Calcium cation interactions with polysaccharides and proteins in wastewater UF membrane fouling

Analysis of UF membrane fouling mechanisms caused by organic interactions in seawater

“…10d). The interaction between multiple organic compounds was also previously reported to have a significant effect on overall fouling behaviours and backwash efficiency (Alazmi et al, 2010). Fig.…”

Hydraulic irreversibility of ultrafiltration membrane fouling by humic acid: Effects of membrane properties and backwash water composition

“…S7). This ion exchange reaction between Na + and Ca-HA is similar to that between Na + and Ca-alginate in NaCl cleaning [43] because both foulants exhibit hydrophilicity and form Ca-organic matter complexes [44,45]. The greater HCE obtained by backwashing with HA solution rather than ultrapure water can be explained by the competitive complexation of Ca 2+ in the fouling layer with the HA molecules in the backwash water.…”

The effect of calcium on the treatment of fresh leachate in an expanded granular sludge bed bioreactor

“…We also noted that the percentage of oxidable fraction reached 45-48% at day 39 and 49, indicating that a great amount of calcium was bounded to organic species as well as carbonates. In connection with the IR observation, the calcium organics could be calcium phosphonates and carboxylates (Alazmi et al, 2010;Renman and Renman, 2010), apart from calcium carbonate/phosphate. The calcium content and fractionation analysis thus demonstrate that the accumulated calcium in granules in the EGSB bioreactor for the treatment of fresh leachate with a high Ca concentration includes not only CaCO 3 , but also some insoluble organic calcium compounds.…”