Final Turbidity Research Articles

A novel γ-chain mutation p.Asp318His in a Chinese family with dysfibrinogenemia.

Congenital dysfibrinogenemia is characterized by reduced fibrinogen activity, but normal immunoreactive fibrinogen levels. Here, we present a novel case with an elevated risk of thrombosis. Coagulation assays, gene analysis, in silico tools, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), fibrin polymerization, thrombin generation assay, and electron microscopy scanning were utilized to elucidate the pathogenic mechanism. The proband manifested with a normal immunologic fibrinogen (2.13 g/l) but reduced functional fibrinogen (0.39 g/l). Subsequent genetic analysis unveiled a novel heterozygous mutation, c.1030G>C (p.Asp318His), in the γ-chain D domain of fibrinogen, which was highly conserved in homologous species and led to enhanced thrombin generation capability. The ability of the proband's fibrinogen to polymerize was significantly impaired, with decreased final turbidity. Scanning electron microscopy indicated that the fibers of the proband were thinner than normal, with smaller pores. Thromboelastography (TEG) results demonstrated prolonged K time, decreased angle value, and a normal confidence interval value in the proband. We present a novel case displaying the γAsp318His mutation, which resulted in dysfibrinogenemia.

Coagulation tests of waste pulp from copper mineral processing

The sustainable use of water in mineral processing is essential for maintaining the ecosystem that supports the mining environment and, consequently, for the operation itself that uses water resources. As an area that has such a finite resource as a basic operating condition and that uses this resource on a large scale, it is necessary to constantly seek to optimize its use, having as pillars quality and economy in the treatment of effluents generated. It is in stages like this that coagulating reagent work. In the processing unit in question, more than 90% of the water is recirculated and reused, a process that relies on the support of a coagulant to accelerate the sedimentation of solids and guarantee the reuse of water of sufficient quality to provide operations with the solvent necessary for the environment. physicochemical. The coagulant currently used in tailings dam operations is aluminum sulfate. Due to the high use and cost spent on this reagent, tests were conducted with two other alternative coagulants (iron III chloride and iron III sulfate), comparing the cost-benefit between the reagents assessed. To this end, a cost-benefit factor was used, calculated using the cost of the reagent, dosage, residual turbidity of the clarified liquid and the sedimentation speed of the solids. After the tests, it was found that aluminum sulfate, the reagent used in the operation until then, was the best option among the reagents assessed. However, a reduction of 21.43% in the dosage currently used of this reagent by the company, maintaining the final turbidity target is possible, thus generating cost reduction.

Baobab Leaf Powder Efficacy as Turbid Water Treatment Biocoagulant

The high cost of treated water makes most rural communities resort to readily available sources that are normally of low quality, which exposes them to waterborne diseases in the process. In the present study, various doses of baobab (Adansonia digitata) leaf powder coagulant (i.e., 0.1, 0.2, and 0.3g per 50 mL turbid water) were added to the surface water sample collected. It was found that increasing the coagulant doses results in either a decrease or increase in the measured parameters, such as pH, turbidity, and electrical conductivity (EC). At constant 30 min coagulation time, pH and EC of the turbid water samples taken were within WHO standards. However, the labeled sample fed with 0.3g of baobab leaf powder coagulant gave the lowest turbidity of 78.7 NTU. A reduction in final turbidity is a clear indication of the coagulation capabilities of baobab leave powder. With this study, baobab leave (as a potential coagulant) is a new addition to the literature, apart from its seed and pulp which have been experimented with previously. Natural coagulants contain some chemicals whose effect on the resulting treated water needs to be examined. If need be, an additional treatment unit must be set up to adsorb or remove those contaminants from the water before proper use.

