Disinfection Treatment Research Articles

Effects of Hypochlorous Acid and Hydrogen Peroxide Treatment on Bacterial Disinfection Treatments in Implantoplasty Procedures.

One of the main problems in oral implantology today is peri-implantitis, which affects almost 20% of dental implants placed in patients. One of the most commonly used techniques to eliminate bacterial biofilm is the implantoplasty, that consists of the mechanical modification of the implant surface topography followed by treatments with chemical reagents for decontamination. In this study, the main aim is to evaluate the use of two different chemical treatments based on hypochlorous acid (HClO) and hydrogen peroxide (H2O2). For this purpose, 75 titanium grade 3 discs were treated with implantoplasty according to established protocols. Twenty-five discs were used as controls, 25 were treated with concentrated HClO and 25 were treated with concentrated HClO followed by treatment with 6% H2O2. The roughness of the discs was determined using the interferometric process. Cytotoxicity with SaOs-2 osteoblastic cells was quantified at 24 and 72 h, whereas bacteria proliferation using S. gordonii and S. oralis bacteria was quantified at 5 s and 1 min of treatment. The results showed an increase in the roughness values, the control discs had an Ra of 0.33 μm and those treated with HClO and H2O2 reached 0.68 μm. Cytotoxicity was present at 72 h, together with a significant proliferation of bacteria. These biological and microbiological results can be attributed to the roughness produced by the chemical agents that triggered bacterial adsorption while inhibiting osteoblast adhesion. The results indicate that even if this treatment can decontaminate the titanium surface after implantation, the produced topography will generate an environment that will not favor long-term performance.

The disinfectant residues promote the leaching of water contaminants from plastic pipe particles

Disinfection treatment is an indispensable water purification process, but it can leave trace concentrations of disinfectant in the purified water. Disinfectants oxidation can age plastic pipes and release hazardous microplastics and chemicals into drinking water. Lengths of commercially-available unplasticized polyvinyl chloride and polypropylene random copolymer water pipe were ground into particles and exposed to micro-molar concentrations of ClO2, NaClO, trichloroisocyanuric acid, or O3 for up to 75 days. The disinfectants aged the plastic and changed its surface morphology and functional groups. Meanwhile, disinfectants could significantly promote the release of organic matter from plastic pipes into the water. ClO2 generated the highest concentrations of organic matter in the leachates from both plastics. Plasticizers, antioxidants and low molecular weight organic matter were detected in all of the leachates. Leachate samples inhibited the proliferation of CT26 mouse colon cancer and induced oxidative stress in the cells. Even trace concentrations of residual disinfectant can constitute a drinking water risk.

Correlation Analysis of the Experimental Data for In-Situ Chlorine Generation in Electrochlorination Process

Even though chlorination is a widely used disinfection technique, it has several disadvantages, such as formation of chlorates during prolonged storage, requirement for skilled supervision during operations, risk of leakage, and related accidents during transport and storage. Electrochlorination (EC) is one of the novel technologies generating in-situ chlorine, thereby limiting most of the disadvantages of conventional chlorination treatment for water disinfection. The correlation between the various influencing parameters for EC, which is important for achieving the optimal conditions for in-situ chlorine generation, is still unclear. The major objective of the present study is to provide a detailed correlation analysis between the parameters influencing the EC process based on the extensive experimental data generated from the developed lab-scale setup for electrochlorination using graphite electrodes and titanium electrodes separately. The present study also examined the rate of loss of the electrode materials to check the longevity of electrodes. The experimental results generated were used for comparative analysis of the EC process for maximum in-situ chlorine generation. A detailed principal component analysis (PCA) was performed for the data generated during experimentation to understand the correlation between the influencing parameters for optimum in-situ chlorine generation. The optimum conditions for maximum in-situ chlorine generation obtained from the experiments were 10 V electric voltage, 60 min electrolysis time, 4 cm distance between electrodes, and 3.5 g/L electrolyte concentration, with maximum chlorine generation of 15.95 mg/L obtained for titanium electrodes using NaCl electrolytes for the developed lab setup. The results of PCA established the correlation between the influencing parameters and concluded that the most significant parameter influencing chlorine generation was electrolyte concentration and electrochlorination time, and electric potential was moderately influential, whereas distance between electrodes was least influential. The rate of material loss was 15.3 mg/min for titanium electrodes and 24 mg/min for graphite electrodes, indicating titanium electrodes are more durable than graphite electrodes during a prolonged EC process. The applicability of the generated chlorine stock solution was also examined for drinking water sample disinfection and found to be effective.

