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By summarizing 187 relevant research articles published in 2019, the review is focused on the research progress of physicochemical processes for wastewater treatment. This review divides into two sections, physical processes and chemical processes. The physical processes section includes three sub-sections, that is, adsorption, granular filtration, and dissolved air flotation, whereas the chemical processes section has five sub-sections, that is, coagulation/flocculation, advanced oxidation processes, electrochemical, capacitive deionization, and ion exchange. PRACTITIONER POINTS: Totally 187 research articles on wastewater treatment have been reviewed and discussed. The review has two major sections with eight sub-topics.

Smoking is the leading cause of premature death in Canada. Smoking also pollutes air and generates litter such as cigarette butts. The use of designated smoking areas (DSAs) is increasingly popular...

With urbanization worldwide in recent decades, anthropogenic dust (AD) emissions due to heavy urban construction and off-road vehicle use have been increasing. Its perturbations on urban air pollution at the global scale are still unclear. Based on observations, we found that a high urban AD optical depth is often accompanied by severe non-dust aerosol optical depth in the planetary boundary layer (PBL), both magnitudes even comparable. To investigate the causes, an AD emission inventory constrained by satellite retrievals is implemented in a global climate model. The results show that AD-induced surface radiative cooling of up to -15.9 +/- 4.0 W m(-2) regionally leads to reduced PBL height, which deteriorates non-dust pollution, especially over India and northern China, in addition to the tremendous direct AD contribution to pollutants. The estimated global total premature mortality due to AD is 0.8 million deaths per year and is more severe in populous regions.

Microplastics (MPs) have been widely detected in drinking water sources and tap water, raising the concern of the effectiveness of drinking water treatment plants (DWTPs) in protecting the public from exposure to MPs through drinking water. We collected and analyzed the available research articles up to August 2021 on MPs in drinking water treatment (DWT), including laboratory- and full-scale studies. This article summarizes the major MP compositions (materials, sizes, shapes, and concentrations) in drinking water sources, and critically reviews the removal efficiency and impacts of MPs in various drinking water treatment processes. The discussed drinking water treatment processes include coagulation-flocculation (CF), membrane filtration, sand filtration, and granular activated carbon (GAC) filtration. Current DWT processes that are purposed for particle removal are generally effective in reducing MPs in water. Various influential factors to MP removal are discussed, such as coagulant type and dose, MP material, shape and size, and water quality. It is anticipated that better MP removal can be achieved by optimizing the treatment conditions. Moreover, the article framed the major challenges and future research directions on MPs and nanoplastics (NPs) in DWT.

The review scans research articles published in 2018 on physico-chemical processes for water and wastewater treatment. The paper includes eight sections, that is, membrane technology, granular filtration, flotation, adsorption, coagulation/flocculation, capacitive deionization, ion exchange, and oxidation. The membrane technology section further divides into six parts, including microfiltration, ultrafiltration, nanofiltration, reverse osmosis/forward osmosis, and membrane distillation. PRACTITIONER POINTS: Totally 266 articles on water and wastewater treatment have been scanned; The review is sectioned into 8 major parts; Membrane technology has drawn the widest attention from the research community.

This paper reviews studies published in 2019, in the area of analytical techniques for determination of pesticides and herbicides. It should be noted that some of the reports summarized in this review are not directly related to but could potentially be used for water environment studies. Based on different methods, the literatures are organized into six sections, namely extraction methods, electrochemical techniques, spectrophotometric techniques, chemiluminescence and fluorescence methods, chromatographic and mass spectrometric techniques, and biochemical assays. PRACTITIONER POINTS: Totally 141 research articles have been summarized. The review is divided into six parts. Chromatographic and mass spectrometric techniques are the most widely used methods.

A review of the literatures published in 2017 on topics relating to analytical methods for pesticides and herbicides is presented in this paper. Based on different techniques, this review is divided into seven parts, i. e., extraction methods, chromatographic or mass spectrometric techniques, electrochemical techniques, spectrophotometric techniques, chemiluminescence and fluorescence methods, biochemical assays and immunoassays, and miscellaneous techniques.

