| Author | Srivastava, Ashok Kumar |
| Call Number | AIT Thesis no.EV-89-25 |
| Subject(s) | Pesticides industry
|
| Note | A thesis submitted in partial fulfillment of t he requirements
for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A laboratory study was conducted to investigate t h e immobilization of the sludges collected from a pesticide industry. The industry was involved in producing a variety of pesticides including organo-chlorines, organ o - phosphates, carbamates and atrizines. Th e binders used in t h is study were ordinary Portland cement (OPC ) and a mixture of ordinary Portland cement (OPC) and rice husk ash (RHA) in 1:1 ratio, commonly known as Portal and rice husk ash cement (PRHAC). The sludge was mixed with cement-sand mortar having a cement to sand ratio of 1:2 , and water to cement ratio as 0.50 for OPC mortar and 0.65 for PRHAC mortar. Physical properties like compressive strength and l each ability were studied to assess t h e effectiveness of the binders in containing the waste within their matrix. Leachability was determined by USEPA Extraction Procedure after a slight modification . Th e compressive strength was found to be inversely proportion a l to the sludge / cement and water/cement ratios, and directly proportional to the curing time. The leachability was found to be directly proportional to t h e sludge/cement and water/cement ratios, a nd the pH of the extractant. Th e compressive strength of OPC mortar was found to be greater than that of PRHAC mortar, in all the tests. On t h e contrary , leachability of the PRHAC mortar was invariably much less t h an t hat of OPC mortar , in a l l the tests. In this way PRHAC was found to be better bilization of the sludges collected from a pesticide industry. The industry was involved in producing a variety of pesticides including organo-chlorines, organ o - phosphates, carbamates and atrizines. Th e binders used in t h is study were ordinary Portland cement (OPC ) and a mixture of ordinary Portland cement (OPC) and rice husk ash (RHA) in 1:1 ratio, commonly known as Portal and rice husk ash cement (PRHAC). The sludge was mixed with cement-sand mortar having a cement to sand ratio of 1:2 , and water to cement ratio as 0.50 for OPC mortar and 0.65 for PRHAC mortar. Physical properties like compressive strength and l each ability were studied to assess t h e effectiveness of the binders in containing the waste within their matrix. Leachability was determined by USEPA Extraction Procedure after a slight modification . Th e compressive strength was found to be inverse l y proportion a l to the sludge / cement and water/cement ratios, and directly proportional to the curing time. The leachability was found to be directly proportional to the sludge/cement and water/cement ratios, a nd the pH of the extractant. The compressive strength of OPC mortar was found to be greater than that of PRHAC mortar, in all the tests. On t h e contrary , leachability of the PRHAC mortar was invariably much less t h an t hat of OPC mortar , in a l l the tests. In this way PRHAC was found to be better immobilizer than OPC. Tests o n t h e leachability of t h e raw sludge demonstrated that the leachability of the un - solidified (raw) sludge was much less than the leachability of the solidified sludge. Therefore it was concluded t h a t the solidification of pesticide industry sludges with cementitious binders was overall not successful . Extraction test conducted on t he raw sludge in alkaline waters also resulted in the leaching of a lot of organics. Literatures on t h e properties of pesticides revealed that most of the pesticides got hydrolysed and disintegrated in the alkaline solutions , a nd t h is explained the high leachability of the pesticide sludge after it was solidified in (alkaline) cement matrix. The applicability of Freundlich' s desorption isotherm was a l so studied in perspective o f t h e leach ability of wastes. The leach ability of both t he mortars were found to closely follow the desorption isotherm. than OPC. Tests o n t h e leachability of t h e raw sludge demonstrated that the leachability of the un - solidified (raw) sludge was much less than t he leachability of the solidified sludge. Therefore it was concluded t h a t the solidification of pesticide industry sludges with cementitious binders was overall not successful . Extraction test conducted on t he raw sludge in alkaline waters also resulted in the leaching of a lot of organics. Literatures on t h e properties of pesticides revealed that most of the pesticides got hydrolysed and disintegrated in the alkaline solutions , a nd t h is explained the high leachability of the pesticide sludge after it was solidified in (alkaline) cement matrix. The applicability of Freundlich' s desorption isotherm was a l so studied in perspective o f t h e leach ability of wastes. The leach ability of both t he mortars were found to closely follow the desorption isotherm. |
| Year | 1989 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Ahn, Kyu-Hong
|
| Examination Committee(s) | Kriengsak Udomsinrot ;
Chongrak Polprasert |
| Scholarship Donor(s) | NORAD (Norwegian Government) |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1989 |