Germination and initial growth of sunflower irrigated with untreated and treated (by

1 distillation and electro-Fenton) landfill leachate 2 3 Michelle Machado Rigo, Paulo Sérgio Alves de Souza, Alexandre Andrade Cerqueira, Julieta 4 Laudelina de Paiva1, Daniel Vidal Perez, Mônica Regina da Costa Marques 5 6 1. Environmental Technology Laboratory, Institute of Chemistry, State University of Rio de Janeiro, 205507 900, Rio de Janeiro-RJ, Brazil. Telephone: +55(21)2334-0563. E-mails: michelle.rigo@gmail.com 8 paulosasouza@gmail.com; alexandrecerq@ig.com.br; paivaj@gmail.com; monicamarques@uerj.br. 9 2. Brazilian Agricultural Research Corporation, Ministry of Agriculture, Livestock and Supply of Brazil, 2246010 000, Rio de Janeiro-RJ, Brazil.Telephone: +55(21)2179-4505.E-mail:daniel.perez@embrapa.br 11

Where GVI is germination speed index, n is the number of seeds newly germinated at time t 169 and t is the day from sowing.

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The emergency speed index (IVE) was calculated using the number of germinated seeds with 171 only primary root counted daily in each repletion, according to equation 2 (POPINIGIS, 1985):

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IVE= ∑ e n ∑ N n ⁄ Where IVE is emergency speedy index, en seedling emergency in the first count, n is the last count 175 at time, Nn is the number of days of seeds at time t, and t is the day from sowing.
Ten normal seedlings were randomly chosen from each repetition of each treatment on the 7 th day, To calculate the leachate and clean water applications, the soil water balance method adapted 213 from Gonçalves et al (2014) was used. This method consists in weighing the vessels where the 214 difference in mass will correspond to the volume of water to be applied to raise the soil to field 215 capacity (saturation with water in the soil, at the level of 100%) (equation 3) To evaluate the effects of leachate doses application on sunflower seedlings growth 228 after 45 days, the following parameters was considered, height of the aerial part (cm), length 229 of the stem (cm) and root system (cm) with the help of a ruler graduated in millimeters, from 230 the neck of the plant to the apex. The fresh matter weighed immediately after each cut and 231 packed in paper bags. The aerial part (stem and leaves) and the root put to dry in an oven with 232 forced air circulation at a 65ºC temperature for 72 hours, until reaching constant masses. At 233 the end, the material was weighed, having the fresh weight and the dry weight of the aerial 234 part and the root. With these data, the plant water loss was assessed (BENINCASA, 2003).

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Seed germination and seeding vitality results were submitted to variance analysis (ANOVA) 265 as well as linear and polynomial (second order) regression tests using the software SAS (version 266 9.1).

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The data related to the greenhouse experiment assayed by using ANOVA and when 268 significant, submitted to Tukey test, adopting a 5% probability level, using the SAS software 269 (version 9.1).

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In this study, two different treatment processes were employed aiming RL agricultural use 307 for irrigation: Electro-Fenton (EFTL) and distillation (DTL1).

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In the EFTL treatment, organic matter is oxidized by OH • radicals produced from the the pH was slightly acid (6.0) and the COD removal was 61 %. EFTL was not able to remove 313 ammonia-nitrogen, which favors its use as fertilizer in the crops. However, salinity and total 314 dissolved solids increased, which may be an impediment to its reuse in irrigation (Bunani et al., . Moreover, DLT1 treated leachate has higher ammonia-nitrogen content and low salinity than 316 EFTL, which can be good features for its reuse in agriculture.

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As excessive salinity and mainly elevate sodium contents are inadequate for agriculture

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The higher salinity attributed to high sulfate content did not influenced the germination velocity but 425 these parameters caused variations in their development processes. Thus, the results described 426 above show that seedling growth sequence in relation to effluent quality was RL>EFTL>DTL1.

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The results presented in Fig. 1A indicate that with the use of crude leachate (RL) at dilution 442 rates from to 50%, germination rates greater than 80% were obtained, indicating the feasibility of

453 454
There was a significant statistical effect (p <0.05) for the factor concentrations of leachate 455 in all variables treated in ANOVA for growth and biomass, after 45 days planting (see 456 supplementary Table 3). Is important to note that with appliance of 25% and 50% RL concentrations, the plants at the 506 end of the experiment showed stunted growth, with small yellowish leaves ( Fig. 9 A and B), probably 507 due to salt deposition on the leaves, since leachate has a high sodium concentration (2,667 mg L-508 ¹). According to Ayers and Westcot (1999), the most common effect of salinity on plants, in general, 509 is the cell expansion limitation due to increased osmotic pressure at the medium and the 510 consequent cell plasmolysis, thus affecting cells division and elongation, impairing plant growth and 511 mass volume. Therefore, the results in Figure 8 indicate that the use of 15% RL concentration is 512 able to promote the sunflower aerial part growth without damaging the leaves, demonstrating that 513 the leachate was not toxic and / or statistically equal to water appliance. The present study evaluated sunflower cultivation until the beginning of its flowering (45 days).

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The analysis of variance results (see supplementary show a statistically significant difference, therefore, there was no effect for applied treatments on 528 these nutrient levels in the plant (Fig. 10 A and D). For nitrogen there were average variations 529 between 35.57 g kg -1 and 41.29 g kg -1 ; for calcium, the averages were between 3.0g kg -1 and 5.0 g

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Phosphorus showed high average levels in drinking water treatment (0%) and mineral 539 fertilization, followed by highest averages for RL treatments with 5% and 15%, being statistically 540 equal to mineral fertilization (Fig. 10 B). For potassium there is a variation of averages between 13.85 g kg -1 up to a maximum of 54.28 548 g kg -1 , with the highest average concentrations being obtained in concentrations of 5% and 15%.

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This effect may be related to the presence of potassium or to excess sodium in the RL (Table 1) 550 that competes for the same active site as potassium, impairing this nutrient absorption by the plant. The variance analysis results by F test for micronutrients such as copper and iron were not 558 significant, indicating that different leachate concentrations did not promote changes in these 559 elements concentrations (see supplementary and manganese were higher than those obtained with using RL (with exception of Zn in RL 5% 566 concentration), which possibly indicates that the content of these elements in the drinking water is 567 higher than in the RL, contributing to the availability of these nutrients for the plants. This explains 568 why the highest zinc average concentration was obtained at a 5% RL concentration (0.250 g kg -1 ), 569 followed by the control (0.200 g kg -1 ). For manganese, the highest averages were obtained in 570 treatments with mineral fertilization, control and in RL dosage of 5%. The cobalt, nickel, cadmium, 571 and lead levels were below the detection limit of the method in analyzed samples.  and pH 3.6 in KCl ( Table 6). The results indicate that the soil pH showed a higher average value in 604 50% RL concentration in both, water and KCl and was observed that an increase in pH occurs with 605 the increase in RL concentrations (Table 6).  Ca² + + Mg² + cmolc kg -1 0,6 0,80ab 0,75b 0,87ab 0,72b 1,05a 0,90ab K + cmolc kg -1 0,14 0,13d 0,27d 0,52bc 0,60b 1,36a 0,20d Na + cmolc kg -1 0,014 0,08c 0,48b 0,53b 0,65b 1,10a 0,07c H + + Al 3+ cmolc kg -1 6,9 6,67ab 6,00bc 6,00bc 5,65c 4,50d 7,00a