Canada has the world's largest oil sands reservoirs. Surface mining and subsequent caustic hot water extraction of bitumen lead to an enormous quantity of tailings (volumetric ratio bitumen:water=9:1). Due to the zero-discharge approach and the persistency of the complex matrix, oil producers are storing oil sands tailings in vast ponds in Northern Alberta. Oil sands tailings are comprised of sand, clay and process-affected water (OSPW). OSPW contains an extremely complex matrix of organic contaminants (e.g., naphthenic acids (NAs), residual bitumen, and polycyclic aromatic hydrocarbons (PAHs)), which has proven to be toxic to a variety of aquatic species. Biodegradation, among a variety of examined methods, is believed to be one of the most cost effective and practical to treat OSPW. A number of studies have been published on the removal of oil sands related contaminants using biodegradation-based practices. This review focuses on the treatment of OSPW using various bioreactors, comparing bioreactor configurations, operating conditions, performance evaluation and microbial community dynamics. Effort is made to identify the governing biotic and abiotic factors in engineered biological systems receiving OSPW. Generally, biofilms and elevated suspended biomass are beneficial to the resilience and degradation performance of a bioreactor. The review therefore suggests that a hybridization of biofilms and membrane technology (to ensure higher suspended microbial biomass) is a more promising option to remove OSPW organic constituents.

Previously, anoxic-aerobic membrane bioreactor (MBR) coupled with mild ozonation pretreatment has been applied to remove toxic naphthenic acids (NAs) in oil sands process-affected water (OSPW). To further improve MBR performance, the optimal operation conditions including hydraulic retention time (HRT) and initial ammonia nitrogen (NH4+-N) need to be explored. In this study, the role of ozone pretreatment on MBR optimization was investigated. Compared with MBR treating raw OSPW, MBR treating ozonated OSPW had the same optimal operation conditions (HRT of 12 h and NH4+-N concentration of 25 mg/L). Nevertheless, MBR performance benefited from HRT adjustment more after ozone pretreatment. HRT adjustment resulted in NA removal in the range of 33–50% for the treatment of ozonated OSPW whereas NA removal for raw OSPW only fluctuated between 27% and 38%. Compared with the removal of classical NAs, the degradation of oxidized NAs was more sensitive to the adjustment of operation conditions. Adjusting HRT increased the removal of oxidized NAs in ozonated OSPW substantially (from 6% to 35%). It was also noticed that microbial communities in MBR treating ozonated OSPW were more responsive to the adjustment of operation conditions as indicated by the noticeable increase of Shannon index and extended genetic distances.

Understanding the coal molecular structure is of paramount importance for the effective utilization of coal. In this paper, the molecular structure of Zhundong coal (ZD) was characterized by physical detection techniques, such as solid state 13C nuclear magnetic resonance spectroscopy (13C-NMR), fourier transform infrared resonance spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The occurrence and distribution of aromatic carbocyclic frameworks were analyzed by 13C-NMR. Based on the FTIR and XPS analysis, the existing forms and the length of the aliphatic chain, the substitution forms of aromatic carbocyclic rings, and different types of functional groups were confirmed. The aliphatic chains and functional groups were introduced into these aromatic carbocyclic frameworks, and the 2D molecular structures model of ZD with the molecular chemical formula as C179H124O21N4 were constructed. The simulated 13C-NMR spectra of which were consistent with the experimental spectra, indicating the accuracy of the 2D ZD molecular structure model. Efforts were made to obtain the energy-minimum conformation of the 3D molecular structure by molecular mechanics (MM) and molecular dynamics (MD). The simulated FTIR spectra of the model were in good agreement with the experimental results, which fully verified the accuracy of the ZD molecular structure. The molecular structure provides a deep reference to understand the structural characteristics of ZD coal at the molecular micro-scale, which would be helpful to understand the reactivity of ZD coal.

