scholarly journals The Treatment of High Concentration Dyeing Wastewater with Pulsed Current Electrocoagulation

2016 ◽  
Vol 10 (5) ◽  
pp. 87 ◽  
Author(s):  
Jun Wang ◽  
Hong Cheng Tan ◽  
Yong Liang Zhang ◽  
Yong Zhang Pan
Keyword(s):  
Electrode Materials ◽  
Ph Value ◽  
Anaerobic Treatment ◽  
Ammonia Nitrogen ◽  
Pulsed Current ◽  
Dyeing Wastewater ◽  
High Concentration ◽  
Operational Conditions ◽  
Effluent Quality ◽  
Pre Treatment

<p>In this study, a small pulsed current electrocoagulation device was used to treat high concentration dyeing wastewater from a specific dyeing mill, and the effects of the electrode materials, reaction time, voltage, pH value, and aeration on the results of the treatment were examined. The results showed that under the following operational conditions: electrode materials were iron electrodes, time period was 15 min, voltage was 120 V, and initial pH was approximately 6, the removal rates of the COD, ammonia nitrogen, and color were 79.45%, 23.89%, and 87.50%, respectively. On this basis, a pulsed current electrocoagulation device, with a handling capacity of 0.5 m<sup>3</sup>/h, was used to conduct a pilot plant test for a period of one month. The results showed that the effluent quality (COD 1217.4 mg/L and NH<sub>4</sub><sup>+</sup>-N 358.2 mg/L on average) of the high-concentration dyeing wastewater, whose COD and NH<sub>4</sub><sup>+</sup>-N concentrations were 5328 mg/L, 595 mg/L, respectively after the treatment of a pulsed current electrocoagulation reactor, was superior to the effluent quality (COD 1400 mg/L and NH<sub>4</sub><sup>+</sup>-N 450 mg/L) of the mill’s actual pre-treatment system (flocculation-anaerobic treatment-acidification), and fully reached the influent requirements of the subsequent aerobic treatment. The results of this study showed that pulsed current electrocoagulation reactors may be effectively used for the pre-treatment of high concentration dyeing wastewater due to the observed advantages, such as good treatment effects, small investment, and economical space occupation.</p>

Isolation and Identification of Ammonibacteria and Ammoniation Characteristic Analysis

2011 ◽  
Vol 340 ◽  
pp. 280-286 ◽  
Author(s):  
Wen Yi Zhang ◽  
Fang Yuan Tan ◽  
Ting Ting Zhao ◽  
Li Qiao Lu ◽  
Ning Han
Keyword(s):  
Organic Nitrogen ◽  
Ph Value ◽  
Ammonia Nitrogen ◽  
Aerobic Bacteria ◽  
Strictly Aerobic ◽  
High Concentration ◽  
Characteristic Analysis ◽  
Isolation And Identification ◽  
Suitable Temperature ◽  
Biochemistry Test

Two strains of T1, Z1 ammonibacterium were isolated from the biofilm of the BAF reactor. According to the morphologic observation and physiological biochemistry test, the strains T1, Z1 were preliminarily identified asProteusandMicrococcus respectively. The research of the strains T1, Z1 for ammoniation characteristics indicated that the suitable temperature was 30°C, the suitable pH value was 7.0 and the best inoculum quantity was 5%. The strain T1 was strictly aerobic bacteria and Z1 was facultative aerobic bacteria. In these operating parameters, two strains of T1, Z1 were good of the degradation of organic nitrogen and the growth rate of ammonia nitrogen could respectively reach up to 86.91% and 69.98%. The strains T1, Z1 had a certainly practical value for treating the waste water with the high concentration of organic nitrogen.

scholarly journals Ammonia Nitrogen Removal from Domestic Wastewater via Nitrification Process Using Aerated Rock Filter

2015 ◽  
Vol 773-774 ◽  
pp. 1350-1354
Author(s):  
Rafidah Hamdan ◽  
Izzati Izwani Ibrahim ◽  
Siti Zahirah Haron
Keyword(s):  
Ph Value ◽  
Low Cost ◽  
Domestic Wastewater ◽  
Treatment Method ◽  
Ammonia Nitrogen ◽  
Warm Climate ◽  
Effluent Quality ◽  
Filter System ◽  
Filter Performance ◽  
Final Effluent

