Abstract: A method of treating flowback and produced water includes transferring flowback and produced water to a chemical treatment apparatus, mixing treatment chemicals with the flowback and produced water, transferring the mixture of treatment chemicals and flowback and produced water to a weir tank comprising a first end, a second end, an internal chamber, and a plurality of baffles positioned throughout the internal chamber to induce turbulent flow, transferring the mixture of treatment chemicals and flowback and produced water to a first settling tank that provides laminar flow, and transferring the mixture of treatment chemicals and flowback and produced water to a second settling tank that provides laminar flow.

Abstract: A mobile water re-use system can include a chemical treatment apparatus, at least one weir tank in fluid communication with the chemical treatment apparatus, and two or more settling tanks in fluid communication with each other and at least one of the settling tanks in fluid communication with the weir tank. The weir tank can have a first end, a second end, an internal chamber, and a plurality of baffles that induce turbulent flow of fluid through the internal chamber. The settling tanks can provide, promote, facilitate, result in, and/or induce laminar flow of fluid through at least a portion of the internal chamber. Weir tanks, settling tanks, and method of treating flowback and produced water are also described.