Pecan shell-based granular activated carbon for treatment of chemical oxygen demand (COD) in municipal wastewater

2004 ◽  
Vol 94 (2) ◽  
pp. 129-135 ◽  
Author(s):  
R.R. Bansode ◽  
J.N. Losso ◽  
W.E. Marshall ◽  
R.M. Rao ◽  
R.J. Portier
2010 ◽  
Vol 62 (11) ◽  
pp. 2669-2677 ◽  
Author(s):  
Lizhang Wang ◽  
Yuemin Zhao

Experiments were performed to reduce chemical oxygen demand (COD) from 4,4′-diaminostilbene-2,2′-disulfonic (DSD) acid manufacturing wastewater using electrochemical oxidation coupled with adsorption by granular activated carbon. The COD removal is affected by the residence time and applied voltage. When the residence time is increased, lower value of COD effluent could be obtained, however, the average current efficiency (ACE) decreased rapidly, and so does the applied voltage. In addition, aeration could effectively enhance COD removal efficiency and protect anodes from corrosion. Furthermore, the acidic condition is beneficial to the rapid decrease of COD and the values of pH effluent are independent of the initial solution pH. The optimization conditions obtained from these experiments are applied voltage of 4.8 V, residence time of 180 min and air–liquid ratio of 4.2 with the COD effluent of about 690 mg L−1. In these cases, the ACE and energy consumption are 388% and 4.144 kW h kg−1 COD, respectively. These perfect results from the experiments illustrate that the combined process is a considerable alternative for the treatment of industrial wastewater containing high concentration of organic pollutants and salinity.


2019 ◽  
Vol 4 (1) ◽  
pp. 1-10
Author(s):  
Aida Isma M.I. ◽  
◽  
Abdo Saad ◽  
Rachid Ali A. ◽  
Kenneth Yeoh ◽  
...  

Combined granular activated carbon adsorption with membrane filtration for high strength wastewater treatment have been carried out. Raw oleo-chemical wastewater and leachate were used as sample. Ultrafiltration is also relatively low cost, easy to backwash and operates up to 3 barg. Experiment was carried out by passing through the sample to an adsorption column for 10 minutes followed by membrane filtration at different transmembrane pressure of 1, 2 and 3 barg. Oleo-chemical samples were analysed for chemical oxygen demand, turbidity, suspended solid and leachate samples were analysed for chemical oxygen demand and ammonia nitrogen according to APHA method. Results showed that the best chemical oxygen demand, suspended solids and turbidity removal for oleo-chemical samples achieved at 2 bar with 64%, 93% and 97%, respectively. Leachate showed the best removal of chemical oxygen demand and ammonia nitrogen achieved at 3 bar, with 76% and 87%, respectively. The adsorption process combined with membrane filtration is feasible as an alternative for conventional biological treatment for high strength wastewater. However, GAC exhaustive breakthrough point requires monitoring.


Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 359
Author(s):  
Liping Zhang ◽  
Shengnian Wu ◽  
Nan Zhang ◽  
Ruihan Yao ◽  
Eryong Wu

Salicylic hydroxamic acid is a novel flotation reagent used in mineral processing. However, it impacts the flotation wastewater leaving behind high chromaticity which limits its reuse and affects discharge for mining enterprises. This study researched ozonation catalyzed by the granular activated carbon (GAC) method to treat the chromaticity of the simulated mineral processing wastewater with salicylic hydroxamic acid. The effects of pH value, ozone (O3) concentration, GAC dosage, and reaction time on chromaticity and chemical oxygen demand (CODCr) removal were discussed. The results of individual ozonation experiments showed that the chromaticity removal ratio reached 79% and the effluent chromaticity exceeded the requirement of reuse and discharge when the optimal experimental conditions were pH value 3, ozone concentration 6 mg/L, and reaction time 40 min. The orthogonal experimental results of catalytic ozonation with GAC on chromaticity removal explained that the chromaticity removal ratio could reach 96.36% and the chromaticity of effluent was only 20 when the optimal level of experimental parameters was pH value 2.87, O3 concentration 6 mg/L, GAC dosage 0.06 g/L, reaction time 60 min respectively. The degradation pathway of salicylic hydroxamic acid by ozonation was also considered based on an analysis with ultraviolet absorption spectrum and high-performance liquid chromatography (HPLC).