Microplastics are an emerging issue in water systems, and an understanding of their occurrence and behavior is complicated by a high diversity in physical (i.e., size and shape) and chemical characteristics. To date, there have been limited studies on microplastics in drinking water treatment processes. As the coagulation-flocculation-sedimentation (CFS) process is the first step of the particle/colloid removal at many plants, its ability to remove microplastics requires further investigation. By performing alum-CFS bench tests, this study examined the removal of carboxylated polystyrene (PS) microspheres in a wide size range (3, 6, 25, 45, and 90 μm) in two types of real surface waters (Grand River and Lake Erie water) that are sources for full-scale drinking water treatment plants. Based on experiments using water from the Grand River with a variety of alum doses (10, 20, 30, 40, and 50 mg/L), a higher alum dose generally led to better removal of microspheres smaller than 90 μm, while an alum dose > 30 mg/L did not substantially improve the removal of particles between 3 and 25 μm. Further experiments indicated that smaller PS microspheres were more effectively removed in both river (Grand River_Dec 06) and lake water (Lake Erie_Nov 29). For example, with an alum dose of 30 mg/L, 75.6 and 85.2% of the 6-μm PS microspheres were removed from Grand River and Lake Erie water, respectively. Moreover, the water source significantly (p = 0.0021) affected the removal of PS microspheres, which may have been primarily related to the difference in turbidity. No impacts of PS microspheres were observed on the removal efficiency for turbidity, natural organic matter fractions, or major metal elements by alum-CFS treatment.

The potential of graphene oxide (GO) in environmental applications, such as the development of antimicrobial materials and low-fouling membranes, has thus far been hindered by an incomplete understanding of bioadhesion mechanisms on GO interfaces. Using atomic force microscopy (AFM)-based single-cell force spectroscopy, we investigate the adhesion of single Pseudomonas fluorescens cells on GO-functionalized interfaces possessing distinct morphologies. Specifically, we investigate Si-GO surfaces, in which Langmuir–Blodgett GO films are transferred to Si wafers by dip-coating, forming an immobilized layer of horizontally arranged GO nanosheets, and PLL-GO surfaces, where GO nanosheets, edge-tethered to poly-l-lysine, form an interface characterized by morphological and conformational disorder. We observe strong adhesion forces on both Si-GO and PLL-GO surfaces; analysis of the pull-off forces in terms of the worm-like chain model reveals that adhesion is driven by hydrophobic interactions between proteinace...

This paper reviews studies published in 2019, in the area of analytical techniques for determination of pesticides and herbicides. It should be noted that some of the reports summarized in this review are not directly related to but could potentially be used for water environment studies. Based on different methods, the literatures are organized into six sections, namely extraction methods, electrochemical techniques, spectrophotometric techniques, chemiluminescence and fluorescence methods, chromatographic and mass spectrometric techniques, and biochemical assays. PRACTITIONER POINTS: Totally 141 research articles have been summarized. The review is divided into six parts. Chromatographic and mass spectrometric techniques are the most widely used methods.

To achieve chemical free cleaning of fouled membrane, a novel electronic-conductive composite membrane was prepared by electrochemical polymerizing polypyrrole (PPy) onto stainless-steel mesh (SSM) in the present study. The permeability of the fabricated conductive membrane can be tuned by adjusting the cycles of electrochemical cyclic voltammetry to a desired permeability level. The membrane has a significantly higher conductivity superior SSM. The anti-fouling performance was tested by using the membrane as the cathode under 2 V during backwash. The results show that under the power-on mode during backwash, the fouling formed during filtering sodium alginate (SA), bovine serum albumin (BSA), humic acid (HA) solution, and secondary effluent can be significantly more reversible than otherwise. According to size exclusion chromatography analysis, large molecular fraction in SA and small organic fractions in HA can be more effectively removed than under normal backwash. Anti-fouling mechanisms unveiled based on atomic force microscopy and Fourier transform infrared spectroscopy analysis suggest that the change of the dipole moment of PPy under applied voltage led to the increase of the electronegativity and hydrophilicity of the membrane surface, which improved hydraulic reversibility of membrane fouling. The fabrication method developed in the present study demonstrates a promising process preparing conductive membranes orientating chemical free cleaning.

