Assessment of assimilative capacity of Kanhan river stretch using MIKE-11 modeling tool.

In the present paper, it is attempted to carry out computer simulation studies for Kanhan river stretch using MIKE-11 modeling tool to evaluate Assimilative Capacity (AC) based on existing and projected waste load scenarios. AC of Kanhan river was estimated in relation to biochemical oxygen demand (BOD) and dissolved oxygen (DO). MIKE-11 model simulates the DO and BOD parameters in a one dimensional fashion by calibrating with field data different constant and model parameters. The modeling studies would help in deciding the appropriate waste load allocation based on stream's AC rather than simple effluent standards. The model studies will provide vital information and greater insight into the impact of point and non-point sources of pollution on quality of Kanhan river in a stretch of 120 km.

Water resources development and management: an experience in rural hilly area.

The Himalayan region of Tehri Garhwal in India has scattered habitations in the villages with scanty, non-perennial and unsafe water resources like springs and streams. Poor environmental conditions arising from unsafe drinking water, inadequate sanitary measures, unhygienic disposal of excreta, sullage and accumulation of solid wastes have resulted in poor public health. The experiences gained through water supply and sanitation studies carried out especially in this rural area have been shared in this paper so as to enable adoption of relevant practices and technologies developed by the National Environmental Engineering Research Institute (NEERI, India) in the affected areas. Environmental protection of the streams and springs for sustained water availability and safe drinking water supply was ensured with active public participation, training, and awareness programs. Various surface rainwater harvesting structures were constructed at suitable sites along with ferro-cement roofwater harvesting tanks in selected villages. The activities related to designing and commissioning of a small slow sand filtration unit were carried out at Chhati (Nakot) village for safe drinking water supply. Chlorination pots were demonstrated and installed in rainwater harvesting tanks for disinfection of water for drinking purpose. Water quality assessment and health survey (parasitic and hemoglobin investigation) in the affected villages were carried out before and after technological intervention. The training and awareness programs were organised for people of 23 villages in the study area covering water and sanitation related topics. The beneficiary's opinions, perceptions, apprehensions, as well as expectations reflected positive approach towards the achievement of anticipated benefits and impacts.

Qualitative evaluation of Kanhan river and its tributaries flowing over central Indian plateau.

Water quality evaluation of Kanhan river and its tributaries viz. Pench and Nag rivers was carried out in order to assess the qualitative changes and possibility of point and non-point pollution loads in these rivers for the post monsoon and summer seasons. pH, turbidity, conductivity, total alkalinity and total hardness were found in the range 7.18.7, 0.835 (NTU), 227970 (microScm(-1)), 7.18.7, 158486 (mg/L) and 142246 (mg/L), respectively. Ca, Mg, Na and K were in the range 2462, 1328, 15183 and 333 mg/L, respectively. The respective ranges of Cl, SO(4), NO(3) and PO(4) were observed between 19102, 823, 332 and 0.11.4 mg/L. DO and COD in the rivers ranged between nil to 8.5 and 7172 mg/L, respectively. Absence of DO and higher COD in Nag river is due to its sewage content from Nagpur city. Nag river showed higher bacterial counts than Kanhan and Pench rivers. The temporal and spatial variability in the river water quality may be attributed to catchment characteristics, agricultural and urban activities in catchment and on the bank of the river. The values of RSC, ESP and SAR indicated that the water of Kanhan and Pench rivers are suitable, whereas that of Nag river is unsuitable for irrigation purpose.

Effect of on-site sanitation on groundwater contamination in basaltic environment--a case study from India.

On-site sanitation is increasingly adopted in urban cities in India. The adoption of on-site sanitation system puts the groundwater resources in the vicinity of the system at a greater risk. Microbial contaminants as well as chemical contaminants like Chloride and Nitrate are generated from human waste. These contaminants travel through the medium and ultimately get in contact with the groundwater. Hence, the groundwater sources are vulnerable to nitrate contamination near the on-site sanitation systems. The present study indicates significant Nitrate and Chloride contamination in samples collected close to on-site sanitation systems. The recommended limit set by the Bureau of Indian standards (BIS) limit of 45 mg/l for Nitrate concentration is also exceeded in few samples. The study indicates that Bacterial as well as Nitrate contamination is more in Monsoon as compared to Summer.

Investigation of the performance of non-conventional pressure filter system in potable water treatment.

The biflow pressure filter system installed at a residential campus was investigated for its performance under different operating conditions. The investigation was carried out to evaluate raw water quality, chemical dosing systems, filter media and overall filtration performance. Treatability studies were carried out to decide optimum doses of chemicals sused in potable water treatment system. It was found that the biflow pressure system could not deliver filtrate of desired quality and therefore its use in potable water treatment may cause ill effects in human-beings.

Performance evaluation of reverse osmosis desalination plants for rural water supply in a developing country--a case study.

