Pemonitoran Intensif Beberapa Nutrien Dalam Sungai Sarawak di Kuching, Sarawak, Malaysia

The variation of several nutrients and water quality parameters in Sarawak River was examined by intensive monitoring, i.e. four times in the morning and also four times in the afternoon. The sampling stations selected were at the Waterfront of Kuching town and at Batu Kitang upstream of the Sarawak River, near to a water intake point. The Batu Kitang station was used as a reference station for water quality comparison. The nutrients examined are ammonium, nitrate, dissolved phosphate, sulphate and major cations (K, Na, Ca, Mg). The levels of ammonium, nitrate, phosphate and sulphate in the Sarawak River at the Waterfront station are 0.03 – 0.67, 0.03 – 0.14, 0.03 – 0.74 and 0.02-0.38 mg/L respectively. The maximum changes in the level of ammonium within a day could be up to 25 folds, whilst that for dissolved phosphate and sulphate were approximately 11 folds. Only nitrate and the major cations were observed to vary by less than two folds during a one-day water monitoring.