Abstract: Many processes generate wastewater streams rich in sulfate and chloride. These salt components are traditionally not recovered and are discharged to the environment. The invention recovers pure water for recycle/reuse and simultaneously generates valuable pure salts of NaCl and Na2SO4 for beneficial reuse, eliminating the waste stream. Process consists of the sequential crystallization of salt products with an intermediate purification step in which a chemical reactant is added to elevate levels of purity. The process is configured to simultaneously achieve zero liquid discharge.

Abstract: Many processes generate wastewater streams rich in sulfate and chloride. These salt components are traditionally not recovered and are discharged to the environment. The invention recovers pure water for recycle/reuse and simultaneously generates valuable pure salts of NaCl and Na2SO4 for beneficial reuse, eliminating the waste stream. Process consists of the sequential crystallization of salt products with an intermediate purification step in which a chemical reactant is added to elevate levels of purity. The process is configured to simultaneously achieve zero liquid discharge.

Abstract: A concrete screed includes an engaging frame for readily engaging the mounting fixture of a skid loader or the like, with a pair of spaced parallel frame arms long enough to keep the skid loader off the concrete form, with a screed blade attached to the distal ends of the two frame arms. A pre-screed screeding blade having a V-shape is fixed to the screed blade for knocking down high spots in poured concrete. The side frame arms are free to pivot up and down at both ends. A pair of pulling arms, each pivotally connected to the screed blade at one end and to a side frame arm at the other, exert the actual pulling force that pulls the screed blade across the poured concrete. A pair of hydraulic vibrators fixed to the screed blade vibrates the screed blade to puddle and settle the concrete for leveling.