Improving performance of proton-exchange membrane (PEM) electro-ozonizers using 3D printing

Ozone (O3) is a powerful oxidant widely used in disinfection and wastewater treatment. In this work, a novel 3-D printed casing for electrochemical cells has been specially designed and manufactured for Proton-Exchange Membrane (PEM) electro-ozonizers, trying to promote an improved fluid dynamic including an efficient evacuation of gases produced during the electrolysis and aiming to minimize the interaction among ozone and scavengers. It is demonstrated that reaching high efficiencies in the electrochemical production of ozone is limited by the action of electrogenerated scavengers, among which cathodically formed hydrogen peroxide outstands. This explains the effects observed regarding current density (higher efficiencies at higher current densities applied, because hydrogen peroxide production is prevented), electrolyte composition (better efficiencies with lower concentrations of non-reacting electrolytes) and operation pressure (better results at lower pressures, because hydrogen peroxide formation depends more importantly on dissolved oxygen than ozone production). A very good performance is obtained, with ozone productions as high as 0.240 mg/(Ah cm2) and maximum current efficiencies of 5.9% under the best operation conditions (1.0 mM of HClO4, 330 mA/cm2 and 1 bar), which demonstrate the suitability of the technology tested and the good perspectives of 3D printing to improve performance of electrochemical processes.

Inactivation Kinetics and Replication Cycle Inhibition of Coxsackievirus B5 by Free Chlorine.

The kinetics of coxsackievirus serotype B5 (CVB5) inactivation with free chlorine is characterized over a range of pH and temperature relevant to drinking water treatment with the primary goal of selecting experimental conditions used for assessing inactivation mechanisms. The inactivation kinetics identified in our study is similar to or slower than experimental data reported in the literature and thus provides a conservative representation of the kinetics of CVB5 inactivation for free chlorine that could be useful in developing future regulations for waterborne viral pathogens including adequate disinfection treatment for CVB5. Untreated and free chlorine-treated viruses, and host cells synchronized-infected with these viruses, are analyzed by a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method with the goal of quantitatively investigating the effect of free chlorine exposure on viral genome integrity, attachment to host cell, and viral genome replication. The inactivation kinetics observed results from a combination of hindering virus attachment to the host cell, inhibition of one or more subsequent steps of the replication cycle, and possibly genome damage.

Emergence of multidrug-resistant Acinetobacter baumannii under fluctuating levofloxacin concentration and its control by chlorine and UV disinfection

Although wastewater treatment plants are considered hotspots for the spread of antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs), few studies have explored the mechanisms underlying the emergence of multidrug-resistance. Using four sequencing batch reactors under fluctuating concentrations of levofloxacin (LVX), we isolated 440 isolates, which were identified based on the sequence of the 16 S rRNA gene and growth at 37 ºC, focusing on potential human pathogens. We then evaluated the multidrug-resistance of 62% of these isolates by determining the minimum inhibition concentration (MIC) of erythromycin, tetracycline, chloramphenicol, and LVX in the emergence of ARB. The average MIC was increased more than 100-fold in the first exposure, whereas did not show the same response after re-exposure due to different LVX concentrations between the 2 conditions. We identified 33 Acinetobacter baumannii isolates that emerged only during re-exposure, especially in R-2 and R-3, in which the LVX concentration was changed from 4 and 16 mg/L, respectively, to 128 mg/L. Moreover, we assessed the disinfection efficiency of chlorine/UV treatment against pathogenic ARB. The growth of multidrug-resistant A. baumannii isolates was decreased by 0.9–7.4 log10 following disinfection treatment with > 0.5 mg /L Cl2 or > 30 min UV irradiation.

Comparison and Efficacy of Breast Pump Cleaning Techniques for Bioburden Reduction.

