Nutrient System and Methods

Abstract

A nutrient system for automatically supplying growth medium to an algae growth system comprises a tank for mixing nutrients, together with a plurality of computer-controlled pumps for supplying metered amounts of selected constituents to the tank. The nutrient mix is heated to a preselected temperature under computer control, and recirculated until the desired uniformity is achieved. The nutrient mix is then supplied to the algae growth system.

Description

FIELD OF THE INVENTION [0001]The present invention relates generally to wastewater treatment systems and methods, and more particularly relates to wastewater treatment systems utilizing anaerobic and aerobic microorganisms for bioremediation.BACKGROUND OF THE INVENTION[0002]The vast majority of the world's wastewater does not undergo treatment of any kind before being dumped into the nearest open water source. This has resulted in an international health crisis, where people die daily for lack of clean water. Unstable ecosystems caused by nutrient rich waste runoff are creating high rates of fish kill, ocean floor plant kill and large concentrations of pathogenic bacteria. This is a direct effect of lack of treatment or poor treatment and disposal of such waste streams. Effects such as disastrous algae blooms in open water sources from eutrophic conditions have drastically increased in the past decade and pose unprecedented environmental problems.[0003]Typical prior art wastewater t...

AI Technical Summary

Benefits of technology

[0009]The present invention provides a system and method for efficient, cost-effective bioremediation of wastewater and other contaminated fluid streams. In one aspect, the invention includes a photobioreactor (hereinafter sometimes “PBR” for simplicity) for growing high concentrations of algae. The PBR comprises a tank having specially configured light pipes distributed therein to cause high density algae growth substantially throughout the tank. Fluid flow in the tank is maintained at a level low enough to prevent damage to the algae while at the same time allowing the fluid to circulate throughout the tank.

[0010]Another aspect of the invention comprises a medium system for supplying nutrients to the PBR or other growth system. The nutrient system can comprise a plurality of separately selected components which are then assembled into a nutrient stream through a plurality of metering pumps, or, in some embodiments, can be derived from a portion of the effluent of an anaerobic digester. In some embodiments, the anaerobic digester forms a first stage of the overall bioremediation system. The anaerobic digester stage, aside from providing a stream rich in micro and macronutrients, also provides significant amounts of CO2 to the PBR, which assists in the growth of algae in the PBR. In addition, the anaerobic digester generates significant quantities of biogas, which can be utilized by a conventional biogas-powered generator to produce at least a portion of the electricity required to operate the bioremediation system of the present invention. Carbon dioxide from the biogas can be used in the lagoon or pond to accelerate algae growth before, after, or instead of burning of the biogas. In the case where the biogas is burned, the resultant heat energy can be used to warm the water in the lagoon, accelerating various of the desirable biological processes ongoing there.

Problems solved by technology

This has resulted in an international health crisis, where people die daily for lack of clean water.

Unstable ecosystems caused by nutrient rich waste runoff are creating high rates of fish kill, ocean floor plant kill and large concentrations of pathogenic bacteria.

This is a direct effect of lack of treatment or poor treatment and disposal of such waste streams.

Effects such as disastrous algae blooms in open water sources from eutrophic conditions have drastically increased in the past decade and pose unprecedented environmental problems.

These systems are expensive to build and to operate, not solely because of the high energy costs incurred in the aeration process, but also because of the manpower required to operate the expensive machinery employed in such systems.

Such mechanical / chemical treatment facilities, even those that are considered “state of the art,” have a price tag in the millions and even up to hundreds of millions of dollars, making them so expensive that many communities, in the US and other parts of the developed world, have in the past been unable to afford such sewage treatment systems.

As a result, the majority of the world's population lives with massive sewage pollution.

Because these prior art systems do not have a mechanism for controlling the algal specie(s) present, their algae cultures drift over time, often with unwanted outcomes.

These undesirable outcomes include the growth of species that cannot be easily separated from the water at the end of processing; the proliferation of species that grow well during “normal” conditions, but are unable to grow in the case of process excursions, e.g. an influx of an industrial pollutant; or the proliferation of algaie species that grow well, but do not perform all of the desired remediation.

Further, absent a mechanism for active replenishment of the algae, wash-out events (e.g. from a rainstorm) can severely dilute the algae culture density, such that the system is unacceptably slow to return to an effective culture density.

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