scholarly journals Digestate Liquid Fraction Treatment with Filters Filled with Recovery Materials

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Ilaria Piccoli ◽  
Giuseppe Virga ◽  
Carmelo Maucieri ◽  
Maurizio Borin
Keyword(s):  
Chemical Oxygen Demand ◽  
Total Nitrogen ◽  
Liquid Fraction ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Green Technology ◽  
Filling Material ◽  
Community Interactions ◽  
Material Particle ◽  
N Removal

Constructed wetlands (CWs) represent a green technology for digestate liquid fraction (DLF) treatment. However, previous research has warned about their performance when treating wastewater with high suspended solid and organic loads. In addition, the high NH4-N concentration typical of this wastewater can compromise vegetation establishment and activity. In view of this, a digestate pretreatment is needed. This study aimed to test the performance of filters filled with recovery materials, such as brick and refractory material, for DLF pretreatment. The effect on DLF physical (electrical conductivity, pH, dissolved oxygen, and temperature) and chemical (total nitrogen, ammonia–nitrogen, nitrate–nitrogen, total phosphorus, soluble phosphorus, and chemical oxygen demand) characteristics was monitored during eight weekly cycles. The effect of filtration on total nitrogen and ammonia–nitrogen removal began after about one month of loading, suggesting that an activation period is necessary for bacteria. For effective N removal, the presence of multiple digestate recirculations per day through the filters appears mandatory to guarantee the alternation of nitrification and denitrification conditions. For P removal, filling material particle size appeared to be more important than its composition. Unclear performances were observed considering chemical oxygen demand. Further studies on filling media and microbial community interactions, and the long-term efficiency of filters, are desirable.

scholarly journals Study on the Decontamination Effect of Biochar-Constructed Wetland under Different Hydraulic Conditions

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 893
Author(s):  
Chuanjie Xing ◽  
Xiangxi Xu ◽  
Zhenghe Xu ◽  
Rongzhen Wang ◽  
Lirong Xu
Keyword(s):  
Chemical Oxygen Demand ◽  
Constructed Wetlands ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Constructed Wetland ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Removal Rates ◽  
Hydraulic Conditions ◽  
Hydraulic Load

To explore the purification effect of biochar-constructed wetlands on rural domestic sewage, six types of biochar-constructed wetlands were constructed for experiments. Under different hydraulic conditions, the removal effects of each biochar-constructed wetland on chemical oxygen demand, ammonia nitrogen, total nitrogen, and total phosphorus in sewage were analyzed. The results showed that the removal rates of the four types of pollutants in each biochar-constructed wetland first increased and then decreased with the increase in hydraulic retention time, and the optimal hydraulic retention time range was 36–48 h. The highest removal rates of chemical oxygen demand, ammonia nitrogen, total nitrogen, and total phosphorus in the wetland were 97.34 ± 0.84%, 95.44 ± 1.29%, 98.95 ± 0.52%, and 97.78 ± 0.91%, respectively. The chemical oxygen demand (COD) removal rate of each biochar-constructed wetland increased first, then decreased with the increase in hydraulic load, and the optimal hydraulic load was 10 cm/d. The removal efficiency of ammonia nitrogen, total nitrogen, and total phosphorus of each biochar-constructed wetland gradually weakened with the increase in hydraulic load, and the optimal hydraulic load range was between 5 and 10 cm/d. Under these conditions, the highest removal rates of chemical oxygen demand, ammonia nitrogen, total nitrogen, and total phosphorus in the wetland were 92.15 ± 2.39%, 98.32 ± 0.48%, 96.69 ± 1.26%, and 92.62 ± 2.92%, respectively. Coconut shell and shell-constructed wetlands with the highest proportion of biochar in the matrix have the best removal effect on pollutants under different hydraulic conditions, and the wastewater purification effect is stronger, indicating that the addition of biochar is helpful for the removal of pollutants in constructed wetlands.

scholarly journals Analysis and investigation of the third drainage ditch pollution situation in Ningxia based on multivariate statistics

2020 ◽  
Vol 145 ◽  
pp. 02082
Author(s):  
Linfeng Tian
Keyword(s):  
Chemical Oxygen Demand ◽  
Multivariate Statistics ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Water Environment ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Drainage Ditch ◽  
The Third ◽  
Social Statistics

