Studies on feasibility of some water quality trading aspects with end-of-pipe treatment augments: Towards enhancement of environmental performance in firms and CETPs

Abstract

Environmental performance is at the heart of the cap and trade approach. The basic idea of this mechanism is to meet environmental goals at lowest possible cost; compared to other environmental policies such as command-and-control or emissions taxes. Simple in concept, emissions trading can become complex in practice when considering all elements that must be in place. Water Quality Trading (WQT), is a type of emission trading, to reduce water pollution to the desired level, with minimum treatment cost. The present investigation has attempted to evaluate the potential of WQT under the Indian scenario and visualize its benefits through reality checks. # A detailed logical framework that links causes and effects of treatment systems has helped derive a body of empirical evidences to substantiate the credibility of some treatment systems. #Assumptions about performance and their determinants helped map relevant correlates. # Field investigations, treatability experiments and mathematical modelling helped derive empirical evidences. # Data on parameters was gathered about the performance of Common Effluent Treatment Plants (CETPs) and Chemical Oxygen Demand (COD) as suitable pollutant to be traded. The investigation was inspired by a survey by the Central Pollution Control Board (CPCB) of 88 industrial clusters across the country. The CPCB reported 43 clusters as critically polluted with a comprehensive environmental pollution index (CEPI) above 70. CETP-Vatva, a site of this study was one of the critically polluted areas with CEPI 74.77 in 2009, 87.46 in 2011 and 83.44 in 2013, quite above the criterion for critically polluted CEPI score. CETP-Vatva demonstrated the fact that WQT context could become increasingly complex, if heterogeneous / diverse industrial sectors are considered for their effluents. This was in contrast to the CETP-Palsana with homogeneous industrial sectors. # Data pertaining to actual effluents released for one hundred and eleven industries on a daily basis for three months at Palsana. & authorized quantity of effluent discharge (QED) for each industry and design capacity of CETP was collected. # The study revealed that as the effluent generation is below the authorized QED, WQT is not possible. However, as the QED increases, WQT can be implemented with cap and trade mechanism. # Simulations as part of this study demonstrated that cap and trade mechanism may be feasible below the breakeven point, i.e. 85% of the authorized QED. # Further, as the authorized QED is lowered, the potential for WQT increased. Thus, WQT with cap and trade seems feasible at CETP, Palsana. Based on the encouraging results for Palsana, studies were initiated at Vatva, that had three functional and major industrial sectors, i.e., Dyes, Dye Intermediates and Textile processing. This heterogeneity in industrial sectors further compounded complexity through diverse scales of production; namely small, medium and large scale. # Thus, for this research, three industries from each sector with a total of nine different industries were chosen. # 2000 L of effluent was collected from each of the industries for detailed investigations. # The initial COD loading observed was in the range of 68 to 7074, 30 to 896 and 100 to 1541 kg COD / day for textile processing, dyes and dye intermediates respectively with significant variation in the qualitative profiles. # The collected effluent was treated by electrocoagulation, Fenton’s reagent and Electrooxidation in batch scale and pilot scale reactors. The batch scale reactors for all the three technologies were of 1Lsize, the pilot-scale reactors were of 25 L, 50 L and 150 L for electrocoagulation, Fenton’s reagent and Electro-oxidation, respectively. # Based on the above it was observed that o A simplistic conclusion that can be common for treatment of effluent from specific sectors cannot be drawn. o The scales of production namely small, medium and large scales determined the extent of COD eliminated across treatment methods. o This was true also for the cost for treatment, related to the quality of effluent and pollution control method. # It was also seen that electrocoagulation could be achieved with least cost for treatment for all effluents, however its COD removal efficiency was less in some cases compared to other technologies. # A hypothetical trading among all selected industries was also evaluated considering different caps on release for COD loading. A stringent cap is introduced, influenced an increasing number of closures of industry if WQT is not implemented. # The mathematical models, formulated as mixed integer programming problems, are limited to watershed trading; implemented and solved through the CPLEX. Results relate to treatments suggested to control pollution, the source, and the overall cost comparison in trading and non-trading scenario. It also revealed changes in the number of credits demanded before and after technology implementation along with changes in the group of buyers and sellers of credits within the sectors. The optimum value of cap for a given scenario was also derived, especially from a regulatory authority point of view. The present research thereby presents much needed evidences about the feasibility of WQT; considering settings unique to the systems chosen.