Grease control

Introduction

Oil and grease in the wastewater cause trouble in the collection system pipes. It decreases pipe capacity and, therefore requires that piping systems be cleaned more often and/or some piping to be replaced sooner that otherwise expected. Oil and grease also hamper effective treatment at the wastewater treatment plant.

Problems caused by wastes from restaurants and other grease-producing establishments have served as the basis for ordinances and regulations governing the discharge of grease materials to the sanitary sewer system. This type of waste has forced the requirement of the installation of preliminary treatment facilities, commonly known as grease traps or interceptors.

PNW technologies approach to grease problems (build-ups and caps) is to reduce the amount of grease in the collection system through biological digestion, which had the advantage to be more cost-efficient than the grease traps and their maintenance.

Problem

The underlying cause of grease problems is the amount of grease being dumped into the wastewater collection system. The secondary cause is the lack of naturally occuring bacteria present in sufficient numbers and types to break down the grease effectively. Grease clings to the walls of the collection system piping. As it makes it way toward the treatment plant, it accumulates on the walls of the piping. And at wetwells, since grease floats, it forms grease caps on the top of the water.

As grease accumulates in the collection system piping the open passage through which the wastewater can flow is constricted. This causes the lift station/pump station pumps to work longer and harder. Further, grease can block a section of piping thereby generating a major maintenance incident. Also, in many cases the grease caps in wetwells must be pumped by a pumper-truck and hauled off. All the above problems increase the operation work, the maintenance costs, and the replacement costs.

Solution

There are strains of aerobic and facultatively anaerobic bacteria that has a great affinity for grease. Unlike enzymes that break-up the grease and pushes it downstream where it can later reform, the grease-loving bacteria eliminate the grease by digesting it, i.e. turning it into microbe protoplasm, biodegradable organics, gas, heat, and water.


PNW propose a bioaugmentation program using Bacta-Pur® XLG removes that the accumulated grease in the collection system, which improves pipe capacity and also reduce the formation of H2S. The Bacta-Pur® product contains a community of natural beneficial microorganisms, which have been selected for their synergistic ability to produce all essential enzymes for fat and grease digestion.