A practitioner’s perspective on the uses and future developments for wastewater treatment modelling

2011 ◽  
Vol 63 (3) ◽  
pp. 516-526 ◽  
Author(s):  
G. T. Daigger

The modern age of wastewater treatment modelling began with publication of the International Water Association (IWA) Activated Sludge Model (ASM) No.1 and has advanced significantly since. Models are schematic representations of systems that are useful for analysis to support decision-making. The most appropriate model for a particular application often incorporates only those components essential for the particular analyses to be performed (i.e. the simplest model possible). Characteristics of effective models are presented, along with how wastewater modelling is integrated into the wastewater project life cycle. The desirable characteristics of wastewater treatment modelling platforms are then reviewed. Current developments of note in wastewater treatment modelling practice include estimates of greenhouse gas emissions, incorporating uncertainty into wastewater modelling and design practice, more fundamental modelling of process chemistry, and improved understanding of the degradability of wastewater constituents in different environments. Areas requiring greater emphasis include increased use of metabolic modelling, characterisation of the hydrodynamics of suspended and biofilm biological treatment processes, and the integration of biofilm and suspended growth process modelling. Wastewater treatment models must also interface with water and wastewater management software packages. While wastewater treatment modelling will continue to advance and make important contributions to practice, it must be remembered that these are complex systems which exhibit counter-intuitive behaviour (results differ from initial expectations) and multiple dynamic steady-states which can abruptly transition from one to another.

2021 ◽  
Vol 9 (2) ◽  
pp. 491-498

Tanning is the process of turning animal hide into leather. The manufacturing process leads to the generation of wastewater, which must be treated before discharge. The treatment processes of this wastewater in India was examined. A systematic review based on Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines was carried out on the electronic database Google Scholar from 2010 to 2020. Wastewater treatment practices in Indian tanneries were looked for and 64 relevant reports and articles were shortlisted and studied. The results showed that coagulation with alum and ferric chloride gave the best results in primary treatment, aerobic and anaerobic processes gave the best results when combined, and tertiary treated water could be reused.


2018 ◽  
Vol 2017 (2) ◽  
pp. 546-551 ◽  
Author(s):  
J. Liu ◽  
M. Tang

Abstract Many industrial parks adopt a two-tier wastewater management framework whereby tenants and the park are required to build satellite and centralized wastewater treatment facilities, respectively. Due to the diversity of industrial wastewaters, the treatment process scheme in the public centralized wastewater treatment plant (WWTP) may not suit the characteristics of all effluents discharged from the tenants. In consideration of varying wastewater biodegradability, the treatment scheme in a centralized WWTP is advised to install two series of treatment processes. In detail, various effluents from the tenants shall be commingled according to their levels of biodegradability. For the non-biodegradable streams, advanced oxidation processes shall be applied in addition to biological treatments. To facilitate the grouping of effluents, each effluent will be evaluated for its biodegradability. An analytical protocol derived from OECD standard (TG302B) was developed and found effective for biodegradability assessment. A case study is described in this paper to showcase the methodology.


2006 ◽  
Vol 5 (4) ◽  
pp. 685-692
Author(s):  
Elisabeta Chirila ◽  
Ionela Carazeanu Popovici ◽  
Techin Ibadula ◽  
Alice Iordache

