Sequential Remediation Processes for a Low Level Pesticide Wastewater

Mariam T. Al hattab, Abdel E. Ghaly

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Department of Process Engineering and Applied Sciences, Faculty of Engineering, Dalhousie University, Halifax, Canada.

DOI: 10.4236/jep.2012.32019                

Abstract

The aim of this study was to develop a remediation system for the treatment of a low-level pesticide wastewater that uses available onfarm organic matter as an absorption media, is capable of reducing the concentration of the pesticide to a safe level and is economically viable for implementation by farmers. The absorption capacity of chopped hay and soybean to the fungicide captan was evaluated under batch conditions and the effectiveness of the composting process in depredating captan in contaminated organic materials was evaluated. The results showed that both hay and soybean plant residues were very effective in absorbing 99.2% and 98.5% of captan form the wastewater after 4 hours, respectively. Because of its availability, hay can be used in an onfarm pesticide immobilization system that consists of shallow reinforced concrete pit (filled with hay) with steel bars across the top for machinery to roll onto and be washed. The wastewater can be retained for 24 hours which is a sufficient time for hay to absorb the captan. The contaminated hay can then be composted. The addition of used cooking oil raised the temperature of the composting mixture to 63?C. Small reductions in moisture content (from 60% to 58.9 %) and C:N ratio (from 30:1 to 28:1) were observed while reductions of 18.92%, 15.56% and 4.8% in the volatile solids, total carbon total Kjeldahl nitrogen were achieved after 10 d of composting, respectively. About 92.4% of the captan was degraded in the first 4 days of composting. Most of captan (92.4%) was degraded during the mesophilic stage (first 3 days). The degradation rate constant for the mesophilic stage (0.724 d^-1) was 2.74 times the degradation rate constant for the thermophilic stage (0.264 d^-1). An onfarm windrow composting process would be very effective in degrading captan contaminated hay. The captan contaminated hay could be mixed with equal amount poultry manure or dairy manure to provide the required bioavailable carbon and nutrients for the composting process. Some used cooking oil could also be added to maintain higher temperature within the compost matrix. The windrows should be mixed on a daily basis to provide sufficient oxygen for the composting microorganisms.

Keywords

Pesticide; Captan; Soybeans; Hay; Absorption; Immobilization; Degradation; Composting

1. Introduction

Pesticides provide the primary means for controlling organisms/pests (fungi, bacteria, insects and weeds) that compete with man for food and fibre or cause injury to man, livestock and crops. They are classified based on the pest they control as shown in Table 1. Their use has dramatically increased since the second world war [1]. Pesticides played a vital role in increasing agricultural production and permitting the economic production of wide ranges of vegetable, fruit, cereal, forage, fibre and oil crops which now constitute a large part of a successful agricultural industry in many countries. They lower crop losses and cost of production per unit output and increase revenue to farmers because of the additional marketable yield obtained with their use. Other benefits include: 1) reduced uncertainty of crop loss from pests, 2) increased profit to farm input suppliers (machinery, fertilizer, chemicals and seed companies) from increased sale, 3) benefit to consumers through decreased price of raw foods or improved quality of food products and 4) benefit to society as whole (farmers, consumers, farm suppliers, food processors) from increased employment opportunities and expanded export of food products [2,3]. As such, society attempts to put a monetary value on these benefits through benefit/cost analysis. Pesticide expenditures account for 13% - 22% of total costs of production per hector. The benefit/cost ratio vary from 4 to 33 (for every dollar spent on pesticide farmers receive an additional of $4 - $33 in revenue) depending upon crop rotation and year [1,4].

Canada account only for 2% of the pesticide use and the pesticide manufacturing industry in Canada is comprised of 39 companies employing 745 people [5]. How-

Table 1. Common types of pesticide.

ever, the extent to which pesticides are used in Canada is indicated by the fact that over 36 million kg of pesticideactive ingredients were used in 2006. This is equivalent to an average application of 0.54 kg/ha of farmland [5,6]. The total sales of these pesticides amounted to $78,054,000, or approximately $2.47 for every person in Canada in 2006 [5,7].