Chemosphere ◽  
2019 ◽  
Vol 234 ◽  
pp. 845-854 ◽  
Author(s):  
Hooman Vatankhah ◽  
Stephanie M. Riley ◽  
Conner Murray ◽  
Oscar Quiñones ◽  
K. Xerxes Steirer ◽  
...  

RSC Advances ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 6452-6459 ◽  
Author(s):  
Guangzhi Xin ◽  
Min Wang ◽  
Lin Chen ◽  
Yuzhou Zhang ◽  
Meicheng Wang ◽  
...  

A novel adsorbent zeolite/N-doped porous activated carbon (ZAC) was prepared by the synthesis of zeolite and mesoporous carbon to remove ammonia nitrogen (NH4+–N) and chemical oxygen demand (COD) from aqueous solution.


Author(s):  
Sheng Dong ◽  
Lijun Liu ◽  
Yuxiu Zhang ◽  
Fajun Jiang

In the drinking water industry, a common advanced treatment process is comprised of treatment with ozone, followed by biological-activated carbon (O3/BAC). However, the bacterial community formation and succession procedures associated with activated carbon have rarely been reported. In this study, the dynamics of bacterial communities at three different depths were investigated using a pilot-scale O3/BAC filter. The average chemical oxygen demand (CODMn), turbidity removal and dissolved oxygen (DO) consumption rate of the filter were 26.43%, 16.57% and 16.4% during the operation period, respectively. Bacterial communities dominated by proteobacteria and Bacteroidetes attached on activated carbon were determined by polymerase chain reaction-density gradient gel electrophoresis (PCR-DGGE). Principal component analysis (PCA) revealed that the compositions and structures of bacterial communities in different layers clustered after fluctuation. A redundancy analysis (RDA) indicated that Ramlibacter henchirensis was positively correlated to chemical oxygen demand (CODMn) removal and nitrate-N removal, and Georgfuchsia toluolica also showed a positive correlation with CODMn removal. Aquabacterium parvum and Phaeobacterium nitratireducens were positively-correlated with turbidity removal. Pedobacter glucosidilyticus and Pseudomonas sp. were associated with high dissolved oxygen (DO) consumption. These results provide insight into the succession characteristics of the bacterial community of O3/BAC treatment and the interactions of the bacterial community with filter operation performance.


2020 ◽  
Vol 12 (21) ◽  
pp. 8847
Author(s):  
Ahmed Sharaf ◽  
Bing Guo ◽  
David C. Shoults ◽  
Nicholas J. Ashbolt ◽  
Yang Liu

Compared with conventionally collected sewage, source-diverted greywater has a higher potential for on-site treatment and reuse due to its lower contaminant levels and large volume. A new design of granular activated carbon (GAC) biofilters was developed by incorporating unsaturated and saturated zones in a single stage to introduce an efficient, passive, and easy-to-operate technology for greywater on-site treatment at the household scale. The design was customized for its intended application considering various aspects including the reactor’s configuration, packing media, and feeding strategy. With the highest hydraulic and organic loadings of 1.2 m3 m−2 d−1 and 3.5 kg COD m−2 d−1, respectively, and the shortest retention time of 2.4 h, the system maintained an average total chemical oxygen demand removal rate of 94% with almost complete removal of nutrients throughout its 253 days of operation. The system showed a range of reduction efficacy towards five surrogates representing viruses, bacteria, and Cryptosporidium and Giardia (oo)cysts. A well-functioning biofilm was successfully developed, and its mass and activity increased over time with the highest values observed at the top layers. The key microbes within the biofilter were revealed. Feasibility of the proposed technology was investigated, and implications for design and operation were discussed.


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