An electrocoagulation reactor apparatus for treatment of a fluid stream, comprising: an electrode packing frame, wherein the electrode packing frame comprises: (i) a pair of opposing inserts (302A, 302B), wherein each of the inserts (302A, 302B) comprises a plurality of insert openings; and (ii)an electrode stack, wherein the electrode stack comprises a plurality of electrode plates, wherein the plurality of electrode plates comprises an upper and a lower terminal electrode plate, and a plurality of intermediate electrode plates sandwiched between the upper and lower terminal electrode plates, wherein each of the terminal electrode plates is configured as an anode or a cathode, wherein each of the terminal electrode plates is configured to be thinner in comparison to the intermediate electrode plates, wherein each of the intermediate electrode plates is bipolar such that a first planar or flat side of each of the intermediate electrode plates is an anode and an opposing planar or flat side of the same intermediate electrode plate is a cathode, and wherein each of the electrode plates (204A, 204B) is horizontally stacked within a pair of opposing insert openings formed on the pair of opposing inserts (302A, 302B); and a cell comprising cylindrical sidewalls, wherein the electrode packing frame is inserted within the cylindrical cell, wherein a conducting bar extends across a length of each of the horizontally stacked upper and lower terminal electrodes. an electrode packing frame, wherein the electrode packing frame comprises: (i) a pair of opposing inserts (302A, 302B), wherein each of the inserts (302A, 302B) comprises a plurality of insert openings; and (ii)an electrode stack, wherein the electrode stack comprises a plurality of electrode plates, wherein the plurality of electrode plates comprises an upper and a lower terminal electrode plate, and a plurality of intermediate electrode plates sandwiched between the upper and lower terminal electrode plates, wherein each of the terminal electrode plates is configured as an anode or a cathode, wherein each of the terminal electrode plates is configured to be thinner in comparison to the intermediate electrode plates, wherein each of the intermediate electrode plates is bipolar such that a first planar or flat side of each of the intermediate electrode plates is an anode and an opposing planar or flat side of the same intermediate electrode plate is a cathode, and wherein each of the electrode plates (204A, 204B) is horizontally stacked within a pair of opposing insert openings formed on the pair of opposing inserts (302A, 302B); and (i) a pair of opposing inserts (302A, 302B), wherein each of the inserts (302A, 302B) comprises a plurality of insert openings; and (ii)an electrode stack, wherein the electrode stack comprises a plurality of electrode plates, wherein the plurality of electrode plates comprises an upper and a lower terminal electrode plate, and a plurality of intermediate electrode plates sandwiched between the upper and lower terminal electrode plates, wherein each of the terminal electrode plates is configured as an anode or a cathode, wherein each of the terminal electrode plates is configured to be thinner in comparison to the intermediate electrode plates, wherein each of the intermediate electrode plates is bipolar such that a first planar or flat side of each of the intermediate electrode plates is an anode and an opposing planar or flat side of the same intermediate electrode plate is a cathode, and wherein each of the electrode plates (204A, 204B) is horizontally stacked within a pair of opposing insert openings formed on the pair of opposing inserts (302A, 302B); and a cell comprising cylindrical sidewalls, wherein the electrode packing frame is inserted within the cylindrical cell,