Catalytic membrane-based oxidation-filtration systems for organic wastewater purification: A review

Enhancing iron redox cycling for promoting heterogeneous Fenton performance: A review

As a new kind of water pollutant, antibiotics have encouraged researchers to develop new treatment technologies. Electrospun fiber membrane shows excellent benefits in antibiotic removal in water due to its advantages of large specific surface area, high porosity, good connectivity, easy surface modification and new functions. This review introduces the four aspects of electrospinning technology, namely, initial development history, working principle, influencing factors and process types. The preparation technologies of electrospun functional fiber membranes are then summarized. Finally, recent studies about antibiotic removal by electrospun functional fiber membrane are reviewed from three aspects, namely, adsorption, photocatalysis and biodegradation. Future research demand is also recommended.

Electrospun Functional Nanofiber Membrane for Antibiotic Removal in Water: Review.

The presence of toxic substances in aquifers, particularly potentially toxic heavy metals, is an important environmental and social concern worldwide. These heavy metals are capable to exert many injurious health effects in human beings by intake of drinking metal-contaminated water. However, very little attention is paid towards quantitative and qualitative analysis of groundwater used for drinking purpose in several less-developed countries. Therefore, this study was intended to estimate, for the first time, the heavy metal levels in groundwater/drinking water in District Vehari, Pakistan. A total of 129 groundwater samples were obtained and subjected to analyze heavy metal concentrations (lead, copper, cadmium, nickel, manganese, chromium, iron, and zinc). Moreover, pH, electrical conductivity, temperature, total dissolved solids, and anion (carbonates, chloride, and bicarbonates) and cation (calcium, potassium, sodium, lithium, and barium) contents of groundwater were also determined. It was noticed that the values of several groundwater physicochemical characteristics such as cation contents, alkalinity, chloride concentration, and especially the concentrations of heavy metals such as Pb (93%), Cd (68%), and Fe (100%) were higher than their limit values given by WHO. Principal component analysis separately grouped heavy metals and physicochemical characteristics of groundwater. The risk assessment indices predicted potential carcinogenic risks due to the consumption of metal-rich groundwater, predominantly with Cd (0.0007–0.03). The mean hazard quotient (HQ) values for all the metals were  1 envisaging non-carcinogenic risk with the consumption of studied groundwater. The findings of the study emphasized on the need of appropriate approaches to remediate groundwater before being used for drinking purpose.

Heavy metal contamination and exposure risk assessment via drinking groundwater in Vehari, Pakistan

Refractory organic pollutants in wastewater have the characteristics of persistence and toxicity, which seriously threaten the health and safety of humans and other organisms. Many researchers have committed to developing effective wastewater treatment technologies in the past few decades. The coupling of membrane technology with persulfate/peroxide-based in situ chemical oxidation (ISCO) not only can successfully overcome the shortcomings of the two single technologies, such as membrane fouling and difficult reuse of some catalysts, but also effectively achieve complementary advantages of pollutant filtration and degradation. Therefore, it has received extensive attention from researchers and is expected to be large-scale applied to actual wastewater treatment. In this review, according to different membrane materials, the common membrane types are briefly summarized, and then the synthesis methods of the catalytic membrane are introduced. In addition, various process configurations coupling membrane filtration with ISCO are researched. Two main modes of the coupling processes can be defined: (i) a one-pot coupling process which simultaneously oxidizes and separates organic pollutants; (ii) a two-stage coupling process, including a pretreatment stage for the removal of foulant forming molecules in the membrane feed water, and a post-treatment stage to further degrade the pollutants of membrane concentrate and permeation fluid. Finally, the major challenges and application prospects of membrane filtration coupled with ISCO in wastewater treatment are discussed.

In situ chemical oxidation: peroxide or persulfate coupled with membrane technology for wastewater treatment

Functional catalytic membrane development: A review of catalyst coating techniques.

Photo-Fenton activation mechanism and antifouling performance of an FeOCl-coated ceramic membrane

Carbamazepine (CBZ) is one of the contaminants of emerging concerns due to its broad distribution in water environments. The present study evaluated various photo-Fenton reactions to achieve enhanced CBZ removal using FeOCl as the photo-Fenton catalyst that exhibited high activity in ·OH generation at a wide range of pH. The effects of UV irradiation, H2O2 concentration, initial CBZ concentration and catalyst dosage on the CBZ degradation efficiency were evaluated with uncertainty analysis. The H2O2 concentration of 10 μM, a catalyst dosage of 0.2 g/L, and the initial concentration of CBZ of 100 μM led to the highest CBZ removal rate of 92 % under UV/H2O2/FeOCl system within 0.5 h The effects of common anions (i.e., CO32−, HCO3, SO42−, NO3- and Cl-) on the CBZ degradation were studied. Three possible degradation pathways and three major degradation by-products were analyzed by LC−ESI−MS, which would provide new insight into the degradation mechanisms of CBZ in photo-Fenton reactions.

Enhanced degradation of carbamazepine in FeOCl based Photo-Fenton reaction

Shenfu New District, located between two old industrial cities, Shenyang and Fushun, is a typical area undergoing industrialization and urbanization in China. The sources and distributions of heavy metals were analyzed in groundwater by multivariate analysis and GIS, and the impact of urbanization on the aqueous distribution of these metals was investigated. The results indicated that the mean contents of zinc (Zn), arsenic (As), cadmium (Cd), and lead (Pb) in the wet periods were about two times of those in the dry period. Nickel (Ni) and chromium (Cr) were considered to be associated with the same anthropogenic origins (i.e., wastewater from agricultural processing). The concentration of Zn was high under natural conditions, but was also affected by human activities (e.g., wastewater from foundry and instrument manufacturers). As, Cd, and Pb are likely derived from both anthropogenic and natural sources (agricultural and water-rock interactions). The spatial distributions of heavy metals in groundwater were region-specific, with the highest concentrations mostly along the Hun River. The heavy metal pollution index (HPI) values from the dry and wet periods showed similar trends at different sampling sites. Only one site’s HPI was above the critical value of 100. These results provide information that can be used to understand potential threats to the groundwater resources of other developing cities.

Fang Liu

Papers

Functional catalytic membrane development: A review of catalyst coating techniques.

Photo-Fenton activation mechanism and antifouling performance of an FeOCl-coated ceramic membrane

Enhanced degradation of carbamazepine in FeOCl based Photo-Fenton reaction

Assessment of trace metal contamination in groundwater in a highly urbanizing area of Shenfu New District, Northeast China

Removal of carbamazepine (CBZ) from synthetic urine by FeOCl-coated ceramic membrane: The study of kinetic modeling.