Overview
Hendrawati and colleagues tested chitosan prepared from shrimp-shell waste as a natural coagulant for turbid lake water from Situ Cipondoh. This is in-scope mitigation evidence for water treatment and metal reduction, not chitosan ingredient occurrence or aluminum contamination evidence.
Key numbers
The abstract reports that chitosan at 20 ppm lowered lake-water turbidity by 94.43%, lowered pH, decreased bacterial counts by +/- 99.18%, and lowered dissolved Mn, Mg, and Fe in the treated water. The same abstract states that chitosan did not change water temperature, did not lower BOD, and did not lower Ca.
Table 1 describes the untreated Situ Cipondoh water before coagulant addition as 30.17 +/- 0.29 degrees C, pH 8.12 +/- 0.02, conductivity 0.28 +/- 0.00 uS, and turbidity 9.53 +/- 0.01 NTU. The table lists the permitted turbidity limit as 5 NTU and pH range as 6.5-8.5.
Table 12 reports the following treated-water values:
| Parameter | Untreated sample | Sample + chitosan | Sample + PAC |
|---|---|---|---|
| Turbidity (NTU) | 20.34 | 0.62 | 7.63 |
| pH | 8.11 | 7.05 | 6.70 |
| Conductivity (us) | 0.28 | 0.255 | 0.28 |
| Temperature (degrees C) | 30.25 | 29.5 | 29.9 |
| Total Coliform (MPN/100 ml) | >1100 | 9 | 460 |
| Mn (mg/L) | 0.4381 | 0.056 | 0.0275 |
| Mg (mg/L) | 4.731 | 4.633 | 4.687 |
| chromium (Cr) (mg/L) | 0.006 | 0.001 | 0.003 |
| Ca (mg/L) | 11.53 | 11.67 | 12.12 |
| Fe (mg/L) | 0.0046 | not detected in extracted table | not detected in extracted table |
| BOD (mg/L) | 5.15 | 9.78 | 2.62 |
Methods (brief)
The study prepared chitosan from shrimp shell by deproteinization, demineralization, and deacetylation. Lake water was treated by jar testing: 150 rpm rapid mixing for 10 minutes, 50 rpm slow mixing for 15 minutes, and about 1 hour settling. Supernatant was tested for turbidity, temperature, pH, conductivity, dissolved metals, total coliform, dissolved oxygen, and BOD. Metals were measured by atomic absorption spectrophotometry.
Related evidence
Update history
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