Kowa Seiko pelletizing chlorination process—Integral utilization of iron pyrites

JOM ◽  
1968 ◽  
Vol 20 (3) ◽  
pp. 63-67 ◽  
Author(s):  
Yasutake Okubo
1986 ◽  
Vol 18 (7-8) ◽  
pp. 257-265 ◽  
Author(s):  
K. Kawamura ◽  
M. Kaneko

In order to evaluate the microbial quality of human wastes and effluents from treatment processes, the microbial flora of samples was examined. Total coliforms, fecal coliforms and fecal streptococci were used as indicator micro-organisms, and Vibrio cholerae non O-1, Salmonella, Staphylococcus aureus and Welchii (Clostridium perfrigens) were selected as pathogenic organisms. Salmonella was detected in only the water samples from the night soil treatment plant, while Staphylococcus aureus was detected in the night soil and the samples from the night soil purification tanks. Vibrio cholerae non 0-1 was not detected in any samples, but Welchii existed in almost all samples. Generally, the density levels and distribution patterns of the indicator micro-organisms were similar to those in the raw wastewaters. The microbial flora was not changed remarkably after the primary sedimentation process and the biological treatment process. After the chlorination process, total colonies, spore-forming bacteria, Welchii, moulds and fecal streptococci could survive, and spore-forming bacteria formed the majority of the total colonies in the well-chlorinated effluents. Welchii at the level of 103/100 ml can be used as the indicator micro-organism to ensure a sanitary safe discharge, because it can survive at the level of 103−104/100 ml even if other indicators and pathogenic micro-organisms are inactivated completely by the chlorination process.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3422
Author(s):  
Giovanni Luongo ◽  
Lorenzo Saviano ◽  
Giovanni Libralato ◽  
Marco Guida ◽  
Antonietta Siciliano ◽  
...  

In recent years, many studies have reported the frequent detection of antihypertensive agents such as sartans (olmesartan, valsartan, irbesartan and candesartan) in the influents and effluents of wastewater treatment plants (WWTPs) and in the superficial waters of rivers and lakes in both Europe and North America. In this paper, the degradation pathway for candesartan (CAN) was investigated by simulating the chlorination process that is normally used to reduce microbial contamination in a WWTP. Twelve isolated degradation byproducts (DPs), four of which were isolated for the first time, were separated on a C-18 column by employing a gradient HPLC method, and their structures were identified by combining nuclear magnetic resonance and mass spectrometry and comparing the results with commercial standards. On the basis of these results, a mechanism of formation starting from the parent drug is proposed. The ecotoxicity of CAN and its DPs was studied by conducting a battery of ecotoxicity tests; bioassays were performed using Aliivibrio fischeri (bacterium), Daphnia magna (planktonic crustacean) and Raphidocelis subcapitata (alga). The ecotoxicity results shed new light on the increased toxicity of DPs compared with the parent compound.


Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2141
Author(s):  
Stavroula Tsitsifli ◽  
Vasilis Kanakoudis

Disinfection is one of the most important water treatment processes as it inactivates pathogens providing safe drinking water to the consumers. A fresh-water distribution network is a complex system where constant monitoring of several parameters and related managerial decisions take place in order for the network to operate in the most efficient way. However, there are cases where some of the decisions made to improve the network’s performance level, such as reduction of water losses, may have negative impacts on other significant operational processes such as the disinfection. In particular, the division of a water distribution network into district metered areas (DMAs) and the application of various pressure management measures may impact the effectiveness of the water chlorination process. Two operational measures are assessed in this paper: (a) the use of inline chlorination boosters to achieve more efficient chlorination; and (b) how the DMAs formation impacts the chlorination process. To achieve this, the water distribution network of a Greek town is chosen as a case study where several scenarios are being thoroughly analyzed. The assessment process utilizes the network’s hydraulic simulation model, which is set up in Watergems V8i software, forming the baseline to develop the network’s water quality model. The results proved that inline chlorination boosters ensure a more efficient disinfection, especially at the most remote parts/nodes of the network, compared to conventional chlorination processes (e.g., at the water tanks), achieving 100% safe water volume and consuming almost 50% less chlorine mass. DMAs’ formation results in increased water age values up to 8.27%, especially at the remote parts/nodes of the network and require more time to achieve the necessary minimum effective chlorine concentration of 0.2 mg/L. However, DMAs formation and pressure management measures do not threaten the chlorination’s efficiency. It is important to include water age and residual chlorine as criteria when optimizing water pressure and the division of DMAs.


