COD, dissolved organic carbon, color, and ammoniacal nitrogen, respectively. The biodegradable COD increased from 26% in raw leachate to 39% in the EC process and 58% in the EO process effluent. The proposed treatment system successfully broke the aromatic structures of the humic substances present in the raw leachate, thereby increasing the content of biodegradable material. Phytotoxicity tests revealed that the proposed treatment system significantly reduced the phytotoxicity of the generated effluents.

Eco-Friendly Engineered Nanomaterials Coupled with Filtering Fine-Mesh Net as a Promising Tool to Remediate Contaminated Freshwater Sludges: An Ecotoxicity Investigation.

The use of eco-friendly engineered nanomaterials represents a recent solution for an effective and safe treatment of contaminated dredging sludge. In this study, an eco-designed engineered material based on cross-linked nanocellulose (CNS) was applied for the first time to decontaminate a real matrix from heavy metals (namely Zn, Ni, Cu, and Fe) and other undesired elements (mainly Ba and As) in a lab-scale study, with the aim to design a safe solution for the remediation of contaminated matrices. Contaminated freshwater sludge was treated with CNS coupled with a filtering fine-mesh net, and the obtained waters were tested for acute and sublethal toxicity. In order to check the safety of the proposed treatment system, toxicity tests were conducted by exposing the bacterium Aliivibrio fischeri and the crustacean Heterocypris incongruens, while subtoxicity biomarkers such as lysosomal membrane stability, genetic, and chromosomal damage assessment were performed on the freshwater bivalve Dreissena polymorpha. Dredging sludge was found to be genotoxic, and such genotoxicity was mitigated by the combined use of CNS and a filtering fine-mesh net. Chemical analyses confirmed the results by highlighting the abetment of target contaminants, indicating the present model as a promising tool in freshwater sludge nanoremediation.

Hybrid resin composite membrane for oil & gas produced water treatment

In this work, a hybrid resin composite membrane was successfully synthesized from a phenyl epoxy/poly (vinyl pyrrolidone)/Fe3O4 resin composite and characterized using a scanning electron microscope (SEM). Performance characteristics such as concentration factor, the flow rate, and permeate flux of the synthesized hybrid resin membrane were investigated. The concertation factor was changed through the experiment from 1 to 1.6. The flow rate changed from 2.5 l/h at the beginning of the experiment to 1.05 l/h by the end of the experiment. The permeate flux was equal to 8.9 l/(m2h) at the beginning of the investigation. It was noticed that the permeate flux decreased over time to 3.76 l/(m2h). In addition, the hybrid resin composite membrane was efficiently used for treating petroleum-produced water (PPW) as an alternative to chemical scale inhibitors. The results showed that the proposed treatment system could successfully remove most scale-forming cations and anions from the PPW. Combining the new prepared resin with membrane could remove several cations and anions from OFPPW at rates ranging from 75% (for Strontium) to 97% (for Barium), while the Iron was 100% removed. Thus, the treated water effluent could be reused safely as injection water in the petroleum production process without concern for forming Barium sulfate and Dolomite scales in the used water.

Design and Performance Investigation of a Solar- Powered Biological Greywater Treatment System in the Iraqi Climate

The increase in population resulted in an increase in the consumption of water. The present work investigates the performance of a recycling solar- powered greywater treatment system for the purposes of irrigation, used to reduce the amount of waste grey water and reduce electricity consumption and reduce the costs of constructing large scale water treatment plants. The system consumes about 3814W per hour and provides water treatment about 1.4 m3 per day. The proposed system is designed to residential, office and governmental buildings application. Tests are conducted in an office building at the Ministry of Science and Technology site in Baghdad. Laboratorial water samples testing analyses are conducted for measuring the COD, BOD5, TDS, NH4, NO3-TN, TOC, TSS, pH and oil and grease content according to the Iraqi standards. Test results revealed a huge decrease in the values of BOD5 and COD for readings for every15 days and for a period of 5 months by removing rate more than 90% and also noting the values of TOC by removing about 80%, this indicates that the results of Laboratory testing have proved the success of the treatment process. The research is divided into two parts, theoretical and practical. The theoretical one includes choosing the type and size of the equipment and the required tools for the treatment system. While the practical one covers implementing a laboratory-scale system for the proposed treatment system and conducting experiments and laboratory analyses of greywater samples. Top of Form

