Tahir Maqbool

• Ph.D.
• Engineering Researcher at University of Alabama

In this study, the spectroscopic indices of soluble microbial products (SMP) were explored using absorption and fluorescence spectroscopy to identify different distinctive biomass growth phases (i.e., exponential phase, pseudo-endogenous phase, and endogenous phase) and to describe the microbial activity of activated sludge in a batch type bioreact...

Membrane fouling and high-strength membrane concentrate production are two limitations of membrane distillation (MD) for landfill leachate treatment. In this study, activated carbon- and biochar-based adsorption processes were integrated into a conventional MD system to overcome these limitations. The organic matter fractionations of the leachate w...

Dissolved organic matter (DOM) in the sediment matrix affects contaminant remediation through consumption of oxidants and binding with contaminants. Yet the change in DOM during remediation processes, particularly during electrokinetic remediation (EKR), remains under-investigated. In this work, we elucidated the fate of sediment DOM in EKR using m...

A composite manganese-based catalytic ceramic membrane (Mn-CCM) was developed by a solid-state sintering method, and its effectiveness toward activation of peroxymonosulfate (PMS) for the degradation of 11 pharmaceutical and personal care products (PPCPs) mixture was tested. The optimized Mn-CCMs/PMS system showed remarkable degradation efficiencie...

The excess sludge generated from the activated sludge process remains a big issue. Sustainable approaches that achieve in situ sludge reduction with satisfactory effluent quality deserve attention. This study explored the sludge reduction performance of sulfidogenic anoxic–oxic–anoxic (AOA) membrane bioreactors. The dynamics of the microbial commun...

A ceramic membrane reactor (CMR) integrated with in-situ UV/O3 was assessed for post-treatment of the effluent out of an up-flow anaerobic sludge blanket (UASB) reactor treating real textile wastewater, focusing on the transformation of dissolved organic matter (DOM). Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) revealed t...

Conventional and advanced biological wastewater treatment systems generate excess sludge, which causes socio-economic and environmental issues. This study investigated the performance of membrane-controlled anoxic-oxic-anoxic (AOA) bioreactors for in-situ sludge reduction compared to the conventional anoxic-oxic-oxic membrane bioreactor (MBRcontrol...

Applications of electrochemical advanced oxidation processes are rising in drinking water treatment for effective mitigation of refractory organic compounds. This study explored the fate of natural organic matter (NOM) (lake water and standard NOM (SRNOM solution)) at molecular-level in the reactive electrochemical membrane (REM) system utilizing F...

Endocrine disrupting compounds (EDCs) in the aquatic systems are of growing concerns that could undermine drinking water safety. In this study, manganese (III) oxide (Mn2O3) based catalytic ceramic membrane (CCM) was developed for the activation of peroxymonosulfate (PMS), and its applicability has been tested in degrading the ten different EDCs (i...

In this study the performance of catalytic ceramic membranes in activating peroxymonosulfate (PMS) for the degradation of emerging organic contaminants (EOCs) was investigated. The catalytic ceramic membrane (MnCM) integrated with Mn2O3 nanoparticles was fabricated by a solid-state sintering method. Physical and chemical properties of MnCM were cha...

Wastewater contains only ∼ 1% impurities that are required to be separated precisely for water recycling and reuse applications, particularly in water scare regions. Membrane-based separation has been recognised as an environmentally-friendly and energy-efficient process for effective pollutant removal and clean water production. To further improve...

Refractory organic matter in different water matrices poses tremendous challenges for treatment processes. The substoichiometric titanium oxide (Ti4O7) anode-designed reactive electrochemical membrane (REM) introduced for this critical problem was comprehensively evaluated in terms of current density, conductivity, membrane flux, total organic carb...

Discharge of untreated or improperly managed landfill leachate could pose a significant threat on environment due to the high strength of complex inorganic composition and abundant refractory humic acid (HA). This is the first work introducing a promising energy efficient technology using Ti4O7 anode reactive electrochemical membrane (REM) coupled...

This research evaluated the performance of reactive electrochemical ceramic membrane (REM) in treating secondary effluent and investigated the fate of dissolved organic matter (DOM) at the molecular level. The role of adsorption, electrosorption, and oxidation in DOM removal was comprehensively elucidated based on fluorescence spectroscopy and high...

Membrane distillation (MD) has attracted significant attention in recent years; however, MD membrane fouling is still a big issue. For the first time, this study explored the performance of a standalone direct contact membrane distillation (DCMD) and an integrated peroxymonosulfate (PMS)/DCMD for the treatment of surface water mainly containing alg...

In recent years, activation of persulfate via Mn-based composites has gained interest due to extraordinary kinetics and performance for the degradation of organic contaminants. However, the potential of pristine manganese oxides (Mn3O4) in removing organic compounds and its mechanism has not been comprehensively explored yet. This study systemicall...