Performance evaluation of two reverse osmosis (RO) desalination plants (DSP) at villages: Melasirupodhu (30 m3 day(-1)) and Sikkal (50 m3 day(-1)) in Ramanathpuram district, Tamil Nadu (India) were studied so as to bring out the state-of-art of their operation and maintenance (O&M). Detailed information on plant design and engineering, water quality, plant personnel, and cost of O&M was collected for a period of three years after commissioning of the two plants. Feed water was brackish, the TDS varied in the range of 6500-8500 mg L(-1) at Melasirupodhu and 5300-7100 mg L(-1) at Sikkal villages. The product water quality was observed to be gradually deteriorating as the salt rejection by the membranes decreased with time. The salt rejection was 97-99% at the time of commissioning of the plants, and came down to 89-90% at the end of 3 years of operation. Product water TDS soon after installation of the plants was excellent and within desirable limits of BIS. After three years of operation, few parameters exceeded the desirable limits, however, they were found to be within permissible limits of BIS. The analyses of the data showed that both plants were operated only at 30-36% of the design capacity. Plant shut-down due to inadequate and erratic power supply, and plant break-down and inherent delay in repairs due to lack of adequate infrastructure were found to be the major causes for the low utilization of the plants. Consequently the recurring cost of product water production enhanced to Rs. 25.0/m3 at Melasirupodhu and Rs. 17.5 m(-3) at Sikkal, as against the estimated cost of Rs. 15.0/m3 and Rs. 11.0/m3, respectively, as per the design. Over the years, the energy consumption for the product water output increased reflecting higher operational pressures needed with the aging of the membranes.

Assessment of slow sand filtration system for rural water supply schemes--a case study.

In India, water supply programmes form a part of National Development Plans and are implemented in a phased manner under the Five-Year Plans. A number of departments and ministries of the Central and State Governments have been vested with the responsibility for water supply and sanitation. Due to inherent advantages of slow sand filters over conventional rapid sand filters, the Panchayat Raj Engineering Department (PRED), Government of Andhra Pradesh has designed and constructed a number of slow sand filter plants for rural water supply schemes in the state. At the instance of Netherland Assisted Project (NAP) Office, Hyderabad, NEERI undertook a critical evaluation of the functioning of three slow sand filter plants in Andhra Pradesh and suggested improvements in construction, operation and maintenance (O&M) including a review of design criteria followed by PRED. The paper presents the outcome of these studies along with suggestions needed to bring about improvements in source protection, design, construction, O&M of slow sand filter and training programme to improve the quality of supervision.

Performance evaluation of water treatment plants based on microfilter technology for rural water supply.

Panchayat Raj Engineering Department (PRED), Government of Andhra Pradesh installed package water treatment plants on a trial basis, in some villages in Krishna district of Andhra Pradesh. These plants with a design capacity of 6000-12000 lph were supplied and erected by a firm in Hyderabad. These plants consist of three stage treatment comprising of pulverized quartz filter bed, activated carbon bed and micro filter unit followed by disinfection. At the request of PRED, comprehensive studies were carried on individual plants which includes a detailed appraisal of the performance of the individual components of the plant, infrastructure at the village level for routine O&M of the plants as also views of the community regarding their acceptability of the system. This paper presents the findings and conclusions of the performance evaluation study.

Urban community perception towards intermittent water supply system.

While evaluating intermittent and continuous water supply systems, consumers opinion survey was undertaken for critical appraisal of both modes of operation. With the help of a pre-designed set of questions relating to various aspects of water supply and the opinion of consumers regarding degree of service, a house to house survey was conducted in the study area of Ghaziabad and Jaipur. The consumer opinion survey clearly indicated a satisfactory degree of service wherever adequate quantity of water was made available irrespective of the mode of water supply. Number of complaints regarding quality of water supplied, timings of supply, low pressures and breakdowns in supply were reported during intermittent water supply. Every family stored water for drinking and other uses. Most of the families discard drinking water once the fresh water supply is resumed next day. Discarded drinking water is usually used in kitchen for washing and gardening. Storage for other purposes depends on economic status and availability of other sources like open dug well in the house. While most of the respondents had no complaints on water tariff, all of them were in favour of continuous water supply.

Urticaria and angioedema from cyclooxygenase-2 inhibitors.

Cyclooxygenase-2 (COX-2) inhibitors celecoxib and rofecoxib have generally been well tolerated. It has been unclear if specific COX-2 inhibitors would cross react with acetylsalicylic acid and typical nonsteroidal antiinflammatory drugs to cause urticaria or angioedema. There are no reports in the literature of hives or angioedema resulting from their use. We describe 3 patients who developed urticaria and/or angioedema from COX-2 inhibitors. With the increasing use of COX-2 inhibitors, one needs to be aware of these side effects and of possible cross reactivity between celecoxib and rofecoxib.