Background: Donor milk is a good alternative for premature babies whose mothers cannot breastfeed. To reduce the risk of milk contamination, donors have to follow some hygiene instructions, including disinfecting their breast pump (BP). This study aims to investigate the efficacy of BP cleaning and disinfection methods. Methods: Contamination of BP parts was performed by passing milk inoculated with Bacillus cereus, Staphylococcus aureus, or Escherichia coli, through BPs. Devices were then rinsed with cold water or cleaned with hot soapy water. Disinfection was achieved using either a microwave or by immersing BP parts in boiling water. After treatment, residual bacteria were recovered by passing sterile phosphate buffer saline (PBS) through BPs before being inoculated on plates and performing bacterial counts. Method efficiency was assessed by comparing BP residual bioburden to results obtained from BPs that have not undergone cleaning or disinfection treatment (controls). Results: Rinsing BP parts with cold water leads to a diminution of residual bacteria in PBS recovered from device. This decrease is even more effective when hot soapy water is used. There is a slight persistence of all bacteria if disinfection of BPs is performed by using a microwave. This persistence reached up to 3.58 colony-forming unit/mL of sporulating B. cereus in PBS eluted from the pump parts. The use of boiling water, with or without cleaning step, removes bacteria to a level such that no residual contamination was observed. Conclusions: Cleaning BP parts in hot soapy water followed by a disinfection in boiling water ensures a completed decontamination of the BP. These results give evidences for instructions to milk bank donors for whom reducing risks of infections to minimal level is essential.

Micropropagation of Hemp (Cannabis sativa L.)

Hemp (Cannabis sativa L.) is commonly grown for the medicinal secondary metabolites produced by pistillate inflorescences. Micropropagation is a valuable method of propagating hemp plants because of the aseptic process and the production of true-to-type propagules. The hemp cultivar TJ’s CBD was used for a series of experiments to compare media inputs and practices for the clonal micropropagation of hemp. For stage I, shoot tips harvested from stock plants that were grown in a growth chamber produced less endogenous contamination in newly established cultures than shoot tips harvested from the greenhouse. In addition, stage I disinfection treatments with 20%, 40%, and 60% bleach (7.5% sodium hypochlorite) for 10 minutes had no differences in surface contamination rates. All concentrations were able to clean explants equally, and no damage to the explants was observed. For stage II, there were no differences in growth and multiplication rate between shoot tip or nodal explants. In addition, no differences were observed between the gelling agent’s agar, agargellan, and gellan gum at standard rates. When basal nutrient formulations were compared at standard rates and with their respective vitamins, Murashige and Skoog, Linsmaier & Skoog, and Driver & Kuniyuki Walnut media were found to be superior to Lloyd & McCown Woody Plant Medium. Media pH levels of 4.0, 5.0, 5.8, 6.0, and 7.0 were compared, and no differences were observed in final fresh weights, shoot lengths, or quality ratings. The pH levels of 5.8, 6.0, and 7.0 generated a greater number of lateral nodes. Sucrose levels of 0%, 1.5%, 3.0%, 4.5%, and 6.0% (wt/vol) were also compared, with the 1.5% and 3.0% rates showing greater fresh weights, shoot lengths, and quality ratings. Growth room temperatures of 22, 24, 26, and 28 °C were compared, with temperatures of 28 and 26 °C generating greater fresh weights, shoot lengths, numbers of nodes, and quality ratings compared with cooler temperatures. The cytokinins 6-enzylaminopurine (BA), 6-(γ,γ-dimethylallylamino) purine (2iP), and thidiazuron (TDZ) were compared at 1.0, 5.0, and 10.0 μM concentrations. The 5.0-μM TDZ treatment generated greater fresh weights and numbers of lateral nodes; however, it also produced the shortest shoot lengths and lowest quality ratings. The 2iP treatments at 1.0 and 5.0 μM, and the BA treatment at 1.0 μM produced the greatest quality ratings. The 5.0-μM 2iP level was considered the best treatment for stage II multiplication based on high ratings, in addition to the greater final fresh weights, shoot lengths, and numbers of nodes that were produced. For stage III experiments, the auxins indole 3-butyric acid (IBA) and 1-naphthylacetic acid (NAA) were compared at concentrations of 0.25, 0.5, and 2.5 μM. Auxin treatments of 0.25 μM NAA, 0.5 μM NAA, and 2.5 μM IBA generated the greatest final shoot fresh weights, root fresh weights, and numbers of nodes. However, the 2.5-μM IBA treatment resulted in a higher overall rating. For stage IV, ex vitro rooting and acclimation trials compared a dome and an intermittent mist system, as well as treated the unrooted cuttings with an externally applied auxin. Acclimating with a dome produced greater shoot heights, fresh shoot weights, and overall ratings compared with the mist system. The auxin treatment mildly increased fresh root weight, but was not as important to acclimation success as the domed environment. It has been concluded that a micropropagation system that uses lower rates of sucrose, higher growing temperatures, and lower rates of the cytokinins BA and 2iP are optimal for the micropropagation of hemp. In addition, when acclimating hemp plants from tissue culture, an in vitro stage III can be bypassed and plants can be rooted ex vitro during stage IV acclimation with a dome with or without additional auxin treatments.

