Ultrafiltration Membranes For Treatment Research Articles

Rationalizing the selection of cleaning solution type through quantum chemical calculations

The surface water sources for water supply are contaminated with substances that cause water discoloration. These substances include soluble humic and fulvic acids, which are retained on the surface during ultrafiltration membrane treatment, forming a fouling layer that deteriorates membrane performance and reduces membrane productivity. These substances also form a mixed fouling layer with water-soluble metals and coagulants. This work proposes a theoretical justification for cleaning solutions capable of restoring the properties of ultrafiltration membranes. Quantum-chemical calculations and modeling were chosen as the method for prediction and justification. EDTA-Na, SDS, and sodium tripolyphosphate can wash away the fouling layer, but it is impossible to justify the use of mixtures of these substances theoretically. As the quantum-chemical analysis showed, each of these substances has a tendency to wash away the fouling layer. However, it is impossible to justify the use of mixtures of these substances from a theoretical point of view. The pollutants in surface waters have a complex organomineral composition. Considering this, optimal components and concentration ratios of reagents for ultrafiltration membrane cleaning cannot be determined using quantum-chemical prediction methods, so experimental studies of cleaning processes are necessary.

Stormwater treatment using an ultrafiltration membrane and pulsatile fluid flow

ABSTRACT A polymeric ultrafiltration (UF) membrane was used for stormwater treatment, with the focus on evaluating the increase in the membrane process productivity by adding pulsatile fluid flow to UF membrane treatment. Sedimentation and sieving were used as pre-treatment. The result showed that increasing the pulse frequency from 0 to 4 Hz increased productivity from −6.6 to 82 LMH. UF membrane removed suspended solids, oil and turbidity below detection limit. The UF membrane also separated total coliforms, E. coli and P. aeruginosa below detection limit. Total organic carbon (TOC) was reduced by between 81%, in average. In addition, the UF membrane was able to reduce BOD7 and COD to below 7 mg/L in the permeate. According to the US EPA, WHO, and national regulations in Canada, Japan, and South Korea, treated stormwater can be used for flushing toilets and streets irrigation and agricultural use.

Alkaline electrolysis of wastewater and low-quality water

Green hydrogen production by water electrolysis is an inevitable solution for global sustainability. However, for making hydrogen energy as next-generation fuel, enough pure water and associated cost is required, which is another critical issue that must be resolved. An attempt has been made to produce hydrogen gas from low-grade and wastewater using alkaline water splitting. The electrodes, electrolyte, voltage, and impurity level have significantly affected hydrogen generation. Turbidity and total dissolved solids have been found to be important factors whose removal can enhance hydrogen production from wastewater. A high-strength sulfonated polyvinylidene fluoride (HSPVDF) ultrafiltration (UF) membrane was used to produce high-quality advanced treated water. Tertiary UF membrane treatment has contributed substantially to residual impurity removal and improved hydrogen generation. The study suggests that wastewater and advanced treated watercan effectively utilize green hydrogen generation with impurity removal. Based on this finding, the potential applicability for achieving energy independence in municipal wastewater treatment plants was examined. Replacing water with wastewater can be a new dimension of the hydrogen economy.

Distribution and removal of antibiotic resistance genes in a landfill leachate treatment process

ABSTRACT Domestic waste landfills have been regarded as the main source of antibiotic resistance genes (ARGs) which are considered to be emerging environmental contaminants. Fluorescent quantitative PCR detection was used to determine the occurrence and abundance of ARGs in a landfill leachate treatment system. Fourteen ARGs were detected initially in the leachate influents. The most abundant ARGs were IntI1, followed by sulI, sulII, sulIII, tetC and tetW. The abundance of ARGs increased in the biological treatment unit and then decreased in the effluent of ultrafiltration membrane treatment. The absolute abundance of ARGs in effluent was 1.05–1.94 orders of magnitude lower than that in influent. There was a very significant strong correlation between various ARGs and heavy metals, especially Zn, Pb, Cu, Cd and As, indicating that there may be obvious co-selection between heavy metals and ARGs. Although the leachate treatment process could effectively reduce the abundance of ARGs, its effect on reducing the number of species of ARGs was relatively limited, which may have potential environmental health risks to the urban sewage plant receiving leachate effluent and the final receiving water body.

