| dc.description | Bangladesh is an agricultural country where industrialization is taking place in a
gradually increasing phase. Bangladesh is located in a sub-tropical area with an average
annual precipitation less than one third of that of the world. Furthermore, spatial and
temporal distribution of the regional precipitation is not integrated and also these
resources are at greater risk to contamination. With increasing global population, the gap
between the supply and demand for water is widening and is reaching such alarming
levels that in some parts of the world it is posing a threat to human existence. Studies in
Bangladesh have (Hakim et al., 2009; Islam et al., 2010) showed that HCO3
-
, Na+
, Ca2+
,
Mg2+ and Cl- were the dominant ions in groundwater collected from different regions.
The main sources of water in Bangladesh are surface waters; rivers, reservoirs, lakes,
canals and ponds; ground water resources are important in some areas (Ahmed and
Rahman, 2003). In Bangladesh concerns over water quality are (i) industrial pollution
near major urban centers (ii) fecal contamination throughout the country (iii)
contamination by agro-chemicals, (iv) saltwater intrusion in coastal areas (v) suspended
sediments, largely from the upper catchments outside Bangladesh (Muyan and Mamun,
2003). Effluents from industries are normally considered as the main industrial pollutants
containing organic and inorganic compounds are discharged into the nearby water bodies
as well as agricultural fields. It makes the water bodies toxic as various industries
discharge the suspended solids, toxic chemicals, oils, greases, dyes, radioactive wastes
and thermal pollutants. As a result the high level of pollutants mainly organic matter in
water causes an increase in BOD, COD, TDS, TSS etc. It makes the water unsuitable for
drinking, irrigation or for other uses | en_US |
| dc.description.abstract | An investigation was carried out to assess the suitability for agricultural purpose of 30
rice mill wastewater samples collected from different locations in Dinajpur district of
Bangladesh. Analyses included pH, EC, TDS (Total dissolved solids), cations and anions
(Ca2+, Mg2+, Na+
, K+
, Cu2+, Mn2+, Fe3+, HCO3
-
, and Cl-
). Several computed variables
such as SAR (Sodium adsorption ratio), hardness (HT), permeability index (PI), and
Kelly‘s ratio to evaluate the suitability of wastewater for specific uses. The wastewater
were found acidic (pH varied from 5.33 to 6.77) that are suitable for rice seedlings.
Wastewater samples contained Ca2+, K+
and Na+
as the dominant cations and HCO3
-
and
Cl- were the dominant anions. According to EC value, the samples were excellent and
good for germination purposes. The SAR value of all waste water samples were
excellent classes. Maximum samples were within hard regarding hardness. Based on,
(HCO3
-
and Cl-
) of rice mills waste water were found to be 'safe' limit for germination.
The correlation coefficient were positive of among pH, EC, TDS, Mg2+, K+
, HT, Ca2+
,
Mg2+, K+
, Na+
and HCO3
-
reproduced that the quality of the free soil solution may
indicate the distribution of Na+
in the absorbed phase. On the other hand, the correlation
coefficient for pH-Temp, pH-P, EC-Temp, Mg-P, P-Fe, Cu-F indicated that the increase
of one parameter will result in the decrease of the aforementioned parameters. After
tested the waste water, further conducted laboratory experiment to determine the effect
of different waste water on germination, seedling growth and mineral composition of
different rice verities. The results revealed that the highest germination (98%, 98% and
100%) was found in BRRI 28, BRRI 58 and Kataribhog, respectively with the treatments
of T4 (Waste water of Birgonj rice mill), T4 (Waste water of Birgonj rice mill) and T1
(Waste water of Dinajpur sadar rice mill). The highest shoot and root weight of seedlings
were found in wastewater treatments in comparison to normal water. The results
indicated that the waste water enhanced the shoot length, root length and nutrient content
in rice plant. However, overall view of rice mill waste water were suitable for seedling
growth and development after proper management. | en_US |