After pesticides are applied to target areas, pesticide residues remain in the containers and application equipment. These residues are removed from applicators by rinsing with water which results in the formation of a low level toxic wastewater. The disposal of pesticidecontaining wastewater represents a problem for many farmers [8]. Currently, disposal of pesticide wastewater is carried out haphazardly by several methods (Table 2). These include: 1) land cultivation, 2) dumping on land, in ditches, in lagoons and in soil pits, and in extreme cases in sewers and streams near the rinsing operation, 3) use of evaporation pond and 3) land filling. These methods of disposal are totally unsafe, as the surface run off will reach streams, rivers and lakes and the infiltration of the wastewater into the localsoil will eventually end up in the ground water.

Pesticides are toxic chemicals that can adversely affect people, pets, livestock, wildlife and desirable plants in addition to the pests they are intended to destroy [9-11]. The resulting ecological impact of unsafe disposal of pesticides can be severe, depending on the type of pesticide and the amount contained in the wastewater. The phenomenon of biomagnification of some pesticides has resulted in reproductive failure of some fish species [12, 13] and egg shell thinning of birds such as peregrine falcons, sparrow hawk and eagle owls [14]. Pesticide toxicity to humans include skin and eye irritation and skin cancer [15]. Therefore, great care must be exercised in the application and disposal of pesticides.