This article takes the third drainage ditch in Ningxia as the research object, and uses the multivariate statistics method to analyze the interrelationship between the four major pollutants at nine regional points in the main pollution ditch section of the third drainage ditch throughout the year from the perspective of time and space, to improve the water environment quality. SPSS (Social Statistics Software Package) is used to analyze chemical oxygen demand, total phosphorus, total nitrogen, ammonia nitrogen, and index of major pollutants of permanganate. The research results show that the main pollutants and the degree of pollution affecting the water quality of the third drainage ditch are: total nitrogen> ammonia nitrogen> total phosphorus> chemical oxygen demand. At the end of San’er, ammonia nitrogen and total nitrogen were the most polluted. At the Dawukou section of San’er, the chemical oxygen demand and total phosphorus were the heaviest.

Overview of Discharges from Pumping Stations and the Consequent Water Pollution Characteristics in Central Shanghai, China

2014 ◽  
Vol 522-524 ◽  
pp. 201-210
Author(s):  
Jian Feng Ye ◽  
Dan Jie Lu
Keyword(s):  
Water Pollution ◽  
Chemical Oxygen Demand ◽  
Total Nitrogen ◽  
Biochemical Oxygen Demand ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Ammonia Nitrogen ◽  
The Past ◽  
Pumping Stations

Discharges from pumping stations to rivers have become an important issue in central Shanghai. Based on the analysis of the contaminant concentrations and the volume of discharged water in central Shanghai over the past five years, this research has identified that the discharges from pumping stations to watercourse were composed of DWDs and WWDs. The total annual discharges were approximately 155 to 202 million cubic meters. The contaminant concentrations in the DWDs were close to those in the local domestic wastewater (DW), while the WWDs usually had higher concentrations of the contaminants than the local DW. In central Shanghai, the total contaminant discharges (2008 to 2012) from pumping stations were 72,900-95,700 t·a-1 for suspended solids (SS), 67,300-88,100 t·a-1 for chemical oxygen demand (COD), 20,200-27,100 t·a-1 for biochemical oxygen demand (BOD5), 2,000-3,000 t·a-1 for ammonia-nitrogen (NH3-N), 4,100-5,900 t·a-1 for total nitrogen (TN), and 800-1,300 t·a-1 for total phosphate (TP).

scholarly journals Effect of hydraulic retention time on chemical oxygen demand and total nitrogen removal in intermittently aerated constructed wetlands

2020 ◽  
Vol 15 (3) ◽  
pp. 1 ◽  
Author(s):  
Isabela Pires da Silva ◽  
Gabriela Barbosa da Costa ◽  
João Gabriel Thomaz Queluz ◽  
Marcelo Loureiro Garcia
Keyword(s):  
Chemical Oxygen Demand ◽  
Constructed Wetlands ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Constructed Wetland ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Intermittent Aeration

   This study evaluated the effect of hydraulic retention time on chemical oxygen demand (COD) and total nitrogen (TN) removal in an intermittently aerated constructed wetlands. Two horizontal subsurface-flow constructed wetlands were used: one without aeration and the other aerated intermittently (1 hour with aeration/7 hours without aeration). Both systems were evaluated treating domestic wastewater produced synthetically. The flow rate into the two CWs was 8.6 L day-1 having a hydraulic retention time of 3 days. The results show that the intermittently aerated constructed wetland were highly efficient in removing COD (98.25%), TN (83.60%) and total phosphorus (78.10%), while the non-aerated constructed wetland showed lower efficiencies in the removal of COD (93.89%), TN (48.60%) and total phosphorus (58.66). These results indicate, therefore, that intermittent aeration allows the simultaneous occurrence of nitrification and denitrification processes, improving the removal of TN in horizontal subsurface-flow constructed wetlands. In addition, the use of intermittent aeration also improves the performance of constructed wetlands in removing COD and total phosphorus.

scholarly journals Synthesis and properties of zeolite/N-doped porous carbon for the efficient removal of chemical oxygen demand and ammonia-nitrogen from aqueous solution

RSC Advances ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 6452-6459 ◽  
Author(s):  
Guangzhi Xin ◽  
Min Wang ◽  
Lin Chen ◽  
Yuzhou Zhang ◽  
Meicheng Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Chemical Oxygen Demand ◽  
Porous Carbon ◽  
Mesoporous Carbon ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Efficient Removal ◽  
Porous Activated Carbon

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.

