Final answer:
Solids contact units in water treatment are highly sensitive to changes in temperature, flow rate, pH, and pressure, as these factors affect the chemical reactions and interactions necessary for effective treatment.
Step-by-step explanation:
Solids contact units are part of a water or wastewater treatment process where solid particles are mixed with a liquid to promote chemical reactions, sedimentation, and other treatment objectives. They are very sensitive to changes in temperature, flow rate, pH, and pressure. This is because the effectiveness of the solid-liquid interactions can be influenced by these parameters, which in turn affects the overall treatment performance. For instance, temperature can affect the reaction rates and solubility of substances, flow rate can impact the residence time and mixing, pH can change the chemistry of the substances involved, and pressure plays a role in the distribution and contact of the solids in the unit.
Systems at Equilibrium
In the broader context of chemical equilibrium, changes to temperature, concentration, and sometimes pressure and volume can disturb a system's balance. These vary the conditions under which reactions occur, thus altering the system's response.
Essential Knowledge in thermodynamics includes understanding that temperature reflects the average kinetic energy of molecules, while pressure denotes the force exerted by a system against the walls of its container. This is articulated by the ideal gas law (PV = nRT), where pressure (P), temperature (T), and volume (V) are interrelated for an ideal gas.