The present disclosure relates to the field of resource utilization-oriented treatment technologies for wastewater, and more particularly, to a resource utilization-oriented treatment method for a spent electroless nickel plating bath. The method includes oxidation de-complexation, synchronous precipitation of nickel and phosphorus, secondary precipitation of nickel, and resource utilization of sodium salt. In the present disclosure, in a reaction process, no sludge is generated to avoid secondary pollution to the environment. Further, the present disclosure has the advantages of short flow and less chemical use, greatly reducing treatment costs. In this way, this method is a low-cost and clean resource utilization-oriented treatment method capable of achieving resource utilization-oriented recovery of nickel, phosphorus, sodium, sulfate radical, or chlorine in the spent electroless nickel plating bath.

Copper-boron-ferrite (CuBFe) composites may be prepared and immobilized on graphite electrodes in a silica-based sol-gel, e.g., from rice husks. Different bimetallic loading ratios can produce fast in-situ electrogeneration of reactive oxygen species, H.sub.2O.sub.2 and .Math.OH, e.g., via droplet flow-assisted heterogeneous electro-Fenton reactor system. Loading ratios of, e.g., 10 to 30 wt. % Fe.sup.3+ and 5 to 15% wt. Cu.sup.2+, can improve the catalytic activities towards pharmaceutical beta blockers (atenolol and propranolol) degradation in water. Degradation efficiencies of at least 99.9% for both propranolol and atenolol in hospital wastewater were demonstrated. Radicals of .Math.OH in degradation indicate a surface mechanism at inventive cathodes with correlated contributions of iron and copper. Copper and iron can be embedded in porous graphite electrode surface and catalyze the conversion of H.sub.2O.sub.2 to .Math.OH to enhance the degradation. Inventive cathodes can be stable catalytically after 20 or more cycles under neutral and acidic conditions.

Copper-boron-ferrite (CuBFe) composites may be prepared and immobilized on graphite electrodes in a silica-based sol-gel, e.g., from rice husks. Different bimetallic loading ratios can produce fast in-situ electrogeneration of reactive oxygen species, H.sub.2O.sub.2 and .Math.OH, e.g., via droplet flow-assisted heterogeneous electro-Fenton reactor system. Loading ratios of, e.g., 10 to 30 wt. % Fe.sup.3+ and 5 to 15% wt. Cu.sup.2+, can improve the catalytic activities towards pharmaceutical beta blockers (atenolol and propranolol) degradation in water. Degradation efficiencies of at least 99.9% for both propranolol and atenolol in hospital wastewater were demonstrated. Radicals of .Math.OH in degradation indicate a surface mechanism at inventive cathodes with correlated contributions of iron and copper. Copper and iron can be embedded in porous graphite electrode surface and catalyze the conversion of H.sub.2O.sub.2 to .Math.OH to enhance the degradation. Inventive cathodes can be stable catalytically after 20 or more cycles under neutral and acidic conditions.

Copperboronferrite (CuBFe) composites may be prepared and immobilized on graphite electrodes in a silica-based sol-gel, e.g., from rice husks. Different bimetallic loading ratios can produce fast in-situ electrogeneration of reactive oxygen species, H.sub.2O.sub.2 and .sup.OH, e.g., via droplet flow-assisted heterogeneous electro-Fenton reactor system. Loading ratios of, e.g., 10 to 30 wt. % Fe.sup.3+ and 5 to 15% wt. Cu.sup.2+, can improve the catalytic activities towards pharmaceutical beta blockers (atenolol and propranolol) degradation in water. Degradation efficiencies of at least 99.9% for both propranolol and atenolol in hospital wastewater were demonstrated. Radicals of .sup.OH in degradation indicate a surface mechanism at inventive cathodes with correlated contributions of iron and copper. Copper and iron can be embedded in porous graphite electrode surface and catalyze the conversion of H.sub.2O.sub.2 to .sup.OH to enhance the degradation. Inventive cathodes can be stable catalytically after 20 or more cycles under neutral and acidic conditions.