The Study of Prediction of Agricultural Source Pollution Emissions of Ammonia Nitrogen (AN) and Chemical Oxygen Demand (COD) Based on Bionic Neural Network Algorithm

2013 ◽  
Vol 461 ◽  
pp. 544-552 ◽  
Author(s):  
Hong Peng Guo ◽  
Gan Yu Feng ◽  
Chun Xia Liu ◽  
Xiao Yi Zhang
Keyword(s):  
Neural Network ◽  
Chemical Oxygen Demand ◽  
Rapid Development ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Average Error ◽  
Research Results ◽  
Network Algorithm ◽  
Neural Network Algorithm ◽  
Pollution Emissions

Nearly 40% of Chinese water pollution comes from agricultural sources of pollution, and the annual emissions are difference. If we want to control pollution emissions effectively, we need to accurately predict the amount of agricultural emissions of Ammonia Nitrogen (AN) and Chemical Oxygen Demand (COD). Due to the complex mechanism of the agricultural non-point source pollution, its emissions are very difficult to measure. Currently, the Bionics Research is in a stage of rapid development, and it continues to expand into many new areas of research. So the comprehensive study of Bionics and pollutant control study will be a good choice. This research used bionic BP（Back Propagation） neural network algorithm, and used pollution census data from 2002 to 2007 and established neural network model with neural network algorithm. And we predicted the agricultural sources of emissions of AN and COD with the data from 2008 to 2010. Finally we compared the predicted value and the actual value. Research results showed that, with using the bionic BP neural network, agricultural sources emissions of AN and COD are evaluated actually and the results indicate that the average error is under 5.0%. Research results proved that the model is effective. The neural network is a scientific predict method for the agricultural sources emissions of AN and COD. It can be widely used in the prediction of agricultural sources emissions of AN and COD.

scholarly journals Efficiency of an Integrated Purification System for Pig Slurry Treatment under Mediterranean Climate

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 208
Author(s):  
Martire Angélica Terrero ◽  
María Ángeles Muñoz ◽  
Ángel Faz ◽  
María Dolores Gómez-López ◽  
Jose A. Acosta
Keyword(s):  
Total Nitrogen ◽  
Liquid Fraction ◽  
Oxygen Demand ◽  
Aeration Tank ◽  
Pig Slurry ◽  
Purification System ◽  
Storage Pond ◽  
Total Nitrogen Removal ◽  
Phase Separator ◽  
Kjeldahl Nitrogen

The intensification of pig production is considered a risky activity for the environment when the generated pig slurry is not adequately treated. In addition, intensive agriculture practices where pig slurry is applied to the cropland could cause nitrate leaching, salinization, and soil pollution (heavy metals and pathogens), thus the development of an eco-friendly system for pig slurry treatment is essential to avoid undesirable environmental impacts. The main objective of this study was to assess the efficiency of an integrated purification system (IPS) for treating pig slurry. The system included a pretreatment module (raw pig slurry tank, phase separator, aeration tank, and settlement tank), constructed wetlands (CWs) that included an unplanted cell and a planted cell, and a storage pond (SP). Pig slurry samples from the pretreatment modules, CWs, and SP were collected in triplicate and physic-chemical and microbial analyses were performed. Results showed that the pretreatment modules decreased the total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) concentrations in the liquid fraction. Higher total nitrogen removal was reported in the planted cell, which decreased from 4.0 g L−1 to 1.9 g L−1 in the inflow and outflow, respectively. Total efficiencies over 85% were found in the planted and unplanted cells for TSS, Kjeldahl nitrogen (KN), chemical oxygen demand (COD), and TP. Microbial parameters were eliminated after the treatment in the planted cell. Therefore, the results indicated that filtration (pretreatment), purification (constructed wetland), and bioremediation (storage pond) constituted an appropriate IPS for treating pig slurry.

scholarly journals Occurrence and Succession of Bacterial Community in O3/BAC Process of Drinking Water Treatment

2019 ◽  
Vol 16 (17) ◽  
pp. 3112 ◽  
Author(s):  
Sheng Dong ◽  
Lijun Liu ◽  
Yuxiu Zhang ◽  
Fajun Jiang
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Bacterial Community ◽  
Dissolved Oxygen ◽  
Chemical Oxygen Demand ◽  
Bacterial Communities ◽  
Oxygen Demand ◽  
Drinking Water Treatment ◽  
Turbidity Removal ◽  
N Removal

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.

scholarly journals Denitrifying Woodchip Bioreactor Leachate Tannic Acid and True Color: Lab and Field Studies

