Retention of organics and degradation of micropollutants in municipal wastewater using impregnated ceramics

Abstract

Pesticides, personal care products, industrial chemicals often pollute surface-and groundwater sources. With trace concentrations and low molecular weights, these micropollutants (MPs) easily penetrate through treatment systems and impose a real health threat on drinking water consumers. The absence of a dedicated MP-retaining treatment technology at water treatment plants results in a constant consumption of MP-contaminated water. Advanced oxidation processes, and in particular the Fenton reaction, can successfully degrade MPs if other, larger, fractions of organics are retained. Here, we suggest a novel combined two-stage retention-degradation approach. Ceramic membranes retain large organics such as bovine serum albumin (BSA). Fenton processes disintegrate nonretained MPs such as methylene blue (MB) and bisphenol A (BPA) that penetrate through the membrane. The efficiency of the suggested approach is high. Single-layered ultrafiltration membrane retains more than 96% BSA and degrades 40-50% of MB and BPA. The degree of degradation depends on both the impregnated metal oxide and the concentration of hydrogen peroxide. Vanadium-based catalysts retain more than 90% MPs but leach into permeate. Ferric oxides were the only stable catalysts that performed better in membranes than when impregnated on α-Al 2 O 3 pellets. A combined retention-degradation can be optimized to result in superior degree of retention. Catalytic ceramic membranes can retain large organic molecules and decompose MPs simultaneously. Three parameters affect the process efficiency: the dynamics of the influent fluid, the catalyst dose and the contact time.

Recent Advances in Biopolymeric Membranes towards the Removal of Emerging Organic Pollutants from Water

“…As it is, the increased utilization of organic products such as pharmaceuticals and pesticides has resulted in the reduction of clean water supplies for communities [52]. Furthermore, these contaminants of emerging concerns (CECs) tend to find their way into water systems [1,53,54]. As such, the most abundant agricultural contaminants include pesticides and herbicides such as atrazine, endosulfan cyanazine, and metribuzin.…”

“…In addition, the pollutants can also pass through drainage systems [1]. These micropollutants accumulate over time and are being progressively detected in water systems [1,54]. The sources of micropollutants and the various ways in which micropollutants find their ways into the water system are summarized in Figure 2.…”

“…Thus, such membranes can withstand the strong oxidizing agents and can therefore be utilized in large organic materials such as dyes' removal applications [68]. Nevertheless, ceramic membranes have lower retention capacity on the removal of smaller organic materials [54,67]. This is because ceramic membranes have larger pores.…”

“…This is because ceramic membranes have larger pores. Hence, ceramic membranes tend to limitedly retain micropollutants [54]. To this end, polymeric membranes are adopted to remove even small organic pollutants, including emerging micropollutants.…”