Abstract: This is a method of filtration of a liquid comprising steps of sequential filtration of said liquid through at least one deep bed medium producing at least one first filtrate followed by at least one membrane medium filtration producing at least one second filtrate, wherein said membrane medium is at least periodically within said deep bed media Many types of deep bed and membrane media can be used. The domain of using contact clarification (direct filtration) can be expanded towards greater solids concentration. Operation and backwash, is simplified, continuous filtration becomes possible. Water can be water from natural source water, process water, wastewater, aqueous or non-aqueous suspensions, emulsions, solutions. Treatment can include mechanical interception of suspended particles, chemical, physical chemical, electrochemical, and biological processes.

Abstract: A method of biological treatment of materials by a combination of at least two groups of microorganisms forming sludges in at least two biological treatment zones treating the said materials wherein for purposes of increasing the treatment efficiency and stability at least one said sludges is conditioned in at least one sludge conditioning zone, whereby converting at least a fraction of at least one said group of organisms into organisms of another group, and thus forming the conditioned sludge, and the said conditioned sludge is fed in at least one said biological treatment zone.

Abstract: A method of controlling wastewater treatment in multi step system comprising at least one anaerobic step and at least one carbon dioxide stripping step by a combination of(1) recuperable abiotic species and carbon dioxide stripping, wherein the recuperable species can be metal ions such as calcium and iron, the said species are charged in the treatment system and form soluble carbonates maintaining the carbonic acid equilibrium and pH in anaerobic process steps and recuperated and retained in the system as insoluble carbonates or hydroxides formed in the carbon dioxide stripping step, and(2) conditioning the sludge by cultivating methanogens in the sludge in a dedicated process zone called sludge conditioner, and recycling the conditioned sludge in the reactor, wherein the volatile fatty acids are rapidly consumed by thus provided methanogens.Dramatic reduction in reagent requirements for pH and other purposes is achieved.