The present disclosure is drawn to evaporation panel assemblies, systems, and methods. For example, a modular evaporation panel system can include a plurality of evaporation panels with individual evaporation panels including evaporation shelves that are laterally elongated, vertically stacked, and spaced apart; vertical support columns positioned along the evaporation shelves to vertically support and separate the evaporation shelves; female-receiving openings defined by multiple evaporation shelves and multiple support columns; and male connectors positioned at lateral ends of the evaporation panels. The male connectors can be releasably receivable by the female-receiving openings of an adjacent evaporation panel, thereby providing modular assembly and disassembly of multiple evaporation panels relative to one another.

The present disclosure is drawn to evaporation panel assemblies, systems, and methods. For example, a modular evaporation panel system can include a plurality of evaporation panels with individual evaporation panels including evaporation shelves that are laterally elongated, vertically stacked, and spaced apart; vertical support columns positioned along the evaporation shelves to vertically support and separate the evaporation shelves; female-receiving openings defined by multiple evaporation shelves and multiple support columns; and male connectors positioned at lateral ends of the evaporation panels. The male connectors can be releasably receivable by the female-receiving openings of an adjacent evaporation panel, thereby providing modular assembly and disassembly of multiple evaporation panels relative to one another.

Examples are disclosed herein that relate to an in-pond water quality maintenance system. One example provides a pond water quality maintenance system, including a skimmer basin configured to collect pond surface debris, the skimmer basin including an upper opening configured to permit a flow of water and debris from a pond surface into the skimmer basin, a strainer basket positioned within the skimmer basin and configured to trap at least some of the debris that enters the skimmer basin through the upper opening, a skimmer pump positioned within the skimmer basin below the strainer basket, the skimmer pump configured to draw water through the strainer basket and to pump the water out of the skimmer basin, and one or more lower openings configured to permit a flow of water into the skimmer basin from a pond depth below the strainer basket.

An air infiltration system for a hydroelectric plant includes a spillway gate and a linearized cone valve coupled to the spillway gate, the linearized cone valve having a pivotable plate assembly. The spillway gate may be a tainter or Stoney gate and the pivotable plate assembly may have a deflection plate. A method of infiltrating air in water released from an impoundment may include: lifting a spillway gate from a resting position proximate a bottom of a spillway; and pivoting a deflection plate coupled to the gate proximate the bottom of the spillway; wherein water flows through an opening disposed between the deflection plate and the gate and is sprayed into an atmosphere to be oxygenated.

A regulating tank includes a tank member having an annular wall to receive wastewater. A circular pipe is connected to the tank member. A draining device drains the wastewater in the tank member to the circular pipe. A plurality of nozzles connected to the circular pipe to eject the wastewater in the circular pipe back to the tank member. When the wastewater is ejected by the nozzles, a temperature of the wastewater is reduced, and dissolved oxygen of the wastewater is increased.

An air infiltration system for a hydroelectric plant includes a spillway gate and a linearized cone valve coupled to the spillway gate, the linearized cone valve having a pivotable plate assembly. The spillway gate may be a tainter or Stoney gate and the pivotable plate assembly may have a deflection plate. A method of infiltrating air in water released from an impoundment may include: lifting a spillway gate from a resting position proximate a bottom of a spillway; and pivoting a deflection plate coupled to the gate proximate the bottom of the spillway; wherein water flows through an opening disposed between the deflection plate and the gate and is sprayed into an atmosphere to be oxygenated.

An air infiltration system for a hydroelectric plant includes a spillway gate and a linearized cone valve coupled to the spillway gate, the linearized cone valve having a pivotable plate assembly. The spillway gate may be a tainter or Stoney gate and the pivotable plate assembly may have a deflection plate. A method of infiltrating air in water released from an impoundment may include: lifting a spillway gate from a resting position proximate a bottom of a spillway; and pivoting a deflection plate coupled to the gate proximate the bottom of the spillway; wherein water flows through an opening disposed between the deflection plate and the gate and is sprayed into an atmosphere to be oxygenated.

A regulating tank of a wastewater treatment system includes a tank member having an annular wall to receive wastewater, a first overflow weir connected to an interior side of the annular wall of the tank member, and a first pump device having a first pump and a first return pipe. The first pump of the first pump device pumps wastewater in the tank member to the first overflow weir through the first return pipe, and then the wastewater flows back to the tank member from the first overflow weir to disturb the wastewater in the tank member.

A regulating tank of a wastewater treatment system includes a tank member having an annular wall to receive wastewater, a first overflow weir connected to an interior side of the annular wall of the tank member, and a first pump device having a first pump and a first return pipe. The first pump of the first pump device pumps wastewater in the tank member to the first overflow weir through the first return pipe, and then the wastewater flows back to the tank member from the first overflow weir to disturb the wastewater in the tank member.

A bio-filter system is disclosed. The disclosed bio-filter system comprises: a transfer pipe for collecting and transferring N.sub.2O generated in any one tank from among an anaerobic tank, an anoxic tank, and an aeration tank; a bio-filter unit including a carrier for removing, by means of microbial reaction, the N.sub.2O discharged from the transfer pipe; and a sewage supply member for spraying sewage into the carrier in order to provide nourishment for microorganisms to the carrier. The bio-filter unit comprises: a filter housing; an induction discharge pipe, which is installed on the lower side of the inside of the filter housing, for inducing the N.sub.2O transferred by the transfer pipe in a transverse direction and enabling same to be discharged upwardly through a nozzle; the carrier, which is disposed on the upper side of the induction discharge pipe inside the filter housing, for removing, by means of microbial reaction, the N.sub.2O discharged through the induction discharge pipe; and a sewage spraying member, which is disposed on the top of the carrier inside the filter housing, for spraying sewage supplied from the sewage supply member to the carrier so as to utilize the sewage as nourishment for microorganisms.