Page 14 November 1977 RAIN Over a year ago, QA T began to catalog various on-site wastewater treatment devices and explore their health implications (more on this in next month's RAIN). During this time, we discovered some small towns which were having centralized chemical waste treatment systems foisted upon them by the local politicians, engineers and developers. We are now beginning to gather information to help towns develop plans for alternative biological waste treatment systems which are far cheaper, less polluting, and a much more ecologically sound way to go. -CC Biological Treatment of _::::--._ Wastewater ~ ~1~,<~- ·---- ~,J/Ji, ,.,tllllf.lJ) ~' -\ ~ "'""',." ·- -..,.,... \ \t:,_~ " ~ ) '!9. • Joyce Hochmuth-Nowell and Wade Rose \ / \ i In the early nineteen hundreds, America turned away f;om ~ ' decentralized sewage treatment and toward centralized collection, treatment and disposal of wastes to sewers. Cheap energy and a growing ability to engineer and build large public works consolidated an approach to wastewater treatment which valued nuts and bolts over more natural processes. Treatment methods developed in Northern Europe that used prodigious amounts of energy treating sewage in the smallest space and the least time possible became the ideal processes. The glittering, complex hardware of physical and chemical centralized treatment plants boosted the Sanitary Engineer out of the muck and into the more acceptable world of mathematical formulas and stainless steel pipes. If central treatment plants were well operated, which was and is not often, they offered a fairly good way to clean up the polluted waters according to three basic standards: Biological Oxygen Demand (BOD), Suspended Solids (SS), and Fecal Coliform Counts. However, those three methods of measuring treatment effectiveness (how much oxygen the wastewater needed to oxidize nutrients, how many solid particles were suspended in the water and how many coliform bacteria existed) are inadequate in light of the pollutants we now know exist in "treated" wastewater. Literature on biological methods of wastewater treatment is becoming available. Here are some of the sources which contain good information. Economic Assessment of Wastewater Aquaculture Treatment Systems, (EPA-600/2-76-293), Upton B. Henderson, 1976, from: National Technical Information Service Springfield, VA 22161 This is an update economic analysis which compares aquaculture to conventional systems. The study concludes that at many water quality levels aquaculture is cheaper than conventional treatment. The volume's appendix gives schematic presentations of 15 different aquaculture treatment strategies. Another serious blow to the old methods of treatment has been the increasing cost of energy. Activated sludge treatment is the most efficient means of conventional treatment. It is also the most energy intensive. Mechanized treatment requires constant energy inputs to make pumps, grit chambers, primary and final clarifiers, trickling filters, sludge digesters and so on, work. Delivering the wastes to the treatment plant often requires more energy than the treatment itself. New standards of water quality and increasing energy costs are requiring new approaches to wastewater treatment. Treatment methods which require more time and space than old methods but rely on natural processes show great promise in bringing better water quality at less cost and less environmental impact. Biological treatment which relies on a mixture of bacteria, protozoa, algae, invertebrates and aquatic animals to break down wastes cannot only treat wastewaters but can produce resources as well: safely reusable water and food. Review of Current Interest and Research in Water HyacinthBased Wastewater Treatment, R. K. Markarian, et al., 1977, (Report No. BCL-OA-TFR-77-1) from: Battelle Columbus Labs 505 King Avenue Columbus, OH 43201 This report serves as a who's who directory of individuals and institutions working in water hyacinth-based aquaculture. The author's conclusions from the nine groups surveyed are that: (1) hyacinth treatment can be a low-cost way to meet stringent effluent requirements and that (2) within three years systems may be available on a widescale commercial basis.
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