Особенности хирургической тактики в лечении переломов проксимального отдела бедренной кости у геронтологических пациентов

The paper is dedicated to improving the treatment outcomes and consequences in elderly patients with femoral neck fracture by improving the diagnostics, osteosynthesis and total hip arthroplasty. The main causes and factors influencing the complication rates and final treatment outcomes in elderly patients with femoral neck fracture were identified. The evidence based diagnostic and treatment algorithm for such patients was designed. The proposed treatment system helped to reduce lethality, general and local complication rates among these patients. The active surgery helps to solve massive healthcare problems by easing the pain in elderly patients, restoring the hip joint mobility and weight bearing ability of extremity, enhancing independent living skills, and improving vitality and psychological state.

Encapsulation of iron nanoparticles with magnesium hydroxide shell for remarkable removal of ciprofloxacin from contaminated water

The rapid evolution of antimicrobial resistant genes (AMRs) in water resources is well correlated to the persistent occurrence of ciprofloxacin in water. For the first time, encapsulated nanoscale zerovalent iron (nZVI) with a shell of magnesium hydroxide (Mg/Fe0) was used to adsorb ciprofloxacin from water. Optimization of the removal conditions exhibited that 5% was the optimum mass ratio between magnesium hydroxide and nZVI [Mg(OH)2/nZVI)] as more than 96% of 100 mg L−1 of ciprofloxacin was removed. In addition, 0.5 g L−1 of Mg/Fe0 showed an extraordinary performance in removing ciprofloxacin over a wide range of pH (3–11) with removal efficiencies exceeded 90%. Kinetic analysis displayed that the kinetic data was well described by both Pseudo first-order and second-order models. Also, the equilibrium data was well fitted by Freundlich isotherm model. In addition, thermodynamic analysis evidenced that the removal of ciprofloxacin by Mg/Fe0 was exothermic, and spontaneous. The experiments also revealed that physisorption and chemisorption were the responsible mechanisms for ciprofloxacin removal. The proposed treatment system remediated 10 litters of 100 mg L−1 of ciprofloxacin solution with 100% overall removal efficiency. This treatment system could be a promising and practical solution to decrease ciprofloxacin concentration in different water bodies.

Преемственность поколений на кафедре травмато- логии и ортопедии в лечении пациентов с переломами шейки бедренной кости

The paper is dedicated to improving the treatment outcomes and their consequences in elderly patients with femoral neck fracture by developing a diagnostic procedure and performing the total hip arthroplasty. The main causes and factors influencing the complication rates and final treatment outcomes in elderly patients with femoral neck fracture were identified. The evidence based diagnostic and treatment algorithm for such patients was designed. The proposed treatment system helped to reduce lethality, general and local complications among patients. The active surgery helps to solve massive healthcare problems by easing the pain in elderly patients, restoring the hip joint mobility and supportive ability of extremity, enhancing independent living skills, and improving vitality and psychological state.

Performance of Anaerobic Hybrid Reactor with Post-Treatment in Intermittent Flow Sand Filter: a Sulfide-Oxidizing Bioprocess for the Treatment of Sanitary Sewage Using Nitrate as Electron Acceptor

The aim of the study was to evaluate the oxidation of sulfides using nitrate as an electron acceptor in an anaerobic hybrid reactor (AHR) connected to an intermittent flow sand filter (IFSF) for post-treatment. The study was carried out in four phases in which the AHR was fed with 100% raw sewage (phase I) followed by phases II, III and IV involving different proportions of raw sewage and recycled nitrified IFSF effluent (83:17, 67:33 and 50:50, respectively). The results showed that 41% of the oxidized forms of sulfur were accumulated in the anaerobic phase with 31% in the form of sulfate and 10% as elemental sulfur. Increased proportions of nitrified IFSF effluent into the AHR favored denitrification and afforded up to 38% removal of nitrogen during the anaerobic stage and 46% in the final effluent. The removal efficiency of total dissolved sulfide by the system was up to 99.3% in phase IV, the influent of which contained the highest proportion of nitrified effluent. It is concluded that the combination of AHR and IFSF offers excellent conditions for the removal of chemical oxygen demand, nitrogen and sulfides from sanitary sewage using nitrate as an electron acceptor. Furthermore, the proposed treatment system represents a low-cost and energy-saving approach that addresses the anaerobic digestion of biosolids as well as the control of malodorous gas formation.

