Paramasivam S, Fortenberry Gamola Z, Julius Afolabi, Sajwan Kenneth S, Alva A K
Department of Natural Sciences and Mathematics, Savannah State University, Savannah, GA 31404, USA.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2008 Feb;43(2):178-85. doi: 10.1080/10934520701781574.
Increase in concentrations of various greenhouse gases and their possible contributions to the global warming are becoming a serious concern. Anthropogenic activities such as cultivation of flooded rice and application of waste materials, such as sewage sludge which are rich in C and N, as soil amendments could contribute to the increase in emission of greenhouse gases such as methane (CH(4)) and nitrous oxide (N(2)O) into the atmosphere. Therefore, evaluation of flux of various greenhouse gases from soils amended with sewage sludge is essential to quantify their release into the atmosphere. Two soils with contrasting properties (Candler fine sand [CFS] from Florida, and Ogeechee loamy sand [OLS] from Savannah, GA) were amended with varying rates (0, 24.7, 49.4, 98.8, and 148.3 Mg ha(-1)) of 2 types of sewage sludge (industrial [ISS] and domestic [DSS] origin. The amended soil samples were incubated in anaerobic condition at field capacity soil water content in static chamber (Qopak bottles). Gas samples were extracted immediately after amending soils and subsequently on a daily basis to evaluate the emission of CH(4), CO(2) and N(2)O. The results showed that emission rates and cumulative emission of all three gases increased with increasing rates of amendments. Cumulative emission of gases during 25-d incubation of soils amended with different types of sewage sludge decreased in the order: CO(2) > N(2)O > CH(4). The emission of gases was greater from the soils amended with DSS as compared to that with ISS. This may indicate the presence of either low C and N content or possible harmful chemicals in the ISS. The emission of gases was greater from the CFS as compared to that from the OLS. Furthermore, the results clearly depicted the inhibitory effect of acetylene in both soils by producing more N(2)O and CH(4) emission compared to the soils that did not receive acetylene at the rate of 1 mL g(-1) soil. Enumeration of microbial population by fluorescein diacetate (FDA) and most probable number (MPN) procedure at the end of 25-d incubation demonstrated a clear relationship between microbial activity and the emission of gases. The results of this study emphasize the need to consider the emission of greenhouse gases from soils amended with organic soil amendments such as sewage sludge, especially at high rates, and their potential contribution to global warming.
各种温室气体浓度的增加及其对全球变暖可能产生的影响正成为一个严重问题。诸如种植淹水水稻以及使用富含碳和氮的废料（如污水污泥）作为土壤改良剂等人为活动，可能会导致甲烷（CH₄）和一氧化二氮（N₂O）等温室气体向大气中的排放量增加。因此，评估用污水污泥改良的土壤中各种温室气体的通量对于量化它们向大气中的释放至关重要。选取了两种性质不同的土壤（佛罗里达州的坎德勒细砂 [CFS] 和佐治亚州萨凡纳的奥吉奇粉质砂 [OLS]），用两种类型的污水污泥（工业来源 [ISS] 和生活来源 [DSS]）以不同速率（0、24.7、49.4、98.8 和 148.3 Mg ha⁻¹）进行改良。将改良后的土壤样品在静态箱（Qopak 瓶）中于田间持水量土壤水分条件下进行厌氧培养。在改良土壤后立即以及随后每天采集气体样品，以评估 CH₄、CO₂ 和 N₂O 的排放情况。结果表明，所有三种气体的排放速率和累积排放量均随着改良剂用量的增加而增加。用不同类型污水污泥改良的土壤在 25 天培养期间气体的累积排放量顺序为：CO₂ > N₂O > CH₄。与用 ISS 改良的土壤相比，用 DSS 改良的土壤气体排放量更大。这可能表明 ISS 中碳和氮含量较低或存在可能的有害化学物质。与 OLS 相比，CFS 的气体排放量更大。此外，结果清楚地表明，与未以 1 mL g⁻¹ 土壤的速率添加乙炔的土壤相比，乙炔对两种土壤都有抑制作用，会产生更多的 N₂O 和 CH₄ 排放。在 25 天培养结束时，通过荧光素二乙酸酯（FDA）和最大可能数（MPN）方法对微生物数量进行计数，结果表明微生物活性与气体排放之间存在明显关系。本研究结果强调，需要考虑用污水污泥等有机土壤改良剂改良的土壤中温室气体的排放情况，尤其是在用量较高时，以及它们对全球变暖的潜在影响。
