A process for simultaneously controlling the pH and level of target ions of a liquid composition in a bioconversion or catalytical system, where an acidic or alkaline component is continuously produced, comprising at least one step of passing said liquid composition through a primary Reverse Electro-Enhanced Dialysis (REED) system, wherein the primary REED system comprises at least one Anion Exchange Reverse Electro-Enhanced Dialysis (AX-REED) membrane stack or at least one Cation Exchange Reverse Electro-Enhanced Dialysis (CX-REED), and further comprising at least one further step of passing said liquid composition through a secondary Reverse Electro-Enhanced Dialysis (REED) system, wherein the secondary REED system comprises at least one Anion Exchange Reverse Electro-Enhanced Dialysis (AX-REED) membrane stack or at least one Cation Exchange Reverse Electro-Enhanced Dialysis (CX-REED) membrane stack, wherein if the primary REED system is an AX-REED, the secondary REED system is a CX-REED, and wherein if the primary REED system is a CX-REED, the secondary REED system is an AX-REED, wherein said primary REED system and said secondary REED system are operated in parallel, thereby simultaneously controlling the pH and level of target ions of the liquid composition, wherein said AX-REED membrane stack has: i) at least two anion-exchange membranes defining a first chamber for a feed solution or a dialysate there between; ii) at least two further chambers for a feed solution or a dialysate, each further chamber being located adjacent to the at least one first chamber; iii) a set of end membranes; and iv) means for applying an electric field over the membranes by means of at least two electrodes; and wherein said CX-REED membrane stack has: i) at least two cation-exchange membranes defining a first chamber for a feed solution or a dialysate there between; ii) at least two further chambers for a feed solution or a dialysate, each further chamber being located adjacent to the at least one first chamber; iii) a set of end membranes; and iv) means for applying an electric field over the membranes by means of at least two electrodes; wherein the feed solution chambers and the dialysate chambers alternate, and where in an Anion Exchange Reverse Electro-Enhanced Dialysis (AX-REED) anion-exchange membranes separate the feed solution chambers from the dialysate chambers and in a Cation Exchange Reverse Electro-Enhanced Dialysis (CX-REED) cation-exchange membranes separate the feed solution chambers from the dialysate chambers. comprising at least one step of passing said liquid composition through a primary Reverse Electro-Enhanced Dialysis (REED) system, wherein the primary REED system comprises at least one Anion Exchange Reverse Electro-Enhanced Dialysis (AX-REED) membrane stack or at least one Cation Exchange Reverse Electro-Enhanced Dialysis (CX-REED), and further comprising at least one further step of passing said liquid composition through a secondary Reverse Electro-Enhanced Dialysis (REED) system, wherein the secondary REED system comprises at least one Anion Exchange Reverse Electro-Enhanced Dialysis (AX-REED) membrane stack or at least one Cation Exchange Reverse Electro-Enhanced Dialysis (CX-REED) membrane stack, wherein if the primary REED system is an AX-REED, the secondary REED system is a CX-REED, and wherein if the primary REED system is a CX-REED, the secondary REED system is an AX-REED, wherein said primary REED system and said secondary REED system are operated in parallel, thereby simultaneously controlling the pH and level of target ions of the liquid composition, wherein said AX-REED membrane stack has: i) at least two anion-exchange membranes defining a first chamber for a feed solution or a dialysate there between; ii) at least two further chambers for a feed solution or a dialysate, each further chamber being located adjacent to the at least one first chamber; iii) a set of end membranes; and iv) means for applying an electric field over the membranes by means of at least two electrodes; i) at least two anion-exchange membranes defining a first chamber for a feed solution or a dialysate there between; ii) at least two further chambers for a feed solution or a dialysate, each further chamber being located adjacent to the at least one first chamber; iii) a set of end membranes; and iv) means for applying an electric field over the membranes by means of at least two electrodes; and wherein said CX-REED membrane stack has: i) at least two cation-exchange membranes defining a first chamber for a feed solution or a dialysate there between; ii) at least two further chambers for a feed solution or a dialysate, each further chamber being located adjacent to the at least one first chamber; iii) a set of end membranes; and iv) means for applying an electric field over the membranes by means of at least two electrodes; i) at least two cation-exchange membranes defining a first chamber for a feed solution or a dialysate there between; ii) at least two further chambers for a feed solution or a dialysate, each further chamber being located adjacent to the at least one first chamber; iii) a set of end membranes; and iv) means for applying an electric field over the membranes by means of at least two electrodes; wherein the feed solution chambers and the dialysate chambers alternate, and where in an Anion Exchange Reverse Electro-Enhanced Dialysis (AX-REED) anion-exchange membranes separate the feed solution chambers from the dialysate chambers and in a Cation Exchange Reverse Electro-Enhanced Dialysis (CX-REED) cation-exchange membranes separate the feed solution chambers from the dialysate chambers.