Table 3 summarizes the treatment methods currently used for pesticide containing wastewater. These include incineration, chemical treatment, physical treatment and biological treatment. These treatment methods either require land or are expensive and suffer from variability of effectiveness [16]. Thus, the development of safe, on farm disposal techniques for agricultural pesticides is necessary.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	J. K. Horowitz and E. Lichtenberg, “Insurance, Moral Hazard, and Chemical Use in Agriculture,” American Journal Agricultural Economics, Vol. 75, No. 4, 1993, pp. 926-935. doi:10.2307/1243980
[2]	E. C. Oerke and H. W. Dehne, “Safeguarding Production- Losses in Major Crops and the Role of Crop Protection,” Crop Protection, Vol. 23, No. 4, 2004, pp. 275-285. doi:10.1016/j.cropro.2003.10.001
[3]	J. Cooper and H. Dobson, “The Benefits of Pesticides to Mankind and the Environment,” Crop Protection, Vol. 26, No. 9, 2007, pp. 1337-1348. doi:10.1016/j.cropro.2007.03.022
[4]	C. Osteen and M. Livingstion, “Pest Management Practices,” 2006. http://www.ers.usda.gov.
[5]	Statistics Canada, “Canadian Industry Statistics,” 2010. http://www.ic.gc.ca.
[6]	OECD, “Statistics from A to Z,” 2007. http://www.oecd.org.
[7]	CropLife, “Plant Science Industry in Canada,” 2007. http://www.croplife.ca.
[8]	P. C. Kearney, M. T. Muldoon, C. J. Somich, J. M. Ruth and D. J. Voaden, “Biodegradation of Ozonated Atrazine as a Wastewater Disposal System,” Journal of Agriculture and Food Chemistry, Vol. 36, No. 6, 1988, pp. 1301-1306. doi:10.1021/jf00084a044
[9]	T. J. Centner, “Unwanted Agricultural Pesticides: State Disposal Programs,” Journal of Environmental Quality, Vol. 27, No. 4, 1998, pp. 736-742. doi:10.2134/jeq1998.00472425002700040002x
[10]	C. Wilson and C. Tisdell, “Why Farmers Continue to Use Pesticides Despite Environmental Health and Sustainability Costs,” Ecological Economics, Vol. 39, No. 3, 2001, pp. 449-462. doi:10.1016/S0921-8009(01)00238-5
[11]	R. L. Ridgway, J. C. Tinney, J. T. MacGregor and N. J. Starler, “Pesticide Use in Agriculture,” Environmental Health Perspectives, Vol. 27, 1978, pp. 103-112. doi:10.1289/ehp.7827103
[12]	D. W. Connell, “Bioaccumulation Behaviour of Persistent Organic Chemicals with Aquatic Organisms,” Review of Environmental Contamination and Toxicology, Vol. 101, 1988, pp. 117-154.
[13]	K. Verschueren, “Handbook of Environmental Data on Organic Chemicals,” Van Nostrand Reinhold, New York, 1977.
[14]	C. E. Lundholm, “DDE-Induced Eggshell Thinning in Birds: Effects of p,p’-DDE on the Calcium and Prostaglandin Metabolism of the Eggshell Gland,” Comparative Biochemistry and Physiology Part C: Pharmacology Toxicology Endocrinology, Vol. 118, No. 2, 1997, pp. 113-128. doi:10.1016/S0742-8413(97)00105-9
[15]	R. Spiewak, “Pesticides as a Cause of Occupational Skin Diseases in Farmers,” Annals of Agricultural and Environmental Medicine, Vol. 8, No. 1, 2001, pp. 1-5.
[16]	N. E. Kowal and H. R. Pahren, “Health Effects Associated with Wastewater Treatment and Disposal,” Journal of Water Pollution Control Federation, Vol. 54, No. 6, 1982, pp. 677-687.
[17]	Wolfram Alpha Knowledge Base, “Wolfram Mathematica Chemical Data,” 2011. http://www.wolframalpha.com.
[18]	Sigma Aldrich, “Material Safety Data Sheet,” 2011. http://www.sigmaaldrich.com.
[19]	A. E. Ghaly, I. Uguw, A. Ergudenler and F. Hamdullahpur, “Development and Evaluation of Straw Chopping System for Fluidized Bed Gasifier,” 7th Canadian Bioenergy R & D Conference, Energy Mines and Kegoures, Sudbury, 24-26 April 1989.