RSC Advances ◽  
2021 ◽  
Vol 11 (24) ◽  
pp. 14746-14754
Author(s):  
Yaoguang Guo ◽  
Zhiyuan Liu ◽  
Xiaoyi Lou ◽  
Changling Fang ◽  
Pu Wang ◽  
...  

A systematic study for degradation kinetics and transformation mechanism of sulfacetamide antibiotic, and the potential formation of H-DBPs represented by HAAs in the chlorination process is explored.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 127
Author(s):  
YongChao Wang ◽  
YinBo Zhu ◽  
HengAn Wu

The porous characteristics of disordered carbons are critical factors to their performance on hydrogen storage and electrochemical capacitors. Even though the porous information can be estimated indirectly by gas adsorption experiments, it is still hard to directly characterize the porous morphology considering the complex 3D connectivity. To this end, we construct full-atom disordered graphene networks (DGNs) by mimicking the chlorination process of carbide-derived carbons using annealing-MD simulations, which could model the structure of disordered carbons at the atomic scale. The porous characteristics, including pore volume, pore size distribution (PSD), and specific surface area (SSA), were then computed from the coordinates of carbon atoms. From the evolution of structural features, pores grow dramatically during the formation of polyaromatic fragments and sequent disordered framework. Then structure is further graphitized while the PSD shows little change. For the obtained DGNs, the porosity, pore size, and SSA increase with decreasing density. Furthermore, SSA tends to saturate in the low-density range. The DGNs annealed at low temperatures exhibit larger SSA than high-temperature DGNs because of the abundant free edges.


1984 ◽  
Vol 5 (3) ◽  
pp. 235-243 ◽  
Author(s):  
KN Tiwari ◽  
BS Dwivedi ◽  
AN Pathak

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1213 ◽  
Author(s):  
Le Wang ◽  
Jinbo Yao ◽  
Jiarong Niu ◽  
Jianyong Liu ◽  
Bo Li ◽  
...  

Wool fibers usually need shrinkproofing finishing. The enzyme process is an eco-friendly technology but the traditional exhaustion treatment usually takes excessive time. This study developed a novel multiple padding shrinkproofing process of wool with Savinase 16L and an organic phosphine compound {[HO(CH2)n]3P, n ∈ (1, 10)}. SEM and XPS analyses were employed to compare the wool treated respectively by exhaustion and by padding to reveal the effect of multiple padding. The results showed that treated wool fiber achieved the requirement of machine-washable (area shrinkage less than 8% according to standard TM 31 5 × 5A) in 2.5 min by the padding process. The padding process can control the adsorbance of enzyme on wool, which makes treatment more uniform and avoids strong damage of the wool. Also, the removal efficiency of the disulfide bond was about 15 times as much as in the exhaustion treatment in 2.5 min. The average catalytic rate of the padding process was 14 times faster than the exhaustion process, and the process time (2.5 min) decreased by 32.5 min compared with the exhaustion process (35 min). Multiple padding techniques can achieve continuous production and replace the environmentally harmful chlorination process. Our results provide the underlying insights needed to guide the research of the enzyme process application.


2005 ◽  
Vol 76 (10) ◽  
pp. 686-690 ◽  
Author(s):  
Shigang Long ◽  
Chunxia Ma ◽  
Zhiquan Wang ◽  
Qingmin Meng ◽  
Xinhua Feng ◽  
...  

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