Improving household water treatment: using zeolite to remove lead, fluoride and arsenic following optimized turbidity reduction in slow sand filtration

Despite the United Nations 2030 agenda, large number of both urban and rural dwellers in low-income countries continue to lack access to improved water. Thus, increased effort is required towards enhancing low-cost drinking water treatment technologies especially for developing countries. Slow sand filter (SSF) is one of the most commonly used low-cost and efficient technologies for treating household drinking water. However, effectiveness of SSF is substantially affected by very high turbidity and relatively large amounts of dissolved heavy metals. To enhance removal of both turbidity and heavy metals, this study optimized sand bed depth (SBD) of SSF and investigated the potential of natural zeolite from Uganda for removal of lead, arsenite (As(III)) and fluoride ions from water. To remove lead ions, the zeolite was used in its natural form. However, to remove As(III) and fluoride, the natural zeolite was modified using hexadecyltrimethylammonium bromide solution. Removal of high turbidity was found to require a large optimal SBD. Furthermore, efficiency of treating synthetic turbid water increased with increasing initial turbidity. Variation of final turbidity with SBD was found to be best described by an exponential function. Optimal SBDs on top of an underdrain gravel layer of 0.2 m were 453, 522, 561, and 580 mm for turbidity of 60, 80, 100, and 120 NTU, respectively. Optimized SBD used achieve at least 95% efficiency in removing suspended particles from water with turbidity 120 NTU was found to save up to 35% of the total cost for acquiring sand volume required by a conventional SSF. For a particular zeolite mass, removal efficiencies of lead, As(III) and fluoride generally increased with increasing contact time. Removal efficiencies of lead, As(III), and fluorides were also shown to increase with increasing zeolite mass. Lead removal efficiencies using natural zeolite were 75 and 98% under 20 and 40 min, respectively. Removal of As(III) using modified zeolite mass was 91% within contact time of 10 min. Adsorption of fluoride on modified zeolite was 80% within 5 min. Adsorption of lead, As(III), and fluorides indicated promising potential of natural zeolites from Uganda for treating polluted water.

Purification of used cooking oil using natural corn cob and carbon corn cob as adsorbent with batch operation

Adsorption is one of the processes used to purify used cooking oil by using adsorbents from natural and carbonized corn cob as part of sustainability. The adsorption process is chosen because it is more economical, efficient, relatively affordable cost, and can be regenerated. This study was conducted in batches to observe changes in the quality of used cooking oil at certain time intervals and to determine the modeling of adsorption kinetics on natural corn cob and carbonized corn cob adsorbents. The sample of this study is 100 ml of used cooking oil with adsorbents in the form of natural corn cob and carbonized corn cob with a mass of 3 grams and a particle size of 70 mesh. This study’s best adsorption result is corn cob carbon adsorbent. This can be seen from the final turbidity value of 37.3 NTU compared to the natural corn cob adsorbent of 37.6 NTU. This study found that the adsorption process that occurs has chemical interactions as evidenced by second-order pseudo-modeling, which has a correlation coefficient close to one.

Study of Flow Rate Effect on Horizontal Flow Concrete Sand Filter Filtration Performance

The need for clean water during the pandemic is significantly increasing due to high public awareness of adopting a clean and healthy lifestyle (PHBS), necessitating more water treatment. Conventional methods are used for water treatment, including coagulation-flocculation system, rapid sand filter, and disinfection. However, these methods have limitations such as reduced capacity and sand filter efficiency, leading to increased backwash costs due to the need for sand replacement caused by particle stratification. In response to these challenges, an innovative method to water treatment is the use of concrete sand filter (CSF). Previous studies predominantly focused on downflow filtration, but there has been limited analysis of horizontal flow. Therefore, this study aimed to assess filtration and backwash effectiveness of CSF with horizontal flow, specifically focusing on the capacity performance in treating water with varying levels of turbidity. Filtration experiment was carried out using simulated water at turbidity of 125 NTU based on the Mataram Channel Turbidity with variations of 0.2, 0.5, 1.0, 5.0, and 10.0 m hour-1, as well as backwash at flow rate of 40.91 m hour-1 for 3 minutes. The variables measured during filtration process included head losses and turbidity at the inlet and outlet of CSF. The results showed that the capacity performance during filtration process was directly proportional to flow rate. Meanwhile, the effectiveness of concrete filter was inversely proportional to flow rate. At initial turbidity <617 NTU, the 3 minutes backwash process obtained lower final turbidity compared to the raw water used, which was 5.19 NTU. Meanwhile, at turbidity 617 NTU, the final turbidity was still high, reaching approximately 14.6–26.4 NTU.

