Landfill leachates as an abiotic disease factor affecting solanaceous crops and olive trees

767 | P a g e C o u n c i l f o r I n n o v a t i v e R e s e a r c h  M a r c h 2 0 1 6 w w w . c i r w o r l d . c o m  Landfill leachates as an abiotic disease factor affecting solanaceous crops and olive trees Hazem Sawalha, Rasha Ma'ali, Anan Hussein 1 Department of Biology &Biotechnology, Arab American University-Palestine hazem.sawalha@aauj.edu 2 Department of Biology &Biotechnology, Arab American University-Palestine 3 Department of Physics, Arab American University-Palestine anan.hussein@aauj.edu ABSTRACT


INTRODUCTION
A landfill or rubbish dump is a place for the disposal of waste materials by burial.Worldwide, landfills are the oldest form of waste treatment and have been the most common methods of organized waste disposal [1].
Landfills may include internal waste disposal sites (where a producer of waste carries out their own waste disposal at the place of production) as well as sites used by many producers.Furthermore, many landfills are used for waste management practices, such as temporary storage, consolidation and transfer, or processing of waste material (sorting, treatment, or recycling) [2].
A large number of adverse impacts may occur from landfill operations.These impacts include: local environment pollution (such as pollution of groundwater and/or aquifers); production of potent gases as methane which is generated by decaying organic wastes.Such gas is explosive and harmful to humans and animals [3,9]; reproduction of disease vectors such as rats, mosquitoes and flies; nuisance problems; and injuries to wildlife and agro ecosystem by causing growth problems for vegetation growing on and adjacent to refuse landfills [4,5].Furthermore, liquid chemicals, known as leachates, which drain or leach from landfills, may contaminate soil with their dissolved and suspended material [6].Sometimes, soil remains contaminated with long after waste dumping has ceased.Such situation causes drastic effect on agriculture as vegetables and other edible plants grown in such soil can absorb such harmful chemicals and accumulate them in their tissues.Sometimes plants are unable to grow and live [7].
Ecologically, contamination of the soil affects the balance of any system depends on soil as a medium.Most plants are unable to adapt and live when the chemistry of the soil changes so radically in a short period of time.The fertility slowly diminishes, making land unsuitable for agriculture and any local vegetation to survive [8].
The current project aims to study the drastic effect on landfill leachates on agriculture and provide guidelines that may additionally help applicants, developers, consultants and the general public identify important design considerations to avoid adverse impacts on agricultural resources and land use.Landfill leachate is liquid that moves through or drains from a landfill.This liquid may either exist already in the landfill, or it may be created after rainwater mixes with the chemical waste Therefore, the project studies the impact of landfill leachate that coming out of the landfills in Palestine on some vegetables and olive trees.The effect on olive trees was studied In Vivo on olive orchards grown near landfills.The other part which studies its effect on vegetables was done under lab condition.The landfills which were selected for the current study are considered the major landfill in northern part of the West Bank.Beside their horrible smell; their environmental impact especially on surrounding vegetation is not yet investigated (

Landfill of study
Landfills located in Jenin governorate were selected around the Jenin city.These landfills are considered the major garbage destination for the north part of the West Bank [11].

Leachate collection
Leachate was collected manually from liquids coming of the landfill.The liquid was filled in bottles with tightly caps and transferred to the lab for further experimentation (Fig 2 ).

Effect of landfill leachate on pepper and tomato
Twenty plants of Bell pepper and tomato each were planted in small pots.The pots were divided into five groups with five replicates.Four groups were irrigated separately with different dilution of landfill leachate including 0x, 2x, 3x and 4x (the number represents the volume of water and x represents the volume of leachate.The fifth group was irrigated with tap water to represent the control treatment of the experiment.The experiment was laid out according to the Completely Randomized Design (CRD) [16].Ten ml of liquid was added to plants every 2 days during the first week and then the amount was adjusted according to plant growth.The plants were incubated under lab condition for further analysis of chlorophyll content and vegetative growth.

Chlorophyll analysis
The amount of Chlorophyll in the leave was determined according to Beer's-Lambert law (A = εbC), where "A" is the absorbance, "ε" is the extinction coefficient, "b" is the path length and "C" is the concentration, described by [12].Leaves were extracted first with 80% acetone aqueous solution.Then the extracts were incubated at -10 degree Celsius.Total chlorophyll was measured at 646, 663 and 750 nm wavelengths using a Perkin-Elmer's spectrophotometer [10].

Vegetative growth measurement
Leaf surface area was measured using the tracing technique according to Ferris et. al. 2001 [13].Paper replica of the surface was compared with the standard data using the following equation: Leaf area (mm 2 ) = weight of leaf tracing (g) x conversion factor (mm 2 gm -1 ).
In addition, plant length was measured using a ruler and the number of dropped leaves was recorded daily as well.

Effect of leachate on olive production
The effect of leachate on olive tree in term of yield was recorded for the previous four years of olive orchards.Data was collected by interviewing and asking expert farmers and/or farm workers.

Statistical analysis
Analysis of the data was performed using the Two-Sample Test of Proportion (TSTP).The results were analyzed by comparing the Computed Z value with its critical one of 1.65 at the level of significance when α=0.05 [14,15]. Where,

Effect of landfill leachate on pepper and tomato
Irrigating pepper and tomato plants with leachates caused drastic effect on vegetative growth.The plants (tomato and pepper) became stunted in growth with obviously decreased leaf surface area when compared with control regardless of dilution used, but the highest drastic effect was obtained when higher concentrations of leachate were used.
The number of dropped leaves was much more in plant treated with absolute leachate when compared with the diluted ones and the control.Statistical analysis revealed significant differences between the control treatments irrigated with   On the other hand, chlorophyll content was more in plant treated with absolute leachate compared with other treatments.The control treatment showed the least amount of chlorophyll content (Table 2).

