pH adjustment improves the removal of disinfection byproduct precursors from sedimentation sludge water

2022 ◽  
Vol 179 ◽  
pp. 106135
Author(s):  
Yunkun Qian ◽  
Yanan Chen ◽  
David Hanigan ◽  
Yijun Shi ◽  
Sainan Sun ◽  
...  
1971 ◽  
Vol 10 (03) ◽  
pp. 245-251 ◽  
Author(s):  
P. Richards ◽  
W. C. Eckelman

SummaryThe full potential use of technetium has not been achieved despite its ideal physical properties, dosimetry and availability because of the complex preparations required for 99mTc radiopharmaceuticals. One of the goals of our work is to develop techniques for the preparation of high-purity 99mTc compounds which can be easily prepared, ideally by adding pertechnetate to a prepared solution.The use of stannous ion as reducing agent for technetium makes it possible to obtain such one-step, high-purity products. All non-radioactive components can be premixed in a single vial before addition of the radioactive pertechnetate. No final pH adjustment, further chemical manipulation or purification is required.Procedures for two instantly labeled compounds have been developed to date: 99mTc DTPA and 99mTc HSA. The 99mTc DTPA is prepared by adding pertechnetate to a previously prepared solution of stannous ion and CaNa3 DTPA which has been stored at pH 4. The 99mTc HSA is prepared by adding pertechnetate to a solution of stannous ion and HSA. The parametric variations and analytical techniques involved in formulating these procedures are described. It appears that development of kits for other biologically interesting compounds may be possible using similar procedures.


1983 ◽  
Vol 22 (05) ◽  
pp. 246-250 ◽  
Author(s):  
M. Al-Hilli ◽  
H. M. A. Karim ◽  
M. H. S. Al-Hissoni ◽  
M. N. Jassim ◽  
N. H. Agha

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.


Fact Sheet ◽  
1997 ◽  
Author(s):  
Michael L. Pomes ◽  
W.R. Green ◽  
E.M. Thurman ◽  
W.H. Orem ◽  
H.T. Lerch

1973 ◽  
Vol 8 (1) ◽  
pp. 110-121
Author(s):  
A. Netzer ◽  
J.D. Norman

Abstract The merits of activated carbon for removal of organic compounds from wastewater have been well documented in the literature. On the other hand there is a lack of published data on the use of activated carbon for the removal of trace metals from wastewater. Experiments were designed to assess the possibility that activated carbon treatment would remove aluminum, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, nickel, silver and zinc from wastewater. All metals studied were tested over the pH range 3-11. Greater than 99.5% removal was achieved by pH adjustment and activated carbon treatment for most of the metals tested.


2021 ◽  
Vol 55 (5) ◽  
pp. 2908-2918
Author(s):  
Joshua M. Allen ◽  
Michael J. Plewa ◽  
Elizabeth D. Wagner ◽  
Xiao Wei ◽  
Gretchen E. Bollar ◽  
...  

Chemosphere ◽  
2021 ◽  
pp. 130643
Author(s):  
Lingxiao Fu ◽  
Xiaofeng Wu ◽  
Yongbin Zhu ◽  
Lei Yao ◽  
Chengqiang Wu ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2031
Author(s):  
Ruben Miranda ◽  
Isabel Latour ◽  
Angeles Blanco

Effluent reuse is a common practice for sustainable industrial water use. Salt removal is usually carried out by a combination of membrane processes with a final reverse osmosis (RO). However, the presence of silica limits the RO efficiency due to its high scaling potential and the difficulty of cleaning the fouled membranes. Silica adsorption has many advantages compared to coagulation and precipitation at high pHs: pH adjustment is not necessary, the conductivity of treated waters is not increased, and there is no sludge generation. Therefore, this study investigates the feasibility of using pseudoboehmite and its calcination product (γ-Al2O3) for silica adsorption from a paper mill effluent. The effect of sorbent dosage, pH, and temperature, including both equilibrium and kinetics studies, were studied. γ-Al2O3 was clearly more efficient than pseudoboehmite, with optimal dosages around 2.5–5 g/L vs. 7.5–15 g/L. The optimum pH is around 8.5–10, which fits well with the initial pH of the effluent. The kinetics of silica adsorption is fast, especially at high dosages and temperatures: 80–90% of the removable silica is removed in 1 h. At these conditions, silica removal is around 75–85% (<50 mg/L SiO2 in the treated water).


Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 878
Author(s):  
Apinya Singkhala ◽  
Chonticha Mamimin ◽  
Alissara Reungsang ◽  
Sompong O-Thong

A sudden pH drops always inhibits the anaerobic digestion (AD) reactor for biogas production from palm oil mill effluent (POME). The pH adjustment of POME by oil palm ash addition and the biogas effluent recycling effect on the preventing of pH drop and change of the archaea community was investigated. The pH adjustment of POME to 7.5 increased the methane yield two times more than raw POME (pH 4.3). The optimal dose for pH adjustment by oil palm ash addition was 5% w/v with a methane yield of 440 mL-CH4/gVS. The optimal dose for pH adjustment by biogas effluent recycling was 20% v/v with a methane yield of 351 mL-CH4/gVS. Methane production from POME in a continuous reactor with pH adjustment by 5% w/v oil palm ash and 20% v/v biogas effluent recycling was 19.1 ± 0.25 and 13.8 ± 0.3 m3 CH4/m3-POME, respectively. The pH adjustment by oil palm ash enhanced methane production for the long-term operation with the stability of pH, alkalinity, and archaea community. Oil palm ash increased the number of Methanosarcina mazei and Methanothermobacter defluvii. Oil palm ash is a cost-effective alkali material as a source of buffer and trace metals for preventing the pH drop and the increased methanogen population in the AD process.


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