Ballas Water and Sediment Control and Management on Ship Using Method D-2: Auto Filter and UV Disinfection Treatment Methods

This study aims to protect the maritime environment from the spread of foreign species or harmful aquatic organisms and pathogens due to the discharge of ballast water from ships in order to prevent, minimize and completely eliminate risks to the environment, human health, wealth and resources arising from the transfer of aquatic organisms. harmful and pathogenic through the control and management of ballast water and sediment from ships, as well as to avoid unwanted side effects from such control and to encourage the development of related science and technology. The problems raised in this study are (1) What is the Ballast Water Exchange Standard (Reg. D-1), (2) What is the Ballast Water Performance Standard (Reg. D-2)?, (3) What is the Ballast Water Management Plan (BWMP) (Rule B-1) and (4) What is the combination of treatment technology. The method used in this research is descriptive qualitative method using data reduction analysis techniques, data presentation, and drawing conclusions as a method to determine the causes and efforts to overcome them. The results show that by applying the Ballast Water Performance Standard (Reg.D-2) with a combination of treatment technology, it can protect the maritime environment with the required ballast water performance standards. As required in the convention concerning the control and management of ballast water and sediment from ships/The International Convention for The Control and Management of Ship's Ballast Water and Sediments, 2004, in this convention it is required that ships of 400 gross tonnage and above are subject to this convention, not including floating platforms, FSUs and FPSOs are required to participate in the survey determined and meet the requirements of the BWM Convention. The conclusion of this study is that by installing BWMT to meet Reg. D-2 can protect the maritime environment from the spread of foreign species or aquatic organisms and pathogens.

Surveillance on ESBL-Escherichia coli and Indicator ARG in Wastewater and Reclaimed Water of Four Regions of Spain: Impact of Different Disinfection Treatments

In the present study, the occurrence of indicator antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) both in the influent and the effluent of four Spanish wastewater treatment plants (WWTPs) was monitored for 12 months, and the susceptibility profiles of 89 recovered extended spectrum β-lactamase (ESBL)-producing Escherichia coli isolates were obtained against a wide range of antimicrobials. The aim of the study was to better understand whether the current wastewater treatment practices allow us to obtain safe reclaimed water mitigating the spread of ARB and ARGs to the environment. Results showed high concentrations of ESBL-producing E. coli as well as a high prevalence of a range of ARGs in the influent samples. The reclamation treatments implemented in the WWTPs were effective in reducing both the occurrence of ESBL E. coli and ARGs, although significant differences were observed among WWTPs. Despite these reductions in occurrence observed upon wastewater treatment, our findings suggest that WWTP effluents may represent an important source of ARGs, which could be transferred among environmental bacteria and disseminate antimicrobial resistance through the food chain. Remarkably, no major differences were observed in the susceptibility profiles of the ESBL E. coli isolated from influent and effluent waters, indicating that water treatments do not give rise to the emergence of new resistance phenotypes.

Smart in-line cleanup cartridge modules and floating sorbent systems for BrO3- removal from natural water sources – An innovative approach

Functionalized montmorillonite–chitosan hybrid systems were developed as novel and cost-effective sorbent materials for the quantitative removal of carcinogenic bromate from natural water sources. The developed materials were custom fabricated via two facile and innovative approaches viz. reusable cartridge as a ‘point of use’ clean up modules and carbon cloth based “floating sorbents”, as a removal strategy at the ‘point of entry’. The packing density and flow rate of inline clean up cartridges as well as the sorbent coating and drying procedure of floating sorbent systems were sequentially optimized and validated. The application potential of the fabricated materials was subsequently explored and the studies revealed excellent removal efficiencies of > 99% for batch and flow based systems. The developed modules could successfully remove bromate levels in spiked natural water samples such as drinking, well and river water, down to 10 µgL−1 with more than 97% efficiency. The findings were substantiated through characterisation studies and detailed mechanistic investigation was carried out to understand the better adsorption characteristics of hybrid functionalized clay-chitosan composite. Consequently, the studies implied that a modular inline clean up cartridge packed with 600 g Mt-H-CTS sorbent connected to a water purification system is sufficient to quantitatively remove as high as 100 µgL−1 bromate for a middle class household on a monthly basis. Furthermore, the rapid and efficient regeneration of the material could improve the longevity and makes it an ideal candidate for post disinfection treatment applications at drinking water outlets such as taps (point of use) as well as for large reservoirs in the form of ‘floating sorbents.

