Research

Several research projects are undertaken by the environmental Engineering Staff, as Undergraduate, Postgraduate, and Staff research projects.

SIDA funded Asian Regional Research Programme on Environmental Technology

Components of the project :

I. Study on the removal mechanisms and efficiencies of selected heavy metals by different adsorbent material commonly available in Sri Lanka . In this respect some of the adsorbents that are readily available in Sri Lanka, hence will be considered are clay tiles (in crushed form), keolinite, modified clay, papaya wood, rice husk, egg shells, crab shells, coconut shells, coir fibre

II. Study on enhancement of natural attenuation by microorganisms.

III. Dissemination of findings to the legislators and stakeholders for implementation.

Key Research activities :

Three 15 m2 SSF wetlands were constructed in order to evaluate the removal efficiencies of heavy metals in galvanizing effluent. The substrates used in the wetlands were calicut roof tiles crushed into 25-50 mm sizes. The porosity of the tile media is 50%. Fairly constant nutrient levels are being maintained throughout the study (i.e., for all 3 wetlands). Urea and KH 2 PO 4 are added as N (50 mg/l) and P (10 mg/l) sources, respectively. On the 105 th day diluted metal finishing effluent containing varying Zn levels are added to the wetland containing Scirpus spp. and was run with a HRT of 7 days. After the 189 th day the flow rate was increased and was run with a HRT of 3.5 days. At present the wetland is operated with a HRT of 3.5 days.

The operational procedure involved in the case of the wetland having Phragmites is similar to the operation of the wetland containing Scirpus and the wetland was run up to a period of 259 days. Nevertheless, due to lack wastewater supply the wetland was not operated in the period of 260 th day to 293 rd day and again during the period of 297 th day to 259 th day. However, from 360 th day this wetland recommenced.

The wetland containing Typha spp. was fed with diluted metal finishing effluent containing varying Zn levels with a 7 day hydraulic retention time (HRT) on the 98 th day of the run and on the 140 th day the reactor operation was temporally suspended due to signs of intense phytotoxicity. Thereafter till the 188 th day the wetland was acclimatized. However on the 189 th day the wetland was restarted with a lower HRT of 3.5 days. At present the wetland is operated with a HRT of 3.5 days.

Since adsorption to tiles were observed to play a major contribution to Zn removal particularly in the first 7.5 m length of the wetlands, known as Section 1 (see results under Appendix section) increasing constantly an isotherm experiment was also performed to identify the maximum adsorption capacities of the crushed tiles. In this regard a laboratory scale sorption experiment was performed for untreated calicut tiles with shaker (221/UA.Pm1, Germany ) over a period of 7.5 days (see section 2.5).

During the total study period pH, Eh and conductivity was measured in-situ and COD and Sulfates were measured according to Standard Methods (APHA, 1995). Zn levels were measured in all components of the wetlands. A mass balance was carried out for three wetlands in 2 components on a weekly basis. In other words the mass balance was carried out for the first 7.5 m length (Section 1) and the remaining 7.5 m length (Section 2) of each wetland separately. The c omponents identified for the mass balance were plants, calicut roof tiles, water and the rest as unaccounted mechanisms which include bacterial biofilm mediated precipitation, adsorption to detritus produced by senescing plants and adsorption to leaves shed by trees occurring in the vicinity of the 3 SSF wetlands.

ASIA-Link Project ( ED WAVE )

The Project is titled "Education tool for training on technologies for efficient water use using virtual application sites (ED-WAVE)", and is funded by the European Commission under Asia-Link Programme. We are carrying out the project jointly with teri School of Advanced Studies of New Delhi (TERI), India , Technical University of Crete (TUC), Greece ; Lappeenranta University of Technology (LUT), Finland ; University of Zaragoza (UNIZAR), Spain ; Kasetsart University (KU), Thailand . It has been approved by the European Commission, and the Grant Contract has been signed between the EC and the main partner, TERI on 11April 2003.

The goal of the project is to develop a sustainable framework for training on technologies for conservation, reclamation and reuse of natural resources. As a model example, this project will focus on improving water efficiency by exposing the target groups to real life applications through virtual industrial and municipal environments created using IT based tools. The activities would involve (i) Analysis of current water use status in select industrial and domestic sectors in Asia and EU (ii) Review of potential technological interventions (iii) Simulation of impacts of technological interventions in the selected sectors, and (iv) Translation of knowledge into electronic teaching material. The two-year project would be targeted at environment educators in Universities in EU and Asia and students enrolled in related courses; further, it would benefit end-users like industries and municipalities, technical service providers, environmental practitioners, & research organizations.

Consultancy Services

The Division of Environmental Engineering is also engaged in Consultancy services. Some of the studies of national interest undertaken by the division during the past few years are:

# Identification of causes for color episodes in Ampara Water Supply Scheme, 2007 done for National Water Supply & Drainage Board
# Rapid Environmental Assessment on Tsunami permanent housing units in Sri Lanka , 2006 done for Ministry of Environmental & Natural Resources
# Identification and rectification of water supply problems faced by Kandalama Hotel, Heritance Hotel and Neptune Hotel, 2006 done for Aitkin Spence Hotels Ltd.
# Rapid Environmental Assessment in tsunami affected area in Sri Lanka (Brown-Study), 2005 done for Ministry of Environment & Natural Resources
# Coastal Resources Management project, 2003
Monitoring of water quality for CCD ,
# Colombo - Katunayaka Expressway Project 2002
Analysis of Soil samples for construction purposes
# Southern Transport Development Project, 2001
Drainage Report - Effect on Ground Water Level and Water Quality
# Consultancy services to review and update the Feasibility & Design Reports, 2001
Wastewater Disposal system for Ratmalana Moratuwa and Ekala / Ja-Ela Industrial Residential Area
# Galle Harbour Environmental Profile for the proposed Harbour Development, 2000
# Environmental Impact Assessment of the proposed New Southern Highway
- for the Road Development Authority
# Initial Environmental Examination for Sitting of Industrial Estates , 1995 / 1996
- for the Ministry Of Industrial Development
# Water Quality Monitoring & Modelling in Kelani River , 1995
- for the Central Environmental Authority and BKH Consultants

The Division also provides consultancy services to state and private sector industries on wastewater treatment, environmental impact assessments and initial environmental examinations and also laboratory testing of water and wastewater samples for chemical and microbiological quality.