A mini-review on membrane fouling Guo, Wenshan; Ngo, Huu-Hao; Li, Jianxin
Bioresource technology,
October 2012, 2012-Oct, 2012-10-00, 20121001, Letnik:
122
Journal Article
Recenzirano
► The cause, fouling phenomena and fouling mechanisms of membrane fouling are reviewed. ► Better understanding of fouling in membrane applications is provided. ► The predominant foulants in various ...membrane applications are reviewed. ► Different fouling mechanisms can provide a really complex matrix.
During the last decades, the interest of using membrane technology has emerged in wastewater treatment as well as drinking water and process water production. However, the impediment of the membrane technology is the fouling problem and consequently higher operating and membrane replacement cost. Hence, better understanding of membrane fouling is not only the key to solve the problems, but also is one of the main factors driving membrane technology forward. This mini-review paper identifies the major foulants and the principal membrane fouling mechanisms such as pore blocking, cake formation, concentration polarization, organic adsorption, inorganic precipitation and biological fouling. It also gives a holistic review about different fouling phenomena during the application of membrane separation technologies in water and wastewater treatment, with specific references to various problems, membranes, treatment processes and its practical applications.
A new hybrid system was developed in this study for the treatment of drinking water consisting of pre-coagulation using polyaluminium chloride (PACl) and membrane filtration (MF) with sponge cubes ...acting as biomass carriers (P-SMF). When compared to a conventional MF (CMF) and a MF after coagulation by utilizing PACl (P-MF), better removal of nutrients, UV254 and dissolved organic carbon (DOC) (>65%) was obtained from the P-SMF. The accumulation of biopolymers (including polysaccharides and proteins), humic substances, hydrophilic organics, and other small molecular weight (MW) organic matter in the CMF led to the most severe membrane fouling coupled with the highest pore blocking and cake resistance. Pre-coagulation was ineffective in eliminating small MW and hydrophilic organic matter. Conversely, the larger MW organics (i.e. biopolymers and humic substances), small MW organics and hydrophilic organic compounds could be removed in significantly larger quantities in the P-SMF by PACl coagulation. This was achieved via adsorption and the biodegradation by attached biomass on these sponges and by the suspended sludge. Further analyses of the microbial community indicated that the combined addition of PACl and sponges generated a high enrichment of Zoolgloea, Amaricoccus and Reyranella leading to the reduction of biopolymers, and Flexibacter and Sphingobium were linked to the degradation of humic substances. Moreover, some members of Alphaproteobacteria in the P-SMF may be responsible for the removal of low MW organics. These results suggest that the pre-coagulation process coupled with adding sponge in the MF system is a promising technology for mitigating membrane fouling.
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•The P-SMF exhibited the lowest membrane fouling, RC and RP.•PACl and sponge eliminated biopolymers, humic substances and small MW organics.•Zoolgloea, Amaricoccus and Reyranella contributed to reduction of biopolymers.•Degradation of humic substances was associated with Flexibacter and Sphingobium.•Removal of low MW organics might be due to some members of Alphaproteobacteria.
•Emerging contaminant removal technologies have been summarized.•MBR, microalgae and activated sludge are effective biological removal processes.•Ozonation/H2O2 and photo-Fenton are highly effective ...chemical removal processes.•Many hybrid systems have enhanced removal capacity of emerging contaminants.•Future research regarding emerging contaminant removal has been proposed.
This review focuses on the removal of emerging contaminants (ECs) by biological, chemical and hybrid technologies in effluents from wastewater treatment plants (WWTPs). Results showed that endocrine disruption chemicals (EDCs) were better removed by membrane bioreactor (MBR), activated sludge and aeration processes among different biological processes. Surfactants, EDCs and personal care products (PCPs) can be well removed by activated sludge process. Pesticides and pharmaceuticals showed good removal efficiencies by biological activated carbon. Microalgae treatment processes can remove almost all types of ECs to some extent. Other biological processes were found less effective in ECs removal from wastewater. Chemical oxidation processes such as ozonation/H2O2, UV photolysis/H2O2 and photo-Fenton processes can successfully remove up to 100% of pesticides, beta blockers and pharmaceuticals, while EDCs can be better removed by ozonation and UV photocatalysis. Fenton process was found less effective in the removal of any types of ECs. A hybrid system based on ozonation followed by biological activated carbon was found highly efficient in the removal of pesticides, beta blockers and pharmaceuticals. A hybrid ozonation-ultrasound system can remove up to 100% of many pharmaceuticals. Future research directions to enhance the removal of ECs have been elaborated.
