Assessments of physico-chemical parameters were carried out during 2012 to 2014. A major and important different water quality parameters were measured in all collected samples, including Water Colour, Air Temperature, Water Temperature, Na+, Ca2++, Mg2+ and Zn3+, Fe3+ and some major anions like Cl-, SO42-, CO32- and SO42-. The results that are recorded in the different stations are compared with the different seasons and also with the different year.
Keywords: Water analysis; Piper; Heavy metal; East siang; Arunachal pradesh
Water is the most vital resources for all kinds of life on this planet. Water is one of the nature’s most important gifts to mankind. River Siang is the main river of East Siang district and also it is one of the most important tributary of the mighty River Brahmaputra drainage system. The environment and the ecosystem were badly affected by social, agricultural and industrial activities of human population. River water and ground water were polluted by the growing use of chemicals in the form of fertilizers and pesticides. The ecosystem could be destabilized and could cause ill effects on the health of the human beings as well as all other living organisms [1,2]. The physical and chemical characteristics of any riverine water, sediments play an important role of ecological significance especially in river ecosystem. It reflects the history of the pollution. All type of organic and inorganic solid and liquid matter present in effluent.
The River Siang, is largest river of Brahmaputra river system, originates from Chema Yungdung Glacier near Kubi at 5150m in Tibet. In Tibet it is popularly known as Tsang-Po, flows in West–East direction. After traversing a distance of about 1625km river in Tibet and then it takes a turn in south direction, enters the territory of India near Tuting in the Upper Siang district of Arunachal Pradesh and flows through North–South direction in East Siang district towards Assam and finally it merges with
Lohit and Dibang in Assam and it becomes the mighty River Brahmaputra [3-5] (Figure 1).
Water was collected and stored in clean polyethylene bottles that have been pre washed with de-ionized water. Air temperature, water temperature and pH were determined in the field because of their unstable nature. Water temperature and air temperature were measured with the help of mercury thermometer and pH was measured with pen type pH meter in the field and other parameters was analyzed in the laboratory using standard procedure of APHA  and using Perkin Elmer Atomic Absorption Spectrophotometer (AAS) .
River Siang is Hill-Stream 1st order river; has colluvial (landslide from adjacent hill slopes delivering sediments and organic matter) valley segment and pool-riffle type of reach. This reach type is most commonly associated with small to mid-size streams and is a quite prevalent type of reach in the rheophilic zones. On the other hand, runs are generally laminar flow of water with sandy substratum. Pools, riffles and runs are generally found to dominate the micro-habitat type with frequent occurrence of trench pools. This river is said to be more entrenched based on V-shaped valley segment. The substrate type has been found to be dominated by gravels and cobbles
with frequently-occurring quite large number of boulders and
some bed rocks .
The relationship(s) of hydro-chemical parameters of the
water of River Siang was obtained through Piper tri-linear
diagram . This diagram effectively classified the water quality
by the distribution of major cations like Na+, Ca2++ and Mg2+ and
some major anions like Cl-, SO4
2- and HCO3
-. This diagram
represents the cations and anions composition of samples on
a single graph, in which, major groupings or trends in the data
could be distinguished visually [10,11].
It consists of geometrical combination of two outer
triangles and a middle or inner diamond shaped quadrilateral.
The distribution of major cations and anions in mg/l were
showed by the left and right and these plotted points in
the triangular fields were projected further into the central
diamond-like quadrilateral structure, which provides the overall
characteristics of the water samples.
The present study on physico-chemical parameters of
River Siang revealed that the piper diagrams of water of all the
studied seasons were presented in Figure 2, 3 & 4. The major ion
chemistry results showed that calcium was the dominant cation
and bicarbonate was the major anion in all the studied seasons.
The plots from the results revealed that in all the water samples,
alkali earth metal elements (Ca2++ and Mg2+) were higher than
alkali elements (Na+) and weak acids (CO3
2- and HCO3
higher than the stronger acids (Cl- and SO4
2-). The chemical
composition of the study area was influenced by rainfall, climate,
rock type, rock division and various human activities [11,12].
Physico-chemical characteristics of surface water varied
according to seasons. Most of the water parameters vary
seasonally. The specific conductivity was observed moderate
during whole studied period; however, it showed a well marked
seasonal pattern. The specific conductivity was found to increase
during the monsoon and pre-monsoon seasons, and in winter
season it was observed as gradual decline of conductivity in River
Siang. Nitrates were one of the most important nutrients and
had been reported to influence the production of microphytes
and macrophytes. Nitrate concentration was also an excellent
parameter to judge the organic pollution. In aquatic ecosystems
nitrogen level was regulated through geological process,
meteorological process and biological process .
Nitrate poisoning occurs when fishes were exposed to
gradually rising nitrate levels over a period of time. In River
Siang, the factors such as ground water inputs, weeds, nitrogen
fixation by blue green algae and weeds were absent. Therefore,
a very low concentration of nitrate was recorded in the entire
stretch of River Siang. The comparatively low concentration
of phosphate at upstream of River Siang can be related to
low human habitation and lack of agricultural and domestic
activities. The minimum values were observed in the monsoon
season, due to the accumulation of large amount of rain water
diluting the concentration. The values of sulphate were recorded
higher in the pre-monsoon season during the whole study period
and seasons. All the parameters of sulphate were found within
the permissible limit of WHO standard value .
Zn was one of the most important trace elements in the body
and particulates in the biological function of several proteins
and enzymes . Zn can be accumulated via the gills of fishes
and the digestive tracks; however the role of water as source
of Zn uptake was not fully elucidated . The agriculture run
off reaches natural water bodies affecting aquatic species and
it turns ecosystem using of large amount of fertilizer of crops.
The sources of Zn in waters of River Siang were due from the
geological rock weathering or from human activities such as
industrial and domestic wastes, water discharges. However, at
high concentrations, zinc exerts adverse effect in fish accruing
structural damage, which affects the growth, development and
survival of fish . The minimum and maximum values of Zn of
river Siang was under the permissible limits of WHO standards.
Iron (Fe) in water has many effects on aquatic life, both good and
bad. Iron comes from various minerals in the soils of river water,
which contains the highest iron concentrations. Iron levels in
water vary depending on several factors and can affect aquatic
populations, behavior and health. The Fe (mg/l) values ranged
between 1.05±0.29 to 4.54±1.19, minimum in winter season of
2013 and maximum in monsoon season of 2012.
The study of physico-chemical parameters of River Siang
revealed that, the river water free from any pollution and physico-chemical parameters were mostly found to be in the
favourable and suitable ranges for the aquatic organisms. If
proper measures were taken for the treatment of sewage before
discharge and restrictions were out on various anthropogenic
activities upstream, the estuary would remain healthy in the
long run. The results that were recorded in the different stations
and different seasons were compared with the World Health
Organization (WHO) and it was found that the water of River
Siang may be suitable for drinking and domestic purposes
because all the values were between WHO limits.