The ZLD System removes dissolved solids from the wastewater and returns distilled water to the process (source). Reverse osmosis (membrane filtration) may be used to concentrate a portion of the waste stream and return the clean permeate to the process. In this case, a much smaller volume (the reject) will require evaporation, thus enhancing performance and reducing power consumption. In many cases, falling film evaporation is used to further concentrate the brine prior to crystallization. Falling film evaporation is an energy efficient method of evaporation, typically to concentrate the water up to the initial crystallization point.
An incinerator is a sophisticated piece of equipment that converts non-recyclable waste to maximum amount of energy and disposes the minimum amount of residues. The incinerator creates an environmentally-optimal solution for medical, hazardous and non-recyclable waste.
Solid waste generate a lot of ashes during the combustion process, this is why the combustion chamber of an incinerator has to evacuate the ashes if the amount of waste is > 90 kg/h. For small amount of waste a static hearth incinerator is suitable, for amount > 300 kg/h a rotary kiln, moving grate or fluidized bed incinerator is used.
Rotary kilns provide long retention, good thermal isolation, and because of the rotation excellent bed rollover. This makes a rotary waste combustion system ideal for all wastes. It especially works well with high glass and other silica that can form slag, causing other types of systems problems.
Static incinerators for gaseous wastes consist usually of a vertical cylindrical chamber internally lined by refractory material with alumina content variable with the type of waste to be burnt.
In case of liquid waste incineration the combustion chamber is horizontal arrangement.
A burner is vertically located on the bottom and is selected in function of the characteristics of waste to be incinerated and in particular of its heat value.
The combustion occurs with excess air which is provided by means of a centrifugal fan.
Depending on their performance characteristics, particularly their nominal pore sizes, membranes used in filtration devices are placed in one of four categories; microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) or reverse osmosis (RO). These categories deal mainly with the membrane’s ability to reject or separate various size particles (or molecules).
Oily wastewaters are generated in many industrial processes, such as petroleum refining, petrochemical, food, leather and metal finishing. Fats, oils and greases (FOG’s) present in these wastewaters have to be removed before the water can be reused in a closed-loop process or discharged into the sewer system or to surface waters. These oily waters are mainly in the form of oil-in-water (O/W) emulsions that pose a great problem in facilities attempting to stay in compliance with discharge limits. Emulsion breaking and oil removal require a basic understanding of the physical properties and chemical composition of O/W emulsions
In domestic environments, Ion Exchange Resins are used to soften water for use in appliances such as washing machines, dishwashers and steam irons. water softening resins are also found in filters used for purification of drinking water, and throw away cartridges. In an industrial context, water softening is used in laundries, in brewing and soft drink manufacture for bottle washing, process water for LP boilers, and process water for industrial and chemical processes which require softened water e.g. textiles.