An underground mining method for unexploited coal in a boundary open-pit mine is provided. A shaft construction platform is arranged at one rock step to two rock steps above a coal seam. Intermediate bridges are built starting from a pit bottom. Mining area clay is laid on a working slope where no intermediate bridge is built and on a side slope with an outcrop of the coal seam as a sealing layer to seal the slopes. Auxiliary vertical shafts and main inclined shafts are dug. The pit bottom is dug downward to form a digging space on a side close to the working slope between two adjacent ones of the intermediate bridges, and clay is filled into the digging space to form an artificial water barrier layer. A roadway communicating the main inclined shafts and the auxiliary vertical shafts is constructed, and a coal seam stope face is arranged.

Managed ecosystems, methods for producing managed ecosystems and methods for using managed ecosystems for sequestering carbon dioxide are described herein. Produced water is obtained and purified to sustain a managed ecosystem with saline-tolerant vegetation. The managed ecosystem biologically sequesters carbon dioxide by photosynthetically absorbing carbon dioxide from the atmosphere and by decomposition into a layer of sediment on the ecosystem floor.

A process includes supplying a waste completion fluid including a viscosifier polymer; and treating the waste completion fluid with a non-oxidizing inorganic acid to form a metal bromide brine. The process also includes coagulating the viscosifier polymer and collecting the viscosifier polymer.

A method for determining a water treatment plan for produced water includes receiving sample water analysis for the produced water, and receiving one or more key performance indicators (KPIs) that each indicate a selected treatment result for the produced water. In addition, the method includes providing the sample water analysis and the KPIs to a machine learning model and determining a water treatment plan for the produced water using the machine learning model, wherein the water treatment plan comprises one or more additives for the produced water that are to provide the produced water with the KPIs.

A wastewater processing method includes introducing wastewater into an upper region of a chamber. The chamber remains at substantially atmospheric pressure. A portion of the wastewater in the chamber is vaporized. Flame is introduced into the chamber and provides for the ignition of a volatile organic compound. The vaporized portion of the wastewater is vented to the atmosphere.

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.

The present embodiments generally relate to the use of one or more polymers, e.g., one or more dry acid polymers and/or one or more dry acid polymers with salt, as flocculants, generally for treating tailings, e.g., oil sands tailings, in need of solid-liquid separation, e.g., in order to efficiently recycle water and/or to reduce the volume of tailings which may be transferred to a tailings pond and/or a dedicated disposal area.

Compositions and methods are provided for use in controlling souring and corrosion causing prokaryotes, such as SRP, by treating oil and gas field environments or treatment fluids with a newly identified bacterial strain ATCC Accession No. PTA-124262 as a self-propagating whole cell that produces an anti-SRP bacteriocin in situ. In another aspect, the methods use one or more toxic peptides or proteins isolated therefrom in methods to control unwanted prokaryotic growth in these environments.

A process of treating nano-filtration membrane retentate comprises introducing seawater comprising a sulfate ion concentration of greater than or equal to 3000 mg/l to the NF membrane to produce a retentate stream and a permeate stream, wherein the retentate stream has a sulfate ion concentration greater than or equal to 10,000 mg/l, and mixing barium additives comprising barium chloride dehydrate (BaCl.sub.2.2H.sub.2O), barium chloride (BaCl.sub.2), or both with the retentate stream to precipitate sulfate from the retentate stream to form barite (BaSO.sub.4) and reduce the sulfate ion concentration, wherein the barium additives are added into the retentate stream at a barium ion concentration of greater than 10,000 mg/l.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.