Effect of leachate on olive production:
The results obtained from olive farmers showed that leachate has drastic effect on olive production.From 2005 to 2009, the amount of olive production went down from an average of 1500 to 560 Kg/hectare for the lands 50 meters far from the landfill.Two years later, the net production went to nil.Furthermore, the adjacent fields exposed to direct leachate flow were destroyed.Statistical analysis emphasized such results (Table 3)

DISCUSSION
The impact of landfill leachate that coming out of landfills on some vegetable plants as well as olive trees grown nearby the dump is one of the major problems facing agriculture in Palestine.Such material could affect plant growth of vegetables and leads to plant death one month after exposure to enough dose of leachate.Similarly, olive trees were affected also with leachate to the extent that the trees lose their vigor and become less productive.In severe cases, some of them may die.
The effect of leachate on the studied plants may be attributed to the toxic and hazardous chemical compounds coming off the chemical reactions that happen in leachate.The typical composition of landfill leachate is summarized in (Table 4) as reported by Tchobanoglous and Kreith [23].Therefore, water resources of plants become polluted when the leachate from the landfill enters surface water or ground water resources.Also, the decomposition of carbonaceous material produces some additional water, and other materials including CH4, CO2 and a mixture of organic acids, aldehydes, alcohols and simple sugars, which dissolve in the leachate cocktail.The precipitation percolates through the waste and takes in dissolved and suspended components from the biodegrading waste, through physical and chemical reactions [17].Results showed that chlorophyll content was much more in plant treated with higher concentration of leachate compared with the other treatments.Such situation may be attributed to the composition of leachate which has very high ammoniacal nitrogen concentration [18].Usually leachate from old landfills is rich in ammonia nitrogen due to the hydrolysis and fermentation of the nitrogenous fractions of the biodegradable wastes [19,22].The research works reported that leachates contain much more organic pollutants than commonly found in any other organic effluent.
On the other hand, the high concentration of organic contaminant and much higher ammoniacal nitrogen of leachate may be responsible for agricultural and environmental problems as well as the loss of vegetation from polluted areas.Furthermore, excessive foliar nitrogen may affect the nutrient balance and increase plant sensitivity to harsh conditions as frost and drought, as well as the biotic factors including pests and pathogens [20].In general, juvenile, fast-growing and well-nourished plants are more likely to be attacked by pests.A high content of amino acids in the plants may result in a more severe attack by sucking parasites [21].

CONCLUSIONS
Actually the production of domestic waste is increasing so much that landfill leachate has become a serious problem in Palestine in terms of the drastic effect on human health, environment and hazard to the agro ecosystem.
The outcomes of leachate irrigation trial have shown drastic effect on plants and phytotoxicity.Other research works have emphasized the importance of high concentration of ammonical-nitrogen of leachate which could be regarded as an alternative nitrogen source for plants [22,24,25,26].Such controversial results may be attributed to variations in the composition complexity of landfill leachate, complexity in determining the phytotoxicity of the test individual and variation in the dilution factor and irrigation schedule.Therefore, a further research work is needed to study such issue and to concentrate on choosing the correct leachate dilution level is essential to safeguard the plants from toxicity damages and ensure healthy plant growth.Expanding trials to irrigate several types of agricultural crops including fruits trees is an indispensable step in the research to determine that plant types that can tolerate leachate Fig 1).
u m e 5 N u m b e r 3 J o u r n a l o f A d v a n c e s i n A g r i c u l t u r e 768 | P a g e C o u n c i l f o r I n n o v a t i v e R e s e a r c h M a r c h 2 0 1 6 w w w .c i r w o r l d .c o m

Fig 2 :
Fig 2: Visual comparison between leachate and water.A: water, B: leachate

1 Y and 2 Y
= Number of affected population type I and II respectively.

1 n and 2 n
= Sample size of population I and II respectively.

=
Sample proportion of population type I and II respectively.
C o u n c i l f o r I n n o v a t i v e R e s e a r c h M a r c h 2 0 1 6 w w w .c i r w o r l d .c o m water and most treatments irrigated with leachate.Plants treated with absolute leachate died first before others plants in the other treatments (

ControlFig 3 :
Fig 3: Effect of leaches on vegetative growth of pepper and tomato.
(Fig 4).C o u n c i l f o r I n n o v a t i v e R e s e a r c h M a r c h 2 0 1 6 w w w .c i r w o r l d .c o m

Fig 4 :
Fig 4: Growth decline symptoms of olive trees grown near the landfills

Table 4 :
Typical data on the composition of leachate in landfills u m e 5 N u m b e r 3 J o u r n a l o f A d v a n c e s i n A g r i c u l t u r e 773 | P a g e C o u n c i l f o r I n n o v a t i v e R e s e a r c h M a r c h 2 0 1 6 w w w .c i r w o r l d .c o m u m e 5 N u m b e r 3 J o u r n a l o f A d v a n c e s i n A g r i c u l t u r e 774 | P a g e C o u n c i l f o r I n n o v a t i v e R e s e a r c h M a r c h 2 0 1 6 w w w .c i r w o r l d .c o m