We often hear about the need for providing clean drinking water to low income areas of the world. One aspect of providing clean water is the need to provide for wastewater treatment. In areas where animal and human wastes are dumped untreated into rivers and streams, the impact manifests itself as increased disease, damage to the aquatic ecosystem, and loss of valuable fresh-water.
In rural areas with little or no indoor plumbing, wastewater treatment can be as simple as the use of a pit latrine where wastes fall to a pit with lime or wood ash added periodically. The pit acts like a septic tank to break down the waste. Once the pit becomes full, the latrine can be moved and the pit planted with a tree to provide valuable future timber.
In more densely populated areas, waste treatment can be done using low cost earthen ponds. These ponds 3 - 5 feet in depth allow for biological decomposition of the waste and reducing in fecal coliforms. Even with a relatively short retention time of 3 - 5 days, this type of pond/lagoon system can substantially improve water quality down stream and eventually in the wells tapping into groundwater.
While the above simple solutions can be done with minimal investment or technical know-how, many residents in these areas need to be educated in the long term value of waste treatment. As we head into the 2015, I am going to put some effort providing information for use rural and developing area waste treatment that can be accomplished without electricity, extensive capital investment, or extensive technical knowledge.
Best wishes for the New Year!
Facilities with seasonal flows such as wineries, vegetable processing, or vacation resorts often have period of low flows at light loadings followed by a rapid increase in both waste volume and concentration. This situation is rarely discussed in textbooks, but is surprisingly common. The challenge is combining equilization, buffering capacity, bioaugmentation, and polymer addition to meet treatment requirements. By fully considering the options before the season flow starts, operators can manage the event with fewer problems.
Here is how I evaluate the various options:
Commercial aquaculture relies on the high density stocking of fish and then feeding a high protein food to maximize growth. By having such high stocking density of usually once type of animal and feeding at high rates, the water is often fouled by the excess fish waste.
The waste creates issues with ammonia/nitrite, cyanobacteria blooms, and buildup of anaerobic sludge layer on the pond bottom. Additionally, the high stress caused by pollution often allows for growth of opportunistic pathogenic microbes.
The earliest solution was to flush the ponds with new water, however downstream pollution and costs associated with water changes led farmers to see if the principals of biological water treatment could be used to improve animal health and lower costs.
Aquaculture products work in three distinct ways (some organisms function in more than one manner).
Erik Rumbaugh has been involved in biological waste treatment for over 20 years. He has worked with industrial and municipal wastewater facilities to ensure optimal performance of their treatment systems. He is a founder of Aster Bio (www.asterbio.com) specializing in biological waste treatment.
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