The combination of ozone and nanofiltration (NF) in drinking water treatment represents a potentially effective method of separating dissolved organic matter (DOM), and thereby reducing the potential formation of disinfection by-products (DBPs). This study has evaluated UV-absorbance and fluorescence-based optical descriptors, such as absorbance sl...

The increasing release of nutrients to aquatic environments has led to great concern regarding eutrophication and the risk of unwanted algal blooms. Based on observational data of 20 water quality parameters measured on a monthly basis at 40 stations from 2011 to 2020, this study applied different Machine Learning (ML) algorithms to suggest the bes...

Delivering drinking water with stable quality in metropolitan cities is a big challenge. This study investigated the year-long dynamics of dissolved organic matter (DOM) in the tap water and source water of a metropolitan city in southern China using fluorescence spectroscopy. The DOM detected in the tap water, and source water of Shenzhen city was...

Cellulose nanofiber (CNF) is a well-known biocompatible polymer with various versatile characteristics. In recent years, nano-sized materials with high flexibility and biocompatibility that exhibit ultraviolet (UV) blocking properties with maximum dispersion have attracted increasing attention, particularly, materials with photocatalytic activity....

Several factors play a role in chlorine consumption in drinking water networks such as microbial contamination and dissolved organic matter (DOM). This study investigated the simultaneous impacts of seasonal variations on chlorine consumption and DOM composition for a year-long period in three different full scale water distribution networks in a s...

In this study, we used stable isotope-labeled soluble microbial products (SMP) and substrates to explore their assimilation into the formation of new biological products (i.e., extracellular polymeric substances and biomass) in two adjacent sequencing batch reactors. The isotope labeling approach along with fluorescence spectroscopy allowed us to d...

The occurrence of mutagenic and carcinogenic N-nitrosamines in drinking water is of great concern. In this study, dynamics and removal of nine N-nitrosamines in three drinking water treatment systems of a southern city of China are monitored during one year of sampling. The impacts of physicochemical treatment units on the removal and generation of...

The presence of carcinogenic N-nitrosamines and dissolved organic matter (DOM) in freshwater is a significant concern from the perspective of public health and water treatment plant operation. This study investigated the N-nitrosamines concentration and their precursors’ distributions, and DOM composition in four reservoirs located in a southern ci...

In this study, impacts of in-situ ozonation applied directly in the membrane tank of a ceramic MBR (Oz-MBR) were assessed to elucidate its implications on micropollutant removal, microbial taxa and membrane fouling. The basic effluent quality (i.e., bulk organics and nutrients) of the MBR without and with in-situ ozonation was comparable. Important...

Owing to the lack of comprehensive studies on the impacts of a high concentration of powdered activated carbon (PAC) in a ceramic membrane bioreactor (MBR), its performance (at 20 g/L) in terms of mixed liquor properties, hydraulic performance and fouling mechanism was elucidated in this study. In addition to the increase in floc size by 29%, zeta...

The protection of skin cells against intense ultra-violet (UV) rays is of greater concern and needs immediate attention. Sustainable efforts and strategies are in progress to minimize the factors that adversely affect skin cells. Herein, we synthesized zinc oxide (ZnO) in the form of core-shell ([email protected]) or reverse core-shell ([email prot...

In this study, the effect of a high concentration of PAC on pollutant removal and microbial communities was systematically investigated. Micropollutant removal by the ‘control’ MBR (without PAC addition) was pollutant-specific and was mainly controlled by their molecular properties. The PAC-MBR achieved enhanced removal of micropollutant by 10% (of...

Integration of an electrochemical process with membrane bioreactor (MBR) has attracted considerable attention in the last decade for simultaneous improvement in pollutant removal and hydraulic performance of MBR. Electrochemical MBR (eMBR) with sacrificial anodes has been observed to achieve enhanced phosphorus (up to 40%) and micropollutant remova...

Nanomaterials (NMs) have received tremendous attention as emerging adsorbents for environmental applications. The ever-increasing release into aquatic systems and the potential use in water treatment processes heighten the likelihood of the interactions of NMs with aquatic dissolved organic matter (DOM). Once DOM is adsorbed on NMs, it substantiall...

N-nitrosamines have been identified as emerging contaminants with tremendous carcinogenic potential for human beings. This study examined the seasonal changes in the occurrence of N-nitrosamines and N-nitrosodimethylamine formation potential (NDMA-FP) in drinking water resources and potable water from 10 drinking water treatment plants in a souther...

This study aims to extend and demonstrate the application of fluorescence spectroscopy for monitoring the water quality of three differently operated full-scale drinking water treatment plants located in the Shenzhen city (China). A ratio of fluorescent organic matter (FDOM), which describes relative changes in humic-like to protein-like fluorescen...

