DESC:A NON-BIOLOGICAL TOOLBOX FOR MONITORING BIOLOGICAL SLUDGE ACTIVITY POTENTIAL IN AEROBIC WASTE WATER TREATMENT PLANT

FIELD OF THE INVENTION:

The present invention relates to an integrated process for monitoring of biological sludge activity. More specifically the present invention relates to the process for monitoring of biological sludge activity in aerobic waste water treatment plants involving non-biological methods. The said process involves measuring of pH, dissolved oxygen uptake, alkalinity and measurement of suspended solids as an integrated tool for monitoring the sludge activity. Advantageously the said process does not require costly instruments and technical expertise and finds application for monitoring of sludge activity in aerobic waste water treatment plants effectively.

BACKGROUND OF THE INVENTION:

Blast furnace coke is produced in the coke oven batteries by carbonization of metallurgical coal. The coal is charged with 6-7% moisture; in addition it has inherent moisture of around 1%. During the process of carbonization, the moisture along with trendy-products of processing water generates a large volume (0.3–0.5 M3effluent/T of coal charge) of effluent which is toxic in nature. The effluents are formed at various sources and have different characteristics and volumes of generation. The mixed effluent is treated in common effluent treatment plant in multiple stages. Aerobic biological treatment form a major part of the treatment process.

While microscopic investigations are often used as a qualitative visual monitoring tool, almost all modern methods of monitoring biological activity require use of “core” biological tools such as 16srRNA sequencing, DNA extraction, PCR-Polymerase chain reaction, DGGE-Denaturing Gradient Gel Electrophoresis. All these requires specialized domain knowledge beyond the purview of operational monitoring in activated sludge processes in various industries in general and steel industry in particular. Various existing processes in the related fields are reviewed as here under.
An itrate biosensor based methodology form on it oringanoxic activated sludge activity (https://www.researchgate.net/publication/8046472) relates to a method based on a nitrate biosensor for in-depth monitoring and study of anoxic activated sludge activities. The resulting data allowed monitoring an oxicrespiration rate of activated sludge (nitrate uptake rate (NUR)) at a high time resolution making it clearly comparable with high frequency oxygen uptake rate (OUR) measurements obtained under aerobic conditions. Further, the anoxic respiration data resulting from a pulse addition of carbon source to endogenously respiring anoxic activated sludge shows a clear start-up phenomenon and storage tail that is usually also observed in high-frequency OUR measurements. Finally, the methodology serves as an anoxic respirometer for activated sludge treatment plants where denitrification process occurs in single-step and can be used for a toxicity and activity monitoring, process control and parameter estimation of the activated sludge process, similar to the aerobic respire meters.

Biological test systems for monitoring the operation of waste water treatment plants
(https://www.sciencedirect.com/science/article/pii/004565359400400O) relates to four different biological test systems for monitoring the biological activity of a laboratory-scale waste water treatment plant which was operated with municipal waste water. The heterotrophic respiration activity test (HRA), dehydrogenize activity test (DHA)and nitrification activity test were used for monitoring the biological activity of the activated sludge, and the luminescent bacteria test was used for screening the effluent of the treatment plant. In shock loading experiments with 2.3- dichlorophenol and 3.5-dichlorophenolitwasshown that both the nitrification and heterotrophic respiration activities and the TOC degradation in the treatment plant were significantly reduced, where as no clear effect on dehydrogenize activity was found. Screening of the effluent revealed a clear increase in luminescent bacteria inhibition during the shock loading experiments.

WO2016004082 on “Method and apparatus for waste water treatment using external selection” relates to a method and an apparatus for biological waste water treatment tha includes a biological selector and a physical selector. The apparatus comprises an internal biological reactor where waste water and recycled biomass are combined to provide a high substrate and high electron acceptor gradient for generating morphological biomass.

Features that favor granule formation over floe and filament formation, and an external gravimetric or external screen selector operating on the biomass waste stream for collecting and retaining dense biomass aggregates including dense granules election and for wasting lighter filaments and floes. The method and apparatus, involve addition of particles to provide cores to promote the formation of aggregates encapsulating the seeded particles. Further, organisms may be selected for biological phosphorus removal, denitrifying methane oxidizers, biological sulfur or sulfide oxidation, methanogenesis.

US20130085683 on “Preventive Activated Sludge Micro life Interpreter”
provides a portable laboratory instrument that incorporates software designed to record laboratory tests results to analyze the biomass of a Waste water Treatment Plant (WWTP) using an Activated Sludge Process. The software uses the values entered by the user and its databank/algorithms to determine the health/age of the biomass. It produces an interpretation of the collected data, and delivers a final set of instructions based on the overall health of the Waste water Treatment Plant (WWTP). The final result is delivered using simple instructions and color coded lights for an easy and quick interpretation.

