The invention discloses an automatic sewage treatment system and a preparation method of biological carrier, comprising an automatic sewage treatment device and a biological carrier, wherein the automatic sewage treatment device comprises a housing; one side of the housing is provided with a sewage inlet, and the other side thereof is provided with a sewage outlet; the sewage inlet is installed on one side of a No. 1 biochemical pool; one side of the No. 1 biochemical pool is connected to a No. 2 biochemical pool through a connecting pipe; the other side of the No. 2 biochemical pool is connected to a No. 3 biochemical pool through the connecting pipe. The preparation method of biological carrier includes material selection, preservation, physical treatment, and cultivation.

Process for upgrading effluent treatment plants for pulp and paper production processes, where salts are removed from the effluent for water reuse and chemical recovery. The process comprises a first dialysis system for salt removal, a second treatment system for recovery or re-concentration, and optionally a post-treatment of the re-concentrate preventing liquid discharges to the environment. In the first system, a reversible electrodialysis or reversible pulsed step is carried out, separating the salts from the effluent, which are sent to the second treatment system to concentrate the salts (re-concentrate) or transform them into useful chemicals for the same process (recovery). Chemical recovery is achieved by electrodialysis with bipolar membranes or metathesis, to reduce the re-concentrate stream, which cannot be reused in the same plant. Lastly, this stream may be treated by spray drying, crystallization or evaporation.

The present invention relates to a membrane separation system including a plurality of separation membrane elements connected to one another, each of the separation membrane elements including a plurality of separation membrane pairs, each separation membrane pair including separation membranes each having a feed-side surface and a permeate-side surface and disposed such that the feed-side surfaces face each other, in which the plurality of separation membrane elements include a first separation membrane element and a second separation membrane element, and at least one first separation membrane element serves as a stage preceding the second separation membrane element.

The present inventors have developed systems and processes for reducing the overall carbon consumption needed for the generation of low COD treated water. In certain aspects, the systems and processes described herein include an oxidation stage (e.g., one that utilizes ozone, hydrogen peroxide, ultraviolet, or a combination thereof for oxidation) between a first activated carbon stage and a second activated carbon stage to reduce a total carbon consumption within the associated system or process.

Methods and systems for calcining dewatered tailings and/or mine waste are disclosed herein. In some embodiments, the method comprises (i) processing dewatered tailings comprising clay minerals, (ii) calcining the processed tailings to produced calcined tailings, and (iii) altering a composition and/or one or more characteristics of the calcined tailings to produce a cementitious product. Altering the composition can include blending the calcined tailings with one or more additives, such as lime, dolomitic lime, lime kiln dust, argillaceous limestone, limestone, pulverized quicklime, ground calcium carbonate, quicklime, gypsum, natural pozzolans, artificial pozzolans, water, flow aids, or the like.

An apparatus for the treatment of acid mine drainage and selective recovery of at least one of metals, critical elements, sulphuric acid and water is disclosed. The apparatus includes at least one electrochemical reactor, at least one catholyte reservoir and at least one anolyte reservoir for containing the acid mine drainage and a buffer, respectively. The reservoirs are in fluid communication with the at least one electrochemical reactor. The apparatus also includes at least one sensor for monitoring a pH of a contents of the reactor; and a power source for supplying an electrical current to the at least one electrochemical reactor. The electrical current is supplied until a predetermined pH is reached for the selective recovery of the at least one of metals, critical elements, sulphuric acid and water. A process for the treatment of acid mine drainage is also disclosed.

A method of processing pulp, extracted from red mud in processing bauxite, includes the following steps. The pulp is filtered to obtain a first filter cake and a first filtrate. Aluminum is leached from the first filter cake by adding, to the first filter cake, sodium hydroxide (NaOH) solution to form an aluminum-containing first slurry. The first slurry is filtered to obtain an aluminum-containing second filter cake and a second filtrate. From the second filtrate, in presence of carbon dioxide gas, first aluminum compounds are filtered out. Aluminum is leached out from the second filter cake by adding, to the second filter cake, NaOH solution to form a second slurry. The second slurry is filtered to obtain a third filter cake and an aluminum-containing third filtrate. From the third filtrate, second aluminum compounds are precipitated out which include sodium hydroaluminocarbonate and aluminum hydroxide.

An apparatus for removing a layer of sediment which has settled on the bottom of a large water body that includes a structural frame configured to contain a bottom water flow and avoid a re-suspension of sediment outside the vicinity of the structural frame. The structural frame has a control zone configured for containing liquid and suspended particles dispersed during removal of bottom sediment in a suctioning area that is at least about 3 square feet. A sediment removing vacuum unit is operably associated with the structural frame to conduct a suctioned bottom water flow.

The invention is in the field of organic sludge digestion from various sources, such as manure, sludge from a wastewater treatment plant, and an organic fraction of dredging sludge. The present method provides advanced control for serially treating aqueous organic sludge by anaerobic digestion. It further relates to dewatering of the obtained biomass.

A pure-water production device including: a first reverse osmosis membrane device to which water to be treated is supplied; a second reverse osmosis membrane device to which permeated water from the first reverse osmosis membrane device is supplied; an electrodeionization device to which permeated water from the second reverse osmosis membrane device is supplied; a brine tank to which concentrated water from the first reverse osmosis membrane device is supplied; and a third reverse osmosis membrane device connected to the brine tank, wherein the second reverse osmosis membrane device is a high-pressure reverse osmosis membrane device, the brine tank is supplied with at least one concentrated water selected from the group consisting of concentrated water from the second reverse osmosis membrane device and concentrated water from the electrodeionization device, wherein permeated water from the third reverse osmosis membrane device is supplied to water to be treated, is used.