In biological wastewater treatment systems, extracellular polymeric substances (EPS) are continuously excreted as a response to environmental changes and substrate conditions. It could severely affect the treatment efficacy such as membrane fouling, dewaterability and the formation of carcinogenic disinfection by-products (DBPs). The heterogeneous...

Extracellular polymeric substances (EPS) from activated sludge comprise many organic constituents with polysaccharides and proteins as the main components of two different functionalities. Despite a number of previous EPS studies, a fundamental question remained unanswered, namely, whether the different EPS components would have the same turnover c...

This study investigated the influence of three different organic carbon sources including sodium acetate (SOD), glucose (GLU), and starch (STAR), on soluble microbial products (SMP), which presumably have dissimilar uptake rates and metabolic pathways, in sequencing batch reactors (SBR) and their subsequent effects on membrane fouling of ultrafiltr...

This study presents the impacts of TiO2 nanoparticles (TNPs) amendment on plant growth, phosphorus (P) content, and dissolved organic matter (DOM) composition in the rhizosphere. For this work, wheat plants (Galaxy-2013) were exposed to soil amended by different amounts of TNPs (i.e., 0, 50, and 100 mg TNP/kg of soil) for 40 days and harvested. The...

In this study, an indigenous activation of persulfate by iron-bearing minerals was examined using peroxymonosulfate (PMS) and peroxydisulfate (PDS) for the dewaterability and extracellular polymeric substances (EPS) composition of anaerobically digested sludge (ADS). Iron minerals originally present in the ADS seemed to operate as an initiator of t...

Much remains unknown about compositional variations in soluble microbial products (SMP) with the shift of the substrate condition from a feast to a famine phase in biological treatment systems. This study demonstrated that the formation of SMP could be suppressed by up to 75% during the famine phase with the addition of essential nutrients. In cont...

Spectroscopic techniques were used to examine the subtle changes in soluble microbial products (SMP) of batch activated sludge bioreactors working at different salinities (i.e., 0%, 1%, 3%, and 5% NaCl). The changes in different fluorescent constituent were tracked by excitation-emission matrix combined with parallel factor analysis (EEM-PARAFAC),...

Metal-free oxidative degradation by persulfate (PS) is an emerging process as green chemistry without any toxic metal leaching to aquatic environments but has never been explored for natural organic matter (NOM) removal to date. In this study, nitrogen-doped reduced graphene oxide (NrGO) was applied as a catalyst first to investigate the degradatio...

The relative ratios of chemical oxygen demand (COD) to nitrogen (N) in wastewater are known to have profound effects on the characteristics of soluble microbial products (SMP) from activated sludge. In this study, the changes in the SMP characteristics upon different COD/N ratios and the subsequent effects on ultrafiltration (UF) membrane fouling p...

Over the last several decades, the frequent occurrence of algal bloom in drinking water supplies, driven by increasing anthropogenic input and climate change, has posed serious problems for membrane filtration processes, resulting in reduced membrane permeability and increased energy consumption. It is essential to comprehensively understand the ch...

Excitation emission matrix-parallel factor analysis (EEM-PARAFAC) and size exclusion chromatography (SEC) were utilized to explore the dynamics in extracellular polymeric substances (EPS), soluble microbial products (SMP), and effluent for the membrane bioreactors at two different organic loading rates (OLRs). Combination of three different fluores...

Osmotic membrane bioreactor (OMBR) was operated to treat high strength wastewater. Cellulose triacetate (CTA) membrane, having effective membrane area of 0.12 m2, in a flat-sheet module configuration was submerged in a bio-tank (working volume 4.5 L). SRT of 20 days and periodic removal of supernatant from settled sludge were maintained to control...

N-acyl homoserine lactones (AHLs) based quorum sensing has been reported to be one of the main causes of biofouling in membrane bioreactor (MBR) for wastewater treatment. In this study, Rhodococcus sp. entrapped in sodium alginate beads with effective volume of 0.1% of bioreactor were used for the degradation of signal molecules to stop quorum sens...

Forward osmosis membranes are less prone to fouling with high rejection of salts, and the osmotic membrane bioreactor (OMBR) can be considered as an innovative membrane technology for wastewater treatment. In this study, a submerged OMBR having a cellulose triacetate membrane, with the active layer facing the feed solution configuration, was operat...

Relaxation or backwashing is obligatory for effective operation of membrane module and intermittent aeration is helpful for nutrients removal. This study was performed to investigate effects of different filtration modes on membrane fouling behavior and treatment in membrane bioreactor (MBR) operated at three modes i.e., 12, 10 and 8 min filtration...