Growth of Chlorella vulgaris in High Concentrations of Nitrate and Nitrite for Wastewater Treatment

2016 ◽  
Vol 4 (4) ◽  
pp. 441-447 ◽  
Author(s):  
Mahboobeh Taziki ◽  
Hossein Ahmadzadeh ◽  
Marcia A. Murry
Keyword(s):  
Wastewater Treatment ◽  
Chlorella Vulgaris ◽  
High Concentrations ◽  
Nitrate And Nitrite

Quality improvement of biosolids by ferrate(VI) oxidation of offensive odour compounds

1996 ◽  
Vol 33 (3) ◽  
pp. 119-130 ◽  
Author(s):  
Allen C. Chao ◽  
Sergio J. de Luca ◽  
Carlos N. Idle
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Potassium Ferrate ◽  
Sulphur Compounds ◽  
Environmental Recovery ◽  
Oxidizing Power ◽  
Aldehydes And Ketones ◽  
High Concentrations ◽  
By Products

Studies concerning the treatment, stabilization and final disposal of biosolids, one of the by-products of wastewater treatment, in environmental recovery, have been intensified by the sanitary and environmental effects of land disposal. The careful assessment of biosolid quality shows that, when appropriately managed, the environmental risks of their uses can be minimized by chemical stabilization, and biosolids could even be used as fertilizer and soil conditioner. A research study of biosolid stabilization was performed using lime as a standard process compared to potassium ferrate (VI). The chances of leaching and solubilization of metals were tested, simulating conditions for disposal in the environment. The sanitary effectiveness in terms of pathogens (bacteria, fungi and helminth eggs) were also evaluated. Experiments were performed on the lime and ferrate(VI) treatment of compounds such as ammonia, nitrate, soluble sulphides, and total sulphates, indicators of odouriferous offensive compounds which might occasionally prevent some uses of the solids, and the results are presented in this paper. Wastewater Treatment Plants emit offensive odours generated during the sewage treatment process, as well as during the treatment and the management of biosolids. This occurs in the drying beds and the spreading of biosolids on land, due to the high concentrations of sulphur compounds, nitrogen compounds, acids and organic compounds (aldehydes and ketones). The potassium ferrate(VI) utilized in the research is a powerful oxidizing agent throughout the pH scale, with the advantage of not generating by-products which will cause toxicity or mutagenicity (DE LUCA, 1981). The ion ferrate(VI) has greater oxidizing power than permanganate, e.g., it oxidizes reduced sulfur forms to sulphate, ammonia to nitrate, hypochlorite to chlorite and chlorite to chlorate(DE LUCA et al., 1992; CHAO et al., 1992). This paper shows that, as expected, the potassium ferrate (VI) treatment replaces several chemical products utilized for odour control of sludges, mainly aggressive odours caused by ammonia and sulphides, through the formation of precipitates with iron compounds. Ferrate (VI) has often been shown to destroy soluble sulphides, transforming them into sulphate. The generation of oxygen in the decomposition of ferrate(VI) increases its oxidizing power. Ferrate(VI) applied to sludges also has the double effect of transforming ammonia into nitrates, such that this product takes the place of sulphates, acting as an electron acceptor, thus preventing the development of further odours when biosolids are utilized.

scholarly journals ANN-Based Soft Sensor to Predict Effluent Violations in Wastewater Treatment Plants

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1280 ◽  
Author(s):  
Ivan Pisa ◽  
Ignacio Santín ◽  
Jose Vicario ◽  
Antoni Morell ◽  
Ramon Vilanova
Keyword(s):  
Wastewater Treatment ◽  
Short Term Memory ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
False Positive Rate ◽  
Soft Sensor ◽  
Aquatic Life ◽  
Pollutant Concentrations ◽  
High Concentrations ◽  
Artificial Neural Network Ann

