The present disclosure provides an in-situ method for removing sulfates. The method comprises delivering at least one low molecular weight organic compound (LMWOC) to soil or groundwater to attain a concentration of the LMWOC of 750-3000 mg/L, such as 1000-2000 mg/L, or about 1500 mg/L, especially whereby sulfate is reduced to below 250 mg/L in the soil or groundwater. The method may further comprise contacting the soil or groundwater with an oxidizer, such as hydrogen peroxide, whereby the concentration of metals or metalloids is reduced in the soil or groundwater.

A system and method for generating base water and precipitate, including combining produced water with seawater to precipitate barium sulfate from barium in the produced water and from sulfate in the seawater, and separating the precipitate to give the base water and the precipitate. The base water may have less than a specified amount of sulfate and be utilized for hydraulic fracturing fluid. The precipitate may give a weighting agent for drilling.

Methods are provided for treating intimately dispersed mixtures of water, bitumen, and fine clay particles, such as oil sands mature fine tailings (MFT). Select methods use dissolved silicate ions and a base (alkali), optionally in combination with a biopolymer, to flocculate a slurry. A mixing regime is disclosed involving the addition to MFT of silicate ions in solution and alkali, to initiate aggregation/destabilization of clay particles. Methods are exemplified that provide distinct sediment layers in conjunction with the release of residual bitumen (for example 40-50% of the initial bitumen content). In these exemplified embodiments, a densely packed bottom layer containing ˜75 wt. % solids showed high yield stress values (3.5-5.5 kPa) and entrapped little residual bitumen (0.2-0.3 wt. %). The methods accordingly segregate a material suitable for reclamation.

A system for reducing contaminants in body of water is shown and described. The system has a first land mass located within a body of water. A sediment trap, located on the floor of the body of water, is configured to collect sediment. Enclosed within the first land mass is a tussock mass area, surrounding a central area, and configured for collecting sediment and building a second land mass. The central area of the system is configured for removing contaminants from sediment. Sediment is moved from the sediment trap to the central area by a first ingress conduit and a pumping system. Filtered water migrates from the central area to outside the first land mass via an egress conduit; contaminated sediment is sequestered in the central area enclosed by the tussock mass area.

A water purification apparatus and a water purification method capable of effectively using a layered double hydroxide and easily being applied are described. A water purification apparatus for removing a polluted substance from polluted water includes a solid-liquid separator that separates the polluted water and a solid material from each other, and a polluted substance remover that removes, by a layered double hydroxide, the polluted substance contained in the polluted water separated by the solid-liquid separator.

The invention provides a dynamic membrane reactor with function of nitrogen and phosphorus removal and an operation method thereof, and comprises a biological treatment system, a dynamic membrane loading system and an automatic system. The operation method comprises the following steps. (1) Before the formation of dynamic membrane, a porous filter for phosphorus removal is used as a cathode, a conductive precision filter screen is used as an anode, and aerobic denitrifying bacteria are inoculated into the dynamic membrane reactor under certain constant current density, hydraulic retention time and flux. (2) After the dynamic membrane is formed, the porous filter for phosphorus removal is used as the anode, the conductive precision filter screen is used as the cathode. And intermittent aeration is started at the anode under certain constant current density. (3) When the transmembrane pressure difference exceeds a certain range, hydraulic backwashing is performed under certain constant current density.

Various embodiments relate to denitrification of water using bacteria. A method of denitrification of water includes deoxygenated water including a water-soluble form of nitrogen. The method includes exposing the deoxygenated water to denitrifying bacteria to convert the water-soluble form of nitrogen in the water to nitrogen gas that is removed and to form a denitrified water. The method also includes reoxygenating the denitrified water. Denitrifying bacterial substrates and methods of making the same are also provided.

An activated sludge process for the treatment of municipal wastewater, particularly applicable to oxidation ditch activated sludge treatment systems which utilize a conventional race track or continuous loop reactor basin configuration. The process removes phosphorus and nitrogen from an activated sludge wastewater treatment system, with an anoxic cycle followed by an aerobic cycle, and followed by a surface wasting cycle until a low flow diurnal period is reached in a diurnal or twenty-four hour period. Automated microprocessor control system using “oxidation-reduction potential” (ORP) and “dissolved oxygen” (DO) as process variable inputs automate aerated and anoxic cycles to optimize phosphorus and nitrogen removal using the available carbon in the influent wastewater resulting in an energy efficient dynamic dissolved oxygen control during the aerated periods.

Metal carbon and oxide nanocomposites prepared by a simple, low energy demanding, and high yield method are provided. The metal carbon nanocomposites can be prepared with or without a support such as silica, graphite, silicates, and zeolites. Both metal carbon and metal oxides nanocomposites are more efficient in catalytic reduction and oxidation of p-nitrophenol and azo dyes than other reported materials. They have high rate constants, number of catalytic cycles and catalytic turn over number (TON) compared to currently used materials.

The present disclosure provides for methods and systems for separating ultrafine particulate pollutants from aqueous suspensions. The present disclosure provide for methods and systems that can reduce the amount of ultrafine particulate pollutants from aqueous solutions, for example storm water runoff, which are not readily or easily removed using current state of the art techniques. In general, methods of the present disclosure provide for removing a portion of target ultrafine particulate pollutants using magnetic nanoparticles, which form aggregates with the ultrafine particulate pollutants. After a time period a magnetic field is applied and the aggregate can be separated from the aqueous suspension. Subsequently, the aggregates can be broken down and the magnetic nanoparticles recycled or reused while the ultrafine particulate contaminants are further processed, recycled, or disposed of.