scholarly journals Coagulation Followed by Ion Exchange to Treat Domestic Sewage

2019 ◽  
Vol 8 (3) ◽  
pp. 6808-6814

The pollutants contained in domestic sewage (DS) was separated using coagulation in first stage followed by ion exchange (IE) in second stage. The coagulants FeCl3 , Alum and Al2 (SO4 )3 .16H2O were used for treatment. Among these, performance of Al2 (SO4 )3 .16H2O and FeCl3 was equally good in term of chemical oxygen demand (COD) removal at their optimum pH and optimum dose. COD values were reduced to 78 and 80 mg/dm3 with Al2 (SO4 )3 .16H2O and FeCl3 from initial value 256 mg/dm3 . The FeCl3 coagulant treated DS was further treated using IE process, which was able to reduce hardness upto 10 mg/dm3 from initial value 580 mg/dm3 . Settling of FeCl3 treated sludge was found to best and design of settler has been presented from experimental data.

Author(s):  
Neela Acharya ◽  
Vijay Kumar ◽  
Vandana Gupta ◽  
Chandrakant Thakur ◽  
Parmesh Kumar Chaudhari

Abstract Domestic sewage (DS) was first treated in aerobic sequential batch reactor (SBR). In order to increase the treated water quality, DS from SBR was further treated using electrocoagulation (EC) and Ion exchange (IE) process. In the SBR study, process parameters such as hydraulic retention time (HRT) and reactor fill time (t f ) was optimized at various volume exchange ratio (VER) of 0.534, 0.4, 0.266, and 0.133. The best HRT and t f were observed to be 0.78 day (d) and 2 h, respectively, providing 72.37% chemical oxygen demand (COD) reduction (initial value of COD = 270 mg/dm3). Kinetics of biodegradation in SBR was also studied. The second stage treatment was performed in EC reactor at 1 ampere (A) current for 30 min electrolysis time (t R). EC reactor, further reduced COD and biological oxygen demand (BOD) up to 72 and 21 mg/dm3 from its average initial COD and BOD of 94 and 23 mg/dm3, respectively. Second stage treatment in IE process reduced hardness, sulphate, and phosphate up to 15, 0.05, and 0.13 mg/dm3 from its initial value 350, 5.48 and 1.16 mg/dm3, respectively. The treated water can be used as potable water after disinfection as its water quality is near to river water.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Jalilzadeh ◽  
Ramin Nabizadeh ◽  
Alireza Mesdaghinia ◽  
Aliakbar Azimi ◽  
Simin Nasseri ◽  
...  

A systematic model for chemical oxygen demand (COD) removal using the ANAMMOX (Anaerobic AMMonium OXidation) process was provided based on an experimental design. At first, the experimental data was collected from a combined biological aerobic/anaerobic reactor. For modelling and optimization of COD removal, the main parameters were considered, such as COD loading, ammonium, pH, and temperature. From the models, the optimum conditions were determined as COD 97.5 mg/L, ammonium concentration equal to 28.75 mg-N/L, pH 7.72, and temperature 31.3°C. Finally, the analysis of the optimum conditions, performed by the response surface method, predicted COD removal efficiency of 81.07% at the optimum condition.


2021 ◽  
Vol 237 ◽  
pp. 77-87
Author(s):  
Ijanu Emmanuel Madu ◽  
Mohamad Anuar Kamaruddin ◽  
Mohd Suffian Mohd Yusof ◽  
Noorzalila Muhammad Niza ◽  
Abdubaki Mohamed Hussen Shadi ◽  
...  

2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.


Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 418 ◽  
Author(s):  
Pedro Cisterna-Osorio ◽  
Verónica Lazcano-Castro ◽  
Gisela Silva-Vasquez ◽  
Mauricio Llanos-Baeza ◽  
Ignacio Fuentes-Ortega

The objective of this work is to evaluate the impact of innovative modifications made to conventional effluent capture and discharge devices used in subsurface flow wetlands (SSFW). The main modifications that have been developed extend the influence of the capture and discharge device in such a way that the SSFW width and height are fully covered. This improved innovative device was applied and evaluated in two subsurface flow wetlands, one on a pilot scale and one on a real scale. To evaluate the impact of the innovative device with respect to the conventional one in the operational functioning of subsurface flow wetlands, the elimination of chemical oxygen demand (COD) was measured and compared. The results show that for the innovative device, the COD removal was 10% higher than for the conventional device, confirming the validity and effectiveness of the modifications implemented in the effluent capture and discharge devices used in SSFW.


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2532
Author(s):  
Can He ◽  
Jianbing Wang ◽  
Heng Xu ◽  
Xiangyu Ji ◽  
Weiyi Wang ◽  
...  

In this work, the treatment of bio-treated coking wastewater (BCW) by catalytic ozonation was conducted in semi-batch and continuous flow reactors. The kinetics of chemical oxygen demand (COD) removal were analyzed using BCWs from five coking plants. An integral reactor with catalytic ozonation stacked by ozone absorption (IR) was developed, and its efficiency was studied. The catalyst of MnxCe1-xO2/γ-Al2O3 was efficient in the catalytic ozonation process for the treatment of various BCWs. The chemical oxygen demand (COD) removal efficiencies after 120 min reaction were 64–74%. The overall apparent reaction rate constants were 0.0101–0.0117 min−1, which has no obvious relationship with the initial COD of BCW and pre-treatment biological process. The IR demonstrated the highest efficiency due to the enhancement of mass transfer and the utilization efficiency of ozone. Bypass internal circulation can further improve the reactor efficiency. The optimal results were obtained with the ozone absorption section accounting for 19% of the valid water depth in the reactor and 250% of circulation flow ratio. The long-term and full-scale application of the novel reactor in a continuous mode indicated stable removal of COD and polycyclic aromatic hydrocarbons (PAHs). The results showed that the system of IR is a promising reactor type for tertiary treatment of coking wastewater by catalytic ozonation.


2013 ◽  
Vol 848 ◽  
pp. 22-25
Author(s):  
Yan Zheng Wang ◽  
Ying Fu ◽  
Man Man Su ◽  
Shan Shan Cai ◽  
Qing Feng Chen

An organic modified poly-polyacrylamide-Al-Zn-Fe (PPAZF) coagulant was prepared by adding polyacrylamide (PAM) as additives in poly-Al-Zn-Fe (PAZF). The coagulation performance of PPAZF was investigated compared to that of PAZF and polyaluminium chloride (PAC) in treating domestic sewage and pharmaceutical wastewater. The results showed that PPAZF not only had better removal of turbidity and chemical oxygen demand (CODCr) than PZAF and PAC at the optimal dosages of 148 mg·L-1, but also produced large and dense flocs. Compared to PAZF and PAC, the removal of CODCr by PPAZF was greatly improved at lower dosage. In addition, experimental results indicated the main mechanism of PPAZF is a comprehensive coagulation effect and chemical reaction.


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.


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