A Case Study of RVPF Filtration of Waste Sludge Using Organic Filter Aids

摘要

Traditionally, filtration using Rotary Vacuum Precoat Filters (RVPF) has been with mineral filter aids like Diatomaceous Earth (DE) or Perlite. While precoat filtration has been a very cost effective and viable technology, growing concerns over health and disposal issues have prompted users to seek out safe alternatives. Newer technologies are often very expensive or limited in capacity to handle these types of waste streams. rnNew innovations in filter aids based on organic, self replenishing raw materials (cellulose, wood and plant fibers) have gained recognition over mineral based filter aids. A variety of advantages are offered to the user: rn1.As a result of their lower Wet Cake Density, specific consumptions can be up to 70% less compared with mineral filter aids. rn2.In many cases higher flow rates and longer cycle times can often be achieved. rn3.The absence of harmful crystalline silica insure against these health hazards, when used under normal conditions. rn4.Disposal options are improved as the filter aid is biodegradable and can be easily used as compost material or in many cases incorporated in animal feed. Other options include incineration or land application. rn5.Organic fibers are non-abrasive and are much less intrusive on equipment such as pumps, pipes and other equipment parts.