Concentrated Leachate Treatment by Electro-Fenton and Electro-Persulfate Processes Using Central Composite Design

Current work deals with the treatment of leachate nanofiltration concentrate which was exposed to ultrafiltration membrane treatment following anaerobic biological process and nitrification–dentrification process before. Advanced electrocoagulation processes [electro-Fenton (EF) and electro-persulfate (EF)] were applied to the wastewater characterized by high inert COD content arising from resistant organic matter. Response surface methodology and central composite design were employed for modeling and optimizing the processes. Adequacy of the model was examined by application of variance analysis that verified the conformity of experimental and predicted data. Under statistically obtained optimized conditions for COD removal (H2O2/COD ratio 1.42, current 2.27 A, pH 2.9, and reaction time 30.3 min for EF; and S2O8−2/COD ratio 1.72, current 1.26 A, pH 5.0 and reaction time 34.8 min for EP processes), predicted COD removal efficiencies were determined to be 67.1% and 72.6% for EF and EP treatments, respectively. By performing experimental sets for validation, 60.8% and 71.4% COD removals through EF and EP processes were obtained under these conditions. NF concentrate COD fractions were also determined before and after treatment processes. Soluble COD fraction increased from 71.4 to 83.2% and 87.7% whereas biodegradable COD fraction increased from 12.2 to 19.2% and 32.5% after EF and EP processes, respectively. Results of the study showed that both EF and EP processes were efficient alternatives for leachate NF concentrate treatment but EP process can be preferred due to lower energy consumption.

Fluorescent characteristic and compositional change of dissolved organic matter and its effect on heavy metal distribution in composting leachates.

Composting leachates were collected to investigate the fluorescent characteristic and compositional change of dissolved organic matter (DOM) and the effects of the DOM and nutrients on heavy metal distribution during a leachate combination treatment process. Excitation-emission matrix (EEM) fluorescence spectra showed that, with the progress of the treatment units, the content of fulvic-like, humic-like, and protein-like substances gradually decreased. One fulvic-like component (C1), three humic-like components (C2, C3, and C4), and three protein-like components (C5, C6, and C7) were identified in the leachate DOM by parallel factor analysis. Anaerobic-aerobic processes removed a large fraction of the tyrosine-like component (C7) and tryptophan-like component (C6) and a small amount of humic-like component (C2), while the membrane bioreactor showed a good removal effect on protein-like component. The ultra-filtration membrane treatment had a removal effect on fulvic-like and humic-like component and other recalcitrant compounds, while the reverse osmosis treatment had a good removal effect on both humic-like and protein-like components. Correlation analysis indicated that Mn and Cr were primarily associated with protein-like components and nutrients in the composting leachates. Ni and Pb were bound to fulvic-like, humic-like, and protein-like components, Co and Zn interacted with inorganic nitrogen and total phosphorus, and Cd only interacted with inorganic nitrogen.

Infectious risk assessment of reclaimed water by UF membrane treatment process focusing attention on norovirus

Abstract The aim of this study was to propose a risk assessment method for infectious diseases, using reclaimed water as a case study. To evaluate the infectious risk of norovirus (NoV) in various applications of the reclaimed water, five types of ultrafiltration (UF) membrane treatments were considered: (1) coagulation with low pH + UF membrane process, (2) UF membrane process alone, (3) UF + ultraviolet (UV) irradiation process, (4) UF + nanofiltration (NF) membrane process, and (5) UF + reverse osmosis (RO) membrane process. These treatments were used in a pilot plant and the NoV concentration after each treatment process was studied over the long term (2010–2014). Infectious risk was described using disability-adjusted life-year (DALY) when the reclaimed water was applied for agricultural irrigation, landscape irrigation, recreational enhancement, and toilet and urinal flushing. The results show that reclaimed water could be considered acceptable for recreational enhancement by adding a UV, an NF membrane, or an RO membrane treatment to the UF membrane treatment process.

