Management of paddy soaking water: as a source for enriched compost making

The effluents discharged from rice mills do not contain toxic compounds, but continuous discharge in to soil or surrounding water bodies cause adverse environmental effects. Hence, the aim of the research was selected as management of paddy soaking water with its composition of nutrients as source for preparation of enriched compost and also is useful for the control of wastewater pollution and make safe the environment with effective usage. The characteristics of the effluent generated from cold soaking were acidic pH of 4.0 with concentration of nitrogen as 98 mg/l, phosphorous (91mg/l), potassium (98 mg/l), and reducing sugar (76 mg/l) and high concentration of COD (2760 mg/l), total dissolved solid (2800 mg/l) and electrical conductivity of 6mS/cm. Wastewater from the paddy soaking was then used as a potential source to an anaerobic composting. The digester with organic solid waste of 5 kg was mixed with 30 lit of rice mill effluent and other with 30 lit of water as control. The experiment was conducted in complete randomize design with three replicates. The use of rice mill wastewater significantly increased the available nitrogen, phosphorous and potassium after completion of 42nd days. Chemical analysis of digestate revealed that nutrition profile for anaerobic compost making of paddy soak water with waste was better than that of water. The C/N ratio decreases with days of composting but the reduction rate was high in paddy soak water than the water treated. Therefore, the rice mill wastewater is useful for compost making in anaerobic condition with the production of enriched compost

Impact of agricultural activities on groundwater quality and its suitability for drinking in Valikamam area, Jaffna Peninsula

In Sri Lanka Water Partnership (Lanka Jalani); International Water Management Institute (IWMI); Unilever-Pureit. Proceedings of the First Young Water Professionals Symposium, Colombo, Sri Lanka, 22-23 November 2012. Colombo, Sri Lanka: Sri Lanka Water Partnership (Lanka Jalani); Colombo, Sri Lanka: International Water Management Institute (IWMI); Colombo, Sri Lanka: Unilever-Purei

Seasonal variation of Nitrate-N in groundwater: a case study from Chunnakam aquifer, Jaffna Peninsula [Abstract only]

In Ileperuma, O.; Priyantha, N.; Chandrajith, R.; Navaratne, A.; Perera, A.; Yatigammana, S.; Wijesundara, S.; Rathnayake, S. (Eds). 2013. Proceedings of the Second International Symposium on Water Quality and Human Health: Challenges Ahead, Peradeniya, Sri Lanka, 15-16 March 2013. Peradeniya, Sri Lanka: University of Peradeniya. Postgraduate Institute of ScienceThe Jaffna Peninsula has four main aquifer systems, of which the largest Chunnakam aquifer is in the Valikamam area. This is an intensively cultivated area in the Jaffna Peninsula, and consequently, excessive application of nitrogen fertilizer is found. Other sources of nitrate include organic manures, and urine and excreta of animals through human activities. The aim of this study was to assess the N-nitrate contamination in drinking water of the Chunnakam aquifer, which was a sub-objective of a research project carried out by the International Water Management Institute (IWMI). Forty four (44) groundwater samples were collected from wells representing different uses and land use patterns. The sampling covered the period from January to December, 2011, representing all seasons. Nitrate-N in sampled water was determined colorimetrically using a spectrophotometer. The spatial variations of the water quality were mapped using ArcGIS 10. Nitrate-N values from domestic, domestic with home garden and public wells ranged from below 0.1 to 12.1 mg L'I. During the rainy season, 38% of the agro-wells exceeded the limit of WHO drinking water guidelines (10 mg L? I) and these were not suitable for drinking purposes. However, this percentage was 15% at the end of the dry season. A decreasing trend in nitrate-N concentration was observed from January to March. During the rainy season, the soil was wet enough up to the water table facilitating nitrate leaching. Nitrate-N found in most of the wells surrounded by areas with highland crops (onions, chillies, tobacco and brinjals) also exceeded the acceptable level (10 rug L'l). Even though these wells are used for agricultural purposes, people who work in the field use agro-wel1s for drinking. This water pollution is very likely related to the heavy use of N-based fertilizers for cultivation in the region. This leads to groundwater unsafe for drinking. Therefore, effective management of groundwater quality in the region is vital and further, creating awareness among population would possibly reduce the excessive use of chemical fertilizers in agriculture

Geo-statistical approach for prediction of groundwater quality in Chunnakam Aquifer, Jaffna Peninsula

Chunnakam aquifer is the main limestone aquifer of Jaffna Peninsula. The population of the Jaffna Peninsula depends entirely on groundwater resources to meet all of their water requirements. Thus for protecting groundwater quality in Chunnakam aquifer, data on spatial and temporal distribution are important. Geostatistics methods are one of the most advanced techniques for interpolation of groundwater quality. In this study, Ordinary Kriging and IDW methods were used for predicting spatial distribution of some groundwater characteristics such as: Electrical Conductivity (EC), pH, nitrate as nitrogen, chloride, calcium, carbonate, bicarbonate, sulfate and sodium concentration. Forty four wells were selected to represent the entire Chunnakam aquifer during January, March, April, July and October 2011 to represent wet and dry season within a year. After normalization of data, variogram was computed. Suitable model for fitness on experimental variogram was selected based on less Root Mean Square Error (RMSE) value. Then the best method for interpolation was selected, using cross validation and RMSE. Results showed that for all groundwater quality, Ordinary Kriging performed better than IDW method to simulate groundwater quality. Finally, using Ordinary Kriging method, maps of groundwater quality were prepared for studied groundwater quality in Chunnakam aquifer. The result of Ordinary Kriging interpolation showed that higher EC, chloride, sulphate and sodium concentrations are clearly shown to be more common closer to the coast, and decreasing inland due to intrusion of seawater into the Chunnakam aquifer. Also higher NO3 - - N are observed in intensified agricultural areas of Chunnakam aquifer in Jaffna Peninsula