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

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.

2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


1990 ◽  
Vol 22 (3-4) ◽  
pp. 65-72 ◽  
Author(s):  
H.-H. Schierup ◽  
H. Brix

Since 1983 approximately 150 full-scale emergent hydrophyte based wastewater treatment plants (reed beds) have been constructed in Denmark to serve small wastewater producers. The development of purification performance for 21 plants representing different soil types, vegetation, and hydraulic loading rates has been recorded. Cleaning efficiencies were typically in the range of 60-80% reduction for BOD, 25-50% reduction for total nitrogen, and 20-40% reduction for total phosphorus. The mean effluent BOD, total nitrogen and total phosphorus concentrations of the reed beds were 19 ± 10, 22 ± 9 and 6.7 ± 3.2 mg/l (mean ± SD), respectively. Thus, the general Danish effluent standards of 8 mg/l for N and 1.5 mg/l for P for sewage plants greater than 5,000 PE cannot be met by the present realised design of EHTS. The main problem observed in most systems is a poor development of horizontal hydraulic conductivity in the soil which results in surface run-off. Since the political demands for effluent quality will be more strict in the future, it is important to improve the performance of small decentral sewage treatment plants. On the basis of experiences from different types of macrophyte based and conventional low-technology wastewater treatment systems, a multi-stage system is suggested, consisting of sedimentation and sand filtration facilities followed by basins planted with emergent and submergent species of macrophytes and algal ponds.


2004 ◽  
Vol 49 (1) ◽  
pp. 139-146 ◽  
Author(s):  
S. Rio ◽  
C. Faur-Brasquet ◽  
L. Le Coq ◽  
D. Lecomte ◽  
P. Le Cloirec

Sewage sludges produced from wastewater treatment plants continue to create environmental problems in terms of volume and method of valorization. Thermal treatment of sewage sludge is considered as an attractive method in reducing sludge volume which at the same time produces reusable by-products. This paper deals with the first step of activated carbon production from sewage sludge, the carbonization step. Experiments are carried out on viscous liquid sludge and limed sludge by varying carbonization temperature and heating rate. The results show that carbonized residue properties are interesting for activated carbon production.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1280 ◽  
Author(s):  
Ivan Pisa ◽  
Ignacio Santín ◽  
Jose Vicario ◽  
Antoni Morell ◽  
Ramon Vilanova

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.


2020 ◽  
Vol 15 (1) ◽  
pp. 160-169 ◽  
Author(s):  
Yeshi Cao ◽  
M. C. M. Van Loosdrecht ◽  
Glen. T. Daigger

Abstract Since about the 1990s China has achieved remarkable progress in urban sanitation. The country has built very extensive infrastructure for wastewater treatment, with 94.5% treatment coverage in urban areas and legally mandated nation-wide full nutrient removal implemented. However, municipal wastewater treatment plants (WWTPs) in China are still confronted with issues rooted in the unique sewage characteristics. This study compares energy recovery, cost of nutrient removal and sludge production between Chinese municipal WWTPs and those in countries with longer wastewater treatment traditions, and highlights the cause-effect relationships between Chinese sewage characteristics – high inorganic suspended solids (ISS) loads, and low COD and C/N ratio, and municipal WWTP process performance in China. Integrated design and operation guidelines for municipal WWTPs are imperative in relation to the unique sewage characteristics in China. Cost-effective measures and solutions are proposed in the paper, and the potential benefits of improving the sustainability of municipal WWTPs in China are estimated.


2017 ◽  
Vol 35 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Michał Marzec

AbstractThe reliability of removal of selected contaminants in three technological solutions of the household sewage treatment plants was analysed in this paper. The reliability of the sewage treatment plant with activated sludge, sprinkled biological deposit and hybrid reactor (activated sludge and immersed trickling filter) was analyzed. The analysis was performed using the Weibull method for basic indicators of impurities, BOD5, COD and total suspended solids. The technological reliability of the active sludge treatment plant was 70% for BOD5, 87% for COD and 66% for total suspended solids. In the sewage treatment plant with a biological deposit, the reliability values determined were: 30% (BOD5), 60% (COD) and 67% (total suspended solids). In a treatment plant with a hybrid reactor, 30% of the BOD5and COD limit values were exceeded, while 30% of the total suspended solids were exceeded. The reliability levels are significantly lower than the acceptable levels proposed in the literature, which means that the wastewater discharged from the analysed wastewater treatment plants often exceeds the limit values of indicators specified in currently valid in Poland Regulation of the Minister of Environment for object to 2000 population equivalent.


2018 ◽  
Vol 28 (3) ◽  
pp. 121-131 ◽  
Author(s):  
Anita Jakubaszek ◽  
Artur Stadnik

Abstract The article analyzes the effectiveness of individual Actibloc wastewater treatment plants (produced by Sotralentz) working in the technology of low-rate activated sludge in the Sequential Batch Reactor (SBR) system. The assessment of the effectiveness of household wastewater treatment plants was made on the basis of pollutants: BOD5, COD, total suspended solids, total nitrogen and total phosphorus. The research objects were four household sewage treatment plants located in: Lubań, Kłębanowice, Stara Rzeka and Kościan. The efficiency of removing pollutants in the examined facilities was in the range of: BOD5 92.2 ÷ 97.2%, COD 82.6 ÷ 89.9%, total suspended solids 90.2 ÷ 96.2%, total nitrogen 50.8 ÷ 83.1%, total phosphorus 46.5 ÷ 73.6%. The treated wastewater met the requirements set out in the Regulation of the Minister of the Environment on the conditions to be met when discharging sewage into water or soil, and on substances particularly harmful to the aquatic environment (Journal of Laws 2014, item 1800) in terms of indicators such as BOD5, COD, total suspended solids and total nitrogen. The effectiveness of phosphorus removal in the studied treatment plants was much lower.


Author(s):  
Donwichai Sinthuchai ◽  
Suwanna Kitpati Boontanon ◽  
Pitchaya Piyaviriyakul ◽  
Narin Boontanon ◽  
Ranjna Jindal ◽  
...  

Abstract Excessive and inappropriate use of antibiotics contributes to the spread of antibiotic resistance in the environment, especially in low- to middle-income countries. This study investigated the occurrence, relative abundance, and fate of eight antibiotics at each treatment stage in four domestic and four hospital wastewater treatment plants (dWWTPs and hWWTPs, respectively), as well as mass loadings into the receiving water environments in Bangkok, Thailand. Samples were prepared by solid-phase extraction and analyzed by high-performance liquid chromatography–tandem mass spectrometry. Antibiotic concentrations were higher in hWWTPs than dWWTPs; approximately 60 times for influents and 10 times for effluents. Ciprofloxacin concentration increased in most dWWTPs, especially in the aeration unit and return sludge, suggesting that it predominantly occurred in the solid phase. Sulfamethoxazole predominantly occurred in the dissolved form, which is more difficult to degrade, and exhibited high concentrations in effluent. Moreover, antibiotic pollutant loadings were approximately 30–3,530 times higher from dWWTPs than from hWWTPs due to higher daily discharges from the domestic sector. These plants are a major point source of antibiotic residue release to aquatic environments; thus, their efficiency should be improved by incorporating advanced treatment processes to ensure effective removal of antibiotics.


Sign in / Sign up

Export Citation Format

Share Document