Catalytic ozonation of ciprofloxacin using γ-Al2O3 nanoparticles in synthetic and real wastewaters

Pollution of water resources and the environment by different antibiotics, as emerging pollutants, is one of the most concerning environmental issues. In this respect, this study investigates catalytic ozonation of ciprofloxacin, as a common antibiotic, using γ-Al2O3 nanoparticles. The proposed treatment system can provide 93% removal efficiency at pH pf 9.5 and 10 mg L−1 initial ciprofloxacin concentration within 60 min contact time. Based on the results, ozonation is responsible for 88% of the ciprofloxacin removal efficiency, at this condition. It is while the removal efficiency of the catalytic ozonation process for real wastewaters is in the range of 14–41.18% due to the scavenging effect of the other contaminants. In general, the γ-Al2O3-based catalytic ozonation process efficiency was a little more effective than ozonation process on degradation of ciprofloxacin in both synthetic and real wastewaters. Furthermore, the pseudo-first-order kinetics model (R2>0.97) presents the best fit of the experimental degradation data.

An optimum treatment for waste electronic home appliance in remote area: The case of Kinmen, Taiwan

An optimum treatment system for the waste electronic home appliance in remote area by local pre-processing and outsourcing post-processing is proposed. The cost reduction potential of the proposed treatment system is presented for main four types of electronic home appliances by the case study of Kinmen, Taiwan. Implementation of local pre-processing in Kinmen, Taiwan can provide 42, 54, 32, and 41 TWD unit cost reduction for television, washing machine, refrigerator, and air conditioner, respectively, comparing to the current treatment system. The different treatment characteristics according to the type of the appliances are the major factors for the applicability and cost reduction potential of the local pre-processing system. The application of this system to other cases is presented by sensitivity analysis with relative labor cost and transportation distance as the parameters. The results and the analysis process can be applied to the domestic systems with regions without recycling facilities, and also the international systems under the extended producer responsibility concept to take back the products for recycling.

Analysis and design of wastewater treatment

The work proposes the reuse of wastewater from the Faculty of Agronomic Engineering of the Technical University of Manabí, located in the Lodana parish in the city of Portoviejo, to irrigate the diversity of plantations that exist in the institution as a banana, cocoa and lemon. In the work, the results of the physical-chemical and bacteriological analysis carried out on the residual water generated in the institution are offered, being able to verify that it does not meet the parameters required to be used in the irrigation of crops. The technical scheme of the proposed treatment system is shown, specifying the structure of the zeolite filter. The calculations made for the technical and structural design of each of the devices that make up the proposed treatment system are provided. The analysis of the performance of the system that is illustrated with a series of data reflected in tables is exposed and where an efficiency between 84% and 88% can be verified. A review of compliance with environmental regulations is carried out and an economic analysis is provided on the cost of the investment for the introduction of the system in the Faculty of Agricultural Engineering of the Technical University of Manabí.

Iopamidol degradation with ZVI- and ZVA-activated chemical oxidation: Investigation of toxicity, anaerobic inhibition and microbial communities