Excessive nitrogen in domestic wastewater discharge accelerates eutrophication in an aquatic ecosystem. To treat wastewater high in nitrogen conventionally are more expensive, complex and generate high amount of sludge. In line with this situation, rock filters (RF) emerged as one of attractive natural wastewater treatment method to treat wastewater high in nutrient because this filter system is easier to maintain, using low-cost filter media, and environmentally-friendly technology. However, studies on the removal of nitrogen in the system are still limited due to nitrification study under warm climate. Thus, an aerated rock filter system has been designed in this study to remove ammonia nitrogen from domestic wastewater using the recommended hydraulic loading rate in warm climate condition. The laboratory aerated rock filter system has been in operated for 2 months with 5 weeks of sampling. The filter influent and effluent samples have been collected and analyzed twice a week for Total Kjeldhal Nitrogen (TKN), ammonia nitrogen (AN), nitrates ,pH, temperature, DO and alkalinity to monitor the filter performance in removing nitrogen. Results from the laboratory experiments show that AN in wastewater was oxidized to nitrate and efficiently removed as the removal of ammonia nitrogen was ranged from 66.05 % to 91.30 % and the removal percentage of TKN was ranged from 63.23 % to 87.68 %. The temperature was in the range of 25°C to 27.5°C, pH value was in the range of 6.34 to 8.04, DO was from 6.64 mg/L to 7.75 mg/L, and the alkalinity was from 15 to 110 as mg /L CaCO3. Therefore, from this laboratory experiment it can be concluded that aerated rock filter system has high potential in removing AN and TKN. The system also able to produce a good final effluent quality which is comply with the effluent requirement for nutrient removal in wastewater under the Environmental Quality Act (Sewage) Regulations, 2009 that is safe to be released to the water body.

Inhibition factor of ammonification in stored urine with fecal contamination

2008 ◽  
Vol 58 (6) ◽  
pp. 1187-1192 ◽  
Author(s):  
S. Hotta ◽  
N. Funamizu
Keyword(s):  
Ph Value ◽  
Fecal Contamination ◽  
Ammonia Nitrogen ◽  
Urea Hydrolysis ◽  
Urea Solution ◽  
Storage Process ◽  
High Concentration ◽  
Inhibition Factor ◽  
Optimum Ph ◽  
Negative Effect

Inhibition factors of urea hydrolysis caused by fecal contamination as source of urease were investigated. The urea hydrolysis was described by initial ammonification rate (IAR). Three factors for the inhibition (pH, free ammonia nitrogen (FAN) and salinity) were investigated in this study. It was found that the optimum pH value for the urea hydrolysis was obtained at pH 7 (30°C). Similar results were obtained from pH 5 to pH 8 whereas pH 9 provided a little amount of negative effect on the hydrolysis. Significant effect of the FAN as inhibition factor on the urea hydrolysis was obtained in the urea solution: the hydrolysis was observed within 120 mg-N/l of the FAN level in artificial urea solution with fecal contamination. However in storage process of real urine the urea hydrolysis was observed until the FAN level increased up to 2,000 mg-N/l. Salinity obviously provided negative effect on the urea hydrolysis in stored urine with fecal contamination at 30°C. It was assumed that high concentration of the NaCl (150 g/l) was required to achieve 50% reduction of the IAR.

REDUCTION OF COD IN NAM SON LANDFILL LEACHATE BY ELECTRO-FENTON AS SECONDARY TREATMENT AFTER ELECTROCOAGULATION PRETREATMENT

2019 ◽  
Vol 57 (6) ◽  
pp. 724
Author(s):  
Son Thanh Le ◽  
Khai Cao LE
Keyword(s):  
Landfill Leachate ◽  
High Strength ◽  
Potential Method ◽  
Ammonia Nitrogen ◽  
Operating Conditions ◽  
Secondary Treatment ◽  
Fenton Process ◽  
High Concentration ◽  
Initial Ph ◽  
Pre Treatment