An MFC-Based Online Monitoring and Alert System for Activated Sludge Process (https://www.nature.com/articles/srep06779) provides the study, based on a simple, compact and submersible microbial fuel cell (MFC), a novel online monitoring and alert system with self-diagnosis function for the activated sludge (AS) process. Such a submersible MFC utilized organic substrates and oxygen in the As reactor as the electron donor and acceptor respectively, and could provide an evaluation on the status of the As reactor and thus give a reliable early warning of potential risks. In order to evaluate the reliability and sensitivity of this online monitoring and alert system, a series of tests were conducted to examine the response of this system to various shocks imposed on the AS reactor. The results indicate that this online monitoring and alert system was highly sensitive to the performance variations of the AS reactor. The stability, sensitivity and repeatability of this online system provide feasibility of being incorporated in to current control systems of waste water treatment plants to real-time monitor, diagnose, alert and control the AS process.

From the above prior known literature it is found that the said processes are biochemical or biological methods.

Thus the resist illumed for a cost effective, simple and rapid process for biological treatment of coke oven effluent through monitoring of sludge activity in aerobic waste water treatment plants involving non-biological methods.

OBJECTS OF THE INVENTION:

The basic object of the invention is to provide a process for monitoring biological sludge activity in aerobic waste water treatment plants through non-biological methods.

Another object of the invention is to provide a process wherein the non-biological methods include monitoring of pH, dissolved oxygen and Mixed Liquor Suspended Solid from the coke oven effluent.

A further object of the invention is directed to the process wherein the pilot plant is conditioned with actual effluent while assessing natural potential of growth of “Culture consortium”.

A still further object of the invention is directed to a process wherein the efficiency of plant culture consortium is monitored in controlled environment.

Yet another object of the invention is directed to a process involving non-biological method of monitoring biological sludge activity in activated sludge process by monitoring pH, aeration flow and dissolved oxygen, measurement of suspended solids.

The said objects are fulfilled in the following description of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:

The invention is described with reference to the drawings of Fig. 1 to Fig. 8 accompanying the provisional specification.
Fig.1 illustrates the beginning of sludge activity when aeration is stopped for a period.
Fig. 2 illustrates monitoring of equilibrium sludge activity through pH monitoring.
Fig. 3 illustrates monitoring of equilibrium sludge activity through DO monitoring.
Fig. 4 illustrates the pattern of pH that denotes sharp change in sludge activity.
Fig. 5 illustrates the pattern of pH that indicates very fast growth with proper pre-treatment of effluent.
Fig. 6 illustrates that when there is no fluctuation in Dissolved Oxygen and Microbial Culture is fully inactive and will not work.
Fig. 7 illustrates that MLSS range when biological activity is sub-optimal.
Fig. 8 illustrates MLSS range when biological activity is optimal.

DETAILEDDESCRIPTIONOF THE INVENTION

According to the invention there is provided a cost-effective non-biological integrated process for monitoring biological sludge activity in aerobic waste water treatment plants which comprises any one or more of the following measuring tools – Measuring of pH, dissolved oxygen uptake, measuring alkalinity and measuring mixed liquor suspended solids.

In one embodiment the tool applied could be on-line measurement of pH for monitoring sludge activity in very short term.

In another embodiment wherein aeration is stopped for a particular period for on-line monitoring of dissolved oxygen in very short term.

In a further embodiment of the invention for monitoring biological sludge activity where off-line measurement of alkalinity is used to monitor activity of sludge in short term.

In still another embodiment of the invention where on-line measurement of suspended solids is used as the tool in the long term.

In a still embodiment where a combination of pH excursion, Dissolved Oxygen uptake, alkalinity measurement and measurement of MLSS is used as the integrated tool.

The present invention is directed to a process for monitoring biological sludge activity in aerobic waste water treatment plants through non-biological methods in activated sludge process.

Biological effluent treatment for coke oven conventionally is designed for a three stage process where two stages constitute an aerobic process and third stage constitutes an anoxic process. The first two stages are arranged in Continuous Stirred Tank Reactors (CSTR) in such a way that the effluent from one reactor is fed to the second reactor through clarifier. The reactors can be operated in batch mode as well as continuous mode. Both sludge culturing and acclimatized sludge utilization is possible in the simulator. In the pilot scale plant where experimental work is carried out there exists facilities for on-line control of Dissolved Oxygen, pH and continuous management of suspended solids, commonly known as Mixed Liquor Suspended Sludge (MLSS) in case of biological waste water treatment. It has been experimentally established that, as detailed in the EXPERIMENTAL given below, so that it is possible to monitor sludge activity no-biologically, through combined monitoring of these parameters. Hence , in combination these can be used as a tool-box for macro scale sludge activity , which is often required in industrial scale since on-line sophisticated biological / non-biochemical methods of monitoring sludge activity is often time consuming and inaccessible.