Effectiveness of Papaya Seeds as a Biocoagulan to Reduce Turbidity in Grained Media Water Treatment

Bedadung River is one of the raw water sources in Jember City. Turbidity is one of the water quality parameters of the Bedadung River. It has exceeded the quality standards, requiring treatment to reduce turbidity through the coagulation-flocculation method with a gravel bed flocculation. The process needs a coagulant. However, commonly found coagulants are made from raw chemical materials that have an impact on the environment and health. Therefore, alternatives are needed, such as coagulants that use natural raw materials, one of which is papaya seeds. This study aims to determine the optimum dose of papaya seed coagulant and the effect of media type (single and multiple media) on the final turbidity using papaya seed coagulant. The research began with the preparation of papaya seed coagulant and determination of the optimum dose, then continued with running reactor. The result shows that the optimum dose of papaya seed biocoagulant to reduce water turbidity of 15-110 NTU is 130 ppm. Application in the reactor, the effect of a media type (single and multiple media) as bed flocculation using coagulant papaya seeds has a significant effect on the final turbidity partially, with a significance value of < 2 x 10−16 < 0.05.

The Effect of Cone Area Variations on the Continuous Discharges Flow (CDF) Method Sedimentation Unit as a New Method for Raw Water Turbidity Removal

The Sedimentation Unit Continuous Discharges Flow (CDF) method is a modification by adding a continuous and controlled discharge flow as a net force acting on the particles to increase the efficiency of turbidity removal by applying the principle of a leaky tank at the bottom of the settling zone. The production capacity of the sedimentation unit using the CDF method is reduced due to the CDF flow of 6% of the flow rate so it needs to be recirculated. This study aims to maintain the production flow rate of the system and increase the efficiency of turbidity removal by recirculating the CDF flow. The research reactor consisted of a coagulation unit, flocculation unit, and sedimentation method using 6% CDF with a flow rate of 240 L/hour and 360 L/hour, and variations in the recirculation flow of 6% CDF to the flocculation unit were 0%, 25%, 50%, 75%, and 100 %. The sedimentation detention time at a flow rate of 240 L/hour and 360 L/hour was 90 minutes and 60 minutes, respectively. Research on a laboratory scale with raw water turbidity of 25,536 NTU. The results showed that the greater the CDF flow recirculation value, the higher the turbidity removal efficiency. Rank Spearman analysis, the correlation value of the CDF flow recirculation value to the efficiency of removal of turbidity is 0.980 and the significance value is 0.00 which means strong and significant. The highest turbidity removal efficiency was achieved at the 100% CDF flow recirculation value, ie at 240 L/hour flow rate was 87.21% with final turbidity 3.267 NTU, while at 360 L/hour flow rate was 82.50% with final turbidity 4,528 NTU. Uprating the flow rate in the experiment was able to produce a final turbidity value that met the drinking water quality standard, which was 5 NTU

Coagulation-flocculation process for greywater treatment using Chitosan and Hibiscus Sabdariffa

Abstract Greywater means faecal free wastewater from households and buildings. Recycled greywater can be used for daily activities where freshwater is not necessary. Coagulation and flocculation technique in water recycling mostly utilize chemical coagulant alum. However, alum residue in water causes neural diseases and the process produces toxic sludge. Hence, natural coagulant is a safer alternate. Previous studies had proved the efficiency of different types of natural coagulant used individually and as a combination. However, the combination of chitosan and H. Sabdariffa had not been tested. The objective of this research is to investigate the efficiency of chitosan and H. Sabdariffa used alone and combined in greywater treatment. Jar test experiment was conducted using 0.5 L greywater in beakers mixed with the coagulants. The pH and coagulant dosage in each beaker were manipulated to determine the optimum condition. The greywater was then mixed rapidly for 4 minutes at 140 rpm, then slowly for 20 minutes at 30 rpm. Before assessing the final turbidity and Chemical Oxygen Demand (COD), the beakers were allowed to settle for an hour. At pH 4, 0.8 mg/L of chitosan reduced turbidity by 51 % and COD by 60 %. With a dosage of 200 mg/L, H. Sabdariffa demonstrated its best effectiveness at pH 2, resulting in an 88 % reduction in turbidity and a 53 % reduction in COD. When chitosan and H. Sabdariffa were combined, the optimal composition was determined to be 40% chitosan and 60% H. Sabdariffa by weight at pH 4, resulting in a turbidity reduction of 94% and a COD reduction of 56%. The same experiment was carried out using alum at pH 6 and a coagulant dose of 200 mg/l, turbidity and COD were reduced by 96% and 62% respectively. respectively. As a result, the performance of chitosan and H. Sabdariffa have been shown to be comparable to alum in the treatment of greywater, separately and in combination.

