A cationic polymer enhanced PAC for the removal of dissolved aquatic organic carbon and organic nitrogen from surface waters

Abstract

Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) are important components of the aquatic environment and may produce harmful disinfection by-products through chlorination associated with water treatment processes. Therefore, it is necessary to remove them from the water. Coagulation is a cost-effective water treatment technique as the key unit in the pretreatment of drinking water but deals with DON poorly. We present a study to investigate the enhancement of poly aluminum chloride (PAC) using a cationic polymer for the removal of both DON and DOC. The cationic dimethyl diallyl ammonium chloride (PDMDAAC) polymer was hybridized with PAC to remove DON and DOC. The results showed that the PDMDAAC increased the charge neutralization capacity of PAC and floc aggregation, thereby increasing the settling efficiency of the flocs. The PDMDAAC increased the amount of colloidal species in PAC, which was beneficial to the formation of adsorption-bridging. With the increase of pH, a greater proportion of colloidal adsorption sites were used in the removal of DON. The DOC, DON, and turbidity removal were dependent on multiple interactions through charge neutralization, adsorption-bridging, and floc sweeping. However, DOC and DON removal were primarily determined by adsorption-bridging and floc sweeping, while turbidity removal was mainly dependent on charge neutralization.

Experimental methods in chemical engineering: Zeta potential

“…[58,61] Other topics relate to nanoparticles in polymers (red cluster) and bioimaging, [43,48] drug delivery (red cluster), [50] and environmental remediation (yellow cluster). [55,57] To gauge research with zeta potential around the globe, we generated a bibliometric map based on co-occurrences that grouped it into four clusters ( Figure 5). Almost 25% of the articles mention Zeta Potential (red cluster, but not shown as it overwhelms the map) and it is a frequent topic in Can.…”

“…[ 58,61 ] Other topics relate to nanoparticles in polymers (red cluster) and bioimaging, [ 43,48 ] drug delivery (red cluster), [ 50 ] and environmental remediation (yellow cluster). [ 55,57 ]…”

“…journal published 16 articles that mention the technique. [43,48,[50][51][52][53][54][55][56][57][58][59][60][61][62][63] The hot topics in the journal relate to the oil industry including asphaltene adsorption on calcite packs, [56] improved heavy oil recovery by injecting alkaline ionic slugs (blue cluster), [54] and rheological properties for composite fluids for fracturing and in mineral processing (green cluster). [58,61] Other topics relate to nanoparticles in polymers (red cluster) and bioimaging, [43,48] drug delivery (red cluster), [50] and environmental remediation (yellow cluster).…”

Variation of Al species during water treatment: correlation with treatment efficiency under varied hydraulic conditions

“…Among them, the Al a often plays the most important role in charge neutralization, the Al b has charge neutralization and adsorption bridging functions, whereas the Al c only has the adsorption bridging effect. The role of these species may change under different conditions (Wang et al 2019). Turbidity removal and organic matter are both affected by the neutralization and the adsorption bridging effect, and competition for adsorption sites would occur between the Al c and the Al b.…”

“…Turbidity removal and organic matter are both affected by the neutralization and the adsorption bridging effect, and competition for adsorption sites would occur between the Al c and the Al b. Previous studies mainly focused on the correlation within coagulant dosage and pH effect (Wang et al 2019). As the hydraulic conditions may affect the final effluent quality, this study mainly focused on the correlation within the range of influence of the hydraulic conditions.…”