[20]	A. E. Ghaly, F. Alkoaik and A. Snow, “Degradation of Pirimiphos-Methyl During Thermophilic Composting of Greenhouse Tomato Plant Residues,” Canadian Biosystem Engineering, Vol. 49, No. 1, 2007, pp. 1-11.
[21]	ASTM, “Annual Book of Standards of the ASTM,” American Society for Testing and Materials, West Conshohocken, 2001.
[22]	F. Alkoaik and A. E. Ghaly, “Influence of Dairy Manure Addition on the Biological and Thermal Kinetics of Com- posting of Greenhouse Tomato Plant Residues,” Waste Management, Vol. 26, No. 8, 2006, pp. 902-913. doi:10.1016/j.wasman.2005.11.023
[23]	S. M. Tiquia, N. F. Y. Tam and I. J. Hodgkiss, “Changes in Chemical Properties during Composting of Spent Pig Litter at Different Moisture Contents,” Agriculture, Ecosystem and Environment, Vol. 67, No. 1, 1998, pp. 79-89. doi:10.1016/S0167-8809(97)00132-1
[24]	T. L. Richard, H. V. M. Hamerlers, A. H. M. Veeken and T. Silva, “Moisture Relationships in Composting Processes,” Compost Science and Utilization, Vol. 10, No. 4, 2002, pp. 286-302.
[25]	A. D. Guardia, P. Mallard, C. Teglia, A. Marin and C. Le Pape, “Comparison of Five Organic Wastes Regarding their Behaviour During Composting: Part I, Biodegradability, Stabilization Kinetics and Temperature Rise,” Waste Management, Vol. 30, No. 3, 2010, pp. 402-414. doi:10.1016/j.wasman.2009.10.019
[26]	A. E. Ghaly, F. Alkoaik and A. Snow, “Thermal Balance of Invessel Composting of Tomato Plant Residues,” Canadian Biosynthesis Engineering, Vol. 48, 2006, pp. 6.13- 6.22.
[27]	L. Hua, W. X. Wu, Y. X. Liu, Y. X. Chen and M. B. McBride, “Effect of Composting on Polycyclic Aromatic Hydrocarbons Removal in Sewage Sludge,” Waste Air Soil Pollution, Vol. 193, No. 4, 2008, pp. 259-267. doi:10.1007/s11270-008-9687-y
[28]	L. P. Walker, T. D. Nock, J. M. Gossett and J. S. VanderGheynst, “The Role of Periodic Agitation and Water Addition in Managing Moisture Limitations during High Solids Aerobic Decomposition,” Process Biochemistry, Vol. 34, No. 6-7, 1999, pp. 601-612. doi:10.1016/S0032-9592(98)00122-8
[29]	J. Y. Wang, O. Stabnikikova, S. T. L. Tay, V. Ivanov and J. H. Tay, “Intensive Composting of Sewage Sludge and Food Waste by Bacillus Thermoamylovorans,” World Journal of Microbiology and Biotechnology, Vol. 19, No. 4, 2003, pp. 427-432. doi:10.1023/A:1023933212654
[30]	K. Hanninen, O. Tolvanen, A. Veijanen and K. Villberg, “Bioaerosols in Window Composting of Source Separated Biowastes. In Biomass for Energy, Environment, Agriculture and Industry,” Proceedings of the 8th European Biomass Conference, Vienna, 3-5 October 1994.
[31]	B. Beck-Friis, S. Smars, H. Jonsson and H. Kirchmann, “Gaseous Emissions of Carbon Dioxide, Ammonia, Nitrous Oxide from Organic Household Waste in a Compost Reactor under Different Temperature Regimes,” Journal of Agricultural Engineering Research, Vol. 78, No. 4, 2001, pp. 423-430. doi:10.1006/jaer.2000.0662
[32]	F. C. Jr Michel, C. A. Reddy and L. J. Forney, “Microbial Degradation and Humification of the Lawn Care Pesticide 2,4-dichlorophenoxyacetic Acid during the Composting of Yard Trimmings,” Applied and Environment Microbiology, Vol. 61, 1995, pp. 933-941.
[33]	F. C. Michel, L. J. Forney, A. J. Huang, S. Drew and M. Czuprenski, “Effects of Turning Frequency, Leaves to Grass Mix Ratio and Windrow vs Pile Configuration on the Composting of Yard Trimming,” Compost Science and Utilization, Vol. 4, No. 3, 1996, pp. 26-43. DOI: 10.1016/S0960-8524(97)00080-1.
[34]	J. Lopez-Real and M. Baptista, “A Preliminary Study of Three Manure Composting Systems and Their Influence on Process Parameters and Methane Emissions,” Compost Science Utilization, Vol. 4, No. 3, 1996, pp. 71-82.
[35]	S. Sadaka and A. El Faweel, “Effects of Aeration and C:N Ratio on Household Waste Composting in Egypt,” MISR Agricultral Engineering Journal, Vol. 11, No. 1, 2003, pp. 36-40.