The effect of –COOH and –NH2 functional groups on adsorptive polysaccharide fouling of a membrane surface was investigated at different pH values. Sodium alginate (SA: rich in –COOH) and chitosan (CTS: rich in –NH2) were selected as typical polysaccharides adsorbed onto the surface of polyvinylidene fluoride (PVDF) and PVDF modified using graphene oxide (GO-PVDF). The adsorption behavior and structure of the fouling layer were determined using quartz crystal microbalance and dissipation (QCM-D) and atomic force microscopy (AFM). The results showed that in the pH range of 4–6, the adherence of polysaccharide fouling and its reversibility were dependent on functional groups. When the organics were rich in –COOH, increase in the pH reduced their deposition on the membrane surface, and alleviated adsorptive fouling and its irreversibility. For the –NH2 functional group, the increase in pH led to more severe polysaccharide fouling due to the decreased degree of protonation, and the resulting fouling maintained high irreversibility. Modification using GO alleviated the adsorptive fouling of these two polysaccharides on PVDF; however, the extent of alleviation was dependent on the abundance of functional groups on the polysaccharides.

This study was focused on how different operating conditions affected the biodegradation of naphthenic acids (NAs) and the microbial community architectures in an anoxic–aerobic membrane bioreactor (MBR) for oil sands process-affected water (OSPW) treatment. After 442 days of continuous optimization, a supplemented NH4–N concentration of 25 mg L−1 and a hydraulic retention time (HRT) of 12 h demonstrated the best removal rates of total classical NAs (37.6%) and total oxidized NAs (23.9%). Neither higher HRTs nor higher supplemented NH4–N concentrations resulted in a better overall removal of NAs. In addition, NAs with larger carbon numbers were generally better degraded, whereas higher cyclicity tended to lessen the biodegradability of NAs. MiSeq sequencing analysis disclosed that orders under Proteobacteria (i.e., Rhodocyclales, Burkholderiales and Nitrosomonadales), Bacteroidetes (i.e., Cytophagales, [Saprospirales] and Flavobacteriales), and Nitrospirae (i.e., Nitrospirales) were the major microbes over the whole study though their relative abundances varied. The results of this study provide insightful information for future studies and application of biological processes for OSPW treatment on a large scale.

Two identical anoxic-aerobic membrane bioreactors (MBRs) were operated in parallel for 742 consecutive days for raw and ozonated oil sands process-affected water (OSPW) treatment. The MBRs not only substantially degraded OSPW classical and oxidized NAs, but also demonstrated outstanding membrane fouling control performance (the MBR receiving raw OSPW experienced its first severe fouling with a transmembrane pressure (TMP) of −35 kPa on Day 433). The mild ozonation (30 mg O 3 /L) pretreatment of OSPW remarkably enhanced OSPW NA degradation, and improved the MBR's fouling control in terms of prolonged long-term slow TMP growth phase and reduced TMP jump frequency. Ozonation substantially altered the feed water organic composition, reshaped the microbial community (e.g., reduced growth of extracellular polymeric substances (EPS) producers and biofilm formation facilitators), and lowered EPS production and EPS protein/polysaccharides (PN/PS) ratio, consequently leading to the better fouling control. Examination on fouling behaviors at different HRTs of the raw OSPW MBR indicates that HRT also played a role in determining the dominating fouling mechanism during the sharp TMP rise phase. Therefore, the results of this study suggest that the low-dose ozone pretreatment is a good option to enhance organic contaminant degradation and alleviate membrane fouling in the MBR for OSPW treatment.

