Cadmium Phytoavailability and Enzyme Activity under Humic Acid Treatment in Fluvo-aquic Soil

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1 IOP Conferene Series: Erth n Environmentl Siene PAPER OPEN ACCESS Cmium Phytovilility n Enzyme Ativity uner Humi Ai Tretment in Fluvo-qui Soil To ite this rtile: Borui Liu et l 2018 IOP Conf. Ser.: Erth Environ. Si View the rtile online for uptes n enhnements. This ontent ws ownloe from IP ress on 16/11/2018 t 20:06

2 IOP Pulishing IOP Conf. Series: Erth n Environmentl Siene (2018) oi : / /108/4/ Cmium Phytovilility n Enzyme Ativity uner Humi Ai Tretment in Fluvo-qui Soil Borui Liu, Qing Hung,* n Yuefeng Su Shool of Mterils Siene n Engineering, Beijing Institute of Tehnology. 5th Zhonggunun South Street, Hiin Distrit, Beijing, Chin lr221@126.om,,* Corresponing uthor:hungqing3121@sin.om, suyuefeng@it.eu.n Astrt. A pot experiment ws onute to investigte the mium (C) vilility to pkhois (Brssi hinensis L.) s well s the enzyme tivities in fluvo-qui soil uner humi i tretment. The results showe tht the phytovilility of C in soil erese grully s humi i onentrtion rose (0 to 12 g kg -1 ), while the tivities of urese (UE), lkline phosphtse (ALP) n tlse (CAT) kept inresing (P < 0.05). The orreltion nlysis inite tht humi i ws effetive for reuing the evsttion to soil enzymes ue to the C pollution. In onlusion, humi i is effetive for the reution of oth C phytovilility n the mge to enzyme tivities ue to C pollution in fluvo-qui soil Key wors: soil pollution; mium; phytovilility; humi i; enzyme. 1. Introution In the lst severl ees, the inresing pplition of grohemils hs rought signifint mount of hevy metls into frmln eosystems [1, 2], whih my le to serious environmentl risk euse of the toxiity, stility n relitrne to ioegrtion. The hevy metls n lso umulte in the rops [3, 4, 5], resulting in mge to humn s helth through the foo hin. The humi i hs moleulr struture with unnt orgni funtionl groups whih n omplex or helte with the hevy metl ions in soil. Bse on the properties, it n e speulte tht humi i hs potentil to inhiit the hevy metls uptke y rops n reue the environmentl risk. The im of the present stuy is to fin out the effet of humi i on the mium (C) phytovilility in fluvo-qui soil. The urese (UE), lkline phosphtse (ALP) n tlse (CAT) tivities re employe to investigte the eotoxiologil effets in the proess in orer to ssess the overll performne of humi i. 2. Mteril n Methos Pot Experiment. The fluvo-qui soil ws ollete from Fngshn Distrit, Beijing, Chin (in the epth of 0-20m). The kgroun C onentrtion ws mg kg-1. The ir-rie n sieve soil Content from this work my e use uner the terms of the Cretive Commons Attriution 3.0 liene. Any further istriution of this work must mintin ttriution to the uthor(s) n the title of the work, journl ittion n DOI. Pulishe uner liene y IOP Pulishing Lt 1