Petroleum industry is one of the fastest growing industries, and it significantly contributes to economic growth in developing countries like India. The wastewater from a petroleum industry consist a ...wide variety of pollutants like petroleum hydrocarbons, mercaptans, oil and grease, phenol, ammonia, sulfide, and other organic compounds. All these compounds are present as very complex form in discharged water of petroleum industry, which are harmful for environment directly or indirectly. Some of the techniques used to treat oily waste/wastewater are membrane technology, photocatalytic degradation, advanced oxidation process, electrochemical catalysis, etc. In this review paper, we aim to discuss past and present scenario of using various treatment technologies for treatment of petroleum industry waste/wastewater. The treatment of petroleum industry wastewater involves physical, chemical, and biological processes. This review also provides scientific literature on knowledge gaps and future research directions to evaluate the effect(s) of various treatment technologies available.
Microalgae are highly adaptable to abiotic stress and produce valuable metabolites, but microalgal commercialization is still difficult because of minimal yields. The application of phytohormone-like ...small biomolecules is effective in simultaneously improving the productivity of valuable microalgal biomass-derived metabolites and stress tolerance. This represents a significant opportunity for microalgal biotechnology.
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•Plastic carriers were modified using sponge and then applied in MBBR.•Sponge modified biocarriers could improve nutrient removal and effluent quality.•The S-MBBR–MBR presented less ...membrane fouling and longer operative time.•SMP in mixed liquor, RC and RP were reduced by the sponge modified biocarriers.•Sponge modified biocarriers could enhance the treatability of the MBBR–MBR system.
In this study, new sponge modified plastic carriers for moving bed biofilm reactor (MBBR) was developed. The performance and membrane fouling behavior of a hybrid MBBR–membrane bioreactor (MBBR–MBR) system were also evaluated. Comparing to the MBBR with plastic carriers (MBBR), the MBBR with sponge modified biocarriers (S-MBBR) showed better effluent quality and enhanced nutrient removal at HRTs of 12h and 6h. Regarding fouling issue of the hybrid systems, soluble microbial products (SMP) of the MBR unit greatly influenced membrane fouling. The sponge modified biocarriers could lower the levels of SMP in mixed liquor and extracellular polymeric substances in activated sludge, thereby mitigating cake layer and pore blocking resistances of the membrane. The reduced SMP and biopolymer clusters in membrane cake layer were also observed. The results demonstrated that the sponge modified biocarriers were capable of improving overall MBBR performance and substantially alleviated membrane fouling of the subsequent MBR unit.
•The use of food-crop related biomass for 1st generation biofuel is unsustainable.•2nd generation lignocellulosic biomass are ready for full commercial exploitation.•3rd generation algal biomass ...represents potential renewable source.•A combination of three generations will need to be met growing energy demand.
Rapid growth in both global energy demand and carbon dioxide emissions associated with the use of fossil fuels has driven the search for alternative sources which are renewable and have a lower environmental impact. This paper reviews the availability and bioenergy potentials of the current biomass feedstocks. These include (i) food crops such as sugarcane, corn and vegetable oils, classified as the first generation feedstocks, and (ii) lignocellulosic biomass derived from agricultural and forestry residues and municipal waste, as second generation feedstocks. The environmental and socioeconomic limitations of the first generation feedstocks have placed greater emphasis on the lignocellulosic biomass, of which the conversion technologies still faces major constraints to full commercial deployment. Key technical challenges and opportunities of the lignocellulosic biomass-to-bioenergy production are discussed in comparison with the first generation technologies. The potential of the emerging third generation biofuel from algal biomass is also reviewed.
