Effects of peat and weathered coal on the growth of Pinus sylvestrisvar. mongolica seedlings on aeolian sandy soil

The experiment was conducted at the Ganqika Sandy Land Ecological Station in Ke抏rqinzuoyihouqi County, Inner Mongolia, in a growing season from April 28 to October 28, 2001. Peat and weathered coal were added to the aeolian sandy soil in different ratios. Two-year-old Pinus sylvestris var. mongolica seedlings and plastic pots were used in the experiment. The experimental results indicated that: 1) the peat and weathered coal could significantly improve the physical and chemical prop-erties of aeolian sandy soil, and thus promoted the growth of seedlings; 2) the effect of peat on seedling growth, including height, base diameter, root length and biomass, presented an order of 8%>10%>5%>2%>0 in terms of peat contents, and the effect of weathered coal on seedling growth presented an order of 5%>8%>10%>2%>0 in terms of weathered coal contents for height and basal diameter, 5%>8%>2% >10%>0 for root length, and 5%>2%>8% >10%>0 for biomass; 3) the effects of peat were generally greater than that of weathered coal. Meanwhile, 8% peat was the best treatment to promote the growth of P. sylvestris var. mongolica seedlings.

Bacterial degradation of coal discard and geologically weathered coal

The biodegradation of coal discard is being intensively studied in South Africa in an effort to develop passive methods for the successful revegetation and rehabilitation of waste dumps, to mitigate pollution, and facilitate mine closure. Bacteria were isolated from slurries of coal tailings and diesel-contaminated soil, screened for coal biodegradation competence, characterized, and the colonization and degradation of coal discard and geologically weathered coal investigated using individual isolates and consortia. Ten novel coal-degrading bacterial strains were isolated and characterized, the gene sequences deposited with GenBank, and the (wild-type) strains deposited at Microbial Culture Collection, India. The results from the present work show that bituminous coal discard and geologically weathered coal is used by these isolates as carbon and energy source. Isolated strains and consortia colonized and degraded both coal substrates. Growth rate of the isolates is faster and stationery phase achieved sooner in minimal medium containing geologically weathered coal. This observation suggests that the oxygen-rich weathered coal is a more friable substrate and thus readily colonised and biodegraded. A reduction in mass of substrate is demonstrated for both individual isolates and consortia. The changes in pH and associated media colouration occurred concomitant with formation of humic acid-like (HS) and fulvic acid-like substances (FS) which is confirmed following analysis of these products by FT-IR spectroscopy. It is concluded that preferential metabolism of alkanes from the coal substrates provided the carbon and energy for bacterial growth and transformation of the substrates to HS and FS.

Acid-base buffer effect of fulvic acid and barium fulvate from weathered coal

The acid-base buffer characteristics of fulvic acid (FA) and barium fulvate (BaFA)were analyzed. Each share of the sample or model agents (phthalic acid and salicylic acid)were separately mixed into a series of shares of dilute solutions of HCI or NaOH with a series of concentration. The original pH values of the solutions were arranged from 2 to 13.Final balanced pH of each share was measured. The pH changes show that FA and BaFApossess buffer ability, whereas the model agents do not. The tendency of balanced pHvalues was 5.4 for FA and 7.4 for BaFA, whereas the original pH was 4.0-8.5; balancedpH changed little. At room temperature, the maximum buffer capacities were as follows:18.11 mmol hydroxyl per gram FA, 11.25 mmol hydroxyl per gram BaFA, 1.19 mmol protonper gram FA, and 1.45 mmol proton per gram BaFA. Mathematics analysis shows thatlogarithm of buffer capacities of FA and BaFA is linearly dependent on original pH. Compared with BaFA and model agents, it is concluded that FA buffer capacity against hydroxylrelies not only on its acidic groups, BaFA buffer capacity against hydroxyl does not rely onits acidic groups, and FA buffer capacity against proton is not related with its carboxyl andphenolic hydroxyl group. The pH values of FA-water solutions with different concentrationsfrom 1 to 10 grams per liter were measured. Their pH values were slightly affected by itsconcentration. Thus, FA possesses a much stronger buffer ability against water dilutionthan common buffer agent. All the pH values of FA water solutions were very nearby 5.4,just the same as the balanced pH tendency for adding FA.

^(15)N NMR Spectroscopic Study on Nitrogen Forms in Humic Substances of Soils

Nitrogen forms of humic substances from a subalpine meadow soil, a latentic red soil and a weathered coal and the effect of acid hydrolysis on N structures of soil humic substances were studied by using 15N cross-polarization magic angle spinning nuclear magnetic resonance (CPMAS NMR) spectroscopy. Of the detectable 15N-signal intensity in the spectra of soil humic substances 71%-79% may be attributed to amide groups, 10%-18% to aromatic/aliphatic amines and 6%~11% to indole- and pyrrole-like N. Whereas in the spectrum of the fulvic acid from weathered coal 46%, at least, of the total 15N-signal intensity might be assigned to pyrrole-like N, 14% to aromatic/aliphatic ammes, and the remaining intensities could not be assigned with certainty. Data on nonhydrolyzable residue of protein-sugar mixture and a 15N-labelled soil fulvic acid confirm the formation of nonhydrolyzable heterocyclic N during acid hydrolysis. Project (No. 39790100) supported by the National Natural Science Foundation of China.