Enhancing the anti-bacterial activity of nanofibrous polyurethane membranes by incorporating glycyrrhizic acid-conjugated β-Cyclodextrin

Licorice contains glycyrrhizic acid, an antibacterial and anti-inflammatory component widely used as an ingredient for disinfection and trauma treatment since ancient times. In this study, antibacterial capsules were prepared by conjugating glycyrrhizic acid as a natural antibacterial substance with β-cyclodextrin. In addition, after mixing it with a polymer solution, it was successfully manufactured into fibers using an electrospinning technology. Through several analyzes, it was confirmed that the antibacterial capsule was well distributed within the prepared electrospinning membrane. The antibacterial test confirmed that glycyrrhizic acid encapsulated with β-cyclodextrin maintains its antibacterial properties. If such electrospun fiber containing an antibacterial capsule is manufactured, it can be applied to trauma treatment such as wound dressing due to its antibacterial effect. In addition, it can be used in various fields such as infection prevention and disease treatment by utilizing the anti-inflammatory and antiviral effects of glycyrrhizic acid.

A novel exposure mode based on UVA-LEDs for bacterial inactivation.

As an emerging UV source, ultraviolet light-emitting diodes (UV-LEDs) are increasingly being used for disinfection purposes. UVA-LEDs have a higher output power, lower cost, and stronger penetration and cause less harm than UVC-LEDs. In this study, a novel exposure mode based on UVA was proposed and well demonstrated by various experiments using S. aureus as an indicator. Compared with single-dose exposure, fractionated exposure with a 15min interval between treatments resulted in increased S. aureus inactivation. A longer interval or lower first irradiation dose was unfavorable for inactivation. Fractionated exposure changed the inactivation rate constant and eliminated the shoulder in the fluence-response curves. This resulted in changing the sensitivity of bacteria to UVA and improving bacterial inactivation. Moreover, the fractioned exposure mode has universality for various bacteria (including gram-positive and gram-negative bacteria). S. aureus was not reactivated by photoreactivation or dark repair after UVA treatment. As expected, the cells were damaged more seriously after fractionated exposure, further suggesting the advantages of this new exposure mode. In addition, the mechanism by which bacteria were inactivated after fractionated exposure was investigated, and it was found that •OH played an important role. A longer interval between treatments showed an adverse effect on inactivation, mainly due to the reduction of •OH and recovery of intracellular GSH. In summary, the current work provides novel ideas for the application of UVA-LEDs, which will give more choices for disinfection treatment.

Detection and quantification of viable but non-culturable Legionella pneumophila from water samples using flow cytometry-cell sorting and quantitative PCR.

Legionella pneumophila is a waterborne pathogen and, as the causative agent of Legionnaires' disease, a significant public health concern. Exposure to environmental stresses, and disinfection treatments, promotes the formation of resistant and potentially infectious viable but non-culturable (VBNC) Legionella. The management of engineered water systems to prevent Legionnaires' disease is hindered by the presence of VBNC Legionella that cannot be detected using the standard culture (ISO11731:2017-05) and quantitative polymerase reaction (ISO/TS12869:2019) methods. This study describes a novel method to quantify VBNC Legionella from environmental water samples using a "viability based flow cytometry-cell sorting and qPCR" (VFC + qPCR) assay. This protocol was then validated by quantifying the VBNC Legionella genomic load from hospital water samples. The VBNC cells were unable to be cultured on Buffered Charcoal Yeast Extract (BCYE) agar; however, their viability was confirmed through their ATP activity and ability to infect amoeba hosts. Subsequently, an assessment of the ISO11731:2017-05 pre-treatment procedure demonstrated that acid or heat treatment cause underestimation of alive Legionella population. Our results showed that these pre-treatment procedures induce culturable cells to enter a VBNC state. This may explain the observed insensitivity and lack of reproducibility often observed with the Legionella culture method. This study represents the first time that flow cytometry-cell sorting in conjunction with a qPCR assay has been used as a rapid and direct method to quantify VBNC Legionella from environmental sources. This will significantly improve future research evaluating Legionella risk management approaches for the control of Legionnaires' disease.

