Total organic carbons

The measurement of total organic carbon (TOC) is the best means of assessing the organic content of a water sample [20]. Organic carbon is oxidized to carbon dioxide (CO,) by heat and oxygen, ultraviolet irradiation, chemical oxidants, or by various combinations of these. The CO, may be measured directly by a non-dispersive infrared analyser or it may be reduced to methane and measured by a flame ionization detector in a gas chromatograph or in a TOC analyser thus equipped. The CO2 may also be titrated chemically. 

After oxidation is complete, the CO, is flushed from the system and measured with a gas chromatographic detector or by absorption in ultra-pure water followed by a conductivity measurement [12]. 

Manufacturer Type Oxidation Catalyst Principle of CO2 Range 

Buhler TOC 1 K2S2O8-H2SO4 AgNOs Conductometry with NaOH 0-1000 

BASF K2S2O8-H2SO4 AgNOa Infrared analyser 0-10  

The Shimadzu TOC-500 total organic carbon analyser is a fully automated system capable of determining between 1 pg/1 and 3000 pg/1 TOC. 

OIC Analytical Instruments produce the fully computerised model 700 TOC analyser. This is applicable to solids. Persulfate oxidation at 90-100 °C followed by non-dispersive infrared spectroscopy is the principle of this instrument. 

The Mitsubishi TSC-10 halogen-sulfur analyser expands the technology of the TOX-10 to include measurement of total chlorine and total sulfur. Model TSX-10, which consists of the TOX-10 analyser module and a sulfur detection cell, measures total sulfur and total chlorine in liquid and solid samples over a sensitivity range of milligrams per litre to a percentage. 

Dohrmann also produces an automated sulfur and chlorine analyser (models TCTS 130/120). This instrument is based on combustion microcoulometric technology. 

Fimg et al. [15] have discussed a thermal combustion-ion chromatographic method for the determination of total organic carbon in industrial and potable waters. This method utilises a tube furnace and readily 

Cation Stationary phase Eluent Camments Detection LD Ref. 

Mn - - Post-column reaction studied interference by chelating agents Spectrometric - [27] 

Cd Anion separation and suppression columns O.OBpM NaHCOj -0.3M NajCOj Metals as EDTA complexes Conductio- -metric [28] 

Fe(lll)/Fe(ll) Cation exchange resin - As the bathophenothroline disulphonic acid complexes Spectrophoto- -metric at 530nm [29] 

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Several methods have been developed to estimate the oxygen demand in waste water treatment systems. Commonly used laboratory methods are biochemical oxygen demand (BOD), chemical oxygen demand (COD), total oxygen demand (TOD), total organic carbon (TOC), and theoretical oxygen demand (ThOD). 

Although httie or no reduction in total organic carbon occurs during ozonation, partially oxidized polar compounds (containing, COOH,... 

Fig. 3. pH Dependence of total organic carbon (TOC) decay during the photooxidation of a landfill leachate using H2O2/uv. Initial TOC concentration,... 

Organic Carbon. The total organic carbon (TOC) in a water sample is determined by injecting a microliter sample into a heated, packed tube in a stream of oxygen. The water is vapori2ed and carbon is converted to carbon dioxide, which is detected with a nondispersive infrared analy2er. 

HAZVVOPER Hazardous waste operators TOC Total organic carbon... 

Semi-conductors Ultra-high purity water Total organic carbon (TOC) reduction... 

SCWO Supercritical Water Oxidation TKN Total Kjeldahl Nitrogen TOC Total Organic Carbon TSS Total Suspended Solids WAO Wet Air Oxidation... 

One important measurement made by geochemists is the Total Organic Carbon (TOC) measurement. The results are expressed as a weight percentage. When the TOC is less than 0.5 percent, the rock is considered unlikely to have enough kerogen to produce oil or gas. 

T0C(Total Organic Carbon) another way of expressing organics, in this case in mg/l as C. 

Total organic carbon (mg/kg) Note 4 <1 Note 4 <0-5 Note 4 <0-5... 

Sole 4 Total organic carbon is not specified but it is staled that values for organic matter depend on circumstances. 

Softening and raising the pH level of the RW tends to increase the rejection rate of silica, boron, and total organic carbon (TOC). It also tends to increase silica solubility, thus reducing the risk of silica deposition on the membrane. 

Additionally, if a selected polymeric DCA is properly matched to a particular boiler operating temperature and pressure, there should be no increase in the total organic carbon (TOC) level of the steam. 

NOTE The decomposition of DEHA should not be considered too seriously because it is very low initially. At 1,500psig, DEHA breakdown only amounts to 3%, as measured by the total organic carbon (TOC) content. Compare this to HQ, which breaks down to the extent of 43% at the same pressure. 

Hansell, D. A. and Peltzer, E. T. (1998). Spatial and temporal variations of total organic carbon in the Arabian Sea. Deep-Sea Res. II (in press). 

Cathanthus roseus Nicotiana tabacum Cinchona robusta Tabernaemontana divaricata 3-1 STR (2 1 wv) D 4.5 cm batch and chemostat N 2.5 -16.7 s Q 0.33 wm t < 30 d biomass production total organic carbon extracellular protein membrane integrity substrate consumption [107]... 

The mineralization of 0.2 mM Indigo Carmine was conducted in a batch photo reactor (0.5 L) in the presence of 8W UVC light and 10 mM H2O2 at different initial solution pHs and 30 C, as described in our previous study [4]. The total organic carbon (TOC) of the... 

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