Treatment of aqueous iopamidol (IOPA, 2 mg/L), an iodinated organic X-ray contrast chemical and micropollutant, with nano-sized zero-valent iron (ZVI) and aluminum (ZVA)-activated hydrogen peroxide (HP) and persulfate (PS) oxidation processes was investigated. Changes in acute toxicity, anaerobic digestion, biogas yield and microbial community were further examined to question the ecotoxicological safety and bioamenability of the proposed treatment systems. For this purpose, two different bioassays were conducted with V. fischeri and P. subcapitata. The cumulative biogas production was monitored in batch anaerobic digestion tests. The microbial community was identified by Illumina MiSeq next generation sequencing (NGS) technology and abundant bacteria and archaea were analysed in the biomass samples taken from anaerobic reactors. The application of activated HP (1.00 mM) and PS (0.50 mM) treatments under acidic conditions (pH 3) resulted in complete IOPA removal. The original IOPA sample caused 5% and 74% inhibitions to V. fischeri and P. subcapitata, respectively. The relative inhibition towards P. subcapitata increased from 74% to 97% and 93% after 5 min HP/ZVI and 120 min PS/ZVA treatments, respectively. No meaningful changes in terms of digestion performance and cumulative biogas production in the presence of untreated and HP/ZVI- or PS/ZVA-treated IOPA samples were evidenced. Moreover, all biomass samples were populated by a bacterial consortium related to different members of Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. Hydrogenotrophic (Methanospirillum, Methanobacterium) and acetoclastic (Methanosaeta, Methanosarcina) methanogens were the prevalent members of archaea at genus level. An increase in relative abundance was only identified in Methanobacterium under the phylum namely Euryarchaeota.

Integration of two-stage nanofiltration with arsenic and calcium intermediate chemical precipitation for gold mining effluent treatment

ABSTRACTThe aim of this study was to evaluate an innovative treatment route for gold-mining effluents rich in calcium, arsenic, and sulfate. This treatment route comprised two nanofiltration (NF) stages and a two-step intermediate precipitation. Arsenic and iron coprecipitation (first step) and calcium carbonate precipitation (second step) were assessed aiming to treat the first-stage NF concentrate and increase the permeate recovery rate in a second-stage NF. The pH, the molar ratio of Fe/As (first step), and the molar ratio of CO3/Ca (second step) were optimized by using rotational central composite design. Under optimal conditions, the arsenic removal was 99.8% (at pH = 7.0 and Fe/As = 4.0), and the calcium removal was 99.5% (at pH 11.5 and CO3/Ca = 3.5). The supernatant of Ca precipitation had very basic pH and had to be acidified before the second-stage NF. The pH 8.5 proved to be the best one regarding retention efficiency and flux. The flux decay of the second-stage NF was attributed to both osmotic pressure increase and reversible fouling resistance. It was concluded that the proposed treatment system is efficient for the treatment of gold-mining wastewater, ensuring higher production of treated effluent and an easy disposable of the final concentrate.

Azo Dye Mineralization by Phanerochaete Chysosporium in a Sequencing Bath Reactor

ABSTRACT The mineralization of the azo dye congo red by the fungi Phanerochaete chrysosporium was studied in two sequential batch bioreactors (R1 and R2), operated in cycles of 48 h (step I) and 24 h (step II). In step I, glucose concentration was 1 g.L-1 in both reactors and in step II, 1 g.L-1 of glucose was maintained in R1, but R2 received no addition of glucose. In step I, the average dye removal efficiencies were 76 ± 29 % (R1) and 53 ± 15% (R2), while in step II the averages recorded for dye removal for R1 and R2 were 84 ± 15 and 70 ± 28%, respectively. The rates of dye removal were 0.04 h-1 in R1 and 0.03 h-1 in R2 in step I. Higher rates were obtained in step II, 0,07 h-1 and 0,02 h-1 for R1 and R2, respectively. The highest dye removal occurred in R1 and, in R2, the residual dye was further removed. Laccase was the oxidised at higher amount, in step I was 54 μmol.min-1 for R1 and 38 μmolmin-1 for R2. The proposed treatment system was very effective in removing the azo dye, however the mineralization may not be complete and some by-products may have been formed, according to spectrofotometric analysis, were the peak corresponding to benzene, 220 nm, persisted.

Feasibility of combined upflow anaerobic sludge blanket-aerobic membrane bioreactor system in treating purified terephthalic acid wastewater and polyimide membrane for biogas purification

Anaerobic processes have become actively practiced for waste and wastewater treatment during the recent years because it can apply for high organic loading whereas the producing biogas can be recovered as a new energy source. This study prompted to look on the feasibility of a combined upflow anaerobic sludge blanket (UASB) and aerated membrane bioreactor (MBR) system for the treatment of purified terephthalic acid (PTA) wastewater and the usage of polyimide membranes for biogas separation. The results revealed that the combined system is robust and flexible in relation to the change in hydraulic retention times (HRTs) and organic loading rates. The overall chemical oxygen demand (COD) removal of 97% with the maximum loading rate of 20gL−1 per day was achieved at 12h HRT. The biogas from the UASB reactor was mainly methane (>62%). The separation between CO2 and CH4 was explored using different concentrations of dense polyimide (PIs) membranes and feed pressure. The results revealed that PIs based membranes possess high potential for CH4 purification with high selectivity and permeability towards CO2 than CH4. The expediency of the proposed treatment system and gas-separating module was seen and thus purified biomethane could be mustered continuously.