2020 ◽  
Vol 63 (6) ◽  
pp. 1747-1757
Author(s):  
Niranga M. Wickramarathne ◽  
Richard A. Cooke ◽  
Ruth Book ◽  
Laura E. Christianson
Keyword(s):  
Chemical Oxygen Demand ◽  
Tannic Acid ◽  
Acid Leaching ◽  
Oxygen Demand ◽  
The Other ◽  
List Type ◽  
N Removal ◽  
Low Concentrations ◽  
True Color ◽  
Over Time

HighlightsOak leached more tannic acid, true color, and chemical oxygen demand (COD) than ash and mixed hardwood chips.The factors became similar (tannic acid, COD) or below stream levels (true color) after flushing.Eleven site-years of field bioreactor data showed decreasing tannic acid and true color over time.Post-startup tannic acid was lower in bioreactor outflow than in area streams.True color did not appear to be a reliable indicator of leachate tannic acid at low concentrations.Abstract. Woodchips have been a preferred denitrifying bioreactor medium to date, but concerns about potential harmful effects of tannins in the leachate have precluded the use of oak chips in many installations. A study was conducted to compare the suitability of oak (genus Quercus) woodchips as a denitrifying bioreactor medium relative to other types of woodchips, both in lab leachate tests and in the context of observed bioreactor leaching in the field. Assessment measures included the content of tannic acid and other compounds in the leachate, as well as leachate color, which can often be high during startup. An 84-day leaching test using rectangular bioreactor cells filled with either oak (Quercus rubra), ash (Fraxinus spp. L.), or a generic hardwood blend showed that oak initially leached higher concentrations of tannic acid, true color, and chemical oxygen demand (COD) than the other two media. The significant differences in leached concentrations among the three wood types were eliminated after a finite leaching period. Tannic acid and true color in 11 site-years of field bioreactor outflow data generally decreased over time, except following a dry period when one of the bioreactors received no drainage inflow for more than two months. The lab and field results indicated the capability of woodchip bioreactors to flush at least these two analytes to ambient stream levels. True color did not appear to be the best parameter for estimating the tannin content of woodchip leachate due to discrepancies at low concentrations. Mass normalized tannic acid leaching ranged from 0.03 to approximately 40 mg tannic acid g-1 woodchip across the lab and field assessments. Oak initially leached more tannic acid, color, and COD than the other wood types, but the eventual similarity among the wood types after flushing with a sufficient number of pore volumes meant that any potentially negative environmental impacts would likely be limited to the startup period or possibly after dry periods. Oak initially eluted higher mean total nitrogen (TN) concentrations than the other wood types, but the treatments were not significantly different by day 3, indicating that biological N removal was not significantly inhibited, even with high concentrations of tannic acid. Keywords: Chemical oxygen demand, Oak, Tannin, Water quality, Wood leachate.

Purification Effect of Lolium multiflorum Ecological Floating Beds System in Urban Malodorous River at Low Temperature

2012 ◽  
Vol 518-523 ◽  
pp. 2686-2689
Author(s):  
Yu Hong Chai ◽  
Wen Yao Yan ◽  
Ming Xin Wang
Keyword(s):  
Low Temperature ◽  
Chemical Oxygen Demand ◽  
Total Nitrogen ◽  
Growth Rates ◽  
Low Temperatures ◽  
Lolium Multiflorum ◽  
Oxygen Demand ◽  
Total Biomass ◽  
Water Plant ◽  
Natural Rivers

An ecological floating beds system was constructed to treat natural urban malodorous river in Changzhou at low temperature. Taking Lolium multiflorum as an example of water plant, the characteristics and contribution of its uptake to total nitrogen (TN), NH4+-N, total phosphorus (TP) and chemical oxygen demand (CODMn) in the system were studied in a period of 80 days. Significant growth of the plant Lolium multiflorum was observed with total biomass ranging from 53 g to 785 g, and the highest growth rates were 8.82 and 9.23 for biomass of above water and under water part, respectively. Different concentrations of TN, NH4+-N, TP and COD were found between in the floating beds and out the floating beds. The highest removal rates of TN, NH4+-N, TP and CODMn using Lolium multiflorum ecological floating beds system were 16.8%, 33.0%,10.8% and 17.8%, respectively. The purification effect of ecological floating beds shows it can be well applied to cleaning natural rivers at low temperatures.

Sign in / Sign up

Export Citation Format

Share Document