Pilot Study on the Combination of Different Pre-Treatments with Nanofiltration for Efficiently Restraining Membrane Fouling While Providing High-Quality Drinking Water

Abstract

Nanofiltration (NF) is a promising post-treatment technology for providing high-quality drinking water. However, membrane fouling remains a challenge to long-term NF in providing high-quality drinking water. Herein, we found that coupling pre-treatments (sand filtration (SF) and ozone–biological activated carbon (O3-BAC)) and NF is a potent tactic against membrane fouling while achieving high-quality drinking water. The pilot results showed that using SF+O3-BAC pre-treated water as the feed water resulted in a lower but a slowly rising transmembrane pressure (TMP) in NF post-treatment, whereas an opposite observation was found when using SF pre-treated water as the feed water. High-performance size-exclusion chromatography (HPSEC) and three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy determined that the O3-BAC process changed the characteristic of dissolved organic matter (DOM), probably by removing the DOM of lower apparent molecular weight (LMW) and decreasing the biodegradability of water. Moreover, amino acids and tyrosine-like substances which were significantly related to medium and small molecule organics were found as the key foulants to membrane fouling. In addition, the accumulation of powdered activated carbon in O3-BAC pre-treated water on the membrane surface could be the key reason protecting the NF membrane from fouling.

Analysis of the seasonal water quality variation at the hydraulic junction of a dual-source water distribution system

“…Compared with the quantitative analysis by UV 254 and DOC, the three-dimensional uorescence spectroscopy method is specialized in both the quantitative and qualitative analysis of organics, which presents high sensitivity and high efficiency without damage to the sample. 6,10,13,21,22,28 We selected samples in July as the target to analyze the constitution of organics in water, and the result is presented in Fig. 5.…”

“…Some reports also indicated they came from protein-like substances. 10,13,21,22,28 Fig. 6 shows the variations in the regional integral volume and its values represent the variations in the concentration of organics in an indirect way.…”

“…Therefore, the investigation of DBPs in DWDSs is benecial to control the impact of DBPs at the safest level possible. [9][10][11][12] The initial stages of urban development are characterized by the relatively compact populations in cities and towns, leading to the establishment of single-source DWDSs to meet the fundamental water needs of residents. Straightforward hydraulic setups within these pipelines facilitate detailed observations and studies concerning the formation, types, and interplay of DBPs.…”

“…Thus, to close the knowledge gap, more efforts should be made to investigate dual-source DWDS, especially in the hydraulic conjunction, which holds signicance in ensuring the water quality of cities. [9][10][11][12]23 The current study conducted a comprehensive one-year investigation to monitor the disinfection byproducts (DBPs) within a dual-source drinking water distribution system (DWDS) located in Suzhou Industrial Park. The traditional technique is competent in coping with small-size pipeline networks with high accuracy.…”

Comparison of Coagulation-Integrated Sand Filtration and Ultrafiltration for Seawater Reverse Osmosis Pretreatment

“…This study contributes to the optimization and enhancement of the pretreatment stage in the SWRO desalination process, and provides guidance for designing more-efficient and sustainable pretreatment schemes. pretreatments nor membrane technologies guarantee the comprehensive removal of DOM from the feedwater of RO systems [12][13][14]. Lin et al [15] showed that aluminum-based coagulants remove more than 60% of fulvic acid-like organics in HA/AOM mixtures while exhibiting minimal removal of aromatic protein-like substances.…”