REUSE OF DAIRY WASTEWATER TREATED BY MEMBRANE BIOREACTOR AND NANOFILTRATION: TECHNICAL AND ECONOMIC FEASIBILITY

This study evaluated the technical and economic feasibility of membrane bioreactors (MBR) followed by nanofiltration (NF) for dairy wastewater treatment in order to reuse the treated effluent. It was observed that the MBR efficiently removed the organic matter and color of the feed effluent; however, due to the high concentration of dissolved solids in the permeate, it was necessary to use nanofiltration as a polishing step. The final treated effluent could be reused in the industry for cooling, steam generation and cleaning of external areas. A preliminary economic analysis showed the feasibility of the proposed system. The internal rate of return was greater than or equal to 32% when membrane lifespan was at least 2 years and the depreciation time was 15 years. The total cost of the proposed treatment system ranged from R$ 9.99/m3 to R$ 6.82/m3, depending on membrane lifespan.

Local material composite sintered systems for fluoride removal

The article elaborates the development of gravity-based water filtration systems capable of removing fluoride using natural organic material. In this study, the precipitation and dissolution reaction occurring in suspension of hydroxyapatite (HAP) as addition of fluoride were investigated under well-defined condition. This process is set to occur in a quasi-static gravity-based water filter system. This system is a (pond sand, organic material (gaur seed powder, neem, sesame sawdust, and Ayurvedic waste), water, and HAP mixture) composite ceramic. This article illustrates these ceramic material systems manufactured using distinct permutations of pond sand and organic materials. HAP is introduced into the composite mix of pond sand and organic materials to manufacture some of the sintered ceramic filtration material systems tested here. The fluoride removal efficiency of these variant systems is discussed. The energy dispersive X-ray spectroscopy studies of the ceramics provided the mineral content within the system variants. At high temperatures beyond 600°C, the sintered hydroxyapatite is observed to have a microstructural transformation from amorphous to crystalline. The surface properties of these sintered as well as raw materials used in the production of the ceramic composite are also investigated. A mathematical multivariate regression model is derived providing a relationship between the effectiveness of the water filtration systems as a function of the raw material composition and properties. The Ayurvedic waste material was found to be a good substitute for HAP for fluoride removal. The proposed treatment system is appropriate and suitable approach for fluoride removal in rural areas, because of its simplicity and easy operation and handling. Since Ayurvedic and organic waste materials are easily available at low cost, the proposed method is very suitable for the people living in low-income rural areas of developing countries like India.

Nanofiltration as tertiary treatment for the reuse of dairy wastewater treated by membrane bioreactor

Due to the growth in the costs of collecting and treating water, and with the treatment and discharge of effluents, reuse has become an increasingly viable option for industries. This study aimed at evaluating the application of membrane bioreactor (MBR) as secondary and nanofiltration (NF) as tertiary treatment for the reuse of dairy wastewater, focusing on determining the best NF operating conditions. MBR showed high removal efficiency for COD (mean of 98%) and nutrients (86% total nitrogen and 89% phosphorus). However, the concentration of dissolved solids in the permeate still prevented its reuse. In order to remove these solids, the MBR permeate was nanofiltrated, and three different cross-flow velocities were evaluated. Due to lower external fouling and better quality of the permeate, the velocity of 7.8m/s was selected as the most suitable for the NF system. The optimum permeate recovery rate was determined to be 45% since, at values higher than this, the quality of the permeate dropped. The proposed treatment system (MBR+NF) showed overall efficiencies of 99.9% for COD and 93.1% for total solids. The final treated wastewater could be reused as water for cooling, steam generation, or washing of external areas and trucks.