Abstract: A process for the removal of heavy metal ions from water and means for efting such removal. The process is based on the growth of the water fern Azolla in solutions of water which contain such ions. Heavy metal ions can be efficiently removed from aqueous solutions by passing these through biomass of Azolla in comminuted form. Such columns also are part of the present invention.

Abstract: This invention is directed to a method for controlling the formation of scale deposits in aqueous systems operated at high pH and/or calcite saturation levels by adding an effective amount, preferably at least 0.1 ppm, of an allyl sulfonate/maleic anhydride polymer to the aqueous system being treated.

Abstract: The present invention relates to a process for the improved separation of clarified liquids from biomass or rather for the separation of clarified sludges in the (aerobic and/or anaerobic) biological treatment of sewage using magnetically separable materials as carrier masses. The carrier masses are organic materials containing magnetically separable inorganic materials incorporated in abrasion-resistant form. These magnetically separable carriers occupy a suspension volume of from 1 to 85% by volume, based on the clarified liquid.The carriers contain magnetically separable inorganic materials incorporated as fillers in organic polymeric materials, particularly in cellular polymeric carriers. Other organic or inorganic fillers may also be used in these organic carriers. The magnetically separable materials used are oxides or mixed oxides of heavy metals, preferably iron oxides, such as Fe.sub.3 O.sub.4 (magnetite) and .gamma.-Fe.sub.2 O.sub.3, which are used in average particle sizes of less than 50 .mu.

Abstract: Apparatus is provided for dewatering an aqueous clay suspension by a process which includes preparing a partly dewatered filter cake and concurrently compressing the partly dewatered filter cake on a filtration drum while applying vacuum suction to it from inside the drum, and then removing the dewatered cake from the filter. The process also purifies the filter cake. An apparatus suitable for carrying out the process comprises a rotary vacuum filter, means for compressing the clay filter cake on the filter medium and means for applying vacuum filtration to the same portion of the cake being compressed. The compression means may comprise a rotatable roll mounted for rolling compressive contact with the filter cake. The rotatable roll may have a non-stick bearing surface to which solids of the filter cake are substantially non-adherent. The rotatable roll may be a pneumatic roll designed to conform to the filter drum and increase the size of the contact zone between the filter drum and the compression roll.

Abstract: Waste water treatment for the removal of heavy metals is optimized by continuously removing and filtering a sample flow of treated waste water subject to pH level control to determine the presence of remaining metals in solution to be precipitated. Filtering of the sample removes metals precipitated by pH level control. Optimized pH level control can cause precipitation of most non-chelated and/or non-complexed metals, so that controlled feeding of a precipitating agent to the treated waste water is effectively determined by only those metals remaining in solution, which are typically either chelated and/or complexed heavy metals. The filtered sample is injected with a diluted solution of the precipitating agent, and then a turbidity meter is used to determine the degree of turbidity of the injected clear sample. The resulting degree of turbidity corresponds to the level of precipitation caused by injection of the diluted precipitating agent.

Abstract: A mobile tank for decontamination of waste or ground water contains multiple cells for biological treatment and clarification of the water. Systems are provided for aerating the treatment cells and for recycling activated bacteria from the clarifier cell to the primary treatment cell.

Abstract: The present invention relates to a high rate method for combining waste materials to produce valuable products for agricultural, horticultural, sylvicultural or public use. Specifically, the present invention combines the steps of alkaline stabilization, beneficiating and pelletizing waste materials, such as wastewater treatment plant sludge or animal excrement and reaction with carbon dioxide, to thereby convert the waste materials to useful products such as soil conditioners or fertilizer supplements.

Abstract: A process for clarifying liquors containing suspended solids is disclosed. The process is applicable to liquors having concentrations of suspended solids ranging from low to high, typically between 0.5 and 40 gm/l. The clarification process is characterized by the addition of flocculent and in excess of 50 gm/l inert particulate material so as to cause the formation of flocs comprising suspended solids and inert particulate material thereby to separate the suspended solids from the liquor. The inert particulate material is selected from silica sand, magnetite, limestone, ilmenite, hematite and calcite.

Abstract: The invention relates to a process for anaerobically degrading highly concentrated process waste waters as obtained particularly in the chemical industry, in paper mills and cellulose plants, fish-processing plants, and in the production and elimination of alcohol or the like, whereby the CSB-content may be up to 10.sup.6 mg/l or more. This process comprises a putrefactive process which is induced in at least one decomposition tank at about 34.degree. C. by circulating normal sewage sludge, whereby upon start-up of the putrefactive process, a change to chemical process waste waters is carried out without adding communal sewage sludge. Subsequently, the sludge is withdrawn from the decomposition tank, flocculated, and returned to the external circulation for circulating the putrefactive sludge in the decomposition tank.

