The present invention provides a method of reducing and controlling a hazardous substance in a process of high-value biological conversion of an urban organic waste. The method includes: 1) mixing a sludge, a first urban organic waste and an organic acid with water for acclimation to obtain an acclimatized sludge; 2) stage 1 of biological conversion: mixing the acclimatized sludge with a second urban organic waste to perform anaerobic culture; 3) stage 2 of biological conversion: adding nitrate and bacteria to continue anaerobic culture so as to obtain an organic acid. In the present invention, sludge microbes are acclimatized and then added to high-value chemicals such as acetic acid, propanoic acid and lactic acid prepared in biological conversion of the urban organic waste and then added with bacteria. Thus, by controlling pH value, microbe addition amount and nitrate concentration, the unfavorable effect of the antibiotics and heavy metal ions.

The invention relates to the use of polymer powder compositions that can be redispersed in water and have cationic functionality, as flocculation aid, for example for dewatering waters or waste waters that are laden with solids.

A process for producing a polyaluminum chlorosulfate (PACS) includes adding an aluminum hydroxychloride (AHC) solution having about 38-43% basicity with (1) aqueous aluminum sulfate to form a solution and mixing a solid AHC with the solution to form an aqueous milky suspension or (2) a solid AHC and solid aluminum sulfate and adding water to the solid mixture to form an aqueous milky suspension, and maintaining the milky suspension for a period sufficient to allow the milky suspension to form a clear to slightly turbid solution including the PACS, the PACS having a basicity of 55 to 75%, the average molecular weight of the PACS is greater than or equal to 95 and less than or equal to 111, and salts present in the PACS comprise 0-1.0% sodium chloride by weight and 0-1.0% sodium sulfate by weight.

The invention discloses a fast biofilm formation method for an organic filler during treatment of sewage with a low C/N ratio, and belongs to the field of biofilm process for sewage treatment. The invention improves the effect of biofilm culturing by changing the micro-interface acting force of the filler and accelerating the attachment and colonization of microorganisms on the filler through increase of bacterial quorum-sensing molecules. As compared with a conventional biofilm culturing method, in the invention the biofilm culturing is rapid and operated conveniently, has strong practicality, and is a fast biofilm formation method for an organic filler, which is adapted for treatment of sewage with a low C/N ratio under an aerobic, anoxic or anaerobic condition.

Compounds and clay composites comprising same having sorbent properties are disclosed. Articles incorporating such composites are also disclosed. Further disclosed are articles comprising said composites and methods of using same for treating organic waste.

A method is disclosed for purifying, by direct osmosis, a first liquid including water and at least one impurity, in which the method comprises the consecutive steps of: contacting the first liquid with a first side of a semi-permeable membrane, a second aqueous liquid containing an osmotic agent being in contact with the second side of the semi-permeable membrane, whereby water is extracted by direct osmosis from the first liquid through the semi-permeable membrane and passes into the second liquid containing the osmotic agent; forming clathrates hydrates of a host molecule in the second liquid containing the osmotic agent into which the water has passed; separating the clathrates hydrates from the second liquid containing the osmotic agent; and dissociating the separated clathrates hydrates to obtain pure water and the host molecule.

[Problem] The purpose of the present invention is to provide a polyamide hollow fiber membrane having such properties that the transmission of fine particles through the membrane can be prevented effectively, the membrane has an excellent water transmissibility, the entire surface of the membrane has excellent hydrophilicity, and impurities such as metal elements are rarely eluted through the membrane. [Solution] A polyamide hollow fiber membrane produced by a TIPS method under specific production conditions has the following characteristic properties: (1) the contact angle of water on the surface of the membrane is 80? or less; (2) the external pressure water transmissibility of the membrane is 50 L/(m.sup.2.Math.atm.Math.h) or more; and (3) the 50 nm-particles blocking ratio of the membrane is 90% or more.

A three-dimensional photo/electrodialysis unit includes four compartments. A first compartment holds a three-dimensional electrode and a group of one or more electrochemically active redox species. A first electroactive cation selective membrane couples the first compartment to a second compartment that provides a first feedstock. An electroactive anion selective membrane couples the second compartment to a third compartment that provides a second feedstock. And a second electroactive cation selective membrane couples the third compartment to a fourth compartment that holds a second group of one or more electrochemically active redox species.

Polyvinyl alcohol (PVA) gel and polyurethane (PU)ZPVA gel and gel beads, methods for making gel and gel beads with immobilized substances such as microorganisms, cells, enzymes, and/or other materials, methods for using gel and gel beads in various applications (e.g., wastewater treatment), and apparatus for manufacturing such gel and gel beads, are described.

Method for treating water for the purpose of reducing the content of organic matter, of micropollutants and of pathogenic agents therein, comprising the supplying of water to be treated directly into a membrane reactor containing at least one filtration membrane and an adsorbent material, stirring the mixture of water and adsorbent, and extracting treated water, characterised in that the adsorbent material consists of micrograins of activated carbon having a real density of at least 0.45, a settling velocity of 30 to 50 m/H, a specific surface area of 400 to 2500 m.sup.2/g, and an average particle size of between 600 and 1300 m, less than 5% by volume of said grains having a size of less than 400 m, in that the concentration of said activated carbon micrograins in said membrane reactor is maintained between 5 and 100 g/L, and in that no other granular or particulate material other than the activated carbon micrograins is used in said reactor, the stirring of said mixture of water and activated carbon micrograins in the membrane reactor being at least partially carried out by air injection into said mixture at a rate of 30 to 60 Nm.sup.3/m.sup.2.Math.H and being sufficiently vigorous to avoid the deposit of activated carbon micrograins on said at least one filtration membrane