Hujan asam

Hujan asam nyaéta hujan atawa bentuk présipitasi lianna anu sacara teu wajar watekna asam, ku naékna kadar ion hidrogén (pH leutik). Balukarna goréng pikeun tutuwuhan, sato cai, jeung infrastruktur. Hujan asam téh balukar tina émisi sanyawaan amonia, karbon, nitrogén, jeung walirang nu ngahiji jeung molekul cai di atmosfir nu ngahasilkeun asam. Pikeun ngungkulanana, pamaréntah sababaraha nagara geus nyieun tarékah ti taun 1970-an, utamana pikeun ngurangan produksi oksida walirang. Najan kitu, ieu prosés mémang lumangsung sacara alami, di antarana tina gelap jeung gunung bitu.

Watesan 
"Hujan asam" téh istilah populér nu nujul ka déposisi baseuh (hujan, salju, hujan és, halimun, awan, ibun) jeung garing (partikel jeung gas) komponén nu watekna asam. Istilah nu leuwih méré nah nyaéta "déposisi asam".

Cai sulingan, nu karbon dioksidana geus dileungitkeun, boga pH nétral 7. Cairan anu pH-na kurang ti 7 boga watek asam, anapon anu leuwih ti 7 watekna basa. Hujan anu 'bérésih' atawa teu ngalaman polusi watekna rada asam, pH kira 5,2, ku sabab karbon dioksida jeung cai di udara jadi asam karbonat, hiji asam lemah, tapi ogé ngandung jat kimia lianna.

H2O (l) + CO2 (g) → H2CO3 (aq)

Asam karbonat bisa diionkeun dina cai jadi ion hidronium jeung karbonat anu kadarna saeutik:

2 H2O (l) + H2CO3 (aq)  CO32− (aq) + 2 H3O<sup>+</sub> (aq)

Déposisi asam salaku isu lingkungan ogé bisa ngawengku asam H2CO3.

Baca ogé 
 Hujan basa
 Polusi udara

Rujukan

Bacaan salajengna 
 John McCormick, Acid Earth: The Global Threat of Acid Pollution (London: éarthscan, 1989) ISBN 1-85383-033-X
 Likens, G. E., R. F. Wright, J. N. Galloway and T. J. Butler.  1979.  Acid rain. Sci. Amer. 241(4):43-51.
 Wéathers, K. C. and G. E. Likens.  2006.  Acid rain.  pp. 1549–1561.  In: W. N. Rom (ed.).  Environmental and Occupational Medicine.  Lippincott-Raven Publ., Philadelphia. Fourth Edition.

Tumbu kaluar 
 National Acid Precipitation Assessment Program Report - a 98-page report to Congress
 Acid rain for schools
  Acid rain for schools - Hubbard Brook 
 U.S. Environmental Protection Agency - New England Acid Rain Program (superficial)
 Acid Rain (more depth than ref. above)
 U.S. Géological Survey - What is acid rain?
 Acid rain analysis - freeware for simulation and evaluation of titration curves and pH calculations
 CBC Digital Archives – Acid Rain: Pollution and Politics
 Larssen, Thorjørn et al. “Acid Rain in China”. Environmental Science and Technology, 40:2, 2006, pp 418-425.
 Acid Rain: A Continuing National Tragedy - a report from The Adirondack Council on acid rain in the Adirondack region
 Assortment of Summaries on Acid Rain
 Acid rain linked to decline of the wood thrush, a songbird of the Eastern Forest 
 Trouble in the Forest, a 1988 documentary hosted by David Suzuki

Kimia lingkungan
Polusi