Application of ANN and RSM Techniques in Optimal Parameter Evaluation for Turbidity Removal from Abattoir Effluent using Valorized Chicken Bone Coagulant

Chicken bone coagulant (CBC) containing high grade hydroxyapatite (HPA) has been applied in the coag-flocculation of abattoir effluent. The influence of process variables (pH, initial concentration, dosage, Temperature, and settling time) on the effluent final turbidity was investigated. Also, the accuracies of two modelling techniques (Response surface methodology, RSM and Artificial neutral network, ANN) in predicting the non-linear nature of the system were compared. The optimization result indicates a final turbidity of 4.96 mg/L (corresponding to 98.28 % removal efficiency) at pH = 6.7, dosage = 1.003 g/L, initial conc. = 182.2 mg/L, coagulation temp. = 345 K and settling time of 36 min. Meanwhile, effluent pH was spotted as the most significant variable, with p-value &lt;0.01%. Furthermore, the error analysis result portrayed the supremacy of ANN over RSM in data prediction accuracy as it signified lower error values (Mean square error, MSE = 13.11 and Absolute average relative deviation, AARD = 1.43%) when compared to those of RSM (MSE = 37.78, AARD = 5.93%). Thus, it was demonstrated that ANN is a better tool for optimization study of the present system.

HIGH TURBIDITY AND COD REMOVAL IN RIVER WATER USING LOW DOSAGE PLANT-BASED TACCA LEONTOPETALOIDES FLOCCULANT (TBPF) FOLLOWED BY ACTIVATED CARBON TREATMENT

Pollution in river water affects human, plant and animal health and activities, and its removal using chemical coagulants is a huge concern. This study aims to reduce turbidity and COD pollutants in river water through coagulation-adsorption process by using Tacca leontopetaloides biopolymer flocculant (TBPF) and powder activated carbon (PAC). In coagulation experiment, TBPF dosages were varied to evaluate the effect on turbidity and COD removal in river water by using Bioblock flocculator followed by adsorption process by adding PAC. The results found that at 200 mg/L of TBPF dosage with 2000 mg/L of PAC, the maximum turbidity and COD removal were obtained at 49% and 81%, respectively. The final turbidity and COD loads were 4.2 NTU and 9.3 mg/L, respectively, which were below the standard limit set for CLASS IIB provided by the National Water Quality Standards of Malaysia (NWQSM). High turbidity and COD removal using low dosage of environmental friendly plant-based TBPF-PAC through coagulation-adsorption process in this study has a great potential for river water treatment, particularly at the domestic area.

Rapid-Slow Sand Filtration for Groundwater Treatment: Effect of Filtration Velocity and Initial Head Loss

Iron (Fe) and manganese (Mn) are two of many substances that are causing harm to human health and various environmental contamination. This study investigates the performance of rapid sand filter as an improvement to the existing commercial filter media. Rapid sand filters were tested using groundwater collected from Kg Budi Kelantan. Groundwater collected were tested using seven velocities ranging from 0.89 to 5.04 m/hr. The concentration of Mn, Fe and turbidity of the treated groundwater were compared. It is found that the highest Mn, Fe and turbidity removal were recorded by using velocity of 4.38 m/hr followed by 2.95 m/hr and 2.4 m/hr. These three velocities represent more than 95% removal of final treated groundwater, where final Fe, Mn and turbidity ranging from 0.06 mg/L to 0.09 mg/L, 0 to 0.4 mg/L and 0.9 to 3.0 NTU, respectively. A positive trend also recorded where the initial head loss of the sand filter is directly proportional to the flow velocity. This means the filter media was still under a clean condition and no accumulation of sediment deposit occurs. The significance of this study to treat groundwater by removing the iron and manganese especially in rural areas were achieved successfully.