Landfill leachate is a high-strength wastewater that is most difficult to deal with because the fluctuating of composition and quality as well as high concentration of specific pollutants (PAH, PCBs, heavy metals) and very high ammonia nitrogen and COD concentrations. So, after a pre-treatment as electrocoagulation, over 73% of COD has been treated from Nam Son landfill leachate, however the output value of COD still exceeds the QCVN 40:2011/BTNMT, column B. So, an electro-fenton process was employed to secondarily treat Nam Son landfill leachate, after an electrocoagulation pre-treatment.  This electro-fenton system used a Pt gauze anode and a commercial carbon felt cathode to electrogenerate in situ hydrogen peroxide and regenerate ferrous ion as catalyst. In this study, the effects of various operating conditions such as initial pH, concentration of Fe2+ catalyst, current applied on reduction of COD in Nam Son landfill leachate were examined. At the optimal condition: applied current of 1A, pH 3, Fe2+ concentration of 0.1m M, Na2SO4 concentration of 0.05 M, 77.2% COD reduction can be reached within 60 min and the output value of COD is 130.9 mg.L-1, according to QCVN 40:2011/BTNMT, column B. The research results indicated that electro-fenton process can promise as a potential method in practice for secondary treatment of landfill leachate.

Advanced Treatment of Textile Wastewater for Reuse by Ozonation-Biological and Membrane Processes

2012 ◽  
Vol 441 ◽  
pp. 578-583 ◽  
Author(s):  
Xiao Jun Wang ◽  
Qi Kun Xu ◽  
Lu Qing Qi
Keyword(s):  
Ph Value ◽  
Membrane Filter ◽  
Textile Wastewater ◽  
Ammonia Nitrogen ◽  
Integrated System ◽  
Total Alkalinity ◽  
Total Hardness ◽  
Advanced Treatment ◽  
Pre Treatment ◽  
Aerated Filter

Ozone and biological aerated filter (BAF) were combined as a pre-treatment of membrane filter for an advanced treatment of textile wastewater. It was found that adding ozone into BAF directly, forming an integrated system, allowed a higher CODcr and color reduction in this study. The optimal ozone dosage in the integrated unit was 20~30 mg/L. After the pre-treatment, the water qualities were CODcr 27.4 mg/L, turbidity 4.2 NTU, SS 3.0 mg/L, ammonia nitrogen 0.7 mg/L and color 2 times on average. In the final stage of the membrane process, the permeate water quality was the following: pH value 7.4~7.9, conductivity 50~200 µs/cm, total hardness 2~10 mg/L, total alkalinity 25~60 mg/L.

scholarly journals Effect of the Application of Advanced Oxidation Technology on the Effectiveness of Anaerobic Treatment of Wastewaters with a High Concentration of Formaldehyde

2013 ◽  
Vol 39 (4) ◽  
pp. 81-91 ◽  
Author(s):  
Marcin Zieliński ◽  
Marcin Dębowski ◽  
Magda Dudek ◽  
Anna Grala
Keyword(s):  
Advanced Oxidation Process ◽  
Biogas Production ◽  
Advanced Oxidation ◽  
Anaerobic Treatment ◽  
High Concentration ◽  
Fenton’S Reaction ◽  
Second Stage ◽  
Advanced Oxidation Technology ◽  
Oxidation Technology ◽  
Pre Treatment

Abstract The objective of this study was to determine the effect of advanced oxidation process with the use of Fenton’s reaction on the effectiveness of anaerobic treatment of wastewaters originating from the wood industry that were characterized by a high concentration of formaldehyde. Experiments were established to analyze changes in COD content and in the concentration of formaldehyde in treated wastewaters, additional analyses were carried out to assay quantitative and qualitative changes in the biogas produced. The first stage of the experiment involved analyses of the effectiveness of the tested wastewaters treatment only in the process of methane fermentation. At the second stage of the experiment, the biological process was preceded by chemical pre-treatment of wastewaters with Fenton’s reagent. The conducted study proved that the investigated variants of chemical pre-treatment of wastewaters had a significant effect on increasing the total biogas production. In contrast, no significant effect of the applied technology was demonstrated on changes in the concentration of the analyzed contaminants in the treated wastewaters.

