The present disclosure relates, in part, to enhanced weathering systems and/or apparatuses and methods of use thereof. In one aspect, the present disclosure provides a method of at least partially sequestering CO.sub.2 from an influent aqueous solution comprising aqueous and/or gaseous CO.sub.2. In another aspect, the present disclosure provides a method of at least partially sequestering CO.sub.2 from a gaseous CO.sub.2 source. In another aspect, the present disclosure provides systems and/or apparatuses suitable for use in the methods described herein. In another aspect, the present disclosure provides a method of optimizing the design and operation of a system for at least partial sequestration of CO.sub.2 from a water source.

The invention relates to a compressed salt block comprising a longitudinally extending elongated body having a vertical longitudinal axis, a top horizontal face, a bottom horizontal face. The block portion has a rectangular cross-section taken in a horizontal plane that is perpendicular to the vertical longitudinal axis, wherein the rectangular cross-section is defined by a major front exterior surface that is a base surface of the block portion, a major rear surface, and a pair of exterior minor surfaces. An extension portion is formed integrally with the major rear surface of the rectangular cross-section of the block portion as a single compressed salt block, wherein the extension portion has a cross-sectional area in said horizontal plane in the form of a right truncated triangle, the extension portion having a first exterior side that is contiguous with one of the pair of exterior minor side surfaces of the block portion, a second side that is contiguous with the major rear surface of the block portion, and an exterior hypotenuse side that extends at an acute angle relative to the base surface of the block portion from a rear edge of the first exterior side toward the major rear surface of the block portion. A horizontal cross section of the elongated body is constant along the vertical longitudinal axis of the elongated body and the exterior hypotenuse side of the extension portion defines a functional face adapted to abut against a vertical wall or an exterior vertical surface of a tank of a water softener apparatus to position the compressed salt block within said water softener apparatus.

The water treatment system includes: an aluminate ion addition part for adding an aluminate ion additive to water to be treated containing at least salt content and silica; a first precipitation part provided on the downstream side of the aluminate ion addition part; a first pH adjustment part provided on the downstream side of the first precipitation part; a first solid/liquid separation part for separating the solid content in the water to be treated; a second pH adjustment part for adjusting the pH of the water to be treated from the first solid/liquid separation part to a second pH level; and a first separation membrane (desalination treatment) apparatus provided on the downstream side of the second pH adjustment part so as to separate the water to be treated into first permeated water and first non-permeated water by removing the salt content in the water to be treated.

The invention relates to a compressed salt block and a liquid treatment apparatus provided therein with at least one such compressed salt block. The liquid treatment apparatus comprises a housing adapted to accommodate at least one liquid treatment tank and at least one compressed salt block. The housing comprises a first space portion for accommodating the at least one liquid treatment tank, and a second space portion for accommodating at least partially the at least one compressed salt block; wherein the at least one compressed salt block comprises an extension portion which extends into a space in the first space portion between an external surface of the at least one liquid treatment tank and an inner wall surface of the housing adjacent the external surface of the at least one liquid treatment tank to thereby position the at least one compressed salt block within the housing. The compressed salt block comprises an elongated body having an irregular cross section, the cross section comprising a base side and a functional side opposing the base side, wherein at least a portion of the functional side forms an acute angle to the base side thereby forming the extension portion of the salt block.

Produced water from a crude oil or natural gas production process is purified using a membrane purification system for petroleum production, agricultural, commercial and domestic uses. The produced water is pretreated to remove, at least, particulates and oil from the produced water. The minimally pretreated water is then purified in a membrane purification system that is operated at conditions such that contaminants are removed. In particular, the membrane purification system is operated with pH adjustments to allow boron and ammonia to be effectively removed. In some embodiments, greater than 95% of the boron content and greater than 95% of the ammonia content are removed. Some method embodiments include no separate ion exchange separation step capable of removing ammonia.

Produced water from a crude oil or natural gas production process is purified using a membrane purification system for petroleum production, agricultural, commercial and domestic uses. The produced water is pretreated to remove, at least, particulates and oil from the produced water. The minimally pretreated water is then purified in a membrane purification system, that is operated at conditions such that membrane scaling is reduced or prevented. In particular, the membrane purification system is operated to maintain the turbidity of clarified water feed to the system or intermediate aqueous streams that are cascading through the membrane purification system. Ensuring that the turbidity of the reject streams generated in the membrane system are useful in achieving long membrane operating life.

Compositions and methods and systems for treating wastewater within a wastewater treatment system of described. In an embodiment, a composition for treating wastewater within a wastewater treatment system and for preventing or reducing the occurrence of struvite scale formation within the wastewater treatment system may include an admixture including a magnesium compound. The admixture may also include a dispersing agent. The admixture may further include at least one of a free magnesium control agent and a seed material. Other compositions and methods are described.

Compositions and methods and systems for treating wastewater within a wastewater treatment system of described. In an embodiment, a composition for treating wastewater within a wastewater treatment system and for preventing or reducing the occurrence of struvite scale formation within the wastewater treatment system may include an admixture including a magnesium compound. The admixture may also include a dispersing agent. The admixture may further include at least one of a free magnesium control agent and a seed material. Other compositions and methods are described.

A method for treating a domestic supply water circuit, that comprises injecting a treatment product comprising silicates into the water flowing in said circuit in order to form a film on the inner surfaces of said circuit, characterised in that the injection of the treatment product comprises at least one step of injecting silicates at a concentration of between 100 and 200,000 milligrams per litre (mg/L) into the water flowing in said circuit for a period of between 10 minutes (min) and 24 hours (h), the flow rate of water flowing in the circuit being controlled within a range of between 0.05 and 100 litres per minute (L/min) and the temperature of water flowing in the circuit being controlled within a range of between 40 and 65 C.

Methods and systems for improving pumping or conveyance efficiencies of wastewater within a wastewater treatment system is described. In an embodiment, an effective amount of a magnesium compound may be added to wastewater within a wastewater treatment system to increase at least one of a pumping and a conveyance efficiency of the wastewater within at least a portion of the wastewater treatment system. In an embodiment, the method may also include measuring at least one or the pumping efficiency and the conveyance efficiency of the wastewater within the portion of the wastewater treatment system. A concentration of the added magnesium compound may be adjusted to increase at least one of the pumping and the conveyance efficiency within the portion of the wastewater treatment system. Other methods and systems are described.