Optimizing the recovery process of ceramic grade calcium fluoride from hydrofluoric/hexafluorosilicic acid wastewater

Chemical precipitation using calcium salts has been widely applied in hydrofluoric acid wastewater treatment due to its simplicity, flexibility and economy. Coagulants/flocculants are used to improve solid-liquid separation in a fine precipitate of calcium fluoride (CaF2). As a result, a large amount of sludge is generated by CaF2 precipitation process. In order to move towards a circular economy, the current study developed an environment-friendly and cost-effective approach to treat concentrated hydrofluoric/hexafluorosilicic acid wastewater (∼117 g F−/L) obtained from an optoelectronic industry in Taiwan and to recover fluoride as the high purity CaF2, as well as to reduce the amount of final waste disposal. The influence of three independent variables, including calcium-to-fluoride molar ratio ([Ca2+/F−], silicon concentration ([Si4+]), and polymer dosage applied, on the purity of recovered CaF2 products, was investigated and optimized by combining response surface methodology (RSM) with central composite design (CCD). The ceramic grade CaF2 of 85.6–87.9% was achieved under the optimum conditions as [Ca2+/F−] of 0.618–0.645, [Si4+] of 1.48 g/L, and polymer concentration of 17.2–17.8 mg/L. The final turbidity, residual fluoride concentration in the supernatants and fluoride removal efficiency were 14.8–16.2 NTU, 62.2–67.6 mg/L and greater than 99%, respectively. The value of R2 = 0.9498 and adjusted R2 = 0.9319 indicated an adequate correlation between experimental results and predictions by the quadratic model. In addition, a new insight into the CaF2 purification method has been proposed based on the idea of pH control.

High Cod and Turbidity Removal in The Treatment of Polluted Pond Water Using Low Dosage of Pineapple Leaf Coagulant: A Preliminary Study

Coagulation process using low dosage of plant-based coagulant to remove high chemical oxygen demand (COD) and turbidity is important for water treatment. This study presents the treatment of pond water using plant-based pineapple leaf coagulant to achieve high COD and turbidity removal. The coagulation was performed using a jar test experiment of pond water at different pH followed by different dosages of pineapple leaf coagulant. It was found that the highest COD and turbidity removal ranged between 94.1 – 94.6 % and 88.3 – 88.4 % at pH 8 respectively, using low dosage (50 mg L-1) of pineapple leaf coagulant. The final COD and turbidity values ranged between 7.3 – 8.0 mg L-1 and 17.7 – 17.8 formazin turbidity unit (FTU) respectively, which are lower compared with results from other studies that used high dosage coagulants. Moreover, the final pH, COD, turbidity, dissolved oxygen (DO), and total suspended solid (TSS) values of the treated pond water were below the standard limits set by the National Water Quality Standards for Malaysia (NWQSM) class IIB, which represents water bodies suitable for recreational use with body contact (DOE, 2016). Therefore, it is expected that the newly-formulated waste utilisation of pineapple leaf coagulant can reduce the usage of chemical coagulants and can further be used for different types of water.

Effects of Calcium and Aluminum on Particle Settling in an Oil Sands End Pit Lake

Surface mining of oil sands ore in Alberta, Canada has generated fluid fine tailings (FFT) that must be reclaimed. End pit lakes (EPLs), which consist of thick deposits of FFT capped with water, have been proposed for FFT reclamation, and Base Mine Lake (BML) is the first full-scale demonstration EPL. However, FFT particle settling and resuspension contributes to high turbidity in the BML water cap, which may be detrimental to the development of an aquatic ecosystem. This study investigated the effect of Ca and Al treatments on turbidity mitigation. The initial turbidity was reduced from 20 NTU to less than 2 NTU in BML surface water treated with 54 mg/L of Ca or 1.1 mg/L of Al. At a concentration of 1.1 mg/L, Al reduced the initial turbidity to a greater extent, and in a shorter time, than 54 mg/L of Ca. Further, resuspended Al-treated FFT particles were 100–700 nm larger in diameter, and thus resettled faster than the resuspended untreated or Ca-treated FFT particles. The final turbidity values 21 days after resuspension of untreated and 1.7 mg/L Al-treated FFT particles in fresh BML surface water were 20.5 NTU and 2.5 NTU, respectively. Thus, Al treatment may be effective in mitigating turbidity in BML through both Al-induced coagulation and self-weight settling of the resuspended Al-treated FFT particles.

