The present disclosure relates to processes for treating wastewater such as acid rock drainage. The processes may, for example, comprise subjecting the wastewater to a microbial fuel cell process, neutralizing the acid with a base comprising calcium to produce an aqueous composition comprising calcium ions and subjecting the aqueous composition comprising calcium ions to a biological precipitation process to precipitate the calcium ions as calcium carbonate.

A water purification apparatus includes a water intake configured to receive water to the water purification apparatus, a filter part including a plurality of filters configured to filter the water and generate purified water, a water outlet including a plurality of water outlet ports configured to discharge the purified water, and one or more pipes that define a water purification path configured to guide the water from the water intake through at least one of the plurality of filters to thereby provide the purified water to at least one of the plurality of water outlet ports.

Described herein is a functional graphene composition comprising a graphene scaffold and one or more metal chelating functional groups covalently bonded to the graphene scaffold and a porous substrate that includes the functional graphene composition. Also provided is a method of removing dissolved metals from an aqueous liquid, such as, acid mine drainage.

In order to solve the problem in the existing conventional water treatment process of low removal efficiency of heavy metal in water, especially lower efficiency for simultaneous removal of heavy metal pollutants during coexisting, a method is provided for removing heavy metal pollutants in water with divalent manganese strengthened ferrate: preparing a ferrate mother liquor having the concentration of 20-10,000 mmol/L; preparing a divalent manganese salt mother liquor having the concentration of 30-10,000 mmol/L; adding the divalent manganese salt mother liquor into water of the heavy metal pollutants; then adding the ferrate mother liquor, and reacting; and then adding a flocculant and precipitating, so that the removal rate of arsenate, chromium, thallium, antimony, chromium and molybdate in water is 90% or more, and the removal rate of heavy metal such as lead and cadmium is 85% or more.

A method and system of removing environmental contaminants from water comprising adding a fatty chemical to form a mixture with the water in which the fatty chemical and the environmental contaminants complex to form molecular complexes. The mixture is then filtered to remove the molecular complexes from the water.

A recycling system includes a reaction kettle, a stirring device, and an electromagnetic device. The reaction kettle is provided with a liquid inlet, a gas inlet, a liquid outlet, and a slag discharge port. The stirring device is arranged on the reaction kettle. The stirring device includes a stirring rod and at least one stirring paddle. One end of the stirring rod extends into the reaction kettle, and the at least one stirring paddle is arranged on the end of the stirring rod. The electromagnetic device includes a first electromagnetic coil, and the first electromagnetic coil is wound on an outer circumferential surface of the reaction kettle. The arrangement of the stirring device allows the geothermal water to fully contact with the gas, which is conducive for the suspension of the ferroferric oxide in the geothermal water.

Formation of CaSO.sub.4 and Fe.sub.2O.sub.3 containing deposits is reduced in a pressure oxidation autoclave and/or adjacent circuits during pressure oxidation of gold-containing ore. The gold-containing ore is combined with water to create an aqueous slurry that is heated and introduced into the autoclave. The method includes providing a scale inhibitor that is free of an organic polymer and includes an inorganic phosphate according to formula (I), (XPO.sub.3).sub.m, wherein X is Na, K, H, or combinations thereof, and m is at least about 6, an inorganic phosphate according to formula (II), Y.sub.n+2P.sub.nO.sub.3n+1, wherein Y is Na, K, H, an organic phosphonate; or combinations thereof, and n is at least about 6. The method includes the step of combining the scale inhibitor and at least one of the gold-containing ore, the water, and the aqueous slurry to reduce scale.

A combined water aeration and filtration unit (WAFU), having a tank with a vent section at a top of said WAFU and above an aeration section above a filtration section at a bottom of said WAFU. The vent section has one or more demisters and one or more vents for detraining water and providing a dry air exit from said WAFU. The air section has a water inlet ending in a spray nozzle near the top of the aeration section to turn incoming dirty water into water droplets and a forced air blower on a side or top of the aeration section for blowing air through said water droplets in rate sufficient to remove volatile organic compounds and precipitate manganese and iron. The aeration section also has one or more annular rings or partially annular baffles on an inside wall of the tank to force water from said inside wall into an interior of the tank. Thus, no water escapes aeration. A backwash collection trough and backwash water outlet are positioned above the filtration section for removing dirty backwash water from the unit. The filtration section has one or more filters therein and a drain and clean water outlet near its bottom for egress of clean water from said WAFU.

The disclosure relates to devices and systems for configurable, contaminant-specific water filtration and treatment under pressure. In particular, the disclosure relates to a contaminant-specific configurable and modular water filter and a water filtration system maintained under positive or negative pressure, comprising modular housings, each housing defining a plurality of reconfigurable compartments operable to accommodate contaminant-specific filtering units in an order configured to minimize pressure drop along the flow direction of the water.

A method of rapid treatment of heavy metal sludge and preparation of ferrite magnets comprises following steps of: providing a sludge, the sludge at least having zinc metal and ferrous metal; adding an iron-containing substance to the sludge; pickling the sludge and the iron-containing substance with sulfuric acid to obtain a pickling solution with zinc ions and iron ions; neutralizing the pickling solution with sodium hydroxide to form hydroxide precipitates; and airing and heating the neutralized pickling solution by an ultrasonic-microwave method so that the hydroxide precipitates undergoing a ferrite magnet reaction, thereby obtaining ferrite magnets with a spathic structure.