3 IOP Pulishing IOP Conf. Series: Erth n Environmentl Siene (2018) oi : / /108/4/ ws introue to the plsti pots (12 10 m) with the mss of 330 g pot-1. CCl2 solution ws e to hieve the C pollution levels (0, 5 n 10 mg kg-1). Uner eh pollution level, the humi i ws e in soil s power n the onentrtions were 0, 3, 6, 9, n 12 g kg-1. The tretments were onute in triplite. The holes on the ottom were sele using glss ement. The N, P n K were e in the soil to reh the following levels: g kg-1, g kg-1, g kg-1, respetively [6]. The pkhoi (Brssi hinensis L.) ws grown in the pots for 40 ys. The moisture ontent in the soil ws mintine t out 75% of the wter-holing pity using istille wter [7]. The plnts were kept uner the onition of 28-14h n 15-10h yles [8]. After hrvest, the plnt n soil smples were rie n sieve using 1-mm nylon mesh for further nlysis. Anlytil Proeure. The prepre plnt smples were igeste with nitri i, perhlori i n hyrofluori i to ssy the C onentrtions whih were etermine with Inutively Couple Plsm Mss Spetrometry (ICP-MS). Soil UE tivity ws etermine y the metho of C.S. Yn [9], n the results were expresse s the onentrtion of NH4+ relese y urese enzymti hyrolysis of ure (mg NH3-N g-1 soil). Soil ALP tivity ws etermine y the metho of M.A. Tti n J.M. Bremner [10], n the results were expresse s the onentrtion of p-nitrophenol (PNP) proue y the enzymti retion (mg PNP g-1 soil). Soil CAT tivity ws mesure y ktitrting resiul H2O2 with KMnO4 [11], n the results were expresse s the volume of 0.02 mol L-1 KMnO4 solution onsume in the titrting proess (ml KMnO4 g-1 soil). All the proesses were onute in triplite. The results were expresse s the mens of replites. The t were grphe n nlyze with Origin 9.1 n SPSS Sttistis 20.0 softwre. 3. Results n isussion C Conentrtion in the Plnt Tissues. The C onentrtions in plnt tissues re shown in Fig 1. With exogenous C in soil, C levels in the tissues of the pkhoi signifintly inrese (P < 0.01), n C onentrtions in the roots were signifintly lrger thn those in the shoots (P < 0.05). As n e seen in the figure, C onentrtions in shoots n roots kept eresing with the humi i onentrtion ugment (0 to 12 g kg-1) y 33.42% to 57.87% (P < 0.05), initing goo effiy for inhiiting C uptke y pkhois. Humi i h gret ffilition to metl tions ue to the existene of funtionl groups or ligns whih oul form heltes with metls [12]. Given the speil moleulr struture, humi i h the potentil to helte with the free C2+ in soil, resulting in lower phytovilility. Fig 1. C onentrtions in plnt tissues uner humi i tretments. () shoot; () root Results of Dunn Multiple Comprison re expresse s letters in the figure. Different letters in eh group inite signifint ifferene (P < 0.05); the sme letters inite tht ifferenes were not signifint. Sme s elow. 2

4 IOP Pulishing IOP Conf. Series: Erth n Environmentl Siene (2018) oi : / /108/4/ Soil Enzyme Ativities. The tivities of UE, ALP n CAT in soil re shown in Fig 2. As n e seen in the figures, the vrying trens of the tivities of the three kins of enzymes were similr. When there ws exogenous C in the soil, the tivities of the enzymes signifintly erese (P < 0.05). The results reflete the C toxiity to miroorgnisms [13, 14], whih might result from the interting with the enzyme-sustrte omplex, enturing the enzyme protein or interting with the protein-tive groups [15]. The tivities of the UE, ALP n CAT kept rising grully with the humi i onentrtion ugment in the soil y 27.25% to 97.18%, 39.56% to 85.85% n 30.71% to 74.84%, respetively (P < 0.05). Correltion mtrix etween C onentrtion in tissue n soil enzymes is shown in Tle 1. The tivities of UE, ALP n CAT in soil were ll negtively orrelte with the C umultion levels in tissue (P < 0.01). soil UE tivity (mg NH 3 -N g -1 ) e () soil CAT tivity (ml KMnO 4 g -1 ) soil ALP tivity (mg PNP g -1 ) () () humi i onentrtion 0 3 g kg -1 6 g kg -1 9 g kg g kg -1 Fig 2. Soil enzyme tivities uner vrious C n humi i tretments. () UE; () ALP; () CAT Tle 1. Correltion mtrix etween C onentrtion in tissue n soil enzymes ( ** P < 0.01) C in tissue UE ALP CAT C in tissue 1 UE ** 1 ALP ** ** 1 CAT ** ** ** 1 The results inite tht the C phytovillility in soil ws n importnt ftor influening the enzyme tivities. Aoring to S.J. Sun et l. [16] n Y.P. Wng et l. [17], there ws negtive orreltion etween hevy metls phytovilility n hevy metls vilility to miroorgnisms in 3

