A method for detecting and controlling the amount of cationic species in a water stream in accordance with embodiments of the present disclosure is carried out by adding a solution containing a pre-determined quantity of a fluorescent tracer to the sample of water stream to obtain a solution comprising a complex. The fluorescence emission spectra of the solution is measured for detecting the presence or absence of the cationic species based on the attenuation and shift of the emission peak in the range of 640 nm to 655 nm.

Methods and nanocomposites for the adsorptive removal of aromatic hydrocarbons such as benzene, toluene, ethyl benzene and xylene from contaminated water sources and systems are provided. The nanocomposites contain carbon nanotubes and metal oxide nanoparticles such as Al.sub.2O.sub.3, Fe.sub.2O.sub.3 and ZnO impregnated on a surface and/or in pore spaces of the carbon nanotubes. Methods of preparing and characterizing the nanocomposite adsorbents are also provided.

This disclosure provides a process based on hydrothermal liquefaction (HTL) treatment for co-processing of high-water-content wastewater sludge and other lignocellulosic biomass for co-production of biogas and bio-crude oil. The mixture of waste activated sludge and lignocellulosic biomass such as birchwood sawdust/cornstalk/MSW was converted under HTL conditions in presence of KOH as the homogeneous catalyst. The operating conditions including reaction temperature, reaction time and solids concentration were optimized based on the response surface methodology for the maximum bio-crude oil production. The highest bio-crude oil yield of around 34 wt % was obtained by co-feeding waste activated sludge with lignocellulosic biomass at an optimum temperature of 310 C., reaction time of 10 min, and solids concentration of 10 wt %. The two by-products from this process (bio-char and water-soluble products) can be used to produce energy as well. Water-soluble products were used to produce biogas through Bio-methane Potential Test (BMP) and were found to produce around 800 mL bio-methane cumulatively in 30 days per 0.816 g of total organic carbon (TOC) or 2.09 g of chemical oxygen demand (COD) of water-soluble products.

A system and a method for treating salt-containing glycerin wastewater are provided, wherein the system for treating the salt-containing glycerin wastewater includes a mixing tank, a filtering device, a distillation column, and a water supply device. The mixing tank is adapted to mix salt-containing glycerin wastewater with a concentrated hydrochloric acid to obtain a mixture. The filtering device communicates with the mixing tank and filters the mixture to obtain an acidic filtrate and a precipitated salt. The distillation column communicates with the filtering device and receives the acidic filtrate from the filtering device. The water supply device supplies water to the acidic filtrate. The system and method for treating the salt-containing glycerin wastewater can effectively recycle hydrochloric acid.

A method for treating an emulsion emanating from a quenching process in production of ethylene that includes online monitoring of zeta potential of the hydrocarbon/water emulsion in a quench water tower and/or a quench water loop. In response to the online monitoring of zeta potential, the method changes the amount of demulsifier being added to the hydrocarbon/water emulsion such that the amount of demulsifier is effective in breaking the emulsion.

The invention relates to a method for the electrochemical purification of chloride-containing, aqueous process solutions, which are contaminated with organic chemical compounds, using a boron-doped diamond electrode at a pH value of at least 9.5.

Provided is a method of treating wastewater and recovering resources in acrylic fiber production, comprising the following steps: 1) filtering wastewater from water-washing and filtering unit of acrylic fiber plants by a filter to intercept and recover high-molecular-weight polymer contained therein, and then making the recovered polymer returned back to the acrylic fiber production and entered the finished product, optionally, reusing part of filtered wastewater as low salinity water in the water-washing and filtering unit; 2) removing non-interceptable high-molecular-weight polymer in the wastewater by subjecting the wastewater to coagulation and air floatation treatment; 3) introducing the effluent into biological treatment unit and adding polyvalent metal ions as an adsorption promoter to increase the removal of the non-biodegradable organics in the biological treatment unit; and 4) removing the organics remained in the effluent from the biological treatment unit by an advanced treatment.

Provided is a wastewater purification method, the method including: supplying a first mixed stream, in which an acid component and wastewater including water, a nitrile-based monomer, and ammonia are mixed, to a first column; recovering the nitrile-based monomer from an upper discharge stream from the first column; supplying a second mixed stream, in which a lower discharge stream from the first column and a base component are mixed, to a second column; and recovering the ammonia from an upper discharge stream from the second column and separating purified wastewater.

A method for removing a fluorine-containing compound from discharge water, which includes bringing discharge water containing two or more fluorine-containing compounds represented by the following general formula (1) or (2) into contact with an adsorbent so as to adsorb the two or more fluorine-containing compounds:
(H(CF.sub.2).sub.mCOO).sub.pM.sup.1General Formula (1):
wherein m is 3 to 19, M.sup.1 is H, a metal atom, NR.sup.b.sub.4, where R.sup.b is the same or different and is H or an organic group having 1 to 10 carbon atoms, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent; and p is 1 or 2;
(H(CF.sub.2).sub.nSO.sub.3).sub.qM.sup.2General Formula (2):
wherein n is 4 to 20; M.sup.2 is H, a metal atom, NR.sup.b.sub.4, where R.sup.b is the same as above, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent; and q is 1 or 2.

A system and a method for treating salt-containing glycerin wastewater are provided, wherein the system for treating the salt-containing glycerin wastewater includes a mixing tank, a filtering device, a distillation column, and a water supply device. The mixing tank is adapted to mix salt-containing glycerin wastewater with a concentrated hydrochloric acid to obtain a mixture. The filtering device communicates with the mixing tank and filters the mixture to obtain an acidic filtrate and a precipitated salt. The distillation column communicates with the filtering device and receives the acidic filtrate from the filtering device. The water supply device supplies water to the acidic filtrate. The system and method for treating the salt-containing glycerin wastewater can effectively recycle hydrochloric acid.