Evaluation of the Irradiation Treatment Effects on Ancient Parchment Samples

In this work, the effect of X-ray irradiation as a disinfection treatment in original ancient parchment samples, belonging to a discarded book cover of a 16th-century archival register, has been evaluated. Specifically, the bacterial and fungal species isolated from the book cover have been characterized and then irradiated with increasing doses of X-rays with the aim to evaluate the effectiveness of the antimicrobial protocol on the isolated microorganisms. The deterioration effects induced by the X-ray treatment as well as the natural aging on the collagen matrix of the parchment sample have been tested by employing several techniques, namely, Light Transmission Analysis, Fiber Optic Reflectance Spectroscopy, Attenuated Total Reflectance-Fourier Transformed Infrared spectroscopy, UV Resonant Raman spectroscopy and Atomic Force Microscopy. The results reveal that the irradiation treatment applied to our ancient parchment samples deteriorated by biological attack and other naturally occurring phenomena, possibly associated with inappropriate conservation conditions, does not seem to induce further damage factors even when large doses of irradiation are employed. The X-rays-based disinfection treatment effects are limited on the collagen support and this confirms the potential of this method in mass disinfection of library and archival materials.

Mathematical Model of Foot and Mouth Disease Considering Vaccination Disinfection And Early Quarantine

Foot and Mouth Disease (FMD) is a highly contagious disease that can infect all cloven hoofed animals. FMD is one of the most important infectious viral diseases in the world. This disease is responsible for international losses in livestock production and trade. In this article, we formulate a mathematical model for the spread of FMD in goat farms that considers early quarantine, vaccination, and disinfection interventions. The model constructed is expressed as a system of ordinary differential equations consisting of eight state variables. We determine the basic reproduction number using the next-generation matrix method. Our numerical simulation results show that vaccination has a very crucial role in controlling the spread of FMD and reducing the basic reproduction number. In addition, quarantine interventions for latent and infectious goats are also effective in controlling the spread of FMD. The basic reproduction number can also be suppressed by disinfection and quarantine interventions. Therefore, we recommend implementing routine vaccination, screening and disinfection programs. In addition, farmer should be given education so that they have the ability to identify goats exposed to FMDV so that quarantine can be carried out early.

Integration of Corn and Cane for Ethanol Production: Effects of Lactobacilli Contamination on Fermentative Parameters and Use of Ionizing Radiation Treatment for Disinfection

Recently, in Brazil, corn ethanol industries are being installed and the integration with sugar/energy-cane has been proposed, using bagasse for cogeneration and the juice to dilute the corn. However, this integration may have some limitations, such as the quality of the cane juice and potential contamination by microorganisms brought with the cane from the field. In this article, we first tested the effects of mixing energy cane juice with corn on fermentative parameters. We also assessed the effects of Lactobacilli. contamination on organic acids produced during the fermentation and fermentation parameters and proposed the use of ionizing radiation to replace antibiotics as a disinfection control method. Our results showed that mixing energy cane juice with corn does not have any negative effect on fermentation parameters, including ethanol production. The contamination with Lactobacilli. considerably increased the production of acetic, lactic, and succinic acid, reducing the pH and ethanol content from 89.2 g L−1 in the sterilized treatment to 72.9 g L−1 in the contaminated treatment. Therefore, for the integration between corn and cane to be applied on an industrial scale, it is essential to have effective disinfection before fermentation. Ionizing radiation (20 kGy) virtually disinfected the wort, showing itself to be a promising technology; however, an economic viability study for adopting it in the industry should be carried out.

New insights into alkalinity regulation in microflocculation-ultrafiltration process: Synergistic mechanisms for scale inhibition, enhanced flocculation and mitigation of membrane fouling

“Ancient Oriental Wisdom” refers to the fact that the Chinese traditional drink boiled water since ancient times, and boiling is the most common method of disinfection and water treatment in household, however, boiling may also generate scale which is harmful to human health. Surface water frequently suffers from issues such as scaling after boiling and natural organic matter (NOM). The microflocculation-ultrafiltration (MUF) process cannot inhibit scale, NOM removal requires improvement, and membrane fouling is still a major limiting factor in its application. The alkalinity regulated microflocculation-ultrafiltration (ARMUF) process can provide three effects simultaneously by regulating alkalinity: (i) significant scale inhibition and almost complete retention of beneficial Ca2+ and Mg2+ in the raw water; (ii) enhanced flocculation effect, increased NOM removal, forming a loose floc and larger floc size, which helps to mitigate membrane fouling; (iii) mitigation of membrane fouling, the ARMUF process showed the lowest total resistance, with significant recovery of membrane characteristics after chemical cleaning. Notably, the ARMUF process was used as the basis for the design and fabrication of a 150 tonnes/day device, demonstrating the engineering application potential of the ARMUF process and providing theoretical and data support for its promotion.

