DBMS for Waste Teatment Monitoring
-- Dr. S. V. Ranade
Introduction
Rapid urbanization and industrial growth have led to environmental pollution. In India, due to various reasons, there is no effective control on pollution due to industries and urban population leading to heavy risk to public health and damage to natural resources. Use of information technology in the field of environmental pollution control can help to a great extent in improving this situation. Environmental Engineering Expertise with IT capabilities can achieve this task if industries come forward for such change and environmental pollution control authorities encourage such efforts by giving subsidy to industries.
Waste characterization
Treatment of industrial waste involves physiochemical and biological methods and their effectiveness depends on the influent characteristics. As there is large variation in flow and characteristics of industrial wastes with time, it is essential to monitor continuous changes in quality and flow. Reliable results can be obtained if extensive statistical techniques are employed to predict the response behavior of various treatment units. Operators and chemists are generally unaware of such methods and they rely on instantaneous values of parameters leading to wrong interpretation and improper corrective action. Simple software routines can be used to calculate statistical parameters of relevance.
Waste Treatment Technology
Due to diversity of pollutant characteristics from various sources, proper monitoring of pollutant concentrations requires well furnished testing equipment, thorough knowledge of analysis procedures and trained personnel. It is also essential to monitor the dynamic nature of receiving bodies like air or water to estimate impact of such pollutants on environment considering dilution and dispersion effects and comparison with permissible limits. This often requires use of advanced mathematics, complex calculations and in depth understanding of mixing phenomenon. As monitoring is done generally by employing temporary manpower through subcontracts to private agencies, such refined analysis is seldom done.
In case of controlling pollution at source through effective treatment, proper design and operation of plants is a must. Design and operation of waste treatment plants in India have remained traditional with use of conventional treatment units and operation by untrained personnel. Due to inadequate design of units, fluctuations in flow and characteristics of wastes the performance of such plants is often far from satisfactory. Design of new treatment technology units or augmentation of existing units in the light of new equipment and process theories can achieve significant improvement in process efficiency and better control. Latest information on novel ideas and case studies is available on number of websites related to academic research and environmental consultancy firms. It is not necessary to have long experience and deep study in the subject. Innovation in approach and development of new suitable technology has become comparative far more easy task due to information technology.
There are various types of treatment flow sheets adopted for waste treatment. However, primary treatment followed by some form of biological treatment is the most method used in most of the cases. Design of treatment units need to be checked for assumptions made about waste characteristics, flow variations, hydraulic and organic loading rates, chemical dose and aeration requirements and treatment efficiencies. It is observed that many a times, inadequacy of treatment units is the cause of plant failure.
The main performance parameters to be monitored and controlled in primary treatment are floating solids, oil and grease and pH. If the design of screen chamber is of adequate capacity and regular cleaning is done, there is effective removal of floating solids. In case of oil and grease removal, pre-separation of oil by providing separate chamber at mill house greatly enhances the removal efficiency.
Activated sludge process is a complex phenomenon and depend on hydraulic and organic loading, air supply and sludge recycle. There are number of operating parameters such as waste characteristics at different stages which include flow, DO, BOD, SS and pH values to more complex operating parameters like HRT, SVI, Return sludge ratio, SRT, wasting of sludge, nutrients and micro flora which require understanding of phenomenon, prediction of effect of these parameters on plant performance and fast corrective action.
Anaerobic process though easier than aerobic process needs careful and constant monitoring of pH as souring of digester may upset the process. Rate of organic loading, relationship between alkalinity and volatile acids concentration and its effect on pH, COD reduction and its relation to biogas recovery are some of the crucial issues which need to be handled by the operator.
Control of such parameters requires skilled and properly trained personnel and input of technical expertise to deal with tricky situations. Most of the plants lack these basic requirements leading to poor plant performance.
Role of Information Technology
Everybody is aware that advances in information technology have opened up new alternatives for better production and quality control. New micro controller based instrument gadgets and servo control operated control units have revolutionised the chemical industry.