Wastewater treatment plants (WWTPs) form an industry whose main goal is to reduce water’s pollutant products, which are harmful to the environment at high concentrations. In addition, regulations are applied by administrations to limit pollutant concentrations in effluent. In this context, control strategies have been adopted by WWTPs to avoid violating these limits; however, some violations still occur. For that reason, this work proposes the deployment of an artificial neural network (ANN)-based soft sensor in which a Long-Short Term Memory (LSTM) network is used to generate predictions of nitrogen-derived components, specifically ammonium ( S N H ) and total nitrogen ( S N t o t ). S N t o t is a limiting nutrient and can therefore cause eutrophication, while nitrogen in the S N H form is toxic to aquatic life. These parameters are used by control strategies to allow actions to be taken in advance and only when violations are predicted. Since predictions complement control strategies, the evaluation of the ANN-based soft sensor was carried out using the Benchmark Simulation Model N.2. (BSM2) and three different control strategies (from low to high control complexity). Results show that our proposed method is able to predict nitrogen-derived products with good accuracy: the probability of detecting violations of BSM2’s limits is 86%–94%. Moreover, the prediction accuracy can be improved by calibrating the soft sensor; for example, perfect prediction of all future violations can be achieved at the expense of increasing the false positive rate.

Indole degrading of ammonia oxidizing bacteria isolated from swine wastewater treatment system

2009 ◽  
Vol 59 (12) ◽  
pp. 2405-2410 ◽  
Author(s):  
Ping Li ◽  
Lei Tong ◽  
Kun Liu ◽  
Yanhong Wang ◽  
Yanxin Wang
Keyword(s):  
Wastewater Treatment ◽  
Biochemical Analysis ◽  
Ammonia Oxidation ◽  
Treatment System ◽  
Swine Wastewater ◽  
Ammonia Oxidizing Bacteria ◽  
16S Rdna Gene ◽  
Wastewater Treatment System ◽  
Nitrate And Nitrite ◽  
Physiological And Biochemical

Three new strains named LPA11, LPB11 and LPC24 were isolated to investigate the patterns of indole degradation and ammonia oxidation in swine wastewater from different parts of a swine wastewater treatment system by the direct spreading plate method. These three isolates were all identified as Pseudomonas putida based on 16S-rDNA gene sequences, main physiological and biochemical analysis. They were capable of decomposing 1.0 mM indole completely in 10, 16 and 18 days respectively. According to the results of HPLC and GC/MS, the possible pathway for the degradation was via oxindole, isatin and anthranilic acid. The three bacteria were capable of oxidizing ammonia, and the strains LPA11 and LPC24 were capable of effectively reducing nitrate and nitrite.

Dairy wastewater treatment in a moving bed biofilm reactor

2002 ◽  
Vol 45 (12) ◽  
pp. 321-328 ◽  
Author(s):  
G. Andreottola ◽  
P. Foladori ◽  
M. Ragazzi ◽  
R. Villa
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Biofilm Reactor ◽  
Dairy Wastewater ◽  
Production Cycle ◽  
Nutrient Loads ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Pre Treatment ◽  
High Concentrations

Dairy raw wastewater is characterised by high concentrations and fluctuations of organic matter and nutrient loads related to the discontinuity in the cheese production cycle and machinery washing. The applicability of a Moving Bed Biofilm Reactor (MBBR) filled with FLOCOR-RMP® plastic media to the treatment of dairy wastewater was evaluated in a pilot-plant. COD fractionation of influent wastewater, MBBR performance on COD and nutrient removal were investigated. A removal efficiency of total COD over 80% was obtained with an applied load up to 52.7 gCOD m−2 d−1 (corresponding to 5 kgCOD m−3d−1). The COD removal kinetics for the MBBR system was assessed. The order of the kinetics resulted very close to half-order in the case of a biofilm partially penetrated by the substrate. The nitrogen removal efficiency varied widely between 13.3 and 96.2% due to the bacterial synthesis requirement. The application of a MBBR system to dairy wastewater treatment may be appropriate when upgrading overloaded activated sludge plants or in order to minimise reactor volumes in a pre-treatment.

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