Nanofiber formation of self‐crosslinking dialdehyde carboxymethyl cellulose/collagen composites

AbstractSelf‐crosslinking dialdehyde carboxymethyl cellulose (DCMC)/collagen (COL) composites were prepared by blending DCMC and COL at different ratios, and the effect of DCMC amounts on composite nanofiber formation and stability were investigated. The more was the DCMC amount, the higher became the cross‐linking degree, thus demonstrating that self‐crosslinking system was successfully constructed. At low amount of DCMC, self‐assembled DCMC/COL composite exhibited typical nanofiber structure similar to COL nanofibers, and the mean diameter of nanofibers increased from 68 ± 12 to 84 ± 15 nm; additionally, the final turbidity of DCMC/COL composite was higher than that of COL, reflecting more nanofibers formed. We conjectured that nanofiber formation was promoted via adding a small amount of DCMC. However, the inhibition of nanofiber formation was detected by reductions in turbidity at 0.3:1 &lt; DCMC/COL ≤ 2.5:1, and the mean diameter of nanofibers decreased to 54 ± 13 nm at a DCMC/COL ratio of 2.5:1. Meanwhile, crosslinking occurred again between adjacent nanofibers during self‐assembly process; therefore, partial nanofibers presented in pairs. At a DCMC/COL ratio of 5:1, nanofiber formation was completely inhibited and DCMC/COL composite consisted of aggregates. In summary, nanofiber formation was first promoted and then inhibited with increased DCMC amounts. Furthermore, low‐ and high‐temperature stability of DCMC/COL nanofibers was better than those of COL nanofibers due to the formation of crosslinks.

Long term evaluation of a pilot scale multimodal algal bioprocess for treatment of municipal wastewater

The feasibility of Multimodal Algal-bacterial Bioprocess (MAB) for the treatment of primary clarified municipal wastewater was demonstrated at a pilot-scale MAB system (0.2 m3/d) installed and operated in Corvallis, Oregon, USA for one year. The system consisted of an anaerobic reactor; mixotrophic and phototrophic ponds followed by algal settlers and a final wetland cell (WC). The wastewater treatment performance was monitored weekly over the one-year period in terms of onsite parameters as pH, dissolved oxygen (DO), oxidation reduction potential (ORP), electrical conductivity (EC), total dissolved solids (TDS),turbidity and chemical parameters (COD, Nitrate-N, Amm.-N and reactive phosphorus). Algal biomass production and algal community analysis in the MAB was determined regularly. A continuous improvement in the mean DO (1.57–13.98 mg/L) and ORP (−140 to +86 mV) was observed throughout the study period. Higher mean pH (8.62) and DO (14 mg/L) in the ponds indicated high algal photosynthesis. The pilot-scale system maintained an average low final effluent turbidity (14.2 NTU), TSS (<30 mg/L) and COD concentrations (~78.3 mg/L) and achieved removal of nitrogen as Amm.-N (76%) and Nitrate-N (34%), phosphorus (DRP: 51%) throughout the experimental period. Particularly in summer, the overall treatment performance was high (70% COD removal; 78% Amm.-N removal; 38% Nit.-N removal; 53% DRP removal) owing to high algal-bacterial activity. The community analysis showed a predominance of diatoms and cyanophycean members in the winter and chlorophycean members especially species Chlorella (~80%) during summer. The average biomass productivities (VSS) in the treatment ponds ranged from 6.75 g/m2/d during winter to 11.47 g/m2/d during summer. Overall, the MAB can effectively treat municipal wastewater; produce quality final effluent and algal bioproducts with minimum energy inputs.

A Rapid Antimicrobial Susceptibility Test for Klebsiella pneumoniae Using a Broth Micro-Dilution Combined with MALDI TOF MS.

BackgroundMatrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) is a novel method that can be used to identify pathogens and has potential applications in the detection of drug-resistant bacteria.PurposeTo evaluate the ability of a MALDI-TOF MS-based broth micro-dilution method in detecting the minimum inhibitory concentration (MIC) values of Klebsiella pneumoniae to ceftriaxone and imipenem.Materials and MethodsSixty strains of K. pneumoniae with different levels of resistance to carbapenems and cephalosporins were randomly collected. The 0.5 McFarland (Mc) concentration of the bacterial suspension was inoculated in cation-adjusted Mueller-Hinton broth (CAMHB) with a final cell turbidity of 5×105 CFU/mL. The broth was incubated with serial concentrations of antibiotics. After centrifuging the bacterial suspensions, the lysed cells were analyzed by MALDI-TOF MS to identify the growth-promoting or inhibitory effects on K. pneumoniae. The molecular mechanisms of resistance were investigated by PCR and DNA sequencing analysis.ResultsThe expression of known resistance genes (blaKPC, blaFOX, blaDHA, blaCTX-M and blaTEM) was detected in the 30 carbapenems-resistant strains. The agreement between the MIC values derived from the MALDI-TOF MS analysis and from the broth micro-dilution method was 61.7% for ceftriaxone and 71.7% for imipenem. According to the Clinical and Laboratory Standards Institute (CLSI) breakpoint of resistance to ceftriaxone and imipenem, the 60 isolates were accurately classified as resistant or susceptible isolates with 100% sensitivity and 100% specificity.ConclusionThe transmission and infection of multidrug-resistant bacteria could be better managed and treated with the rapid identification of strains and antimicrobial susceptibility. A MALDI-TOF MS-based susceptibility test could be used to identify resistance of K. pneumoniae within a short time-frame. This approach could potentially be used as a supplementary antimicrobial susceptibility test that could be investigated on more bacterial species combined with different antibiotics.

Evaluation of Moringa oleifera Extract as a Biocoagulant to Remove Microcystis aeruginosa Cells and Dissolved Metabolites

Cyanobacteria are microorganisms capable of releasing toxic metabolites in freshwater, deleterious to humans and other living organisms even in very low concentrations. Removing both cyanobacteria cells and their metabolites in conventional water treatment systems is still a challenge that needs to be addressed. This paper evaluated the use of Moringa oleifera saline extract and polyaluminum chloride (PACl) as coagulants in order to remove cells and metabolites of M. aeruginosa from water. Samples consisted of synthetic water spiked with humic acid and M. aeruginosa cells, with a final turbidity of 25 NTU. Coagulation/flocculation/dissolved air flotation (C/D/DAF) tests were performed with 50 mg/L of M. oleifera coagulant, combined with different proportions of PACl (10–50%). For removal of metabolites, 25 μg/L of microcystin and 50 ng/L of 2-MIB and geosmin were spiked in water samples. The best results were obtained with 70:30 M. oleifera:PACl, achieving removal efficiencies of 81.37%, 74.69%, and 71.06% for turbidity, color, and cell density, respectively. For microcystin, 2-MIB, and geosmin, after filtration (30 min), global removal efficiencies (clarification + filtration) of 99.45%, 62.37%, and 100%, respectively, were obtained, using Sand+GAC filter. The results suggest that the substitution of PACl by M. oleifera extract can be a good option to remove cyanobacteria cells from water, and high removal efficiencies of metabolites can be achieved after the complete proposed treatment.

Turbidity reduction by household scale electrocoagulation device

Pollutant parameter that often exceed the standard is turbidity, then the turbidity parameter was the main concern in this research. The electrocoagulation method is an alternative for treating water without using chemicals. This study aims to reduce the turbidity and develop previous research on electrocoagulation methods into a pilot scale with a flow rate of 0.01 L/sec. The flow rate 0.01 L/sec illustrates the water requirements for one household. In this study the electrocoagulation method was tested by the variation of electrode plates 1, 2 and 3 pairs with 3, 5, 7 and 10 Volts to treat artificial sample water with an initial turbidity of 100 NTU made from sample of raw water from Cikapundung River as one of main drinking water sources in Bandung. The optimal conditions obtained in the preliminary study were retested with turbidity variations of 25, 50, 100, 200, 300 and 400 NTU. The optimal condition of the electrocoagulation process is obtained in the variation of 2 pairs of plates with a voltage of 7 Volts and current density 23.53 A/m2. The variation can treat raw water with an initial turbidity up to 400 NTU until it reaches a quality standard with a final turbidity of 3.40 NTU and the percentage of removal is 99.15%.