The present disclosure relates to processes for treating wastewater such as acid rock drainage. The processes may, for example, comprise subjecting the wastewater to a microbial fuel cell process, neutralizing the acid with a base comprising calcium to produce an aqueous composition comprising calcium ions and subjecting the aqueous composition comprising calcium ions to a biological precipitation process to precipitate the calcium ions as calcium carbonate.

Provided are a household toilet waste treatment system and a method of treating toilet waste using the same, the household toilet waste treatment system comprising a solid-liquid separation toilet, a biological treatment apparatus, a sterilization apparatus, and a combustion apparatus. The combustion apparatus complements a slow biological treatment apparatus to allow continuous treatment of the household toilet waste in a unit space without long-distance piping connections.

The invention relates to a method for treating wastewater in an activated sludge process, which comprises a biological treatment step followed by a sedimentation step for separation of sludge and treated effluent water. The method comprises directing a part of the treated effluent water as a backflow from the sedimentation step to the biological treatment step, the backflow having an original pH value; adjusting the backflow pH from the original pH value to a first pH value between the sedimentation step and the biological treatment step, and adding a coagulant and/or an oxidant to the backflow after the adjustment of the backflow pH to the first pH value and before backflow's entry to the biological treatment step.

Disclosed are methods of treating wastewater using a membrane bioreactor and achieving a target phosphorus concentration for the membrane permeate stream. These methods include the steps of dosing a wastewater stream with a rare earth clarifying agent and passing the dosed wastewater stream through the membrane to obtain a membrane permeate stream with a permeate concentration that is less than the phosphorus concentration of the influent stream. This permeate concentration also can be equal to or less than a target phosphorus concentration. In the methods as disclosed herein, the rare earth clarifying agent can be chloride salts of one or more rare earth elements and in certain embodiments, the rare earth clarifying agent can be CeCl.sub.3 and LaCl.sub.3.

A system for cleaning wastewater, includes: an absorption-biodegradation-denitrification (ABN) reactor, a sequential adsorption reactor, a disinfection reactor, and a sludge anaerobic fermentation reactor. The ABN reactor is an integrated reactor including: a biosorption tank, an intermediate sedimentation tank, a biologically-enhanced degradation tank, a denitrification biofilter, and a secondary sedimentation tank. The pretreated wastewater is introduced into the ABN reactor for removal of chemical oxygen demand, nitrogen and phosphorus; the ABN reactor effluent is introduced into the sequential adsorption reactor for the removal of high-risk pollutants; the sequential adsorption reactor effluent is introduced into the disinfection reactor for the elimination of viruses and other pathogenic microorganisms; the sludge produced by the ABN reactor is introduced into the anaerobic sludge fermentation reactor for alkaline fermentation. The system is effective for removing high-risk pollutants and reducing effluent toxicity, which can be used for the upgrading and reconstruction of the wastewater treatment system.

The present disclosure relates to processes for treating wastewater such as acid rock drainage. The processes may, for example, comprise subjecting the wastewater to a microbial fuel cell process, neutralizing the acid with a base comprising calcium to produce an aqueous composition comprising calcium ions and subjecting the aqueous composition comprising calcium ions to a biological precipitation process to precipitate the calcium ions as calcium carbonate.

The disclosure provides a compact and high-rate bioreactor for wastewater treatment comprising a feeding port for introducing a feed of waste material, a reaction zone in liquid communication with the feed port when the bioreactor is in operation and having an aerator to provide an airlift configuration in the reaction zone; a settling zone comprising a separator for separating a liquid effluent from solid particles; a liquid effluent outlet port for withdrawing the liquid effluent; and a solids outlet port for removing solids. Further provided is a spiral separator for use in a bioreactor and a system comprising the bioreactor and a membrane separator to provide hygienic water.

A wastewater treatment method applicable to new or existing enhanced biological phosphorus removal (EBPR) treatment process designs which utilize the sequencing batch reactor (SBR) process activated sludge process treatment tanks. The method improves the performance and efficiency in the treatment of municipal and industrial wastewater to remove phosphorus (P) and nitrogen (N). The method includes ceasing reaction cycles when a derivative of rate of change of the input flow volume of the air stream into the tank needed to maintain a low-range of dissolved oxygen (DO), in which an oxidation reduction potential (ORP) setpoint reaches a derivative value indicating that conversion of the ammonia nitrogen in the influent wastewater content to a nitrite or to a nitrate is complete.

The disclosure belongs to the field of sewage treatment technology, in particular to a low-carbon nitrogen and phosphorus removal system and process for sewage treatment. The system of the disclosure includes a primary sedimentation fermentation tank, a mainstream modified A.sup.2O unit and a bypass anammox unit. The disclosure sets a denitrification phosphorus removal functional zone in the anoxic tank of the A.sup.2O system, and sets a deoxygenation zone in the aerobic tank. Combined with the primary sedimentation fermentation tank, the efficient utilization of the carbon source of the A.sup.2O process is strengthened. The system has good effluent quality and does not require the addition of a carbon source, and the aeration energy consumption is low, which achieves efficient and low-carbon nitrogen and phosphorus removal.

A water treatment system that removes calcium and magnesium using coagulants and pH controls, aqueous phase organic materials from water using a biological removal system that includes microorganisms and a physical separation system that includes sparging equipment for sparging the water to remove non-aqueous phase liquid organic materials, volatile phase organic materials. An apparatus, system and method for pretreating oilfield produced water to completely remove or significantly reduce concentrations of substances that are known to interfere with downstream recovery of metals including lithium. This technology facilitates a more efficient and cost-effective extraction method from alternate sources to meet the increasing global demand.