The invention relates to a method for treating wastewater in an activated sludge process, which comprises a biological treatment step followed by a sedimentation step for separation of sludge and treated effluent water. The method comprises directing a part of the treated effluent water as a backflow from the sedimentation step to the biological treatment step, the backflow having an original pH value; adjusting the backflow pH from the original pH value to a first pH value between the sedimentation step and the biological treatment step, and adding a coagulant and/or an oxidant to the backflow after the adjustment of the backflow pH to the first pH value and before backflow's entry to the biological treatment step.

A modular versatile physicochemical water treatment system and method are provided for treating various water types. The system features an acceleration chamber module combining a static mixer for hydrodynamic cavitation, an ultrasonic transducer assembly (25-40 kHz) for acoustic cavitation, permanent magnets for a static magnetic field, and a magnetic field generating coil for variable multipole magnetic fields, including square and/or triangular waveforms, controlled by a central control unit. Optional modules include a chemical dosing module (Fe.sup.3+/H.sub.2O.sub.2 or O.sub.3/H.sub.2O.sub.2) and an electrolysis module with automatic polarity reversal. The method involves selectively and coordinately applying these effects, tailored to the water type, to achieve optimal treatment efficiency.

Copper-boron-ferrite (CuBFe) composites may be prepared and immobilized on graphite electrodes in a silica-based sol-gel, e.g., from rice husks. Different bimetallic loading ratios can produce fast in-situ electrogeneration of reactive oxygen species, H.sub.2O.sub.2 and .Math.OH, e.g., via droplet flow-assisted heterogeneous electro-Fenton reactor system. Loading ratios of, e.g., 10 to 30 wt. % Fe.sup.3+ and 5 to 15% wt. Cu.sup.2+, can improve the catalytic activities towards pharmaceutical beta blockers (atenolol and propranolol) degradation in water. Degradation efficiencies of at least 99.9% for both propranolol and atenolol in hospital wastewater were demonstrated. Radicals of .Math.OH in degradation indicate a surface mechanism at inventive cathodes with correlated contributions of iron and copper. Copper and iron can be embedded in porous graphite electrode surface and catalyze the conversion of H.sub.2O.sub.2 to .Math.OH to enhance the degradation. Inventive cathodes can be stable catalytically after 20 or more cycles under neutral and acidic conditions.

A method of removing chemical contaminants from a composition comprising an active, a solvent, and a contaminant can include providing an initial feed supply, wherein the initial feed supply comprises the active, the solvent, and the contaminant, wherein the contaminant can include 1,4 dioxane, dimethyl dioxane, or a combination thereof; including filtering the initial feed stock through a nanofilter.

Copper-boron-ferrite (CuBFe) composites may be prepared and immobilized on graphite electrodes in a silica-based sol-gel, e.g., from rice husks. Different bimetallic loading ratios can produce fast in-situ electrogeneration of reactive oxygen species, H.sub.2O.sub.2 and .Math.OH, e.g., via droplet flow-assisted heterogeneous electro-Fenton reactor system. Loading ratios of, e.g., 10 to 30 wt. % Fe.sup.3+ and 5 to 15% wt. Cu.sup.2+, can improve the catalytic activities towards pharmaceutical beta blockers (atenolol and propranolol) degradation in water. Degradation efficiencies of at least 99.9% for both propranolol and atenolol in hospital wastewater were demonstrated. Radicals of .Math.OH in degradation indicate a surface mechanism at inventive cathodes with correlated contributions of iron and copper. Copper and iron can be embedded in porous graphite electrode surface and catalyze the conversion of H.sub.2O.sub.2 to .Math.OH to enhance the degradation. Inventive cathodes can be stable catalytically after 20 or more cycles under neutral and acidic conditions.

Disclosed is a device for selective oxidation of macromolecular organic pollutants using free radicals produced in a heterogeneous Fenton reaction. The device includes a heterogeneous Fenton reaction unit and an electrochemical cell. The heterogeneous Fenton reaction unit includes a reactor and an anion exchange membrane. The anion exchange membrane is disposed in the reactor and separates the reactor into a first chamber and a second chamber. The first chamber is filled with a catalyst and the wastewater to be treated; and the second chamber is filled with a dielectric material. The electrochemical cell is configured to supply an electric field to the reactor, so that organic acids generated by a heterogeneous Fenton reaction move from the first chamber into the second chamber.