An ethoxylated pentaerythritol core hyperbranched polymer with dithiocarboxylate as side group and terminal group and its applications as a heavy metal chelating agent are disclosed, which relates to the field of chemical and environmental protection technology. The hyperbranched polymer has a chemical formula of C[CH.sub.2OCH.sub.2CH.sub.2OCOCH.sub.2CH.sub.2N(CSSM)CH.sub.2CH.sub.2NHCSSM].sub.4, wherein M is Na.sup.+, K.sup.+ or NH.sub.4.sup.+. A preparation method of the hyperbranched polymer is simple, the raw materials are easily available, and it is easy to be industrialized. The hyperbranched polymer is able to be used as a heavy metal chelating agent. Its special three-dimensional space structure is able to alternately chelate with heavy metals to form a large three-dimensional molecular conjugate with low solubility, strong stability, and compactness, which is able to effectively treat wastewater and waste containing heavy metals.

Provided are an extract, which is a fractionated component 1 of a water extract of a plant powder, wherein the fractionated component 1 is a fractionated component having a fractionation molecular weight of 12,000 or greater, wherein an ethanol-undissolved component of the fractionated component 1 exhibits a peak attributable to carboxylic acid in a Fourier transform infrared spectroscopy (FT-IR) measurement and exhibits a peak attributable to cellulose in a gas chromatography mass spectrometry (GC-MS) measurement, and wherein an ethanol-dissolved component of the fractionated component 1 exhibits a peak attributable to carboxylic acid in the FT-IR measurement and exhibits a peak attributable to a plant protein in the GC-MS measurement, and a water-purifying agent containing the extract.

A method for treating tailings substrate from mining or oil sands separation process, the tailings substrate comprising an aqueous phase with suspended solid particulate material. In the method, a flocculating agent is added to the tailings substrate, flocs are allowed to form and the formed flocs are separated from the aqueous phase. The flocculating agent comprises a degraded polyacrylamide comprising at least anionic units and having a process water viscosity reduced by 25-99%, preferably 50-99%, compared to a substantially similar polyacrylamide that has not been degraded by a degradation agent, measured at a shear rate 1 s.sup.1 as a 0.4-0.8 weight-% solution of polymer in process water.

An in situ remediation process for a PFAS-contaminated site includes sub-surface injection of slurry containing activated carbon in combination with a substances that promotes formation of an activated carbon emulsion and retention of PFAS by a solid matrix at said site, thereby removing said PFAS from groundwater.

A method of water treatment includes providing water that includes at least one contaminant. An effective amount of at least one filter media is added to the to the water that includes at least one contaminant. The water and the at least one filter media are agitated to form a homogeneous mixture. A cationic biopolymer is added to the homogeneous mixture of water and the at least one filter media. The water is separated from the at least one contaminant and the at least one filter media.

Methods and systems are disclosed for optimization of coagulation and/or flocculation in a water treatment process. According to exemplary embodiments, samples are taken from an aqueous liquid and the samples are monitored with an imaging device to capture visual data of particles dispersed or suspended in the liquid. The particles are classified into particle types based on the visual data and a particle size distribution indication is computed for each classified particle type. The particle size distribution indication is then compared to a predetermined particle size distribution value, and in response to a difference detected, dosage of at least one coagulation and/or flocculation agent in the water treatment process can be adjusted.

The present invention is directed at COD removal mixture comprising a) at least one inorganic coagulant; b) activated carbon, c) at least one organic coagulant; and d) optionally water wherein the mixture is a powder and a method of clarifying industrial waste water using the COD removal mixture.

A chemically modified polysaccharide additive may be introduced to a wastewater stream in an effective amount to remove oil-coated particulates and/or heavy metal contaminants from the wastewater stream. The chemically modified polysaccharide includes at least one sulfur-containing moiety and/or nitrogen-containing moiety and the contaminants may be removed by using this chemically modified polysaccharide to capture the contaminants and separating out the captured contaminants.

Methods for removing oxyanions from water according to the following steps: (i) dissolving an oxyanion precipitating compound into the aqueous source to result in precipitation of an oxyanion salt of the oxyanion precipitating compound; and (ii) removing the oxyanion salt from the water containing the oxyanion to result in water substantially reduced in concentration of the oxyanion; wherein the oxyanion precipitating compound has the following composition: ##STR00001##
wherein A is a ring-containing moiety and X.sup.m is an anionic species with a magnitude of charge m. The invention employs bis-iminoguanidinium compounds according to Formula (1a) as well as neutral precursor compounds according to Formula (1), which can be used for removing undesirable species from aqueous solutions or air, such as removal of sulfate from water and carbon dioxide from air.

A method includes mixing seawater with a two-part additive system configured to precipitate sulfate from the seawater; removing the sulfate precipitates from the seawater; and delivering the seawater into an oilfield reservoir.