Author(s):  
N. Zaletova ◽  
S. Zaletov

Биологический метод очистки сточных вод представляет собой сложный многокомпонентный процесс, ключевой составляющей которого является работа ферментной системы. Известно, что одним из важнейших ферментов, обеспечивающих биологический процесс, являются дегидрогеназы. Полностью сложнейший механизм действия ферментов до конца пока не раскрыт, однако в практике контроля процессов биологической очистки используется показатель дегидрогеназной активности ила. Результаты исследований позволили дополнить имеющуюся информацию фактическими данными о взаимообусловленности уровня дегидрогеназной активности ила и показателей отдельных технологических параметров биологической очистки. Показано, что режим работы аэротенков (нагрузка на ил, доза активного ила и др.) и величина показателей исходной дегидрогеназной активности и дегидрогеназной активности этого же образца ила со слабо концентрированным раствором (ДАИН2О) связаны между собой и зависят от нагрузки на ил по органическим веществам. Полученные результаты исследования могут быть использованы для контроля биологического процесса очистки сточных вод.The biological method of wastewater treatment is a comprehensive multicomponent process the activities of the enzyme system being the key component of it. It is known that dehydrogenases have been one of the most important enzymes the ensure the biological process. The complicated mechanism of the action of enzymes has not been fully described so far however, in the practice of monitoring biological treatment processes, an indicator of the dehydrogenase activity of sludge is used. The research results provided for supplementing the available information with actual data on the interdependence of the level of dehydrogenase activity of sludge and indicators of individual process parameters of biological treatment. It was shown that the mode of operation of aeration tanks (organic matter load on sludge, dose of activated sludge, etc.) and the values of the initial dehydrogenase activity and dehydrogenase activity of the same sludge sample with weakly concentrated solution (DASН2О) are interconnected and depend on the organic load on sludge. The results of the study can be used to control the biological process of wastewater treatment.The biological method of wastewater treatment is a comprehensive multicomponent process the activities of the enzyme system being the key component of it. It is known that dehydrogenases have been one of the most important enzymes the ensure the biological process. The complicated mechanism of the action of enzymes has not been fully described so far however, in the practice of monitoring biological treatment processes, an indicator of the dehydrogenase activity of sludge is used. The research results provided for supplementing the available information with actual data on the interdependence of the level of dehydrogenase activity of sludge and indicators of individual process parameters of biological treatment. It was shown that the mode of operation of aeration tanks (organic matter load on sludge, dose of activated sludge, etc.) and the values of the initial dehydrogenase activity and dehydrogenase activity of the same sludge sample with weakly concentrated solution (DASН2О) are interconnected and depend on the organic load on sludge. The results of the study can be used to control the biological process of wastewater treatment.


1989 ◽  
Vol 21 (8-9) ◽  
pp. 805-814 ◽  
Author(s):  
F. R. Christensen ◽  
G. Holm Kristensen ◽  
J. la Cour Jansen

Experimental investigations on the kinetics of wastewater treatment processes in biofilms were performed in a laboratory reactor. Parallel with the kinetic experiments, the influence of the biofilm kinetics on the biofilm structure was studied at macroscopic and microscopic levels. The close interrelationship between biofilm kinetics and structural changes caused by the kinetics is illustrated by several examples. From the study, it is evident that the traditional modelling of wastewater treatment processes in biofilm reactors based on substrate removal kinetics alone will fail in many cases, due to the inevitable changes in the biofilm structure not taken into consideration. Therefore design rules for substrate removal in biofilms used for wastewater treatment must include correlations between the removal kinetics and the structure and development of the biological film.


1992 ◽  
Vol 26 (1-2) ◽  
pp. 407-415 ◽  
Author(s):  
D. A. Barton ◽  
J. J. McKeown ◽  
W. Chudyk

A model of organic compound removal by biological wastewater treatment processes receiving pulp and paper industry wastewaters has been developed and initial model verification performed at a single mill site. This paper presents the results of further model verification conducted at multiple mill sites, including replication of the original site. In addition, VOC losses at other unit processes are quantified. Activated sludge basin chloroform volatilization rates are predicted to within twelve percent of the measured rates. Predicted overall methanol removals are consistent with observed removals although difficulties encountered during off-gas sampling preclude determination of the extent of removal due to volatilization.


1998 ◽  
Vol 38 (2) ◽  
pp. 9-15 ◽  
Author(s):  
J. Guan ◽  
T. D. Waite ◽  
R. Amal ◽  
H. Bustamante ◽  
R. Wukasch

A rapid method of determining the structure of aggregated particles using small angle laser light scattering is applied here to assemblages of bacteria from wastewater treatment systems. The structure information so obtained is suggestive of fractal behaviour as found by other methods. Strong dependencies are shown to exist between the fractal structure of the bacterial aggregates and the behaviour of the biosolids in zone settling and dewatering by both pressure filtration and centrifugation methods. More rapid settling and significantly higher solids contents are achievable for “looser” flocs characterised by lower fractal dimensions. The rapidity of determination of structural information and the strong dependencies of the effectiveness of a number of wastewater treatment processes on aggregate structure suggests that this method may be particularly useful as an on-line control tool.


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