Effect of non-thermal ultraviolet and ultrasound technologies on disinfection of meat preparation equipment in catering industry.

In recent years, ultraviolet and ultrasound treatments are gaining attraction as promising green decontamination technologies to ensure microbial safety in food industry. Decontamination by ultraviolet light is a physical process defined by the transfer of electromagnetic energy from a light source to an organism's cellular material and depended on the emission of radiation in the ultraviolet region (100-400 nm), specifically the UV-C region (200-280 nm) which has been demonstrated to be germicidal. Ultrasound technology is defined as sound waves with high and low frequency beyond the limit of human hearing and shows a decontamination effect that occurs as a consequence of cavitation at high power (low frequency) in general. In the present study, it was aimed to determine the effectiveness of ultraviolet light (254 nm, 10 min) and high frequency ultrasound techniques (40 kHz, 10 min) in reducing total aerobic mesophilic bacteria, yeast and mold, Esherichia coli/coliform and Salmonella spp. on the equipment surfaces used in the catering facility. For this purpose, the equipment (cutting knife, meat grinder knife, knife sharpener, cut-proof glove) used in the meat preparation department of catering facility were selected for the treatments. According to the results, appreciable reductions were achieved in total aerobic mesophilic bacterial counts of the ultraviolet treated samples (maximum difference 2.61 log cfu/cm2) and the ultrasound treated samples (maximum difference 4.07 log cfu/cm2). After ultraviolet treatment, Salmonella spp. were totally inhibited on the contaminated surfaces. Furthermore, Escherichia coli/coliform was not detected in the samples after both treatments whereas it was detected before the treatments. It has been concluded that the techniques are effective in reducing microbiological load and also ultraviolet treatment is effective on pathogenic microorganisms on food contact surfaces. As a result, the ultraviolet and ultrasound techniques are effective treatments for equipment disinfection in the catering sector and can be used industrially as it gives successful results.

Effectiveness of Ceramic Filter Water Treatment Method in Improving Drinking Water Quality and Reducing Water-Related Disease: Systematic Review and Meta-Analysis

Lack of access to improved drinking water sources is global problem. Millions of peoples cannot get safe drinking water as defined by the World Health Organization (WHO) Guidelines for Drinking Water Quality. Untreated drinking water has been reported in different studies as one of the major contributors to the human health problem (water related disease) such as cholera, typhoid, viral hepatitis and dysentery, and responsible for death of people in million each year. Middle and low-income countries more affected by the problem. To scope up this problem many of these countries started to use household level water treatment methods like: chlorination, solar disinfection and ceramic water treatment method. The aim of this study is to pool out the available research evidence on the effectiveness of the ceramic filter water treatment method in reducing diarrhea in both children and adults. Searches were conducted in PubMed, Google Scholar databases and references to other studies. The review included RCT studies on both children and adults found anywhere in the world regardless of sex, ethnicity and socioeconomic status, and religion which were published or conducted in English from December 2000 to January 2022. Studies that compared the diarrhea incidence between the intervention groups who were exposed to ceramic filter disinfection water treatment and the control group who were not exposed to such water treatment. Two independent reviewers critically reviewed and appraised the selected studies. Effect sizes were expressed in risk ratio and in their 95% CIs. 9 eligible studies were identified out of total of 14,007 studies pooled from data bases. In all identified studies, ceramic filter water treatment method reduced the risk of diarrhea in both children and adults. The estimated pooled risk ratio of diarrhea among participants who used ceramic filter disinfection water treatment method was 0.49 (0.41, 0.57). The overall pooled results of the study show that using of ceramic disinfection water treatment method had reduced the risk of diarrheal disease by 51%. This study indicates using of ceramic disinfection water treatment method significantly reduced the risk of diarrheal disease both in children and adults.