•Dynamic behaviour of the column was described by S-shaped breakthrough curves.•Several models were applied to simulate the continuous biosorption.•Thomas and Dose Response models suitable for ...breakthrough prediction.•Desorption study indicated that metal-loaded modified MMBB could be eluted by HCl.•Applicability of biosorbent was tested using semi-simulated wastewater.
A continuous fixed-bed study was carried out utilising a breakthrough biosorbent, specifically multi-metal binding biosorbent (MMBB) for removing cadmium, copper, lead and zinc. The effect of operating conditions, i.e. influent flow rate, metal concentration and bed depth was investigated at pH 5.5±0.1 for a synthetic wastewater sample. Results confirmed that the total amount of metal adsorption declined with increasing influent flow rate and also rose when each metal concentration also increased. The maximum biosorption capacities of 38.25, 63.37, 108.12 and 35.23mg/g for Cd, Cu, Pb and Zn, respectively, were achieved at 31cm bed height, 10mL/min flow rate and 20mg/L initial concentration. The Thomas model better described the whole dynamic behaviour of the column rather than the Dose Response and Yoon–Nelson models. Finally, desorption studies indicated that metal-loaded biosorbent could be used after three consecutive sorption, desorption and regeneration cycles by applying a semi-simulated real wastewater.
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•fBC removed ∼100% of EDC mixture from water and wastewater.•Sorption affinities decreased as E1 > E2 ≥ EE2 > 4tBP > BPA > E3.•Sorption in wastewater was reduced by 38–50% due to ...sodium laryl sulphonate.•π-π EDA interactions with H-bond formation were main sorption mechanism.
Sorptive removal of six phenolic endocrine disrupting chemicals (EDCs) estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2), bisphenol A (BPA) and 4-tert-butylphenol (4tBP) by functionalized biochar (fBC) through competitive interactions was investigated. EDC sorption was pH dependent with the maximum sorption at pH 3.0–3.5 due to hydrogen bonds and π-π interactions as the principal sorptive mechanism. Sorption isotherm of the EDCs was fitted to the Langmuir model. Sorption capacities and distribution coefficient values followed the order E1 > E2 ≥ EE2 > BPA > 4tBP > E3. The findings suggested that EDC sorption occurred mainly through pseudo-second order and external mass transfer diffusion processes, by forming H-bonds along with π-π electron-donor–acceptor (EDA) interactions at different pH. The complete removal of ∼500 μg L−1 of each EDC from different water decreased in the order: deionised water > membrane bioreactor (MBR) sewage effluent > synthetic wastewater. The presence of sodium lauryl sulphonate and acacia gum in synthetic wastewater significantly suppressed sorption affinity of EDCs by 38–50%, hence requiring more fBC to maintain removal efficacy.
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•Removal of antibiotics and their effects on membrane fouling in AnMBRs are reviewed.•AnMBRs are efficient for treating antibiotic wastewater mainly by biodegradation.•The presence of ...antibiotics in AnMBRs will aggravate membrane fouling.•Integrating AnMBRs with biofilm carriers and BES is efficient in fouling control.
Antibiotic wastewater has become a major concern due to the toxicity and recalcitrance of antibiotics. Anaerobic membrane bioreactors (AnMBRs) are considered alternative technology for treating antibiotic wastewater because of their advantages over the conventional anaerobic processes and aerobic MBRs. However, membrane fouling remains the most challenging issue in the AnMBRs’ operation and this limits their application. This review critically discusses: (i) antibiotics removal and antibiotic resistance genes (ARGs) in different types of AnMBRs and the impact of antibiotics on membrane fouling and (ii) the integrated AnMBRs systems for fouling control and removal of antibiotics. The presence of antibiotics in AnMBRs could aggravate membrane fouling by influencing fouling-related factors (i.e., sludge particle size, extracellular polymeric substances (EPS), soluble microbial products (SMP), and fouling-related microbial communities). Conclusively, integrated AnMBR systems can be a practical technology for antibiotic wastewater treatment.
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