Biocrude oil production from Chlorella sp. cultivated in anaerobic digestate after UF membrane treatment

Algae cultivation in animal wastewater could recover nutrient resources, and harvest considerable amount of algae biomass for biofuel conversion. In this study, Chlorella sp. cultivated in ultrafiltration (UF) membrane treated anaerobic digestion effluent of chicken manure was converted into biocrude oil through hydrothermal liquefaction (HTL). The potential of biocrude production from grown Chlorella sp. was studied through changing the operational conditions of HTL, i.e., holding temperature (HT, 250°C-330°C), retention time (RT, 0.5-1.5 h), and total solid (TS) (15 wt%-25 wt%) of the feedstock. The highest biocrude oil yield was 32.9% at 330°C, 1.5 h and 20 wt% TS. The single factor experiments of HT also suggested that the biocrude oil yield decreased when the temperature was higher than 330°C. There were no significant differences of elemental contents in biocrude samples. The maximum higher heating values (HHV) of Chlorella sp. biocrude was 40.04 MJ/kg at HT of 330°C, RT of 1 h and TS of 15 wt%. This study suggests the great potential for energy recovery from Chlorella sp. cultivated in UF membrane treated anaerobic digestion effluent via HTL. Keywords: microalgae, wastewater, hydrothermal liquefaction, anaerobic digestion effluent DOI: 10.3965/j.ijabe.20171001.2700 Citation: Wang M, Wang X F, Zhu Z B, Lu J W, Zhang Y H, Li B M, et al. Biocrude oil production from Chlorella sp. cultivated in anaerobic digestate after UF membrane treatment. Int J Agric & Biol Eng, 2017; 10(1): 148－153.

Hypolipidemic effects of crude green tea polysaccharide on rats, and structural features of tea polysaccharides isolated from the crude polysaccharide

Crude tea polysaccharide (crude TPS) was prepared from instant green tea by ethanol precipitation followed by ultrafiltration membrane treatment and its effects on blood lipid, liver lipid, and fecal lipid levels were examined with Sprague–Dawley rats fed a high-fat diet. Although crude TPS showed no effects on the serum lipid levels, it suppressed the liver lipid accumulation and increased the fecal excretion of dietary fat. Then, the structural features of crude TPS were investigated. After separation of crude TPS by DEAE-cellulose and gel-filtration column chromatography, two kinds of neutral tea polysaccharides (NTPS-LP and NTPS-HH) and an acidic polysaccharide (ATPS-MH) were obtained. According to monosaccharide composition, methylation, and NMR analyses, NTPS-LP, NPTS-HH, and ATPS-MH were presumed to be starch, arabinogalactan with β-1,3-linked galactosyl backbone blanched at position 6 and with 1,5-linked arabinofuranosyl residues, and α-1,4-linked galacturonic acid backbone with arabinogalactan region, respectively.

The extraction of sericin protein from silk reeling wastewater by hollow fiber nanofiltration membrane integrated process

Sericin protein having high additional value in many industries such as textiles, pharmaceuticals and cosmetics is always discharged in silk reeling wastewater which causes serious environmental pollution. In this paper, different combined process of acidulation precipitation–ultrafiltration (UF)–nanofiltration (NF) was investigated and optimized to recover high-purity sericin protein from silk reeling wastewater. Inner-pressure hollow fiber polyamide NF composite membrane was prepared through the interfacial polymerization. The results showed that the recovery of sericin protein in the supernatant liquid after acidulation precipitation treatment could reach 72.1% when using the UF membrane (MWCO 6000)–NF membrane integrated process. When the mixture of sericin protein precipitation and concentrated liquid after UF and NF filtration was diluted four times, the better comprehensive results were achieved. The loss rate of sericin protein and the salt content of concentrated liquid was 34.1% and 29.1%, respectively while the conductivity after UF membrane treatment was lower than that of the local tap water. More than 86% sericin protein from cocoon cooking wastewater, refining wastewater and mixed wastewater could be recovered by the optimized UF–NF combination process. Using 0.2molL−1 hydrochloric acid as the cleaning agent could effectively recover the water flux of NF membrane.

Enhancing Efficiency of Full-Scale Ultrafiltration Membrane Treatment for Increased Capacity and Lower Operating Costs

At time of commissioning, the Racine, Wisconsin, USA ultrafiltration (UF) membrane treatment system fail short of meeting its operational goals concerning capacity and chemical cleaning intervals. The systematic optimization of this 189-million-litre-per-day (MLD) capacity UF system provided tangible operational benefits, which included a 30-percent reduction in power use, a 50-percent reduction in chlorine chemical use, a 36-percent reduction in citric acid use and a simultaneous 7-percent increase in net treatment capacity of the system. In addition, the optimization program reduced the level of buildup of foulants on the surface of the membranes. This paper summarizes the optimization procedures followed at Racine, discussing how similar measures may be applicable to other water treatment facilities.