The huge amount of toxic oil sands process-affected water (OSPW) stored in northern Alberta is of great concern to the public health and aquatic life. Therefore, cost-effective and more efficient approaches for OSPW treatment are urgently needed. In this study, mild ozonation followed by a modified Luzack–Ettinger membrane bioreactor (MLE-MBR) were employed for the treatment of OSPW. It was shown that with a utilized ozone dose of 30 mg/L, 42.5–47.4% of classical naphthenic acids (NAs) were removed with toxicity reduction towards Vibrio fischeri . While ozonation targeted the heteroatomic NAs and classical NAs with high cyclicity and carbon number, MBR showed its advantages in removing oxidized NAs and classical NAs with less hydrogen deficiency. With excellent nitrification and denitrification performance, MBR achieved the removal of 46% for classical NAs, indicating the success of sludge acclimation in the MBR. Thauera became the most dominating bacterial genus in MBR, revealing its potentials in OSPW treatment. Compared with MBR treating raw OSPW, ozone pretreatment contributed to improved denitrification and NA removal in MBR. Moreover, it altered microbial community structure, thus delaying the occurrence of membrane fouling. During 426 days of continuous operation, no severe membrane fouling was observed as the transmembrane pressure (TMP) of the MLE-MBR never exceeded −12 kPa. With a reduction of classical NAs by around 70%, our results indicated that the MLE-MBR coupled with ozonation, is a promising approach for removing recalcitrant organics in OSPW.

We investigated the contribution of different functional groups on polysaccharides to membrane fouling. To achieve so, we examined the adsorption of two typical polysaccharides, i.e., glucan (only –OH) and sodium alginate (enriched –COOH) on surfaces of PVDF membranes with and without graphene oxide (GO) modification. The results suggest that the interaction between carboxyl groups and Ca2+ significantly altered the particle size and charge of sodium alginate. Resultantly, the irreversible fouling of PVDF membrane surface caused by polysaccharide (i.e., sodium alginate) adsorption became more reversible when the concentration of Ca2+ exceeded a critical value. In comparison, glucan containing only hydroxyl groups exhibited unidirectional increase in irreversible fouling along with the increased Ca2+ concentration. Modification of PVDF membrane using GO did alleviate adsorptive fouling, but the Ca2+ bridging between the modified membrane surface and sodium alginate makes the fouling less reversible. Therefore, foulant property and water chemistry should be taken in to account in evaluating the performance of membrane hydrophilization using GO.

This review covers research articles published in 2017 on topics relating to physico-chemical processes for water and wastewater treatment. The paper divides into nine sections, i. e., membrane technology, ion exchange, capacitive deionization, granular filtration, coagulation/flocculation, sedimentation, flotation, oxidation and adsorption. The membrane technology part includes six parts, including microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), forward osmosis (FO), and membrane distillation (MD).

This study compared microbial characteristics and oil sands process-affected water (OSPW) treatment performance of five types of microbial biomass (MBBR-biofilm, IFAS-biofilm, IFAS-floc, MBR-aerobic-floc, and MBR-anoxic-floc) cultivated from three types of bioreactors (MBBR, IFAS, and MBR) in batch experiments. Chemical oxygen demand (COD), ammonium, acid extractable fraction (AEF), and naphthenic acids (NAs) removals efficiencies were distinctly different between suspended and attached bacterial aggregates and between aerobic and anoxic suspended flocs. MBR-aerobic-floc and MBR-anoxic-floc demonstrated COD removal efficiencies higher than microbial aggregates obtained from MBBR and IFAS, MBBR and IFAS biofilm had higher AEF removal efficiencies than those obtained using flocs. MBBR-biofilm demonstrated the most efficient NAs removal from OSPW. NAs degradation efficiency was highly dependent on the carbon number and NA cyclization number according to UPLC/HRMS analysis. Mono- and di-oxidized NAs were the dominant oxy-NA species in OSPW samples. Microbial analysis with quantitative polymerase chain reaction (q-PCR) indicated that the bacterial 16S rRNA gene abundance was significantly higher in the batch bioreactors with suspended flocs than in those with biofilm, the NSR gene abundance in the MBR-anoxic bioreactor was significantly lower than that in aerobic batch bioreactors, and denitrifiers were more abundant in the suspended phase of the activated sludge flocs.