EXPERIMENTAL
Pilot plant start up involved running of the pilot plant with actual effluent. To start with, pilot plant was run in continuous mode with aeration of actual effluent without any seed culture for understanding effect of aeration on raw effluent. The objective was to ‘condition’ the pilot plant components with actual effluent while assessing natural potential of growth of ‘Culture Consortium’.

Thus, the process comprises the step of conditioning of the pilot plant components with actual effluent by running the pilot plant in continuous mode with aeration of actual effluent without any seed culture for understanding effect of aeration on raw effluent, while assessing natural potential of growth of “Culture consortium”.

The next step comprises “simulation” of actual plant process wherein the actual activated sludge mixed waste water from AerationTank1of the Steel Plant was put in first aerobic rector and waste water from Aerobic tank2 of Steel Plant was put in second aerobic reactor of Pilot Plant; to take care of the environmental changes these were run in batch mode for few days and then made continuous. The same was carried out with sufficient aeration and proper process management. The objective of this phase of experimental activities was to explore limits of efficiency of plant culture consortium in controlled environment.

In next phase the pilot plant was run in batch mode with return sludge being used as seed culture of First aerobic reactor in Pilot Plant; the other reactor is used to “mimic” the first aerobic reactor. In the first aerobic reactor occasional manual interventions of pH is resorted to; however, in the “mimic” reactor no such interventions takes place.

Consequent set of experiment is performed similar to earlier set of experiment with batch studies being carried out with return sludge of Aerobic Reactor2 of the Steel Plant being used for batch studies in reactor2 of pilot plant with other reactor being used to “mimic” the batch but without any interventions.

Next set of experiments involves continuous operation of Pilot plant involving first and second aerobic reactors with occasional manual interventions for pH and feed management. The experimental variables at this stage are pH, flow and dissolved oxygen. In this phase of experimentation protocol followed was generally, as and when practicable, that followed in laboratory stage process development experiments.

Based on the learning of these set of experiments, fresh batch culturing in both reactors started with combination of on-line and off-line interventions on a 24X7 basis with best practicable process management and control.

During these batch phase of experimental work the bio-culture was required to be monitored for their growth potential. The data generated in these phases of experimentation as shown in the accompanying Fig. 1 to 8 shows that it is possible to develop a non-biological method of monitoring biological sludge activity inactivated sludge process.

The present invention therefore provides a process wherein pH excursion is used as a non-line tool of monitoring sludge activity in very short term. The aeration is stopped for a particular period for monitoring of sludge activity through on-line monitoring of dissolved oxygen in the effluent in very short term. The said process involves off-line measurement of Alkalinity for monitoring of activity of sludge in short term and on-line measurement of suspended solids for monitoring of sludge activity in long term.

It is thus possible by way of the present invention to provide a non-biological method for monitoring biological sludge activity in activated sludge process in a simple and cost effective manner without involving any technical expertise wherein pHexcursion, DO uptake, alkalinity and MLSS can be used as an Integrated tool for monitoring of sludge activity.

While there has been shown and described some preferred embodiments of the invention many more embodiments with minor variations and changes apparent to those skilled in the art may be possible and those embodiments are also intended to be encompassed within the ambit of the invention claimed hereinafter.
,CLAIMS:WE CLAIM:

1. A cost-effective non-biological integrated process for monitoring biological sludge activity in aerobic waste water treatment plants comprising any one or more of the following measuring tools:
measuring of pH, dissolved oxygen uptake, measuring alkalinity and measuring mixed liquor suspended solids ( MLSS).

2. An integrated process for monitoring biological sludge activity as claimed in claim 1, wherein pH excursion is used as an on-line tool for monitoring sludge activity in very short term.

3. An integrated process for monitoring biological sludge activity as claimed in claim 1, wherein aeration is stopped for a particular period for on-line monitoring of dissolved oxygen in very short term.

4. An integrated process for monitoring biological sludge activity as claimed in claim 1, where off-line measurement of alkalinity is used to monitor activity of sludge in short term.

5. An integrated process for monitoring biological sludge activity as claimed in claim 1, wherein on-line measurement of suspended solids is used as the tool in the long term.

6. An integrated process for monitoring biological sludge activity as claimed in claim 1, where a combination of pH excursion, Dissolved Oxygen uptake, measurement of alkalinity and measurement of MLSS is used as the integrated tool.

7. An integrated process for monitoring biological sludge activity as claimed in claim 1, wherein the efficiency of plant culture consortium is monitored in controlled environment.