Operation of Submerged Hollow Fiber Ultrafiltration Membrane for Treatment of Secondary Effluent

Operation of Submerged Hollow Fiber Ultrafiltration Membrane for Treatment of Secondary Effluent

Design and construction of a water potabilization membrane facility and its application to the third world countries. Preliminary tests

In many areas of underdeveloped countries population is supplied with water from rivers, lakes, etc., without applying any water treatment in most cases this water contains a certain amount of virus, bacteria and other microorganisms, which can cause several diseases. The research group of the Chemical and Nuclear Engineering Department of the Polytechnic University of Valencia (Spain) is working in the project: Design and Construction of a Water Potabilization Membrane Facility and its Application to the Third World Countries (AQUAPOT) in collaboration with the non-governmental organization Association for the Cooperation with Ecuador (ACOEC). In this project, membrane technology is proposed as an option to the current system of treatment. The object of the AQUAPOT project is the design and construction of an ultrafiltration membrane treatment unit, with spiral configuration, applicable to urban supplying systems in underdeveloped countries, which cannot guarantee an accurate disinfection of water. Before being placed definitively in Ecuador, the ultrafiltration facility has to be tested in order to prove its right operation. For so, an ultrafiltration unit similar to the one that is being constructed for being applied in Ecuador has been tested with water in much worse microbiological conditions than the water of Ecuador. The aim of this work is to describe these preliminary tests and analyze the ultrafiltration facility performance.

Design of a membrane facility for water potabilization and its application to Third World countries

The origin of this work is the necessity of guaranteeing water quality in underdeveloped countries where the population is supplied with water from rivers, lakes, etc. This water contains a certain number of viruses, bacteria and other microorganisms, which can cause some diseases. In these countries water disinfection methods are not usually applied or cannot be ensured an appropriate effectiveness. On many occasions water is used in the same condition as it is found at the source. This fact causes a high rate of infection that, although not grave in most cases, has been the origin of major epidemics in some circumstances. Membrane technology that allows disinfection on the basis of molecular size of particles is proposed as an option to the current system of treatment. Membrane processes carry out disinfection by means of size exclusion. At the end of the treatment, chlorination at low doses can be a way of keeping water in good condition for long periods of time. The aim of this work is design an ultrafiltration membrane treatment unit, with a spiral configuration, applicable to urban supply systems in underdeveloped countries, which cannot guarantee sufficient water disinfection. The proposed membrane module can be extended to N units, with a consequent increment of treated product, adapting the system to demand. An alternative for the design described has been considered. This option consists of a tubular module of manual operation. This facility intends to provide small communities that are geographically isolated from important urban centres with high-quality water.

Antigenicity of Whey Protein Hydrolysates Fractionated with Ultrafiltration Membrane.

Whey protein concentrate (WPC) hydrolysates were prepared with trypsin and treated with microfiltration (MF) and/or ultrafiltration (UF) membrane. HPLC and the immunoreactivity test in vitro (inhibition enzyme-linked immunosorbent assay: inhibition ELISA) were performed on these hydrolysates. Although the insoluble materials were removed from the hydrolysates, no differences were recognized in the patterns of HPLC before or after MF treatment. The main peaks of fraction obtained by MF membrane treatment showed a molecular weight range of 1000 to 6000. On the other hand, fractions by UF membrane treatment were between 1000 and 3000. From the results of the inhibition ELISA, it was recognized that the antigenicity of fractions after UF membrane treatment dropped fron 1/30 to 1/200 compared with the WPC hydrolysate.

Characteristics of the gel layer during the treatment of soybean cooking drain from a miso (fermented soy paste) factory by ultrafiltration and reverse osmosis.

The gel layer formed on the ultrafiltration membrane in treatment of soybean cooking drain from a Miso factory was scratched out, and its characteristics were analyzed by total solid, total carbon and total nitrogen. Components accumulated in a gel layer were determined by gel chromatography. From these results, it became clear that the gel layer consisted of soybean protein and high molecular weight polysaccharides, and the accumulation of the former was much greater than that of the latter. Rejection ability of the gel layer for low molecular weight solutes was analyzed quantitatively by the method of steric hindrance-pore model developed in the model solution in our previous work. Rejections estimated by this method with some assumptions agreed well with experimental values. Thus, it was verified that this analytical method was useful for the actual waste water.