5 IOP Pulishing IOP Conf. Series: Erth n Environmentl Siene (2018) oi : / /108/4/ soil. Therefore, humi i oul reue the C phytovilility n toxiity to miroorgnisms in soil t the sme time, leing to improvement of enzyme tivities. 4. Conlusion Humi i n influene the C phytovilility in fluvo-qui soil s well s the enzyme tivities. When humi i is pplie, C phytovilility kept eresing with the onentrtion ugment (0 to 12 g kg-1), while the enzyme tivities (UE, ALP n CAT) kept inresing. The enzyme tivities re negtively orrelte with the C uptke levels in plnt, initing the C toxiity to miroorgnisms is the reson for the isturne to enzyme tivities n humi i n reue the mge. In onlusion, humi i is effetive for C phytovilility reution in fluvo-qui soil, whih n lso reue the evsttion to soil enzyme tivities ue to the C pollution. Aknowlegements This work ws finnilly supporte y the Beijing Key Lortory Constrution Projet, Beijing Muniipl Eution Commission Joint Constrution Progrm ( ). Referenes [1] S.C. Wong, X.D. Li, G. Zhng, S.H. Qi n Y.S. Min: Environ. Pollut. Vol. 119 (2002), p [2] Y.S. Xi, F.B. Li, H.F. Wn, J. M, G.Y. Yng, T.B. Zhng n W. Luo: J. Environ. Si. Vol. 16 (2004), p [3] Y. Yng, F.S. Zhng, H.F. Li n R.F. Jing: J. Environ. Mnge. Vol. 90 (2009), p [4] Y.M. Zhng, J. Yin, Y.J. Shi, X.L. Lu n C.Y. Hu: Commun. Soil Si. Plnt Anl. Vol. 43 (2012), p [5] C.Y. Chng, H.Y. Yu, J.J. Chen, F.B. Li, H.H. Zhng n C.P. Liu: Environ. Monit. Assess. Vol. 186 (2014), p [6] X.X. Long, X.E. Yng, W.Z. Ni, Z.Q. Ye, Z.L. He, D.V. Clvert n P.J. Stoffell: Commun. Soil Si. Plnt Anl. Vol. 34 (2003), p [7] W. Liu, Q. Zhou, J. An, Y. Sun n R. Liu: J. Hzr. Mter. Vol. 173 (2010), p [8] W. Liu, Q. Zhou, Z. Zhng, T. Hu n Z. Ci: J. Agr. Foo Chem. Vol. 59 (2011), p [9] C.S. Yn: Reserh Metho of Soil Fertility (Agriulture Press, Chin 1988). (in Chinese) [10] M.A. Tti n J.M. Bremner: Soil Biol. Biohem. Vol. 1 (1969), p [11] J.L. Johnson n K.L. Temple: Soil Si. So. Am. J. Vol. 28 (1964), p [12] A. Mhr, P. Wng, R. Li n Z. Zhng: Peosphere Vol. 25 (2015), p [13] S.P. Deng n M.A. Tti: Biol. Fert. Soils Vol. 24 (1997), p [14] R. Kızılky, T. Aşkın, B. Byrklı n M. Sğlm: Eur. J. Soil Biol. Vol. 40 (2004), p [15] P. Nnnipieri, in: Soil Biot: Mngement in Sustinle Frming Systems, eite y C.E. Pnkhurst, B.M. Doue, V.V.S.R. Gupt n P.R. Gre, CSIRO, Est Melourne, Vitori, Austrli (1995) [16] S.J. Sun, J. Xu, S.G. Di n X. Hn: Biome. Environ. Si. Vol. 19 (2006), p [17] Y.P. Wng, J.Y. Shi, Q. Lin, X.C. Chen: J. Environ. Si. Vol. 19 (2007), p