Possible operational problems in wastewater and water treatment plants are listed below. Our company is a professional treatment company that installs treatment plants in Turkey as well as foreign countries.

Operational Problems That May Occur in Mechanical Equipment

The mechanical part of the purification; screens, aerators, grinders, scrapers, pumps, etc. forms. Malfunctions in mechanical equipment can be seen due to reasons such as increased load as a result of the sudden arrival of large and occlusive materials, equipment errors, and lack of timely maintenance-controls.

Insufficient physical treatment can also render components such as pumps and blowers unusable. For this reason, the plant project should be done correctly and appropriately considering the wastewater character and environmental conditions.

Operational Problems in Biological Treatment Systems

Activated sludge process is the most preferred among biological treatment systems. The reason for this is that it is easy to operate, economical and environmentally friendly. Bulking, sludge floating and foam formation are among the frequently encountered operational problems in plants using activated sludge process. These problems usually occur in the biological reactor, in the pre-post sedimentation basins.

Sludge Bulking

Sludge bulking is generally defined as a high suspended solids concentration value at the treatment outlet, as a result of poor precipitation in the settling unit in wastewaters with low settling properties. When sludge rises, the flocs cannot be compressed and good precipitation cannot be seen. Mixing of these flocs into the effluent results in inadequate disinfection, deterioration of effluent filters and water quality.

Sludge bulking occurs in two ways;

• “Filamentous bulking” in case of predominance of filamentous microorganisms,
• When extracellular biopolymers multiply in excess amounts, "viscous bulking"

The filamentous bulking problem is the most common sludge bulking problem. Waste water characteristics (flow rate change, pH, temperature, nutrient content, etc.), design errors (insufficient air, insufficient mixing, insufficient pump capacity, etc.), changes in operating conditions (Low F/M ratio, nutrient deficiency, Low O.O. concentration etc.).

Floating Sludge

Sludge with good settling feature can be seen floating when settling time is kept short. The main reason for this is that the nitrogen gas released in the denitrification process raises the flocs along with it and carries them to the tank surface. Nitrogen gas is often trapped between the flocks, causing the flocks to decrease in density and float. Sludge floating is frequently seen in systems where sludge age (SRT) is kept low.

Scum Formation

When the Nocardia and Microthrix parvicella bacteria, which have a filamentous structure, become dominant in the activated sludge processes, scum formation is observed in the water. Since these bacteria have a hydrophobic surface, they cling to air bubbles and this causes the formation of scum in the wastewater. Generally, the scum formed is a thick layer and brown in color.

Scum formation may occur in diffuser and mechanical aeration, but it is more common in waters with diffuser aeration at high flow rates. Nocardia foam can also be formed frequently in anaerobic and aerobic sludge digesters, aeration tank or final settling tank.

In biological processes, the formation of white scum is a sign that the plant is functioning well. It is an indication that the water coming out of the process will be of good quality.

Microorganism Inhibition

In biological processes, purification is carried out by microorganism activities. Since microorganisms are living things just like us, they develop depending on the temperature, the amount of oxygen and nutrients in the environment. Changes or deficiencies in these environmental conditions cause the growth of microorganisms to stop, die or overgrow. It is desired that the microorganisms be in optimum conditions and in quantity (neither less nor more).

Heavy metals in the environment, pH, dissolved oxygen, toxic substances, temperature, etc. Parameters affect the microorganism activities and cause a change in the efficiency of the treatment.

Odor Problem

Odor problems may occur in treatment plants due to the gas released by organic substances and chemicals in wastewater as a result of biological activities. In facilities that are not adequately ventilated, anaerobic conditions may occur and sulfurous compounds such as methane and H2S may be released. These gases are also the main cause of odor.