Abstract: A method of enhancing the efficacy of anti-microbial chemical compounds in an aqueous medium comprising adding an anionic chemical species to the medium. The anion acts as a competing electron receptor of the terminal cellular reduction reaction. This results in a weakening of the microorganism leaving it more vulnerable to effective action by the anti-microbial chemical.

Abstract: An improved method for removing contaminants from industrial, municipal or food processing wastewater systems comprising generating amorphous precipitated magnesium silicate by separately adding aqueous solutions of magnesium chloride and sodium silicate.

Abstract: A method of separating a heavy metal ion from an aqueous solution containing the heavy metal ion, comprising the step of bringing a chitosan derived from a chitosan-producing microorganism into contact with said aqueous solution. The chitosan used, which can be produced by a simple process, has good heavy metal ion adsorptivity; this method can effectively separate heavy metal ion from a solution containing it.

Abstract: A method is for operating a boiler to heat a bioreactor with gases produced from the bioreactor, while supplying excessive hot water to outside of a system. In the method, the boiler is operated to turn on and off depending upon temperature of a hot water tank when a level of a gas holder is higher than an intermediate level H.sub.1. Hot water is unconditionally supplied to the outside of the system when the level of the gas holder is higher than a high level H.sub.2, and hot water is supplied to the outside when temperature of the hot water tank is higher than an intermediate temperature L.sub.1 and the level of the gas holder is between the high level H.sub.2 and the intermediate level H.sub.1. The supply of the hot water is stopped when the level of the gas holder is less than the intermediate level H.sub.1.

Abstract: A sewage treatment plant in which sewage is introduced into a tank or other suitable container, to form a mixed biomass and sewage liquid for treatment within the tank, by means of both fixed and suspended biomass. The fixed biomass attaches itself to a plurality of free draining media surfaces that are alternately exposed and submerged by the raising and lowering of liquid levels within the tank. The raising and lowering of the liquid surfaces is achieved by displacing liquid with pressurized air from an inverted box that also contains a plurality of media surfaces. The treated sewage overflows into a final zone which contains random media surfaces. Surplus sludge collecting in the final zone is fed back close to the inlet by gravity through a non-return valve.

Abstract: A hollow fiber membrane bioreactor process for continuous selective removal of organic toxicants or other oleophilic solutes present in an aqueous process stream wherein low concentration levels of said toxicant are removed from the aqueous process stream by being extracted and concentrated by the permeably selective hollow fiber membrane and then provided to a microorganism for metabolization into a water soluble metabolite. The water soluble metabolite is prevented from reentering the aqueous process stream and removed from the bioreactor in the aqueous nutrient effluent stream.

Abstract: This present invention relates to a method of dehydrating a wet sludge. The wet sludge which is subjected to a preliminary dehydration by gravity dehydration or the like, is pelletized by a pelletizer, and obtained pellets of the sludge are subjected to compression dehydration with a pair of endless filter fabrics.

Abstract: A packing element having a cylindrical outer cover (11) with at least one guiding surface (16, 20, 21) of holohedral construction and dividing the outer cover (11) into several subspaces (19). The outer cover (11) has web ribs (12), running in the longitudinal direction of the cover, and annular ribs (13), running perpendicularly to the web ribs, thus forming approximately square net openings (14).

Abstract: Municipal sanitary sewage sludge is disposed of by an improved partial oxidation process without polluting the environment. Aqueous slurries of sewage sludge are upgraded by hydrothermal treatment, preferably while being sheared, concentrated, and then mixed with a supplemental fuel, preferably coal. A pumpable aqueous slurry of sewage sludge-coal and/or petroleum coke is thereby produced having a greater total solids and heat content (HHV) as well as containing an increased amount of sewage sludge for reacting with free-oxygen containing gas in a free-flow partial oxidation gas generator. Hot quench water or steam produced by cooling the hot raw effluent stream of synthesis gas, reducing gas or fuel gas from the gasifier may provide heat for the hydrothermal step.

Abstract: A method and apparatus for removing oil from the produced water that is associated with the production of hydrocarbons. The method consists of providing a plurality of serially connected individual compartments with each compartment connected to the next compartment by a flow path that induces the oil droplets to coalesce. The method may also include the use of parallel plate coalescers and gas flotation devices to aid in treating.

Abstract: The separation of different types of particulate matter in a carrier liquid is obtained by using an ultrasonic standing wave and relying on the different acoustic responses of the different particle types. By varying the acoustic energy propagation cyclically a more effective separation rate can be obtained, with a more readily attracted particle type being subjected to a further discrimination step in each cycle. The cyclical energy variation may be in the intensity of the standing wave, e.g. using suppression means, and/or the velocity of the standing wave relative to the liquid medium, e.g. using phase control means.