It is now possible to compile, store and process large static or dynamic data with the use of computers. Data storage cost has become very low and vast information in multimedia format can be stored on CDs. Internet has provided a gateway to unlimited information available on any topic from the world knowledge pool. Lot of technical information can be downloaded at a fraction of cost. However, majority of environmental consultants in India are unaware of this fact and are still sticking to age old design methods and traditional treatment technology.
Review of Database Management System
A database management system (DBMS) consists of a collection of interrelated data and a collection of programs to access that data. The primary goal of a DBMS is to provide an environment that is both convenient and efficient for the user to retrieve required information in proper format and to store the information securely and in classified form with minimum storage space.
Though there are various methods and computer programming languages available for developing suitable software, for environmental engineer, visual basic is a simplest language which can easily mastered in short time and is and powerful enough to apply for all necessary tasks in waste treatment automation system. Visual Basic programming language with back end database support of MSAccess, Oracle or SQL can be employed to write customized software programs for following
To determine flow and characteristic variations in waste streams at various stages
To develop inventory of waste treatment equipment and materials with necessary maintenance schedules.
To apply mathematical theories of treatment, dilution and dispersion of pollutants.
To describe the relationships between parameter values and their effect on plant performance and treatment efficiency.
To provide ready reckoner tips from instrument manuals, guidelines, Do’s and Do’nts, explanations, trouble shooting information.
The program can be designed for single user or multi user facility can be incorporated to provide simultaneous data entry. The user interface can be provided in regional language for uneducated operators to understand the status of plant, problem nature and corrective action to improve the performance. Audio and red light alert systems can help in attracting attention of the workers if there is failure of some unit or parameter value exceeds permissible level needing immediate action. The reports can be generated with charts and graphs in ready submission format. The entire history data of quality parameters of raw and treated wastes can be stored on CDs for analysis and future reference.
It has been promptly employed in water and waste treatment plants in the west. This being the scenario in advanced countries, India has not yet initialized this process in environmental engineering field.
Chemical industry has already adopted this technology for process control and quality monitoring of raw materials and finished products. Most of the industries have necessary instrumentation for the main plant and extension of such facilities to ETP can be done easily by modernization of the laboratory and treatment units. In fact, it should be made mandatory for new factories and phased implementation for existing effluent treatment plants considering the present unsatisfactory conditions as regards pollution control objectives.
Number of commercial software programs are available for managing inventory, monitoring test parameters and process control in chemical industry, However, in case of Effluent Treatment Plants, there are few imported software programs available which can handle all functions in the ETP and govern the plant performance. Moreover, these programs heavily depend on complete automation and data logging facilities which are not present in most of the effluent treatment plants. It is therefore necessary to develop tailor made customized software to cater the needs of waste treatment plants in India with typical blending of manual and automatic control devices. Enterprise resource planning in pollution control technology can provide better control over performance parameters and environmental technologists should take full advantage of the advances in the field of information technology.
Dnyandeep Infotech Pvt. Ltd. is developing such a comprehensive and flexible hardware-software package with control panel for easy and effective operation of plants. It is proposed that temperature, pH and flow measurements, chemical dose adjustments, operation of valves should be done by providing appropriate microcontroller based instrumentation with data logging and integration facilities. Inventory analysis, maintenance schedules and trouble shooting know how can be embedded in customized software which can accept the automatic data logging as well as manual data entry to suit typical Indian scenario. It can assist in material balance calculations, detection of losses, identify possibilities of waste minimization. Timely reports can be prepared easily. For large industrial units, intranet solutions with multi user operation can be developed.
The key data and reports can be remotely accessed via internet to authorized persons. Interactive website will be linked to such in plant software system such that online training and advice can be obtained from consultants in case of difficulty. Implementation of such a system will help the law enforcement authorities in monitoring the effluent quality and investigating the failure reasons in plant operation.