[36]	M. Fang, J. W. C. Wong, K. K. Ma and M. H. Wong, “Co-Composting of Sewage Sludge and Coal Fly Ash: Nutrient Transformations,” Bioresource Technology, Vol. 67, No. 1, 1999, pp. 19-24. doi:10.1016/S0960-8524(99)00095-4
[37]	S. M. Tiquia and N. F. Y. Tam, “Fate of Nitrogen during Composting of Chicken Litter,” Environmental Pollution, Vol. 110, No. 3, 2000, pp. 535-541. doi:10.1016/S0269-7491(99)00319-X
[38]	N. Morisaki, C. G. Phae, K. Nakasaki, M. Shoda and H. Kubota, “Nitrogen Transformation during Thermophilic Composting,” Journal Fermentation and Bioengineering, Vol. 67, No. 1, 1989, pp. 57-61. doi:10.1016/0922-338X(89)90087-1
[39]	M. F. Hamoda, H. A. Abu Qdais and J. Newham, “Evaluation of Municipal Solid Waste Composting Kinetics,” Resources, Conservation and Recycling, Vol. 23, No. 4, 1998, pp. 209-223. doi:10.1016/S0921-3449(98)00021-4
[40]	K. L. Larsen and D. M. McCartney, “Effect of C:N Ratio on Microbial Activity and N Retention: Bench-Scale Study Using Pulp and Paper Biosolids,” Compost Science and Utilizaiton, Vol. 8, No. 2, 1998, pp. 147-159.
[41]	F. Buyuksonmez, R. Rynk, T. F. Hess and E. Bechinski, “Occurrence, Degradation and Fate of Pesticides during Composting,” Compost Science and Utilization, Vol. 7, No. 4, 1999, pp. 66-82.
[42]	C. A. Reddy and F. C. Michel, “Fate of Xenobiotics During Composting,” Proceedings of the 8th International Symposium on Microbial Ecology, Magnolia Publishing, Halifax, 9-14 August 1998.
[43]	P. Fogg, A. B. Boxall, A. Walker and A. Jukes, “Pesticide Degradation in a Biobed Composting Substrate,” Pest Management Science, Vol. 59, No. 5, 2003, pp. 527-537. doi:10.1002/ps.685
[44]	F. Rocha and A. Walker, “Simulation of the Persistence of Atrazine in Soil at Different Sited in Portugal,” Weed Research, Vol. 35, No. 3, 1995, pp. 179-186. doi:10.1111/j.1365-3180.1995.tb02031.x
[45]	C. R. Lemmon and H. M. Pylypiw Jr., “Degradation of Diazinon, Chlorpyrifos, Isofenphos and Pendimethalin in Grass and Compost,” Bulletin of Environmental Contamination and Toxicology, Vol. 48, No. 3, 1992, pp. 409-415. doi:10.1007/BF00195640
[46]	C. Vandervoort, M. J. Zabik, B. Branham and D. W. Lickfeldst, “Fate of Selected Pesticides Applied to Turf Grass: Effects of Composting on Residues,” Bulletin of Environmental Contamination and Toxicology, Vol. 58, No. 1, 1997, pp. 38-45. doi:10.1007/s001289900297
[47]	W. J. Lyman, W. F. Reehl and D. H. Rosenblatt, “Handbook of Chemical Property Estimation Methods,” Ame- rican Chemical Society, Washington, 1990.
[48]	T. C. Wang and M. E. Hoffman, “Degradation of Organophosphorous Pesticides in Coastal Water,” Journal of the Association of Official Analytical Chemists, Vol. 74, No. 5, 1991, pp. 883-886.
[49]	R. T. Haug, “The Practical Handbook of Composting Engineering,” Lewis Publisher, Boca Raton, 1993.
[50]	I. S. Eneji, E. Buncel and G. W. VanLoon, “Degradation and Sorption of Pirimiphos-Methyl in Two Nigerian Soils,” Journal of Agriculture and Food Chemistry, Vol. 50, No. 20, 2002, pp. 5634-5639. doi:10.1021/jf0203747
[51]	V. Leoni, C. Cremisini, R. Giovinazzo, G. Puccetti and M. Vitali, “Activated Sludge Biodegradation Test as a Screening Method to Evaluate Persistence of Pesticides in Soil,” Science of the Total Environment, Vol. 123-124, 1992, pp. 279-289. doi:10.1016/0048-9697(92)90153-J
[52]	R. O. Hermanutz, L. H. Mueller and K. D. Kempfert, “Captan Toxicity to Fathead Minnows (Pimephales Promelas), Bluegills (Lepomis Macrochirus), and Brook Trout (Salvelinus Gontinalis),” Journal of the Fisheries Research Board of Canada, Vol. 30, No. 12, 1973, pp. 1811-1817. doi:10.1139/f73-291