State of the Art Review on Landfill and Leachates Treatment in China

2011 ◽  
Vol 347-353 ◽  
pp. 2078-2084
Author(s):  
Chen Yan Hu
Keyword(s):  
Solid Waste Management ◽  
Ph Value ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Suspended Solid ◽  
Municipal Solid Waste Management ◽  
Chemical Treatments ◽  
Pre Treatment ◽  
Engineering Practices ◽  
Physical And Chemical

The main objectives of this study were to describe the municipal solid waste management, leachate characteristics of China landfills, and to summarize the present research of leachate treatments in china such as biological treatment, physical and chemical treatment and land treatment. In the survey of leachate from landfill in Chinese megapolis, the quality is characterized by chemical oxygen demand (COD) of 1500-80000 mg/L, biochemical oxygen demand (BOD) of 200-35000 mg/L, ammonia nitrogen (NH3-N) of 50-2400 mg/L, total nitrogen of 80-2600 mg/L, suspended solid of 30-7000 mg/L and pH value of 5-7.8. In engineering practices of China, the biological systems are usually adopted. Meanwhile, as far as the special quality of leachate is concerned, some chemical treatments are used as the pre-treatment or post-treatment to promote the effluent or improve the biological degradability of leachate.

Removal of cyanide from acrylonitrile wastewater using gas membrane

2011 ◽  
Vol 64 (11) ◽  
pp. 2274-2281 ◽  
Author(s):  
Jinling Wu ◽  
Jianlong Wang ◽  
Haiyang Liu ◽  
Shijun He ◽  
Xia Huang
Keyword(s):  
Membrane Fouling ◽  
Removal Rate ◽  
Treatment Strategies ◽  
Pilot Scale ◽  
Inorganic Salts ◽  
Operational Parameters ◽  
High Concentration ◽  
Operational Conditions ◽  
Industrial Wastewaters ◽  
Pre Treatment

Acrylonitrile wastewater is one of the most refractory industrial wastewaters as it contains cyanide at a high concentration. This study introduced a safe, effective and economic strategy, that is, use of the gas membrane to acrylonitrile wastewater treatment. Due to the complicated constituents of acrylonitrile wastewater, cyanide removal rate by gas membrane is very low. In order to enhance HCN removal, the operational conditions were optimized; pre-treatment strategies for fouling mitigation were also proposed and tested for acrylonitrile wastewater. The optimal operational parameters were achieved at an acidified pH of 5.0, wastewater velocity of 0.14 m s−1, NaOH concentration of 10% and a temperature of 40 °C. The major factor affecting HCN removal was the pH of the acidified wastewater. The reason for the low removal rate was further explored and found to be the decrease of HCN transfer coefficient, which was caused by membrane fouling. Furthermore, the predominant foulants have been identified as colloidal organic materials and inorganic salts. Alkalization, which is effective in reducing these materials, has been proven to be most effective in mitigating membrane fouling and improving HCN removal, which was also confirmed by a pilot-scale study. The overall removal rate was therefore significantly enhanced to 87.1%.

scholarly journals Dynamics of Fermentation Parameters and Bacterial Community in High-Moisture Alfalfa Silage with or without Lactic Acid Bacteria

2021 ◽  
Vol 9 (6) ◽  
pp. 1225
Author(s):  
Shanshan Zhao ◽  
Fengyuan Yang ◽  
Yuan Wang ◽  
Xiaomiao Fan ◽  
Changsong Feng ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Bacterial Community ◽  
Ph Value ◽  
Ammoniacal Nitrogen ◽  
High Concentration ◽  
High Moisture ◽  
Acid Accumulation ◽  
Alfalfa Silage ◽  
Fermentation Parameters

The aim of this study was to gain deeper insights into the dynamics of fermentation parameters and the bacterial community during the ensiling of high-moisture alfalfa. A commercial lactic acid bacteria (YX) inoculant was used as an additive. After 15 and 30 days of ensiling, the control silage (CK) exhibited a high pH and a high concentration of ammoniacal nitrogen (NH3-N); Enterobacter and Hafnia-Obesumbacterium were the dominant genera. At 60 d, the pH value and the concentration of NH3-N in CK silage increased compared with 15 and 30 d, propionic acid and butyric acid (BA) were detected, and Garciella had the highest abundance in the bacterial community. Compared with CK silage, inoculation of YX significantly promoted lactic acid and acetic acid accumulation and reduced pH and BA formation, did not significantly reduce the concentration of NH3-N except at 60 d, and significantly promoted the abundance of Lactobacillus and decreased the abundance of Garciella and Anaerosporobacter, but did not significantly inhibit the growth of Enterobacter and Hafnia-Obesumbacterium. In conclusion, high-moisture alfalfa naturally ensiled is prone to rot. Adding YX can delay the process of silage spoilage by inhibiting the growth of undesirable microorganisms to a certain extent.

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