Batch experiments were performed to evaluate biodegradation of raw and ozonated oil sands process-affected water (OSPW) under denitrifying anoxic and nitrifying aerobic conditions for 33 days. The results showed both the anoxic and aerobic conditions are effective in degrading OSPW classical and oxidized naphthenic acids (NAs) with the aerobic conditions demonstrating higher removal efficiency. The reactors under nitrifying aerobic condition reduced the total classical NAs of raw OSPW by 69.1 %, with better efficiency for species of higher hydrophobicity. Compared with conventional aerobic reactor, nitrifying aerobic condition substantially shortened the NA degradation half-life to 16 days. The mild-dose ozonation remarkably accelerated the subsequent aerobic biodegradation of classical NAs within the first 14 days, especially for those with long carbon chains. Moreover, the ozone pretreatment enhanced the biological removal of OSPW classical NAs by leaving a considerably lower final residual concentration of 10.4 mg/L under anoxic conditions, and 5.7 mg/L under aerobic conditions. The combination of ozonation and nitrifying aerobic biodegradation removed total classical NAs by 76.5 % and total oxy-NAs (O3–O6) by 23.6 %. 454 Pyrosequencing revealed that microbial species capable of degrading recalcitrant hydrocarbons were dominant in all reactors. The most abundant genus in the raw and ozonated anoxic reactors was Thauera (~56 % in the raw OSPW anoxic reactor, and ~65 % in the ozonated OSPW anoxic reactor); whereas Rhodanobacter (~40 %) and Pseudomonas (~40 %) dominated the raw and ozonated aerobic reactors, respectively. Therefore, the combination of mild-dose ozone pretreatment and subsequent biological process could be a competent choice for OSPW treatment.

The release of oil sands process-affected water (OSPW) into the environment is a concern because it contains persistent organic pollutants that are toxic to aquatic life. A modified Ludzack-Ettinger membrane bioreactor (MLE-MBR) with a submerged ceramic membrane was continuously operated for 425 days to evaluate its feasibility on OSPW treatment. A stabilized biomass concentration of 3730 mg mixed liquor volatile suspended solids per litre and a naphthenic acid (NA) removal of 24.7% were observed in the reactor after 361 days of operation. Ultra Performance Liquid Chromatography/High Resolution Mass Spectrometry analysis revealed that the removal of individual NA species declined with increased ring numbers. Pyrosequencing analysis revealed that Betaproteobacteria were dominant in sludge samples from the MLE-MBR, with microorganisms such as Rhodocyclales and Sphingobacteriales capable of degrading hydrocarbon and aromatic compounds. During 425 days of continuous operation, no severe membrane fouling was observed as the transmembrane pressure (TMP) of the MLE-MBR never exceeded -20 kPa given that the manufacturer's suggested critical TMP for chemical cleaning is -35 kPa. Our results indicated that the proposed MLE-MBR has a good potential for removing recalcitrant organics in OSPW.

Maritime search and rescue decision-making is a complicated system, for different emergencies at sea, and at different time or reaction stages, in accordance with the relevant emergency plans, the decision-making must be timely adjusted. Under the current environment of informatization and networking, it is imperative to establish a distributed maritime search and rescue distributed intelligent decision support system. A maritime search and rescue intelligent decision support system is studied in this article and system analysis, design and implementation are described. The results show that during the course of decision-making the human interference can be reduced relying on maritime search and rescue decision support system, and the system can evaluate the hazards of disaster, the effect of the emergency response action and the cost-effective of rescue resources. In one word, it can assist RCC to make scientific decisions quickly and accurately.