The present invention relates to a process for the controlling the sodium and sulfur levels in a pulp mill, comprising the steps of: a) providing a pulp mill stream comprising sulfide and having a total alkali concentration of at least 2 Molar; b) supplying a portion of the pulp mill stream to a reactor comprising sulfide oxidizing bacteria and removing sulfide from the pulp mill stream by subjecting said stream to sulfide oxidizing bacteria in the presence of oxygen, and at a pH in the range 8 to 11, to oxidize the sulfide to elemental sulfur, c) withdrawing from the reactor a treated pulp mill stream comprising sulfur, wherein the portion of the pulp mill stream is mixed with a portion of the sulfide oxidizing bacteria present in the reactor prior to supplying the pulp mill stream to the reactor in step b).

The present disclosure relates to a filter material which can be used in reducing the content of contaminants in a raw gas or liquid and a device which comprises the filter material. The disclosure also relates to a method for reducing the content of contaminants in a raw gas or liquid which applies the filter material and/or device.

The present invention provides for a genetically modified host cell or bacterium capable of producing an organic molecule, wherein the bacterium is capable of using hydrogen sulfide as an electron donor, carbon dioxide (CO.sub.2) as a carbon source, and/or nitrate as an electron acceptor. The present invention is useful in the wastewater treatment industry, in particular in municipal wastewater treatment plants (WWTP).

A method includes preparing a natural seashell, calcining the seashell at a high temperature to clear organic substances from the seashell, processing and reacting the seashell at a high temperature, grinding and screening the seashell, and mixing the ground seashell with microorganism strains to form a water deodorizer. The water deodorizer includes a powder having a porous structure, and multiple microorganism strains mixed with the powder. The powder has an interior provided with a plurality of pores. The powder is made of a natural seashell which is processed at a high temperature, and is ground and screened to form the porous structure. The microorganism strains are filled in the pores of the powder and cover outer surfaces of the pores of the powder. The powder has a diameter of 0.4-10 m.

Disclosed are a method and a device for treating high ammonia-nitrogen wastewater using a microbial electrolysis cell (MEC) assisted SANI system, including an SANI system, an MEC and a power supply. The cathode chamber and anode chamber of the MEC are separated by a separator and are respectively connected to the cathode and anode of the power supply, and a cathode electrode is enriched with hydrogen autotrophic denitrifying bacteria. The cathode chamber has two main functions. Firstly, a higher denitrification efficiency is achieved due to the enriched hydrogen autotrophic denitrifying bacteria; and secondly, the alkalinity produced in the cathode can adjust the pH of the nitrification chamber. In addition, the cathode chamber can oxidize the residual sulfide in the effluent to meet the discharge standard. This system retains the advantage of less sludge in a SANI process, but also can be applied to the treatment of wastewater with high ammonia-nitrogen.

A sulphur denitrification system includes a liquid input fluidly coupled to a source of saltwater that includes nitrate; a liquid output fluidly coupled to the source of saltwater; a plurality of vertically-oriented tanks, at least one of the tanks including a liquid inlet that is fluidly coupled to the liquid input to receive a flow of the saltwater, a volume configured to enclose a plurality of sulphur particles that support denitrification bacteria that biologically transform the nitrate into at least one of nitrous oxide or nitrogen gas, and a liquid outlet fluidly coupled to the liquid output and the liquid inlets of the tanks; and a circulation system configured to circulate a portion of the saltwater though the liquid input to the liquid inlets of the plurality of tanks, through the plurality of tanks, and from the liquid outlets of the tanks to the liquid output and the liquid inlets of the tanks.

In some embodiments, the invention provides a method for converting of a flue gas desulfurization (FGD) waste product to a gypsum-enriched product by fostering growth of sulfur oxidizing bacteria (SOB) in the FGD waste product. Also provided are isolated sulfur oxidizing bacteria cultures as well as kits comprising an isolated sulfur oxidizing bacteria culture and written instructions for fostering the growth of the isolated sulfur oxidizing bacteria culture in FGD waste product to product a gypsum-enriched product.

An advanced nitrogen removal method using partial nitrification-denitrification coupled two-stage autotrophic denitrification. Sewage is introduced into a first pool for partial nitrification-denitrification treatment, and then introduced into a first regulating reservoir. Dissolved oxygen content in the first pool is kept at 0.4-0.6 mg/L. Water is discharged when a molar ratio of nitrite nitrogen to ammonia nitrogen in the first regulating reservoir is 1.0-1.3:1. Effluent in the regulating reservoir is introduced into a second pool for anaerobic ammonia oxidation treatment, and then introduced into a second regulating reservoir. In the second pool, pH is 7.0-7.4, a temperature is 22-28 C. Effluent in the second regulating reservoir and sulfides are introduced into a third pool for denitrification treatment. Water is discharged. In the third pool, pH is 7.5-8.0, a temperature is 28-32 C., a mass ratio of sulfur to nitrogen is 1.9-2.0:1.

The present invention relates to a bio-assisted treatment of wastewater containing sulphide, phenols and hydrocarbons. Further, the present invention relates to a process for eliminating sulphide and other sulphur compounds including, but not limited to, mercaptans, disulfides, PAHs, phenols and hydrocarbons.

A continuous flow granular/flocculent sludge wastewater process selects for granule biomass capable of nitrogen and phosphorus removal and controls granule size and concentration of granular and flocculent sludge for optimal nutrient, organic, and solids removal in a smaller footprint. It includes anaerobic, anoxic, and aerobic process zones, a high soluble biodegradable COD loaded first reactor in anaerobic or anoxic zones, a granular sludge classifier with recycle of underflow granular sludge to the first reactor, a secondary clarifier to settle flocculent sludge and particulates and recycle of flocculent sludge from the secondary clarifier underflow to an aerobic process zone. Wasting of sludge from the two separate recycle lines controls the bioprocess flocculent and granular sludge concentrations and SRTs. Bypass around and recycle flow to the classifier to maintain desired flow under various influent flow conditions aid control of granule size. On/off mixer operation of anaerobic and anoxic reactors may be used.